Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METHOD FOR
VERTEBRAL LOAD AND LOCATION SENSING
FIELD
[0001] The present invention pertains generally to surgical electronics,
and particularly to
methods and devices for assessing alignment and surgical implant parameters
during spine
surgery and long-term implantation.
BACKGROUND
[0002] The spine is made up of many individual bones called vertebrae,
joined together
by muscles and ligaments. Soft intervertebral discs separate and cushion each
vertebra from
the next. Because the vertebrae are separate, the spine is flexible and able
to bend. Together
the vertebrae, discs, muscles, and ligaments make up the vertebral column or
spine. The spine
varies in size and shape, with changes that can occur due to environmental
factors, health,
and aging. The healthy spine has front-to-back curves, but deformities from
normal cervical
lordosis, thoracic kyphosis, and lumbar lordosis conditions can cause pain,
discomfort, and
difficulty with movement. These conditions can be exacerbated by herniated
discs, which can
pinch nerves.
[0003] There are many different causes of abnormal spinal curves and
various treatment
options from therapy to surgery. The goal of the surgery is a usually a solid
fusion of the
curved part of the spine. A fusion is achieved by operating on the spine,
adding bone graft,
and allowing the vertebral bones and bone graft to slowly heal together to
form a solid mass
of bone. Alternatively, a spinal cage is commonly used that includes bone
graft for spacing
and fusing vertebrae together. The bone graft may come from a bone baffl( or
the patient's
own hipbone. The spine can be substantially straightened with metal rods and
hooks, wires or
screws via instrumented tools and techniques. The rods or sometimes a brace or
cast hold the
spine in place until the fusion has a chance to heal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Various features of the system are set forth with particularity in
the appended
claims. The embodiments herein, can be understood by reference to the
following
description, taken in conjunction with the accompanying drawings, in which:
[0010] FIG. 1 illustrates a spinal alignment system in accordance with an
example
embodiment;
[0011] FIG. 2 illustrates a user interface showing spinal alignment and
view projections
in accordance with an example embodiment;
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[0012] FIG. 3 illustrates the wand and the receiver of the spinal alignment
system in
accordance with an example embodiment;
[0013] FIG. 4 illustrates multiple sensorized devices for determining
spinal alignment in
accordance with an example embodiment;
[0014] FIG. 5 illustrates sensorized placement for determining spinal
parameters in
accordance with an example embodiment;
[0015] FIG. 6 illustrates placement of multiple sensors for determining
spinal conditions
in accordance with an example embodiment;
[0016] FIG. 7 illustrates a sensorized spinal instrument in accordance with
an example
embodiment;
[0017] FIG. 8 illustrates an integrated sensorized spinal instrument in
accordance with an
example embodiment;
[0018] FIG. 9 illustrates an insert instrument with vertebral components in
a non-limiting
example;
[0019] FIG. 10 illustrates the spinal instrument positioned between
vertebra of the spine
for parameter sensing in accordance with an example embodiment;
[0020] FIG. 11 illustrates a user interface showing a perspective view of
the sensorized
spinal instrument of FIG. 10 in accordance with an example embodiment;
[0021] FIG. 12 illustrates the sensorized spinal instrument positioned
between vertebra
of the spine for intervertebral position and force sensing in accordance with
an example
embodiment;
[0022] FIG. 13 illustrates a perspective view of a user interface showing
the sensorized
spinal instrument of FIG. 12 in accordance with an example embodiment;
[0023] FIG. 14 illustrates the sensorized spinal insert instrument for
placement of a spine
cage in accordance with an example embodiment;
[0024] FIG. 15 illustrates a perspective view of a user interface showing
the sensorized
spinal insert instrument of FIG. 14 in accordance with an example embodiment;
[0025] FIG. 16 is a block diagram of the components of the spinal
instrument in
accordance with an example embodiment;
[0026] FIG. 17 is a diagram of an exemplary communications system for short-
range
telemetry in accordance with an example embodiment;
[0027] FIG. 18 illustrates a communication network for measurement and
reporting in
accordance with an example embodiment; and
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[0028] FIG. 19 depicts an exemplary diagrammatic representation of a
machine in the
form of a computer system within which a set of instructions, when executed,
may cause the
machine to perform any one or more of the methodologies disclosed herein.
DETAILED DESCRIPTION
[0029] While the specification concludes with claims defining the features
of the
embodiments of the invention that are regarded as novel, it is believed that
the method,
system, and other embodiments will be better understood from a consideration
of the
following description in conjunction with the drawing figures, in which like
reference
numerals are carried forward.
[0030] As required, detailed embodiments of the present method and system
are disclosed
herein. However, it is to be understood that the disclosed embodiments are
merely exemplary,
which can be embodied in various forms. Therefore, specific structural and
functional details
disclosed herein are not to be interpreted as limiting, but merely as a basis
for the claims and
as a representative basis for teaching one skilled in the art to variously
employ the
embodiments of the present invention in virtually any appropriately detailed
structure.
Further, the terms and phrases used herein are not intended to be limiting but
rather to
provide an understandable description of the embodiment herein.
[0031] Broadly stated, embodiments of the invention are directed to a
system and method
for vertebral load and location sensing. A spine measurement system comprises
a receiver
and a plurality of wands coupled to a remote display that visually presents
positional
information. The wands can be placed on vertebra, or thereto touched, to
report various
aspects of spinal alignment. The positional information identifies an
orientation and location
of a wand and corresponding vertebrae of the spine. The system provides
overall alignment
plus the ability to track vertebral movement during a surgical operation. The
system can
propose and present intra-operative spine corrections in response to
positional information
captured during the procedure and previously recorded positional data related
to a pre-
operative spine condition.
[0032] The spine measurement system further includes a load balance and
alignment
system to assess load forces on the vertebra in conjunction with overall
spinal alignment. The
system includes a spine instrument having an electronic assembly and a
sensorized head
assembly that can articulate within a vertebral space. The sensorized head can
be inserted
between vertebra and report vertebral conditions such as force, pressure,
orientation and edge
loading. A GUI is used in conjunction therewith to show where the spine
instrument is
positioned relative to vertebral bodies as the instrument is placed in the
inter-vertebral space
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during the surgical procedure. The system can report optimal prosthetic size
and placement in
view of the sensed load and location parameters including optional
orientation, rotation and
insertion angle along a determined insert trajectory.
[0033] An insert instrument is also provided herein with the load balance
and alignment
system for inserting a vertebral component such as a spine cage or pedicle
screw. The system
in view of previously captured parameter measurements can check and report if
the
instrument is edge loading during an insertion. It shows tracking of the
insert instrument with
the vertebral component and provides visual guidance and feedback based on
positional and
load sensing parameters. The system shows three-dimensional (3D) tracking of
the insert
instrument in relation to one or more vertebral bodies whose orientation and
position are also
modeled in 3D.
[0034] FIG. 1 illustrates a spinal alignment system 100 in a non-limiting
example. The
system 100 comprises a wand 103 and a receiver 101 that can be communicatively
coupled to
a remote system 105. In general, one or more wands communicate with the
receiver 101 to
determine positional information that includes one of an orientation,
rotation, angle, and
location of a spinal region. The receiver 101 transmits positional information
or data 117
regarding the wand 103 to the remote system 105. The positional information
includes
orientation and translation data used to assess an alignment (or predetermined
curvature) of
the spine 112. The remote system 105 can be a laptop or mobile workstation
that presents a
Graphical User Interface (GUI) 107. The GUI 107 contains a workflow that shows
the spine
112 and reports spinal alignment in view of positional information. As one
example, the user
interface can show an existing alignment 114 of the spinal vertebrae with
respect to a post-
surgical target alignment 113.
[0035] The alignment system 100 can be communicatively coupled to a
database 123
system such as a server 125 to provide three-dimensional (3D) imaging (e.g.,
soft tissue) and
3D models (e.g., bone) captured prior to, or during, surgery. The 3D imaging
and models can
be used in conjunction with the positional information to establish relative
location and
orientation. The server 125 may be local in near vicinity or remotely accessed
over the
intern& 121. As one example, the server 125 provides 3D spine and vertebra
models. A CAT
scanner (not shown) can be employed to produce a series of cross-sectional x-
ray images of a
selected part of the body. A computer operates the scanner, and the resulting
picture
represents a slice of the body. The server 125 produces a three-dimensional
(3D) model from
the slices. The server 125 can also provide 3D models generated from Magnetic
Resonance
Imaging (MRI) scanners (not shown). The server 125 may also support
fluoroscopic imaging
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to provide real-time moving images of the internal structures of a patient
with respect to the
alignment system 100 devices through the use of X-ray source (not shown) and
fluorescent
screen.
[0036] The spine alignment system 100 reports overall alignment and
instrument (e.g.,
wand 103 and receiver 101) orientation plus the ability to track isolated
vertebral movement.
The receiver 101 precisely tracks the location of the wand 103 at a particular
vertebra and
along the spine 112 to determine the positional information. The receiver 101
is shown
coupled (e.g., pinned, screwed, affixed) to the sacrum. However, it can be
located anywhere
along the vertebrae of the spine. Alternatively, it can be mounted to a stand
in the vicinity of
the spine 112. The wand 103 and receiver 101 are sensorized devices that can
transmit their
position via ultrasonic, optical, or electromagnetic sensing. In the example,
the wand 103 and
the receiver 102 utilize ultrasonic transducers and are line of sight devices.
The sensors may
be externally mounted on the wand 103 away from the wand tip, or in some
cases, within the
wand tip. The wand 103 can be held in the hand or affixed to the spine via a
mechanical
assembly. In one embodiment, the components for generating all alignment
measurements
(e.g. receiver 101 and wand 103) reside within a sterile field 109 of an
operating room. The
sterile field 109 can also be called a surgical field. Typically, the remote
system 105 is
outside the sterile field 109 of the operating room. The components used
within the sterile
filed 109 can be designed for a single use. In the example, the wand 103,
receiver 102, or
both are disposed of after being used intra-operatively.
[0037] One example of an ultrasonic sensing device is disclosed in U.S.
Patent
Application 11/683,410 entitled "Method and Device for Three-Dimensional
Sensing" filed
March 7, 2007 the entire contents of which are hereby incorporated by
reference. One
example of optical sensing includes three or four active IR reflectors on the
wand 103 with
corresponding high-speed camera elements on the receiver 101 for optical
tracking, or
alternatively high-speed photo-diode elements for detecting incident light
beam angles and
thereafter triangulating a wand position. One example of electromagnetic
sensing includes
metallic spheres on the wand whose spatial location is determined by
evaluating changes in
generated magnetic field strengths on the receiver 103.
[0038] Many physical parameters of interest within physical systems or
bodies can be
measured by evaluating changes in the characteristics of energy waves or
pulses. As one
example, changes in the transit time or shape of an energy wave or pulse
propagating through
a changing medium can be measured to determine the forces acting on the medium
and
causing the changes. The propagation velocity of the energy waves or pulses in
the medium is
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affected by physical changes in of the medium. The physical parameter or
parameters of
interest can include, but are not limited to, measurement of load, force,
pressure,
displacement, density, viscosity, and localized temperature. These parameters
can be
evaluated by measuring changes in the propagation time of energy pulses or
waves relative to
orientation, alignment, direction, or position as well as movement, rotation,
or acceleration
along an axis or combination of axes by wireless sensing modules or devices
positioned on or
within a body, instrument, equipment, or other mechanical system.
Alternatively,
measurements of interest can be taken using film sensors, mechanical sensors,
polymer
sensors, mems devices, strain gauge, piezo-resistive structure, and capacitive
structures to
name but a few.
[0039] FIG. 2 illustrates a graphical user interface (GUI) 150 of the
system 100 showing
spinal alignment and view projections in a non-limiting example. The view
projections
provide three-dimensional visualization to the surgical procedure and system
devices of FIG.
1 while displaying the quantitative measurements in real-time. Each view
projection can be
separately configured to show a different perspective of the spine with
superimposed spine
alignment information. The first view projection 210 shows a sagital view
(i.e., front to
back). The second view projection 230 shows a coronal view (i.e., side to
side). The sagital
and coronal views provide sufficient spatial information to visualize spine
alignment with
only two viewing projections. The view projections can be customized for
different view
angles and scene graphs.
[0040] As one example, the surgeon can hold the wand 103 and trace a
contour of the
spine, for instance, to determine the severity (or correction) of a scoliosis
condition. This may
be done prior to a surgery while the patient is standing to provide an
indication of the
patient's posture and spine curvature. The surgeon holds the wand and follows
the contour of
the spine. The GUI 108 visually shows the spinal contour from the positional
information
captured from the wand 103 during the trace. An alignment angle is then
calculated from first
order statistics and geometry (e.g., see angle points R, P1 and P2, where R is
reference
alignment, P1 is location of receiver 101, and P2 is point registered by wand
103). The
alignment angle indicates the offset of the spinal alignment, and when
projected in the view
planes, shows the deviation error in the sagital and coronal planes. The GUI
108 can then
report the required compensatory correction. In the current example, for
instance, it reports a
+4cm forward required displacement in display box 146 to correct for sagital
deviation of the
angle between line 152 and line 154, and a +2cm right required displacement in
display box
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148 to correct for coronal deviation of the angle between line 158 and line
156. This provides
the surgeon with the minimal visual information to provide surgical alignment
corrections.
[0041] Alternatively, a fast point-registration method can be employed to
assess spinal
alignment. The point registration method permits the surgeon to quickly assess
spinal
alignment with minimal registration. The user holds the wand and points and
clicks on
vertebra to create a point curve, which is converted to a line. In a first
step A, the receiver 101
is positioned at a stationary location, for example, on a stand near the
operating table.
Alternatively, the receiver 101 can be rigidly pinned to the sacrum as shown
in FIG. 1. In a
second step B, the surgeon identifies three or more anatomical features on a
reference bone
with the wand 103 tip, such as points along the posterior iliac crest or
dorsal surface on the
sacrum. The system 100 determines the reference bone orientation from the
registered wand
tip spatial locations, for example, in a <x,y,z> Cartesian coordinate system
relative to the
receiver 101 origin. The system 100 then retrieves the associated 3D model
spine components
(e.g., sacrum, vertebra, etc.) from the image server 125, and displays them on
the GUI 108
with the proper scaling and orientation (morphing and warping) in accordance
with the
reference bone orientation. Once the 3D model registration is complete, and
while the patient
remains stationary, the surgeon then registers one of the vertebrae, for
example cervical
vertebrae (C1-C7), in a third step C. The system 100 then has sufficient
registered points to
create a local coordinate system relative to the reference bone, generate a
curve and line
segment and report overall alignment as shown in FIG. 2. The spinal alignment
is reported in
view of a predetermined curvature or a straightness of the spine, for example,
showing line
152 versus desired (pre-op planning) line 154.
[0042] FIG. 3 illustrates a non-limiting example of the wand 103 and the
receiver 101,
though, not all the components shown are required; fewer components can be
used depending
on required functionality. The receiver 101 and wand 103 and communication
modes of
operations there between are disclosed in U.S. Patent Application 12/900,662
entitled
"Navigation Device Providing Sensory Feedback" filed 10/8/2010; the entire
contents of
which are hereby incorporated by reference. Briefly, the current dimensions
permit touchless
tracking with sub millimeter spatial accuracy (<1mm) up to approximately 2m in
distance.
Either device and can be configured to support various functions (e.g., hand-
held, mounted to
object) and neither is limited to the dimensions described below.
[0043] The wand 103 is a hand-held device with a size dimension of
approximately 10cm
in width, 2cm depth, and an extendable length from 18cm to 20cm. As indicated
above, the
wand 103 can register points of interest (see points A, B, C), for example,
along a contour of
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an object or surface, which can be shown in a user interface (see GUI 107 FIG.
1). As will be
discussed ahead, the wand 103 and receiver 101 can communicate via ultrasonic,
infrared and
electromagnetic sensing to determine their relative location and orientation
to one another.
Other embodiments incorporating accelerometers provide further positional
information.
[0044] The wand 103 includes sensors 201-203 and a wand tip 207. The
sensors can be
ultrasonic transducers, Micro Electro Mechanical Element (MEMS) microphones,
electromagnets, optical elements (e.g., infrared, laser), metallic objects or
other transducers
for converting or conveying a physical movement to an electric signal such as
a voltage or
current. They may be active elements in that they are self-powered to transmit
signals, or
passive elements in that they are reflective or exhibit detectable magnetic
properties.
[0045] In one embodiment, the wand 103 comprises three ultrasonic
transmitters 201-203
each transmitting ultrasonic signals through the air, a controller (or
electronic circuit) 214 for
generating driver signals to the three ultrasonic transmitters 201-203 for
generating the
ultrasonic signals, an user interface 218 (e.g., button) that receives user
input for performing
short range positional measurement and alignment determination, a
communications module
216 for relaying the user input and receiving timing information to control
the electronic
circuit 214, and a battery 218 for powering the electronic circuit 218 and
associated
electronics on the wand 103. The controller 214 is operatively coupled to the
ultrasonic
transmitters 201-203. Transmitters 201-203 transmit sensory signals in
response to a
directive by the controller 214. The wand 103 may contain more or less than
the number of
components shown; certain component functionalities may be shared as
integrated devices.
[0046] Additional transmitter sensors can be included to provide an over-
determined
system for three-dimensional sensing. As one example, each ultrasonic
transducer can
perform separate transmit and receive functions. One such example of an
ultrasonic sensor is
disclosed in U.S. Patent 7,725,288 the entire contents of which are hereby
incorporated by
reference. The ultrasonic sensors can transmit pulse shaped waveforms in
accordance with
physical characteristics of a customized transducer for constructing and
shaping waveforms.
[0047] The wand tip 207 identifies points of interest on a structure, for
example, an
assembly, object, instrument or jig in three-dimensional space but is not
limited to these. The
tip does not require sensors since its spatial location in three-dimensional
space is established
by the three ultrasonic transmitters 201-203 arranged at the cross ends.
However, a tip sensor
219 can be integrated on the tip 207 to provide ultrasound capabilities (e.g.,
structure
boundaries, depth, etc.) or contact based sensing. In such case, the tip 207
can be touch
sensitive to register points responsive to a physical action, for example,
touching the tip to an
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anatomical or structural location. The tip can comprise a mechanical or
actuated spring
assembly for such purpose. In another arrangement it includes a capacitive
touch tip or
electrostatic assembly for registering touch. The wand tip 207 can include
interchangeable,
detachable or multi-headed stylus tips for permitting the wand tip to identify
anatomical
features while the transmitters 201-203 remain in line-of-sight with the
receiver 101 (see FIG.
1). These stylus tips may be right angled, curved, or otherwise contoured in
fashion of a pick
to point to difficult to touch locations. This permits the wand to be held in
the hand to
identify via the tip 207, points of interest such as (anatomical) features on
the structure, bone
or jig.
[0048] The user interface 218 can include one or more buttons to permit
handheld
operation and use (e.g., on/off/reset button) and illumination elements to
provide visual
feedback. In one arrangement, an 8-state navigation press button 209 can
communicate
directives to further control or complement the user interface. It can be
ergonomically located
on a side of the wand to permit single-handed use. The wand 103 may further
include a haptic
module with the user interface 218. As an example, the haptic module may
change
(increase/decrease) vibration to signal improper or proper operation. The wand
103 includes
material coverings for the transmitters 201-202 that are transparent to sound
(e.g., ultrasound)
and light (e.g., infrared) yet impervious to biological material such as
water, blood or tissue.
In one arrangement, a clear plastic membrane (or mesh) is stretched taught; it
can vibrate
under resonance with a transmitted frequency. The battery 218 can be charged
via wireless
energy charging (e.g., magnetic induction coils and super capacitors).
[0049] The wand 103 can include a base attachment mechanism 205 for
coupling to a
structure, object or a jig. As one example, the mechanism can be a magnetic
assembly with a
fixed insert (e.g., square post head) to permit temporary detachment. As
another example, it
can be a magnetic ball and joint socket with latched increments. As yet
another example, it
can be a screw post or pin to an orthopedic screw. Other embodiments may
permit sliding,
translation, rotation, angling and lock-in attachment and release, and
coupling to standard jigs
by way of existing notches, ridges or holes.
[0050] The wand 103 can further include an amplifier 213 and an
accelerometer 217. The
amplifier enhances the signal to noise ratio of transmitted or received
signals. Accelerometer
217 identifies 3 and 6 axis tilt during motion and while stationary.
Communications module
216 may include components (e.g., synchronous clocks, radio frequency `RF'
pulses, infrared
'IR' pulses, optical/acoustic pulse) for signaling to the receiver 101. The
controller 214, can
include a counter, a clock, or other analog or digital logic for controlling
transmit and receive
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synchronization and sequencing of the sensor signals, accelerometer
information, and other
component data or status. The battery 218 powers the respective circuit logic
and
components. Infrared transmitter 209 pulses an infrared timing signal that can
be
synchronized with the transmitting of the ultrasonic signals (to the
receiver).
[0051] Controller 214 can utilize computing technologies such as a
microprocessor (uP)
and/or digital signal processor (DSP) with associated storage memory 208 such
as Flash,
ROM, RAM, SRAM, DRAM or other like technologies for controlling operations of
the
aforementioned components of the device. The instructions may also reside,
completely or at
least partially, within other memory, and/or a processor during execution
thereof by another
processor or computer system. An Input/Output port permits portable exchange
of
information or data for example by way of Universal Serial Bus (USB). The
electronic
circuitry of the controller 214 can comprise one or more Application Specific
Integrated
Circuit (ASIC) chips or Field Programmable Gate Arrays (FPGAs), for example,
specific to a
core signal-processing algorithm. The controller 214 can be an embedded
platform running
one or more modules of an operating system (OS). In one arrangement, the
storage memory
may store one or more sets of instructions (e.g., software) embodying any one
or more of the
methodologies or functions described herein.
[0052] The receiver 101 comprises a processor 233 for generating timing
information,
registering a pointing location of the wand 103 responsive to the user input,
and determining
short range positional measurement and alignment from three or more pointing
locations of
the wand 103 with respect to the receiver 101. The receiver has size
dimensions of
approximately 2cm width, 2cm depth, and a length of 10cm to 20cm. It includes
a
communications module 235 for transmitting the timing information to the wand
103 that in
response transmits the first, second and third ultrasonic signals. The
ultrasonic signals can be
pulse shaped signals generated from a combination of amplitude modulation,
frequency
modulation, and phase modulation. Three microphones 221-223 each receive the
first, second
and third pulse shaped signals transmitted through the air. Receiver 101 can
be configured
lineal or in more compact arrangements, it can comprise a triangular shape.
One example of a
device for three-dimensional sensing is disclosed in U.S. Patent Application
11/683,410
entitled "Method and Device for Three-Dimensional Sensing" filed March 7, 2007
the entire
contents of which are hereby incorporated by reference.
[0053] The memory 238 stores the ultrasonic signals and can produce a
history of
ultrasonic signals or processed signals. It can also store wand tip positions,
for example,
responsive to a user pressing the button to register a location. The wireless
communication
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interface (Input/Output) 239 wirelessly conveys the positional information and
the short-
range alignment of the three or more pointing locations to a remote system.
The remote
system can be a computer, laptop or mobile device that displays the positional
information
and alignment information in real-time as described ahead. The battery powers
the processor
233 and associated electronics on the receiver 101. The receiver 101 may
contain more or
less than the number of components shown; certain component functionalities
may be shared
or therein integrated.
[0054] Additional ultrasonic sensors can be included to provide an over-
determined
system for three-dimensional sensing. The ultrasonic sensors can be MEMS
microphones,
receivers, ultrasonic transmitters or combination thereof As one example, each
ultrasonic
transducer can perform separate transmit and receive functions. One such
example of an
ultrasonic sensor is disclosed in U.S. Patent 7,414,705 the entire contents of
which are hereby
incorporated by reference. The receiver 101 can also include an attachment
mechanism 240
for coupling to bone or a jig by way of the pin 251. As one example,
attachment mechanism
240 can be a magnetic assembly with a fixed insert (e.g., square post head) to
permit
temporary detachment. As another example, it can be a magnetic ball and joint
socket with
latched increments.
[0055] The receiver 101 can further include an amplifier 232,
communications module
235, an accelerometer 236, and processor 233. The processor 233 can host
software program
modules such as a pulse shaper, a phase detector, a signal compressor, and
other digital signal
processor code utilities and packages. The amplifier 232 enhances the signal
to noise of
transmitted or received signals. The processor 233 can include a controller,
counter, a clock,
and other analog or digital logic for controlling transmit and receive
synchronization and
sequencing of the sensor signals, accelerometer information, and other
component data or
status. The accelerometer 236 can identify axial tilt (e.g., 3 and 6 axis)
during motion and
while stationary. The battery 234 powers the respective circuit logic and
components. The
receiver includes a photo diode 241 for detecting the infrared signal and
establishing a
transmit time of the ultrasonic signals to permit wireless infrared
communication with the
wand.
[0056] The communications module 235 can include components (e.g.,
synchronous
clocks, radio frequency `RF' pulses, infrared 'IR' pulses, optical/acoustic
pulse) for local
signaling (to wand 102). It can also include network and data components
(e.g., Bluetooth,
ZigBee, Wi-Fi, GPSK, FSK, USB, R5232, IR, etc.) for wireless communications
with a
remote device (e.g., laptop, computer, etc.). Although external communication
via the
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network and data components is herein contemplated, it should be noted that
the receiver 101
can include a user interface 237 to permit standalone operation. As one
example, it can
include 3 LED lights 224 to show three or more wand tip pointing location
alignment status.
The user interface 237 may also include a touch screen or other interface
display with its own
GUI for reporting positional information and alignment.
[0057] The processor 233 can utilize computing technologies such as a
microprocessor
(uP) and/or digital signal processor (DSP) with associated storage memory 238
such a Flash,
ROM, RAM, SRAM, DRAM or other like technologies for controlling operations of
the
aforementioned components of the terminal device. The instructions may also
reside,
completely or at least partially, within other memory, and/or a processor
during execution
thereof by another processor or computer system. An Input/Output port permits
portable
exchange of information or data for example by way of Universal Serial Bus
(USB). The
electronic circuitry of the controller can comprise one or more Application
Specific
Integrated Circuit (ASIC) chips or Field Programmable Gate Arrays (FPGAs), for
example,
specific to a core signal processing algorithm or control logic. The processor
can be an
embedded platform running one or more modules of an operating system (OS). In
one
arrangement, the storage memory 238 may store one or more sets of instructions
(e.g.,
software) embodying any one or more of the methodologies or functions
described herein.
[0058] In a first arrangement, the receiver 101 is wired via a tethered
electrical
connection (e.g., wire) to the wand 103. That is, the communications port of
the wand 103 is
physically wired to the communications interface of the receiver 101 for
receiving timing
information. The timing information from the receiver 101 tells the wand 103
when to
transmit and includes optional parameters that can be applied to pulse
shaping. The processor
233 on the receiver 101 employs this timing information to establish Time of
Flight
measurements in the case of ultrasonic signaling with respect to a reference
time base.
[0059] In a second arrangement, the receiver 101 is communicatively coupled
to the
wand 103 via a wireless signaling connection via wireless I/0 239. A signaling
protocol is
disclosed in U.S. Patent Application 12/900,662 entitled "Navigation Device
Providing
Sensory Feedback" filed 10/8/2010; the entire contents of which are hereby
incorporated by
reference. An infrared transmitter 209 on the wand 103 transmits an infrared
timing signal
with each transmitted pulse shaped signal. It pulses an infrared timing signal
that is
synchronized with the transmitting of the ultrasonic signals to the receiver.
The receiver 101
can include a photo diode 241 for determining when the infrared timing signal
is received. In
this case, the communications port of the wand 103 is wirelessly coupled to
the
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communications interface of the receiver 101 by way of the infrared
transmitter and the photo
diode for relaying the timing information to within microsecond accuracy (-1mm
resolution).
The processor 233 on the receiver 101 employs this infrared timing information
to establish
the first, second, and third Time of Flight measurements with respect to a
reference transmit
time.
[0060] FIG. 4 illustrates multiple sensorized wands for evaluating spinal
alignment 300
in a non-limiting example. As shown, multiple sensorized wands 301-304 can be
employed
to track individual vertebral movement and/or alignment relative to other
tracked vertebrae.
Each of the wands may be of a different size and sensor configuration. The
wands are
lightweight components that can span dimensions between 4 cm to 12 cm, and
width of less
than or equal to lcm. In general, the wands 301-304 have a form factor easily
held by hand
or can be attached and supported by the muscular-skeletal system. For example,
a first wand
301 may have a wider and longer sensor span than another wand 303. This can
enhance
communication between the wands 301-304 and receiver 308. Each wand can have a
separate
ID to identify it from the others, for example, stored as a characteristic low
frequency
magnetic wavelength unique to the wand. The system 100 can identify the wands
via the
passive magnetic field and determine position via the one or more ultrasonic,
optical,
electromagnetic elements, or (passive/active) sensors.
[0061] In conjunction with the illustration of FIG. 4, a workflow method is
herein
contemplated. At a first workflow step 311, the receiver 308 is positioned in
proximity to the
surgical area and where the wands are expected to be used. As previously
noted, the receiver
308 is placed on a stand or affixed to the sacrum (or other bony region) to
track a wand's
orientation and location. A wand may be held in a hand and used to register
anatomic features
on sacrum, for example, point and click the wand tip to a bone feature. This
point registration
captures anatomical points, which are then used to retrieve a 3D spine model
with proper
orientation and dimension. At step 312, the wand can then be used to register
points on a
vertebra to assess a location of that vertebra. In a first arrangement, the
wand can be affixed
to the vertebra directly without any wand tip point registration. This
provides one point for
assessing spatial location at the insertion point but not necessarily
orientation (three-
dimensional information).
[0062] In a second arrangement, the wand is first used to register points
on the surface of
the vertebra and then inserted therein. The registration captures anatomical
vertebra points,
which are then used to retrieve a 3D vertebra model with proper orientation
and dimension.
This permits the system 100 to track the vertebra with proper scaling and
position when the
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wand is inserted therein. During the registration and positioning of the
receiver on the sacrum
and each wand on the vertebrae, the system 100 provides a real-time view of
the instrument
tracking as shown in step 313. That is, it produces a virtual environment
showing the 3D
model of the spine, sensorized wands 301-304 and receiver 308.
[0063] FIG. 5 illustrates sensorized placement for determining spinal
conditions in a non-
limiting example. As previously noted, the wand-tip may also include a sensor,
such as a
biometric transducer. The wand tip when used to register a point of interest
can also capture
biometric data directly related to the insertion site. The wand tip can also
disengage the
biometric transducer and leave it positioned at the site of contact. The
illustrations of FIG. 5
and 6 illustrate the placement of the wand tip sensor, which in some
configurations deploys
its tip sensor in-situ for long term implantation. The system 100 can also
enable a transfer of
energy waves in a vibratory pattern that can mimic load on the bone and lead
to improved
bone mineral content and density. The sensors can also send energy waves
through or across
an implant to, thus, aid in healing of a fracture.
[0064] Accordingly, a method is herein provided for detecting biometric
parameters,
which are a function of sensorized placement including position and
orientation. The method
includes providing a biometric transducer on a moving component of a vertebral
joint,
transmitting an energy wave (e.g., ultrasonic, optical, electromagnetic) from
the biometric
transducer into a procedure area different from the moving component of the
vertebral joint
during vertebral joint or spine motion, quantatively assessing the behavior of
the energy wave
during the vertebral joint motion; and based upon the assessed behavior and
vertebral joint
motion, determining a current status or at least one parameter of the
procedure area selected
from the group consisting of pressure, tension, shear, load, torque, bone
density and bearing
weight. Alternatively, an insertible head assembly incorporating one or more
sensors can be
used to measure the biometric parameter of interest. In the example, the
biometric transducer
can detect and transmit information regarding motion and loads of vertebra. As
one example,
the sensors can detects abnormal motion of the orthopedic joint by evaluating
a frequency or
periodicity of the assessed behavior, for example, as the vertebral joint is
flexed during
movement.
[0065] As one example shown in FIG. 5, a single sensor 352 can be implanted
on a bone
or prosthetic component of the vertebral joint (e.g., vertebra) to assess
behavior of the
vertebral joint during movement, such as, a quality or functionality of the
joint mechanics as
related to pressure, tension, shear, bone density and bearing weight. The
sensor 352 in this
embodiment is at a fixed location on the bone (vertebra) and moves with the
vertebra 358
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during motion relative to the procedure area 360. As shown, the procedure area
360
comprises vertebra 354, disc 356, and vertebra 358. The procedure area 360 is
relatively
stationary with respect to the sensor since the vertebra primarily moves the
single sensor. The
single sensor in this arrangement is exposed to various changes in the
parameter of interest
(e.g., pressure, tension, shear, bone density, and bearing weight) in the
procedure area as a
result of the motion. As one example, the sensor is compressed through the
range of joint
movement consequent to actions applied at different locations in the joint
during the motion.
During motion, sensor 352 assesses the energy waves in the procedural area; an
adjacent area
is also assessed because the movement of the vertebra (and accordingly the
sensor focus)
changes with respect to the procedure area as a result of the motion. The
position of sensor
352 (by way of the wand when attached thereto) is also determined in relation
to the other
vertebra and used to catalog changes in the sensed parameter with respect to
orientation,
location and position.
[0066] One advantage of placing sensor 352 on a moving component (e.g.,
vertebra,
prosthetic implant) and transmitting an energy wave into a procedure area
different from the
moving component of the vertebral joint, with knowledge of its location and
orientation, is
that it effectively changes the distance between sensor 352 and the procedure
area which
changes the resolution and focus of sensor 352 as well as forces thereon. The
positional
information also indicates periodicity of movement as related to changes in
the sensed
parameter. As one example, sensor 352 operating in a switched transmit and
receive mode
can take measurements at different depths of the procedure area without
incurring operational
changes. Sensor 352 as a result of the changing distance due to joint
movement, can take
different measurements without sensor adjustment that could otherwise require
changing a
frequency, amplitude, or phase of the transmitted energy wave, for example, to
match
impedances.
[0067] As one example, biometric sensor 352 can be an ultrasound device.
Quantitative
ultrasound, in contrast to other bone-densitometry methods that measure only
bone-mineral
content, can measure additional properties of bone such as mechanical
integrity. Propagation
of the ultrasound wave through bone is affected by bone mass, bone
architecture, and the
directionality of loading. Quantitative ultrasound measurements as measures
for assessing the
strength and stiffness of bone are based on the processing of the received
ultrasound signals.
The speed of sound and the ultrasound wave propagates through the bone and the
soft tissue.
Prosthetic loosening or subsidence, and fracture of the femur/tibia/acetabulum
or the
prosthesis, are associated with bone loss. Consequently, an accurate
assessment of
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progressive quantifiable changes in periprosthetic bone-mineral content may
help the treating
surgeon to determine when to intervene in order to preserve bone stock for
revision
arthroplasty. This information helps in the development of implants for
osteoporotic bone,
and aids in the evaluation of medical treatment of osteoporoses and the
effects of different
implant coatings.
[0068] FIG. 6 illustrates multiple sensorized placements for determining
spinal
conditions in a non-limiting example. As previously noted, the wand-tip may
also include a
sensor, such as a biometric transducer. The wand tip when used to register a
point of interest
can also capture biometric data directly related to the insertion site. The
wand tip can also
disengage the biometric transducer and leave it positioned at the site of
contact.
[0069] Accordingly, a method is herein provided for detecting biometric
parameters
comprising providing a second biometric transducer at the procedure area that
is different
from the moving component of the vertebral joint, and quantatively assessing
the behavior of
the energy wave based on a relative separation of the first biometric
transducer and second
biometric transducer during the vertebral joint motion. A current status or at
least one
parameter of the procedure area is determined from the assessed behavior and
vertebral joint
motion. The parameter is one of strain, vibration, kinematics, and stability.
A first biometric
transducer or the second biometric transducer can include a transceiver for
transmitting data
relating to the at least one biometric parameter to an external source for
assessment.
[0070] As shown in FIG. 6 sensor 352 can be implanted on a bone or
prosthetic
component of an vertebral joint (e.g., vertebra) and a sensor 366 can be
positioned at a
different position in the procedure area for assessing behavior of the
vertebral joint during
movement. Sensor 352 in this embodiment is at a fixed location on the bone
(vertebra) and
moves with the vertebra during joint motion relative to sensor 366 in the
procedure area. The
sensor 366 can be on a different bone. Although both sensors can move, sensor
352 in effect
can be considered moving relative to sensor 366 and is relatively displaced as
indicated. The
sensors 352 and 366 allow evaluation of the host bone and tissue regarding,
but not limited to
bone density, fluid viscosity, temperature, strain, pressure, angular
deformity, vibration, load,
torque, distance, tilt, shape, elasticity, motion, and others.
[0071] The dual sensor arrangement shown can evaluate of bone integrity.
For instance,
in a vertebral joint, sensors 352 and 366 coupled to a first and second
vertebra assess the bone
density. External and internal energy waves sent by sensor 352, sensor 366, or
both according
to the invention can be used during the treatment of fractures and spinal
fusions. With two
deployed sensors, the distance between the sensors can be determined at the
area of concern
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and the power field that can be generated. The energy fields can be standard
energy sources
such as ultrasound, radiofrequency, and/or electromagnetic fields. The
deflection of the
energy wave over time, for example, will allow the detection of changes in the
desired
parameter that is being evaluated. As an example, a first sensor placed on a
distal end of the
femur bone can assess bone density from a second sensor embedded on a proximal
end of the
tibia bone during vertebral movement.
[0072] One advantage of two or more sensors is that they move closer and
farther apart
relative to one another as a result of the motion; actions that improve an
assessment of the
energy wave, for example, due to the frequency characteristics of the sensors
and impedance
characteristics of the procedure area under investigation. Again, the relative
separation of
sensors 352 and 366 may permit taking different measurements without sensor
adjustment
that could otherwise require changing a frequency, amplitude, or phase of the
transmitted
energy wave, for example, to match impedances. In the current example, the
measurement of
bone is based on the processing of the received ultrasound signals. Speed of
the sound and
the ultrasound velocity both provide measurements on the basis of how rapidly
the ultrasound
wave propagates through the bone and the soft tissue. These measures
characteristics permit
creation of a rapid three-dimensional geometry, which information can be
processed by the
system 100 in conjunction with positional, orientation and location
information. Because the
sensors span a joint space, they can detect changes in the implant function.
Examples of
implant functions include bearing wear, subsidence, bone integration, normal
and abnormal
motion, heat, change in viscosity, particulate matter, kinematics, to name a
few.
[0073] FIG. 7 illustrates a sensorized spinal instrument 400 in a non-
limiting example. A
side view and a top view are presented. Spinal instrument 400 comprises a
handle 409, a
shaft 430, and a sensored head 407. The handle 409 is coupled at a proximal
end of the shaft
430 and the sensored head 407 is coupled to a distal end of the shaft 430. In
one
embodiment, handle 409, shaft 430, and sensored head 407 form a rigid
structure that does
not flex when used to distract or measure a spinal region. Spinal instrument
400 includes an
electronic assembly 401 operatively coupled to one or more sensors in sensored
head 407.
The sensors are coupled to surfaces 403/406 on moving components 404/405 of
sensored
head 407. The electronic assembly 401 is located towards the proximal end of
the shaft 407
or in handle 409. As shown, the electronic assembly 401 is coupled to shaft
409. Electronic
assembly 401 comprises electronic circuitry that includes logic circuitry, an
accelerometer,
and communication circuitry. In one embodiment, surfaces 403 and 406 of
sensored head
407 can have a convex shape. The convex shape of surfaces 403 and 406 support
placement
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of sensored head 407 within the spinal region and more specifically between
the contours of
vertebrae. In one embodiment, sensored head 407 is height adjustable by way of
the top
component 404 and the bottom component 405 through a jack 402 that evenly
distracts and
closes according to handle 409 turning motion 411. Jack 402 is coupled to
interior surfaces
of components 404 and 405 of sensored head 407. Shaft 430 includes one or more
lengthwise passages. For example, interconnect such as a flexible wire
interconnect can
couple through one lengthwise passage of shaft 430 such that electronic
assembly 401 is
operatively coupled to one or more sensors in sensored head 407. Similarly, a
threaded rod
can couple through a second passage of shaft 430 for coupling handle 409 to
jack 404 thereby
allowing height adjustment of sensored head 407 via rotation of handle 409.
[0074] Spine instrument 400 can also determine an orientation by way of
embedded
accelerometers. The sensored head 407 supports multiple functions that include
the ability to
determine a parameter of the procedure area (e.g., intervertebral space)
including pressure,
tension, shear, load, torque, bone density, and/or bearing weight. In one
embodiment, more
than one load sensor can be included within sensored head 407. The more than
one load
sensors can be coupled to predetermined locations of surfaces 403 and 406.
Having more
than one load sensor allows the sensored head 407 to measure load magnitude
and the
position of applied load to surfaces 403 and 406. The sensored head 407 can be
used to
measure, adjust, and test a vertebral joint prior to installing a vertebral
component. As will be
seen ahead, the alignment system 100 evaluates the optimal insertion angle and
position of
the spine instrument 400 during intervertebral load sensing and replicates
these conditions
when using an insert instrument.
[0075] In the present invention these parameters can be measured with an
integrated
wireless sensored head 407 or device comprising an 0 encapsulating structure
that supports
sensors and contacting surfaces and i0 an electronic assemblage that
integrates a power
supply, sensing elements, ultrasound resonator or resonators or transducer or
transducers and
ultrasound waveguide or waveguides, biasing spring or springs or other form of
elastic
members, an accelerometer, antennas and electronic circuitry that processes
measurement
data as well as controls all operations of energy conversion, propagation, and
detection and
wireless communications. The sensored head 407 or instrument 400 can be
positioned on or
within, or engaged with, or attached or affixed to or within, a wide range of
physical systems
including, but not limited to instruments, appliances, vehicles, equipments,
or other physical
systems as well as animal and human bodies, for sensing and communicating
parameters of
interest in real time.
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[0076] An example of using the spinal instrument 400 is in the installation
of a spinal
cage. The spinal cage is used to space vertebrae in replacement of a disc. The
spinal cage is
typically hollow and can be formed having threads for fixation. Two or more
cages are often
installed between the vertebrae to provide sufficient support and distribution
of loading over
the range of motion. In one embodiment, the spinal cage is made titanium for
lightweight
and strength. A bone growth material can also be placed in the cage to
initiate and promote
bone growth thereby further strengthening the intervertebral area long-term.
The spinal
instrument 400 is inserted in the gap between vertebrae to measure load and
position of load.
The position of load corresponds to the vertebral area or surfaces applying
the load on the
surfaces 403 or 406 of sensored head 407. The angle and position of insertion
of the sensored
head 407 of spinal instrument 400 can also be measured. The load magnitude and
position of
load measurement are used by the surgeon to determine an implant location
between the
vertebrae and the optimal size of the spinal cage for the implant location.
The optimal size
will be a cage height that when loaded by the spine falls within a
predetermined load range.
Typically, the height of sensored head 407 used to distract and measure force
applied by the
vertebrae of interest is equal to the cage height implanted in a subsequent
step. After
removing the sensored head 407 from the vertebrae the spinal cage can be
implanted in the
same region. The loading on the implanted spinal cage is approximately equal
to the
measurements made by spinal instrument 400 and applied to sensor head 407. In
one
embodiment, the angle and position of the insertion trial measurement is
recorded by spinal
instrument 400 or a remote system coupled thereto. The angle and position
measurements
are subsequently used to guide the spinal cage into the same region of the
spine in an
identical path as spinal instrument 400 during a measurement process.
[0077] FIG. 8 illustrates an integrated sensorized spinal instrument 410 in
a non-limiting
example. In particular, the electronic assembly 401 is internal to the
integrated instrument
410. It includes an external wireless energy source 414 that can be placed in
proximity to a
charging unit to initiate a wireless power recharging operation. The wireless
energy source
414 can include a power supply, a modulation circuit, and a data input. The
power supply can
be a battery, a charging device, a capacitor, a power connection, or other
energy source for
generating wireless power signals that can transfer power to spinal instrument
410. The
external wireless energy source 414 can transmit energy in the form of, but
not limited to,
electromagnetic induction, or other electromagnetic or ultrasound emissions.
In at least one
exemplary embodiment, the wireless energy source includes a coil to
electromagnetically
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couple and activate (e.g., power on) with an induction coil in sensing device
when placed in
close proximity.
[0078] The electronic assembly 401 transmits measured parameter data to a
receiver via
data communications circuitry for permitting visualization of the level and
distribution of the
parameter at various points on the vertebral components. The data input can
also be an
interface or port to receive the input information from another data source,
such as from a
computer via a wired or wireless connection (e.g., USB, IEEE802.16, etc.). The
modulation
circuitry can modulate the input information onto the power signals generated
by the power
supply. Sensored head 407 has wear surfaces that are typically made of a low
friction
polymer material. Ideally, the sensored head 407 when inserted between
vertebrae has an
appropriate loading, alignment, and balance similar that is similar to a
natural spine.
[0079] FIG. 9 illustrates an insert instrument 420 with vertebral
components in a non-
limiting example. Electronic assembly 401 as described herein similarly
supports the
generation of orientation and position data of insert instrument 420. By way
of the alignment
system 100, the user can replicate the insertion angle, position and
trajectory (path) to achieve
proper or pre-planned placement of the vertebral component. Alternatively, an
accelerometer
in electronic assembly 401 can provide location and trajectory information.
Insert instrument
420 comprises a handle 432, a neck 434, and a tip 451. An attach/release
mechanism 455
couples to the proximal end of neck 434 for controlling tip 451.
Attach/release mechanism
455 allows a surgeon to retain or release vertebral components coupled to tip
451. In the
example, handle 432 extends at an angle in proximity to a proximal end of neck
434.
Positioning of handle 432 allows the surgeon to accurately direct tip 451 in a
spinal region
while allowing access to attach/release mechanism 455.
[0080] In a first example, the vertebral component is a spine cage 475. The
spine cage
475 is a small hollow cylindrical device, usually made of titanium, with
perforated walls that
can be inserted between the vertebrae of the spine during a surgery. In
general, a distraction
process spaces the vertebrae to a predetermined distance prior insertion of
spine cage 475.
Spine cage 475 can increase stability, decrease vertebral compression, and
reduce nerve
impingement as a solution to improve patient comfort. Spine cage 475 can
include surface
threads that allow the cage to be self-tapping and provide further stability.
Spine cage 475
can be porous to include bone graft material that supports bone growth between
vertebral
bodies through cage 475. More than one spine cage can be placed between
vertebrae to
alleviate discomfort. Proper placement and positioning of spine cage 475 is
important for
successful long-term implantation and patient outcome.
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[0081] In a second example, the vertebral component is a pedicle screw 478.
The
pedicle screw 478 is a particular type of bone screw designed for implantation
into a vertebral
pedicle. There are two pedicles per vertebra that couple to other structures
(e.g. lamina,
vertebral arch). A polyaxial pedicle screw may be made of titanium to resist
corrosion and
increase component strength. The pedicle screw length ranges from 30mm to
60mm. The
diameter ranges from 5.0mm to 8.5mm. It is not limited to these dimensions,
which serve as
dimensional examples. Pedicle screw 478 can be used in instrumentation
procedures to affix
rods and plates to the spine to correct deformity, and/or treat trauma. It can
be used to
immobilize part of the spine to assist fusion by holding bony structures
together. By way of
electronic assembly 401 (which may be internally or externally integrated),
the insert
instrument 420 can determine depth and angle for screw placement and guide the
screw
therein. In the example, one or more accelerometers are used to provide
orientation, rotation,
angle, or position information of tip 451 during an insertion process.
[0082] In one arrangement, the screw 478 is embedded with sensors. The
sensors can
transmit energy and obtain a density reading and monitor the change in density
over time. As
one example, the system 100 can thus monitor and report healing of a fracture
site. The
sensors can detect the change in motion at the fracture site as well as the
motion between the
screw and bone. Such information aids in monitoring healing and gives the
healthcare
provider an ability to monitor vertebral weight bearing as indicated. The
sensors can also be
activated externally to send energy waves to the fracture itself to aid in
healing.
[0083] FIG. 10 illustrates a perspective view of the spinal instrument 400
positioned
between vertebrae of the spine for sensing vertebral parameters in a non-
limiting example. In
general, a compressive force is applied to surfaces 403 and 406 when sensored
head 407 is
inserted into the spinal region. In one embodiment, sensored head 407 includes
two or more
load sensors that identify magnitude vectors of loading on surface 403,
surface 406, or both
associated with inter-vertebral force there between. In the example shown, the
spinal
instrument 400 is positioned between vertebra (L5) and the Sacrum (S) such
that a
compressive force is applied to surfaces 403 and 406. One approach for
inserting the
instrument 400 is from the posterior (back side) through a minilaparotomy as
an endoscopic
approach may be difficult to visualize or provide good exposure. Another
approach is from
the anterior (front side) which allows the surgeon to work through the abdomen
to reach the
spine. In this way spine muscles located in the back are not damaged or cut;
avoiding muscle
weakness and scarring. Spinal instrument 400 can be used with either the
anterior or posterior
spine approach.
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[0084] Aspects of the sensorized components of the spine instrument 400 are
disclosed in
U.S. Patent Application 12/825,638 entitled "System and Method for Orthopedic
Load
Sensing Insert Device" filed June 29, 2010, and U.S. Patent Application
12/825,724 entitled
"Wireless Sensing Module for Sensing a Parameter of the Muscular-Skeletal
System" filed
June 29, 2010 the entire contents of which are hereby incorporated by
reference. Briefly, the
sensored head 407 can measure forces (Fx, Fy, and Fz) with corresponding
locations and
torques (e.g. Tx, Ty, and Tz) and edge loading of vertebrae. The electronic
circuitry 401 (not
shown) controls operation and measurements of the sensors in sensored head
407. The
electronic circuitry 401 further includes communication circuitry for short-
range data
transmission. It can then transmit the measured data to the remote system to
provide real-
time visualization for assisting the surgeon in identifying any adjustments
needed to achieve
optimal joint balancing.
[0085] A method of installing a component in the muscular-system is
disclosed below.
The steps of the method can be performed in any order. An example of placing a
cage
between vertebrae is used to demonstrate the method but the method is
applicable to other
muscular-skeletal regions such as the knee, hip, ankle, spine, shoulder, hand,
arm, and foot.
In a first step, a sensored head of a predetermined width is placed in a
region of the muscular-
skeletal system. In the example, the insertion region is between vertebrae of
the spine. A
hammer can be used to tap an end of the handle to provide sufficient force to
insert the
sensored head between the vertebrae. The insertion process can also distract
the vertebrae
thereby increasing a separation distance. In a second step, the position of
the load applied to
the sensored head is measured. Thus, the load magnitude and the position of
the loading on
the surfaces of the sensored head are available. How the load applied by the
muscular-
skeletal system is positioned on the surfaces of the sensored head can aid in
determining
stability of the component once inserted. An irregular loading applied to
sensored head can
predict a scenario where the applied forces thrust the component away from the
inserted
position. In general, the sensored head is used to identify a suitable
location for insertion of
the component based on quantitative data. In a third step, the load and
position of load data
from the sensored head is displayed on a remote system in real-time.
Similarly, in a fourth
step, the at least one of orientation, rotation, angle, or position is
displayed on the remote
system in real-time. Changes made in positioning the sensored head are
reflected in data on
the remote system display. In a fifth step, a location between vertebrae
having appropriate
loading and position is identified and the corresponding quantitative
measurement data is
stored in memory.
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[0086] In a sixth step, the sensored head is removed. In a seventh step,
the component is
inserted in the muscular-skeletal system. As an example, the stored
quantitative
measurement data is used to support the positioning of the component in the
muscular-
skeletal system. In the example, the insertion instrument can be used to
direct the component
into the muscular-skeletal system. The insertion instrument is an active
device providing
orientation, rotation, angle, or position of the component as it is being
inserted. The
previously measured direction and location of the insertion of the sensored
head can be used
to guide the insertion instrument. In one embodiment, the remote system
display can aid in
displaying relational alignment of the insertion instrument and component to
the previously
inserted sensored head. The insertion instrument in conjunction with the
system can provide
visual, vocal, haptic or other feedback to further aid in directing the
placement of the
component. In general, the component being inserted has substantially equal
height as the
sensored head. Ideally, the component is inserted identical in location and
position to the
previously inserted sensored head such that the loading and position of load
on the
component is similar to the quantitative measurements. In an eighth step, the
component is
positioned identically to the previously inserted sensored head and released.
The insertion
instrument can then be removed from the muscular-skeletal system. In a ninth
step, at least
the sensored head is disposed of
[0087] Thus, the sensored head is used to identify a suitable location for
insertion of the
component. The insertion is supported by quantitative measurements that
include position
and location. Furthermore, the approximate loading and position of loading on
the
component is known after the procedure has been completed. In general, knowing
the load
applied by the muscular-skeletal system and the position on the surfaces of
the component
can aid in determining stability of the component long-term. An irregular
loading applied on
the component can result in the applied forces thrusting the component away
from the
inserted position.
[0088] FIG. 11 illustrates a graphical user interface (GUI) 500 showing a
perspective
view of the sensorized spinal instrument of FIG. 10 in a non-limiting example.
The user
interface 500 is presented by way of the remote system 105 and alignment
system 100 (see
FIG. 1). The GUI 500 includes a window 510 and a related window 520. The
window 520
shows the spine instrument 400 and sensor head 407 in relation to a vertebra
522 under
evaluation. In this example, a perspective (top) view of the vertebra is
shown. It indicates a
shaft angle 523 and a rotation component 524 which reveal the approach angle
and rotation
of the spine instrument 400, for instance, as it is moved forward into the
incision. The
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window 520 and corresponding GUI information is presented and updated in real-
time during
the procedure. It permits the surgeon to visualize use of the spine instrument
400 and the
sensed parameters. The window 510 shows a sensing surface (403 or 406) of the
sensored
head 407. A cross hair 512 is superimposed on the sensor head image to
identify the
maximal point of force and location. It can also lengthen to show vertebral
edge loading. A
window 513 reports the load force, for example, 201bs across the sensor head
surface. This
information is presented and updated in real-time during the procedure.
[0089] As previously noted, the system 100 can be used intra-operatively to
aid in the
implantation of the prosthesis/instrumentation/hardware by way of parameter
sensing (e.g.,
vertebral load, edge loading, compression, etc.). The components such as
receiver 101,
plurality of wands 103, and spinal instrument 400 remain within the surgical
field when used.
The remote system 105 is typically outside the surgical field. All
measurements are made
within the surgical field by these components. In one embodiment, at least one
of the
receiver 101, plurality of wands 103, and spinal instrument are disposed of
after the
procedure is completed. In general, they are designed to be powered for a
single use and
cannot be re-sterilized.
[0090] In the spine, the affects on the bony and soft tissue elements are
evaluated by the
system 100, as well as the soft tissue (e.g., cartilage, tendon, ligament)
changes during
surgery, including corrective spine surgery. The sensors are then used during
the operation
(and post-operatively) to evaluate and visualize changes over time and dynamic
changes. The
sensors can be activated intra-operatively when surgical parameter readings
are stored.
Immediately post-operatively, the sensor is activated and a baseline is known.
[0091] The sensor system 100 allows evaluation of the spine and connective
tissue
regarding, but not limited to bone density, fluid viscosity, temperature,
strain, pressure,
angular deformity, vibration, load, torque, distance, tilt, shape, elasticity,
and motion.
Because the sensors span a vertebral space, they can predict changes in the
vertebral
component function prior to their insertion. As previously noted, the system
100 is used to
place the spine instrument 400 in the inter-vertebral space, where it is shown
positioned
relative to the vertebral body 522. Once it is placed and visually confirmed
in the vertebral
center, the system 100 reports any edge loading on the instrument which in
turn is used to
size a proper vertebral device and insertion plan (e.g., approach angle,
rotation, depth, path
trajectory). Examples of implant component function include bearing wear,
subsidence, bone
integration, normal and abnormal motion, heat, change in viscosity,
particulate matter,
kinematics, to name a few.
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[0092] FIG. 12 illustrates the sensorized spinal instrument 400 positioned
between
vertebra of the spine for intervertebral position and force sensing in a non-
limiting example.
As shown, sensored head 407 of spinal instrument 400 is placed between
vertebrae a L4 and
L5 vertebrae. The spinal instrument 400 distracts the L4 and L5 vertebrae the
height of
sensored head 407 and provides quantitative data on load magnitude and
position of load. In
one embodiment, spinal instrument 400 communicates with a first wand 510 and a
second
wand 520 positioned adjacent on each side thereof A long shaft 514 is provided
on each
wand to permit placement within vertebra of the spine and also line up with
other wands and
an electronic assembly 401 of the spine instrument 400. Wand 510 tracks an
orientation and
position of vertebra L4, while wand 520 tracks an orientation and position of
vertebra L5.
This permits the system 100 to track an orientation and movement of the spine
instrument
400 relative to movement of the neighboring vertebra. Each wand is sensorized
similar to the
spine instrument 400. Wand 510 and wand 520 respectively includes a sensor 512
and a
sensor 513. Sensors 512 and 513 can transmit and receive positional
information. The
electronic assembly 401 in conjunction with wands 510 and 520 dually serves to
resolve an
orientation and position of the spine instrument 400 during the procedure. One
example of an
ultrasonic positional sensing is disclosed in U.S. Patent Application
12/764,072 entitled
"Method and System for Positional Measurement" filed April 20, 2010 the entire
contents of
which are hereby incorporated by reference.
[0093] FIG. 13 illustrates a perspective view of a user interface 600
showing the
sensorized spinal instrument of FIG. 12 in a non-limiting example. User
interface 600 is
presented by way of the remote system 105 and alignment system 100 (see FIG.
1). The GUI
600 includes a first window 610 and a related second window 620. The second
window 620
shows the spine instrument and sensored head 407 in relation to a vertebral
component 622
under evaluation. In this example, a sagital (side) view of the spine column
is shown. It
indicates a shaft angle 623 and a rotation component 624 which reveal the
approach angle
and rotation of the spine instrument and sensored head 407. The second window
620 and
corresponding GUI information is presented and updated in real-time during the
procedure.
It permits the surgeon to visualize the sensored head 407 of the spinal
instrument 400 and the
sensed load force parameters. The first window 610 shows a sensing surface of
the sensor
head (see FIG. 7). A cross hair 612 is superimposed on the image of sensored
head 407 to
identify the maximal point of force and location. It can also adjust in width
and length to
show vertebral edge loading. Another GUI window 613 reports the load force
across the
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sensored head 407 surface. The GUI 600 is presented and updated in real-time
during the
procedure.
[0094] FIG. 14 illustrates a perspective view of sensorized spinal insert
instrument 420
for placement of spine cage 475 in a non-limiting example. Insert instrument
420 provides a
surgical means for implanting vertebral component 475 (e.g. spine cage,
pedicle screw,
sensor) between the L4 and L5 vertebrae in the illustration. Mechanical
assembly tip 451 at
the distal end of neck 434 permits attaching and releasing of the vertebral
component by way
of attach/release mechanism 455. The vertebral component 475 can be placed in
the back of
the spine through a midline incision in the back, for example, via posterior
lumbar interbody
fusion (PLIF) as shown. The insert instrument 420 can similarly be used in
anterior lumbar
interbody fusion (ALIF) procedures.
[0095] In one method herein contemplated, the position of the cage prior to
insertion is
optimally defined for example, via 3D imaging or via ultrasonic navigation as
described with
the wands 510 and 520 with spinal instrument 400 shown in FIGS. 12 and 13. The
load
sensor 407 (see FIG. 12) is positioned between the vertebra to assess loading
forces as
described above where an optimal insertion path and trajectory is therein
defined. The load
forces and path of instrument insertion are recorded. Thereafter as shown in
FIG. 14, the
insert instrument 420 inserts the final spinal cage 475 according to the
recorded path and as
based on the load forces. During the insertion the GUI as shown in FIG. 15
navigates the
spinal instrument 420 to the recorded insertion point. Spinal insert
instrument 420 can be
equipped with one or more load sensors serving as a placeholder to a final
spinal cage. After
placement of spinal cage 475 between the vertebra, release of the spine cage
from insert
instrument 420, and removal of the insert instrument 420, the open space
occupied around the
spinal cage is then closed down via rods and pedicle screws on the neighboring
vertebra. This
compresses the surrounding vertebra onto the spinal cage, and provides
stability for verterbral
fusion. During this procedure, the GUI 700 of FIG. 15 reports change in spinal
anatomy, for
example, Lordosis and Kyphosis, due to adjustment of the rods and tightening
of the pedicle
screws. Notably, the GUI 700 also provides visual feedback indicating which
the amount and
directions to achieve the planned spinal alignment by way of instrumented
adjustments to the
rods and screws.
[0096] FIG. 15 illustrates user interface 700 showing a perspective view of
the
sensorized spinal insert instrument 420 of FIG. 14 in a non-limiting example.
The user
interface 700 is presented by way of the remote system 105 and alignment
system 100 (see
FIG. 1). The GUI 700 includes a first window 710 and a related second window
720. The
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second window 720 shows insert instrument 420 and vertebral component 475 in
relation to
the L4 and L5 vertebrae under evaluation. In this example, a sagital (side)
view of the spine
column is shown. It indicates a shaft angle 723 and a rotation component 724
which reveal
the approach angle and rotation of the insert instrument 420 and vertebral
component 475.
The second window 720 and corresponding GUI information is presented and
updated in
real-time during the procedure. It permits the surgeon to visualize the
vertebral component
475 of the insert instrument 420 according to the previously sensed load force
parameters.
[0097] The first window 710 shows a target (desired) sensored head
orientation 722 and a
current instrument head orientation 767. The target orientation 722 shows the
approach angle,
rotation and trajectory path previously determined when the spine instrument
400 was used
for evaluating loading parameters. The current instrument head orientation 767
shows
tracking of the insert instrument 420 currently used to insert the final cage
475. The GUI 700
presents the target orientation model 722 in view of the current instrument
head orientation
767 to provide visualization of the previously determined surgical plan.
[0098] Recall, FIGs 10, 11, 12, and 13 illustrated the spine instrument 400
assessed
optimal procedural parameters (e.g., angle, rotation, path) in view of
determined sensing
parameters (e.g., load, force, edge). Once these procedural parameters were
determined, the
system 100 by way of the GUI 700 now guides the surgeon with the insert
instrument 420 to
insert the vertebral components 475 (e.g., spine cage, pedicle screw). In one
arrangement, the
system 100 provides haptic feedback to guide the insert instrument 420 during
the insertion
procedure. For example, it vibrates when the current approach angle 713
deviates from the
target approach angle, provides a visual cue (red/green indication), or when
the orientation
767 is not aligned with the target trajectory path 722. Alternatively, vocal
feedback can be
provided by system 100 to supplement the visual information being provided.
The GUI 700
effectively recreates the position and target path on the sensorized insert
instrument 420
through visual and haptic feedback based on the previous instrumenting.
[0099] The loading, balance, and position can be adjusted during surgery
within
predetermined quantitatively measured ranges through surgical techniques and
adjustments
using data from the sensorized devices (e.g., 101, 103, 400, 420, 475) of the
alignment and
load balance system 100. Both the trial and final inserts (e.g., spine cage,
pedicle screw,
sensors, etc.) can include the sensing module to provide measured data to the
remote system
for display. A final insert can also be used to monitor the vertebral joint
long term. The data
can be used by the patient and health care providers to ensure that the
vertebral joint or fused
vertebrae is functioning properly during rehabilitation and as the patient
returns to an active
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normal lifestyle. Conversely, the patient or health care provider can be
notified when the
measured parameters are out of specification. This provides early detection of
a spine
problem that can be resolved with minimal stress to the patient. The data from
final insert
can be displayed on a screen in real time using data from the embedded sensing
module. In
one embodiment, a handheld device is used to receive data from final insert.
The handheld
device can be held in proximity to the spine allowing a strong signal to be
obtained for
reception of the data.
[00100] A method of distracting a spinal region is disclosed below. The steps
of the
method can be performed in any order. Reference can be made to FIG. 10, FIG.
11, FIG. 12,
FIG. 13, and FIG. 14. An example of placing a prosthetic component such as a
spinal cage
between vertebrae is used to demonstrate the method but the method is
applicable to other
muscular-skeletal regions such as the knee, hip, ankle, spine, shoulder, hand,
arm, and foot.
In general, quantitative measurement data needs to be collected on the spine
region. The
spinal instrument, alignment devices, and insert instrument disclosed herein
can be used to
generate a database of quantitative data. At this time there is a dearth of
quantitative
measurement data due to the lack of active tools and measurement devices. The
measurement
data generated by the tools during prosthetic component installation can be
correlated with
other short-term and long-term data to determine the effect of load, position
of load, and
prosthetic component alignment as it relates to patient health. The system
disclosed herein
can generate data during prosthetic component installation and is applicable
for providing
long-term periodic measurement of the implant and spinal region. Thus, the
result of the
distraction method is to generate sufficient data that supports an
installation procedure that
reduces recovery time, minimizes failures, improves performance, reliability,
and extends
device life expectancy.
[00101] In a first step, a spinal instrument is inserted to distract the
spinal region. The
spinal instrument includes sensors for generating quantitative measurement
data in real-time
during surgery. In a second step, a load applied by the spinal region to the
spinal instrument
is measured. The spinal instrument has a first height such that the spinal
region is distracted
to the first height. The system indicates measurement data by visual, audio,
or haptic means.
In one example, the system discloses that the load measurement from the spinal
instrument is
outside a predetermined load range. The predetermined load range used by the
system to
assess the spinal region can be determined by clinical study. For example, the
predetermined
load range can support device installation by correlating load measurement
data to outcomes
of the surgical procedure. In general, a measurement outside the predetermined
load range
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may statistically increase a chance of device failure. In a third step, the
spinal region is
distracted to a second height. In a fourth step, the load applied by the
spinal region to the
spinal instrument at the second height is measured. The system indicates that
the load
measurement from the spinal instrument is within the predetermined load range.
Having the
measured load within the predetermined load range reduces failures due to
excessive loading
on the prosthetic component. In general, the process can be repeated as many
times as
required at different distraction heights until the spinal instrument
measurement indicates that
the measured load is within the predetermined load range.
[00102] In a
fifth step, at least one of orientation, rotation, angle, or position of the
spinal
instrument is measured. In one embodiment, the measurement can correspond to
the portion
of the spinal instrument inserted in the spinal region. For example, the
position data can
relate to a sensored head of the spinal instrument. The data can be used to
place a prosthetic
component in a similar position and at the same trajectory as measured by the
spinal
instrument. In a sixth step, loading applied by the spinal region to the
spinal instrument can
be monitored on the remote system. In the example, the remote system includes
a display
that allows viewing of the data in real-time during the procedure. In a
seventh step, the
height of the spinal instrument can be adjusted. As disclosed, the spinal
instrument can
include a scissor type mechanism to decrease or increase height of the
distraction surfaces. In
one embodiment, the handle of the spinal instrument is rotated to change
distraction height.
The adjustment can be made while monitoring the load data on the remote system
in real-
time. In general, the height is adjusted until the measured load is within the
predetermined
load range. In an eighth step, the height is increased or decreased such that
the adjusted
height corresponds to a height of a prosthetic component. In one embodiment, a
prosthetic
component having the same distraction height can be placed in the location of
the load
measurement in the spinal region. The prosthetic component is loaded similarly
to the load
measurement when aligned to the trajectory and placed in a same location as
the spinal
instrument.
[00103] In a ninth step, the spinal instrument measures a position of applied
load. The
spinal instrument may have a surface coupled to the spinal region. In the
example, more than
one sensor is coupled to a surface of the spinal instrument to support
position of load
measurement. The position of load provides quantitative measurement data on
how the force,
pressure, or load would be applied to the prosthetic component when placed in
the spinal
region. For example, an incorrect position of load could produce a situation
where the
prosthetic component would be unstable in the location and eventually be
forced from the
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spinal region causing a catastrophic failure. In one embodiment, position of
load data from
the spinal instrument may be used to assess the position for prosthetic
component placement.
The quantitative data can include a predetermined range or area that
corresponds to the
measurement surface of the spinal instrument for assessing position of load.
In a tenth step,
the spinal instrument is moved to a different location in the spinal region
when the position of
load applied by the spinal region to the spinal instrument is outside a
predetermined position
range. The new location can be assessed by load magnitude and position of load
quantitative
data as a site for the prosthetic component.
[00104] In an eleventh step, an appropriate location in the spinal region is
identified for a
prosthetic component when the measured quantitative data falls within the
predetermined
load range and the predetermined position range. As mentioned previously,
placing the
prosthetic component in an area of the spinal region measuring within the
predetermined load
range and the predetermined position range produces positive outcomes and
lowers failure
rate based on clinical evidence. In a twelfth step, the prosthetic component
is placed in the
location measured by the spinal instrument. The prosthetic component placed in
the location
will have an applied load magnitude and position of load by the spinal region
similar to that
measured by the spinal instrument. The prosthetic component is inserted into
the spinal
region having a similar trajectory as the spinal instrument. In the example,
the trajectory and
position of the spinal instrument during the measurement process is recorded.
In a thirteenth
step, the insertion process of the prosthetic component can be further
supported by comparing
the trajectory of the prosthetic component to the trajectory of the spinal
instrument. In one
embodiment, the surgeon can be provided visual, haptic, or audio feedback to
aid in the
alignment of the prosthetic component to the location. In a fourteenth step,
the trajectories of
the prosthetic component and the spinal instrument are viewed on a remote
system. The
remote system can show the actual or simulated position and trajectory of the
prosthetic
component in relation to the position and trajectory of the spinal instrument
when identifying
the location in the spinal region. In one embodiment, the surgeon can mimic
the trajectory
with a device or insert instrument that holds the prosthetic component through
a visualization
or overlay on the spinal instrument location data displayed on the remote
system. As
disclosed herein, the spinal instrument can have a mechanism such as a scissor
jack that can
change the height of the distracting surfaces. A rod for raising and lowering
the scissor jack
couples to the handle of the spinal instrument. In a fifteenth step, the
handle of the spinal
instrument can be rotated to change the distraction height. In a sixteenth
step, a visual, audio,
or haptic signal is provided when the load applied by the spinal region to the
spinal
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instrument are within the predetermined load range. Similarly, in a
seventeenth step, a visual,
audio, or haptic signal is provided when the load applied by the spinal region
to the spinal
instrument is within the predetermined position range.
[00105] FIG. 16 is a block diagram of the components of spinal instrument 400
in
accordance with an example embodiment. It should be noted that spinal
instrument 400 could
comprise more or less than the number of components shown. Spinal instrument
400 is a self-
contained tool that can measure a parameter of the muscular-skeletal system.
In the example,
the spinal instrument 400 measures load and position of load when inserted in
a spinal region.
The active components of spinal instrument 400 include one or more sensors
1602, a load
plate 1606, a power source 1608, electronic circuitry 1610, a transceiver
1612, and an
accelerometer 1614. In a non-limiting example, an applied compressive force is
applied to
sensors 1602 by the spinal region and measured by the spinal instrument 400.
[00106] The sensors 1602 can be positioned, engaged, attached, or affixed to
the surfaces
403 and 406 of spinal instrument 400. In general, a compressive force is
applied by the spinal
region to surfaces 403 and 406 when inserted therein. The surfaces 403 and 406
couple to
sensors 1602 such that a compressive force is applied to each sensor. In one
embodiment, the
position of applied load to surfaces 403 and 406 can be measured. In the
example, three load
sensors are used in the sensored head to identify position of applied load.
Each load sensor is
coupled to a predetermined position on the load plate 1606. The load plate
1606 couples to
surface 403 to distribute a compressive force applied to the sensored head of
spinal instrument
400 to each sensor. The load plate 1606 can be rigid and does not flex when
distributing the
force, pressure, or load to sensors 1606. The force or load magnitude measured
by each
sensor can be correlated back to a location of applied load on the surface
403.
[00107] In the example of intervertebral measurement, the sensored head having
surfaces
403 and 406 can be positioned between the vertebrae of the spine. Surface 403
of the
sensored head couples to a first vertebral surface and similarly the surface
406 couples to a
second vertebral surface. Accelerometer 1614 or an external alignment system
can be used to
measure position and orientation of the sensored head as it is directed into
the spinal region.
The sensors 1602 couple to the electronic circuitry 1610. The electronic
circuitry 1610
comprises logic circuitry, input/output circuitry, clock circuitry, D/A, and
A/D circuitry. In
one embodiment, the electronic circuitry 1610 comprises an application
specific integrated
circuit that reduces form factor, lowers power, and increases performance. In
general, the
electronic circuitry 1610 controls a measurement process, receives the
measurement signals,
converts the measurement signals to a digital form, supports display on an
interface, and
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initiates data transfer of measurement data. Electronic circuitry 1610
measures physical
changes in the sensors 1602 to determine parameters of interest, for example a
level,
distribution and direction of forces acting on the surfaces 403 and 406. The
insert sensing
device 400 can be powered by an internal power source 1608. Thus, all the
components
required to measure parameters of the muscular-skeletal system reside in the
spinal instrument
400.
[00108] As one example, sensors 1602 can comprise an elastic or compressible
propagation
structure between a first transducer and a second transducer. The transducers
can be an
ultrasound (or ultrasonic) resonator, and the elastic or compressible
propagation structure can
be an ultrasound waveguide. The electronic circuitry 1610 is electrically
coupled to the
transducers to translate changes in the length (or compression or extension)
of the
compressible propagation structure to parameters of interest, such as force.
The system
measures a change in the length of the compressible propagation structure
(e.g., waveguide)
responsive to an applied force and converts this change into electrical
signals, which can be
transmitted via the transceiver 1612 to convey a level and a direction of the
applied force. For
example, the compressible propagation structure has known and repeatable
characteristics of
the applied force versus the length of the waveguide. Precise measurement of
the length of
the waveguide using ultrasonic signals can be converted to a force using the
known
characteristics.
[00109] Sensors 1602 are not limited to waveguide measurements of force,
pressure, or
load sensing. In yet other arrangements, sensors 1602 can include piezo-
resistive,
compressible polymers, capacitive, optical, mems, strain gauge, chemical,
temperature, pH,
and mechanical sensors for measuring parameters of the muscular-skeletal
system. In an
alternate embodiment, a piezo-resistive film sensor can be used for sensing
load. The piezo-
resistive film has a low profile thereby reducing the form factor required for
the
implementation. The piezo-resistive film changes resistance with applied
pressure. A voltage
or current can be applied to the piezo-resistive film to monitor changes in
resistance.
Electronic circuitry 1610 can be coupled to apply the voltage or current.
Similarly, electronic
circuitry 1610 can be coupled to measure the voltage and current corresponding
to a resistance
of the piezo-resistive film. The relation of piezo-resistive film resistance
to an applied force,
pressure, or load is known. Electronic circuitry 1610 can convert the measured
voltage or
current to a force, pressure, or load applied to the sensored head.
Furthermore, electronic
circuitry 1610 can convert the measurement to a digital format for display or
transfer for real-
time use or for being stored. Electronic circuitry 1610 can include
converters, inputs, outputs,
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and input/outputs that allow serial and parallel data transfer whereby
measurements and
transmission of data can occur simultaneously. In one embodiment, an ASIC is
included in
electronic circuitry 1610 that incorporates digital control logic to manage
control functions
and the measurement process of spinal instrument 400 as directed by the user.
[00110] The accelerometer 1614 can measure acceleration and static
gravitational pull.
Accelerometer 1614 can be single-axis and multi-axis accelerometer structures
that detect
magnitude and direction of the acceleration as a vector quantity.
Accelerometer 1614 can also
be used to sense orientation, vibration, impact and shock. The electronic
circuitry 1610 in
conjunction with the accelerometer 1614 and sensors 1602 can measure
parameters of interest
(e.g., distributions of load, force, pressure, displacement, movement,
rotation, torque, location,
and acceleration) relative to orientations of spinal instrument 400. In such
an arrangement,
spatial distributions of the measured parameters relative to a chosen frame of
reference can be
computed and presented for real-time display.
[00111] The transceiver 1612 comprises a transmitter 1622 and an antenna 1620
to permit
wireless operation and telemetry functions. In various embodiments, the
antenna 1620 can be
configured by design as an integrated loop antenna. The integrated loop
antenna is configured
at various layers and locations on a printed circuit board having other
electrical components
mounted thereto. For example, electronic circuitry 1610, power source 1608,
transceiver
1612, and accelerometer 1614 can be mounted on a circuit board that is located
on or in spinal
instrument 400. Once initiated the transceiver 1612 can broadcast the
parameters of interest
in real-time. The telemetry data can be received and decoded with various
receivers, or with a
custom receiver. The wireless operation can eliminate distortion of, or
limitations on,
measurements caused by the potential for physical interference by, or
limitations imposed by,
wiring and cables coupling the sensing module with a power source or with
associated data
collection, storage, display equipment, and data processing equipment.
[00112] The transceiver 1612 receives power from the power source 1608 and can
operate
at low power over various radio frequencies by way of efficient power
management schemes,
for example, incorporated within the electronic circuitry 1610 or the
application specific
integrated circuit. As one example, the transceiver 1612 can transmit data at
selected
frequencies in a chosen mode of emission by way of the antenna 1620. The
selected
frequencies can include, but are not limited to, ISM bands recognized in
International
Telecommunication Union regions 1, 2 and 3. A chosen mode of emission can be,
but is not
limited to, Gaussian Frequency Shift Keying, (GFSK), Amplitude Shift Keying
(ASK), Phase
Shift Keying (PSK), Minimum Shift Keying (MSK), Frequency Modulation (FM),
Amplitude
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Modulation (AM), or other versions of frequency or amplitude modulation (e.g.,
binary,
coherent, quadrature, etc.).
[00113] The antenna 1620 can be integrated with components of the sensing
module to
provide the radio frequency transmission. The antenna 1620 and electronic
circuitry 1610 are
mounted and coupled to form a circuit using wire traces on a printed circuit
board. The
antenna 1620 can further include a matching network for efficient transfer of
the signal. This
level of integration of the antenna and electronics enables reductions in the
size and cost of
wireless equipment. Potential applications may include, but are not limited to
any type of
short-range handheld, wearable, or other portable communication equipment
where compact
antennas are commonly used. This includes disposable modules or devices as
well as reusable
modules or devices and modules or devices for long-term use.
[00114] The power source 1608 provides power to electronic components of the
spinal
instrument 400. In one embodiment, power source 1608 can be charged by wired
energy
transfer, short-distance wireless energy transfer or a combination thereof.
External power
sources for providing wireless energy to power source 1608 can include, but
are not limited
to, a battery or batteries, an alternating current power supply, a radio
frequency receiver, an
electromagnetic induction coil, a photoelectric cell or cells, a thermocouple
or thermocouples,
or an ultrasound transducer or transducers. By way of power source 1608,
spinal instrument
400 can be operated with a single charge until the internal energy is drained.
It can be
recharged periodically to enable continuous operation. The power source 1608
can further
utilize power management techniques for efficiently supplying and providing
energy to the
components of spinal instrument 400 to facilitate measurement and wireless
operation. Power
management circuitry can be incorporated on the ASIC to manage both the ASIC
power
consumption as well as other components of the system.
[00115] The power source 1608 minimizes additional sources of energy radiation
required
to power the sensing module during measurement operations. In one embodiment,
as
illustrated, the energy storage 1608 can include a capacitive energy storage
device 1624 and
an induction coil 1626. The external source of charging power can be coupled
wirelessly to
the capacitive energy storage device 1624 through the electromagnetic
induction coil or coils
1626 by way of inductive charging. The charging operation can be controlled by
a power
management system designed into, or with, the electronic circuitry 1610. For
example, during
operation of electronic circuitry 1610, power can be transferred from
capacitive energy
storage device 1624 by way of efficient step-up and step-down voltage
conversion circuitry.
This conserves operating power of circuit blocks at a minimum voltage level to
support the
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required level of performance. Alternatively, power source 1608 can comprise
one or more
batteries that are housed within spinal instrument 400. The batteries can
power a single use of
the spinal instrument 400 whereby the device is disposed after it has been
used in a surgery.
[00116] In one configuration, the external power source can further serve to
communicate
downlink data to the transceiver 1612 during a recharging operation. For
instance, downlink
control data can be modulated onto the wireless energy source signal and
thereafter
demodulated from the induction coil 1626 by way of electronic circuitry 1610.
This can serve
as a more efficient way for receiving downlink data instead of configuring the
transceiver
1612 for both uplink and downlink operation. As one example, downlink data can
include
updated control parameters that the spinal instrument 400 uses when making a
measurement,
such as external positional information, or for recalibration purposes. It can
also be used to
download a serial number or other identification data.
[00117] The electronic circuitry 1610 manages and controls various operations
of the
components of the sensing module, such as sensing, power management,
telemetry, and
acceleration sensing. It can include analog circuits, digital circuits,
integrated circuits, discrete
components, or any combination thereof In one arrangement, it can be
partitioned among
integrated circuits and discrete components to minimize power consumption
without
compromising performance. Partitioning functions between digital and analog
circuit
enhances design flexibility and facilitates minimizing power consumption
without sacrificing
functionality or performance. Accordingly, the electronic circuitry 1610 can
comprise one or
more integrated circuits or ASICs, for example, specific to a core signal-
processing algorithm.
[00118] In another arrangement, the electronic circuitry 1610 can comprise a
controller
such as a programmable processor, a Digital Signal Processor (DSP), a
microcontroller, or a
microprocessor, with associated storage memory and logic. The controller can
utilize
computing technologies with associated storage memory such a Flash, ROM, RAM,
SRAM,
DRAM or other like technologies for controlling operations of the
aforementioned
components of the sensing module. In one arrangement, the storage memory may
store one or
more sets of instructions (e.g., software) embodying any one or more of the
methodologies or
functions described herein. The instructions may also reside, completely or at
least partially,
within other memory, and/or a processor during execution thereof by another
processor or
computer system.
[00119] The electronics assemblage also supports testability and calibration
features that
assure the quality, accuracy, and reliability of the completed wireless
sensing module or
device. A temporary bi-directional coupling can be used to assure a high level
of electrical
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observability and controllability of the electronics. The test interconnect
also provides a high
level of electrical observability of the sensing subsystem, including the
transducers,
waveguides, and mechanical spring or elastic assembly. Carriers or fixtures
emulate the final
enclosure of the completed wireless sensing module or device during
manufacturing
processing thus enabling capture of accurate calibration data for the
calibrated parameters of
the finished wireless sensing module or device. These calibration parameters
are stored
within the on-board memory integrated into the electronics assemblage.
[00120] Applications for the electronic assembly comprising the sensors 1602
and
electronic circuitry 1610 may include, but are not limited to, disposable
modules or devices
as well as reusable modules or devices and modules or devices for long-term
use. In addition
to non-medical applications, examples of a wide range of potential medical
applications may
include, but are not limited to, implantable devices, modules within
implantable devices,
intra-operative implants or modules within infra-operative implants or trial
inserts, modules
within inserted or ingested devices, modules within wearable devices, modules
within
handheld devices, modules within instruments, appliances, equipment, or
accessories of all of
these, or disposables within implants, trial inserts, inserted or ingested
devices, wearable
devices, handheld devices, instruments, appliances, equipment, or accessories
to these
devices, instruments, appliances, or equipment.
[00121] FIG. 17 is a diagram of an exemplary communications system 1700 for
short-
range telemetry in accordance with an exemplary embodiment. As illustrated,
the
communications system 1700 comprises medical device communications components
1710
in a spinal instrument and receiving system communications in a processor
based remote
system. In one embodiment, the receiving remote system communications are in
or coupled
to a computer or laptop computer that can be viewed by the surgical team
during a procedure.
The remote system can be external to the sterile field of the operating room
but within
viewing range to assess measured quantitative data in real time. The medical
device
communications components 1710 are operatively coupled to include, but not
limited to, the
antenna 1712, a matching network 1714, a telemetry transceiver 1716, a CRC
circuit 1718, a
data packetizer 1722, a data input 1724, a power source 1726, and an
application specific
integrated circuit (ASIC) 1720. The medical device communications components
1710 may
include more or less than the number of components shown and are not limited
to those
shown or the order of the components.
[00122] The receiving station communications components 1750 comprise an
antenna
1752, a matching network 1754, a telemetry receiver 1756, the CRC circuit
1758, the data
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packetizer 1760, and optionally a USB interface 1762. Notably, other interface
systems can
be directly coupled to the data packetizer 1760 for processing and rendering
sensor data.
[00123]
Referring to FIG. 16, the electronic circuitry 1610 is operatively coupled to
one
or more sensors 602 of the spinal instrument 400. In one embodiment, the data
generated by
the one or more sensors 602 can comprise a voltage, current, frequency, or
count from a
mems structure, piezo-resistive sensor, strain gauge, mechanical sensor,
pulsed, continuous
wave, or other sensor type that can be converted to the parameter being
measured of the
muscular-skeletal system. Referring back to FIG. 17, the data packetizer 1722
assembles the
sensor data into packets; this includes sensor information received or
processed by ASIC
1720. The ASIC 1720 can comprise specific modules for efficiently performing
core signal
processing functions of the medical device communications components 1710. The
ASIC
1720 further provides the benefit of reducing a form factor of the tool.
[00124] The CRC circuit 1718 applies error code detection on the packet data.
The cyclic
redundancy check is based on an algorithm that computes a checksum for a data
stream or
packet of any length. These checksums can be used to detect interference or
accidental
alteration of data during transmission. Cyclic redundancy checks are
especially good at
detecting errors caused by electrical noise and therefore enable robust
protection against
improper processing of corrupted data in environments having high levels of
electromagnetic
activity. The telemetry transmitter 1716 then transmits the CRC encoded data
packet through
the matching network 1714 by way of the antenna 1712. The matching networks
1714 and
1754 provide an impedance match for achieving optimal communication power
efficiency.
[00125] The receiving system communications components 1750 receive
transmissions
sent by spinal instrument communications components 1710. In one embodiment,
telemetry
transmitter 1716 is operated in conjunction with a dedicated telemetry
receiver 1756 that is
constrained to receive a data stream broadcast on the specified frequencies in
the specified
mode of emission. The telemetry receiver 1756 by way of the receiving station
antenna 1752
detects incoming transmissions at the specified frequencies. The antenna 1752
can be a
directional antenna that is directed to a directional antenna of components
1710. Using at
least one directional antenna can reduce data corruption while increasing data
security by
further limiting the data is radiation pattern. A matching network 1754
couples to antenna
1752 to provide an impedance match that efficiently transfers the signal from
antenna 1752 to
telemetry receiver 1756. Telemetry receiver 1756 can reduce a carrier
frequency in one or
more steps and strip off the information or data sent by components 1710.
Telemetry
receiver 1756 couples to CRC circuit 1758. CRC circuit 1758 verifies the
cyclic redundancy
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checksum for individual packets of data. CRC circuit 1758 is coupled to data
packetizer
1760. Data packetizer 1760 processes the individual packets of data. In
general, the data that
is verified by the CRC circuit 1758 is decoded (e.g., unpacked) and forwarded
to an external
data processing device, such as an external computer, for subsequent
processing, display, or
storage or some combination of these.
[00126] The telemetry receiver 1756 is designed and constructed to operate on
very low
power such as, but not limited to, the power available from the powered USB
port 1762, or a
battery. In another embodiment, the telemetry receiver 1756 is designed for
use with a
minimum of controllable functions to limit opportunities for inadvertent
corruption or
malicious tampering with received data. The telemetry receiver 1756 can be
designed and
constructed to be compact, inexpensive, and easily manufactured with standard
manufacturing processes while assuring consistently high levels of quality and
reliability.
[00127] In one configuration, the communication system 1700 operates in a
transmit-only
operation with a broadcasting range on the order of a few meters to provide
high security and
protection against any form of unauthorized or accidental query. The
transmission range can
be controlled by the transmitted signal strength, antenna selection, or a
combination of both.
A high repetition rate of transmission can be used in conjunction with the
Cyclic Redundancy
Check (CRC) bits embedded in the transmitted packets of data during data
capture operations
thereby enabling the receiving system to discard corrupted data without
materially affecting
display of data or integrity of visual representation of data, including but
not limited to
measurements of load, force, pressure, displacement, flexion, attitude, and
position within
operating or static physical systems.
[00128] By limiting the operating range to distances on the order of a few
meters the
telemetry transmitter 1716 can be operated at very low power in the
appropriate emission
mode or modes for the chosen operating frequencies without compromising the
repetition rate
of the transmission of data. This mode of operation also supports operation
with compact
antennas, such as an integrated loop antenna. The combination of low power and
compact
antennas enables the construction of, but is not limited to, highly compact
telemetry
transmitters that can be used for a wide range of non-medical and medical
applications.
[00129] The transmitter security as well as integrity of the transmitted data
is assured by
operating the telemetry system within predetermined conditions. The security
of the
transmitter cannot be compromised because it is operated in a transmit-only
mode and there
is no pathway to hack into medical device communications components. The
integrity of the
data is assured with the use of the CRC algorithm and the repetition rate of
the
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measurements. The risk of unauthorized reception of the data is minimized by
the limited
broadcast range of the device. Even if unauthorized reception of the data
packets should
occur there are counter measures in place that further mitigate data access. A
first measure is
that the transmitted data packets contain only binary bits from a counter
along with the CRC
bits. A second measure is that no data is available or required to interpret
the significance of
the binary value broadcast at any time. A third measure that can be
implemented is that no
patient or device identification data is broadcast at any time.
[00130] The telemetry transmitter 1716 can also operate in accordance with
some FCC
regulations. According to section 18.301 of the FCC regulations the ISM bands
within the
USA include 6.78, 13.56, 27.12, 30.68, 915, 2450, and 5800 MHz as well as
24.125, 61.25,
122.50, and 245 GHz. Globally other ISM bands, including 433 MHz, are defined
by the
International Telecommunications Union in some geographic locations. The list
of prohibited
frequency bands defined in 18.303 are "the following safety, search and rescue
frequency
bands is prohibited: 490-510 kHz, 2170-2194 kHz, 8354-8374 kHz, 121.4¨ 121.6
MHz,
156.7-156.9 MHz, and 242.8¨ 243.2 MHz." Section 18.305 stipulates the field
strength and
emission levels ISM equipment must not exceed when operated outside defined
ISM bands.
In summary, it may be concluded that ISM equipment may be operated worldwide
within
ISM bands as well as within most other frequency bands above 9 KHz given that
the limits
on field strengths and emission levels specified in section 18.305 are
maintained by design or
by active control. As an alternative, commercially available ISM transceivers,
including
commercially available integrated circuit ISM transceivers, may be designed to
fulfill these
field strengths and emission level requirements when used properly.
[00131] In one configuration, the telemetry transmitter 1716 can also operate
in unlicensed
ISM bands or in unlicensed operation of low power equipment, wherein the ISM
equipment
(e.g., telemetry transmitter 1716) may be operated on ANY frequency above 9
kHz except as
indicated in Section 18.303 of the FCC code.
[00132] Wireless operation eliminates distortion of, or limitations on,
measurements
caused by the potential for physical interference by, or limitations imposed
by, wiring and
cables coupling the wireless sensing module or device with a power source or
with data
collection, storage, or display equipment. Power for the sensing components
and electronic
circuits is maintained within the wireless sensing module or device on an
internal energy
storage device. This energy storage device is charged with external power
sources including,
but not limited to, a battery or batteries, super capacitors, capacitors, an
alternating current
power supply, a radio frequency receiver, an electromagnetic induction coil, a
photoelectric
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cell or cells, a thermocouple or thermocouples, or an ultrasound transducer or
transducers.
The wireless sensing module may be operated with a single charge until the
internal energy
source is drained or the energy source may be recharged periodically to enable
continuous
operation. The embedded power supply minimizes additional sources of energy
radiation
required to power the wireless sensing module or device during measurement
operations.
Telemetry functions are also integrated within the wireless sensing module or
device. Once
initiated the telemetry transmitter continuously broadcasts measurement data
in real time.
Telemetry data may be received and decoded with commercial receivers or with a
simple,
low cost custom receiver.
[00133] FIG. 18 illustrates a communication network 1800 for measurement and
reporting
in accordance with an example embodiment. Briefly, the communication network
1800
expands spinal alignment system 100, spinal instrument 400, and insert
instrument 420 to
provide broad data connectivity to other devices or services. As illustrated,
spinal alignment
system 100, spinal instrument 400, and insert instrument 420 can be
communicatively
coupled to the communications network 1800 and any associated systems or
services.
[00134] As one example, spinal alignment system 100, spinal instrument 400,
and insert
instrument 420 can share its parameters of interest (e.g., distributions of
load, force, pressure,
displacement, movement, rotation, torque and acceleration) with remote
services or
providers, for instance, to analyze or report on surgical status or outcome.
In the case that a
sensor system is permanently implanted, the data from the sensor can be shared
for example
with a service provider to monitor progress or with plan administrators for
surgical planning
purposes or efficacy studies. The communication network 1800 can further be
tied to an
Electronic Medical Records (EMR) system to implement health information
technology
practices. In other embodiments, the communication network 1800 can be
communicatively
coupled to HIS Hospital Information System, HIT Hospital Information
Technology and
HIM Hospital Information Management, EHR Electronic Health Record, CPOE
Computerized Physician Order Entry, and CDSS Computerized Decision Support
Systems.
This provides the ability of different information technology systems and
software
applications to communicate, to exchange data accurately, effectively, and
consistently, and
to use the exchanged data.
[00135] The communications network 1800 can provide wired or wireless
connectivity
over a Local Area Network (LAN) 1801, a Wireless Local Area Network (WLAN)
1805, a
Cellular Network 1814, and/or other radio frequency (RF) system. The LAN 1801
and
WLAN 1805 can be communicatively coupled to the Internet 1820, for example,
through a
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central office. The central office can house common network switching
equipment for
distributing telecommunication services. Telecommunication services can
include traditional
POTS (Plain Old Telephone Service) and broadband services such as cable, HDTV,
DSL,
VoIP (Voice over Internet Protocol), IPTV (Internet Protocol Television),
Internet services,
and so on.
[00136] The communication network 1800 can utilize common computing and
communications technologies to support circuit-switched and/or packet-switched
communications. Each of the standards for Internet 1820 and other packet
switched network
transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP, RTP, MMS, SMS) represent
examples of
the state of the art. Such standards are periodically superseded by faster or
more efficient
equivalents having essentially the same functions. Accordingly, replacement
standards and
protocols having the same functions are considered equivalent.
[00137] The cellular network 1814 can support voice and data services over a
number of
access technologies such as GSM-GPRS, EDGE, CDMA, UMTS, WiMAX, 2G, 3G, WAP,
software defined radio (SDR), and other known technologies. The cellular
network 1814 can
be coupled to base receiver 1810 under a frequency-reuse plan for
communicating with
mobile devices 1802.
[00138] The base receiver 1810, in turn, can connect the mobile device 1802 to
the
Internet 1820 over a packet switched link. The internet 1820 can support
application services
and service layers for distributing data from spinal alignment system 100,
spinal instrument
400, and insert instrument 420 to the mobile device 502. The mobile device
1802 can also
connect to other communication devices through the Internet 1820 using a
wireless
communication channel.
[00139] The mobile device 1802 can also connect to the Internet 1820 over the
WLAN
1805. Wireless Local Access Networks (WLANs) provide wireless access within a
local
geographical area. WLANs are typically composed of a cluster of Access Points
(APs) 1804
also known as base stations. Spinal alignment system 100, spinal instrument
400, and insert
instrument 420 can communicate with other WLAN stations such as laptop 1803
within the
base station area. In typical WLAN implementations, the physical layer uses a
variety of
technologies such as 802.11b or 802.11g WLAN technologies. The physical layer
may use
infrared, frequency hopping spread spectrum in the 2.4 GHz Band, direct
sequence spread
spectrum in the 2.4 GHz Band, or other access technologies, for example, in
the 5.8 GHz
ISM band or higher ISM bands (e.g., 24 GHz, etc.).
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[00140] By way of the communication network 1800, spinal alignment system 100,
spinal
instrument 400, and insert instrument 420 can establish connections with a
remote server
1830 on the network and with other mobile devices for exchanging data. The
remote server
1830 can have access to a database 1840 that is stored locally or remotely and
which can
contain application specific data. The remote server 1830 can also host
application services
directly, or over the intern& 1820.
[00141] FIG. 19 depicts an exemplary diagrammatic representation of a machine
in the
form of a computer system 1900 within which a set of instructions, when
executed, may
cause the machine to perform any one or more of the methodologies discussed
above. In
some embodiments, the machine operates as a standalone device. In some
embodiments, the
machine may be connected (e.g., using a network) to other machines. In a
networked
deployment, the machine may operate in the capacity of a server or a client
user machine in
server-client user network environment, or as a peer machine in a peer-to-peer
(or distributed)
network environment.
[00142] The machine may comprise a server computer, a client user computer, a
personal
computer (PC), a tablet PC, a laptop computer, a desktop computer, a control
system, a
network router, switch or bridge, or any machine capable of executing a set of
instructions
(sequential or otherwise) that specify actions to be taken by that machine. It
will be
understood that a device of the present disclosure includes broadly any
electronic device that
provides voice, video or data communication. Further, while a single machine
is illustrated,
the term "machine" shall also be taken to include any collection of machines
that individually
or jointly execute a set (or multiple sets) of instructions to perform any one
or more of the
methodologies discussed herein.
[00143] The computer system 1900 may include a processor 1902 (e.g., a central
processing unit (CPU), a graphics processing unit (GPU, or both), a main
memory 1904 and a
static memory 1906, which communicate with each other via a bus 1908. The
computer
system 1900 may further include a video display unit 1910 (e.g., a liquid
crystal display
(LCD), a flat panel, a solid-state display, or a cathode ray tube (CRT)). The
computer system
1900 may include an input device 1912 (e.g., a keyboard), a cursor control
device 1914 (e.g.,
a mouse), a disk drive unit 1916, a signal generation device 1918 (e.g., a
speaker or remote
control) and a network interface device 1920.
[00144] The disk drive unit 1916 may include a machine-readable medium 1922 on
which
is stored one or more sets of instructions (e.g., software 1924) embodying any
one or more of
the methodologies or functions described herein, including those methods
illustrated above.
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The instructions 1924 may also reside, completely or at least partially,
within the main
memory 1904, the static memory 1906, and/or within the processor 1902 during
execution
thereof by the computer system 1900. The main memory 1904 and the processor
1902 also
may constitute machine-readable media.
[00145] Dedicated hardware implementations including, but not limited to,
application
specific integrated circuits, programmable logic arrays and other hardware
devices can
likewise be constructed to implement the methods described herein.
Applications that may
include the apparatus and systems of various embodiments broadly include a
variety of
electronic and computer systems. Some embodiments implement functions in two
or more
specific interconnected hardware modules or devices with related control and
data signals
communicated between and through the modules, or as portions of an application-
specific
integrated circuit. Thus, the example system is applicable to software,
firmware, and
hardware implementations.
[00146] In accordance with various embodiments of the present disclosure, the
methods
described herein are intended for operation as software programs running on a
processor,
digital signal processor, or logic circuitry. Furthermore, software
implementations can
include, but not limited to, distributed processing or component/object
distributed processing,
parallel processing, or virtual machine processing can also be constructed to
implement the
methods described herein.
[00147] The present disclosure contemplates a machine readable medium
containing
instructions 1924, or that which receives and executes instructions 1924 from
a propagated
signal so that a device connected to a network environment 1926 can send or
receive voice,
video or data, and to communicate over the network 1926 using the instructions
1924. The
instructions 1924 may further be transmitted or received over a network 1926
via the network
interface device 1920.
[00148] While the machine-readable medium 1922 is shown in an example
embodiment to
be a single medium, the term "machine-readable medium" should be taken to
include a single
medium or multiple media (e.g., a centralized or distributed database, and/or
associated
caches and servers) that store the one or more sets of instructions. The term
"machine-
readable medium" shall also be taken to include any medium that is capable of
storing,
encoding or carrying a set of instructions for execution by the machine and
that cause the
machine to perform any one or more of the methodologies of the present
disclosure.
[00149] The term "machine-readable medium" shall accordingly be taken to
include, but
not be limited to: solid-state memories such as a memory card or other package
that houses
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one or more read-only (non-volatile) memories, random access memories, or
other re-
writable (volatile) memories; magneto-optical or optical medium such as a disk
or tape; and
carrier wave signals such as a signal embodying computer instructions in a
transmission
medium; and/or a digital file attachment to e-mail or other self-contained
information archive
or set of archives is considered a distribution medium equivalent to a
tangible storage
medium. Accordingly, the disclosure is considered to include any one or more
of a machine-
readable medium or a distribution medium, as listed herein and including art-
recognized
equivalents and successor media, in which the software implementations herein
are stored.
[00150] Although the present specification describes components and functions
implemented in the embodiments with reference to particular standards and
protocols, the
disclosure is not limited to such standards and protocols. Each of the
standards for Internet
and other packet switched network transmission (e.g., TCP/IP, UDP/IP, HTML,
HTTP)
represent examples of the state of the art. Such standards are periodically
superseded by
faster or more efficient equivalents having essentially the same functions.
Accordingly,
replacement standards and protocols having the same functions are considered
equivalents.
[00151] The illustrations of embodiments described herein are intended to
provide a
general understanding of the structure of various embodiments, and they are
not intended to
serve as a complete description of all the elements and features of apparatus
and systems that
might make use of the structures described herein. Many other embodiments will
be apparent
to those of skill in the art upon reviewing the above description. Other
embodiments may be
utilized and derived therefrom, such that structural and logical substitutions
and changes may
be made without departing from the scope of this disclosure. Figures are also
merely
representational and may not be drawn to scale. Certain proportions thereof
may be
exaggerated, while others may be minimized. Accordingly, the specification and
drawings
are to be regarded in an illustrative rather than a restrictive sense.
[00152] Such embodiments of the inventive subject matter may be referred to
herein,
individually and/or collectively, by the term "invention" merely for
convenience and without
intending to voluntarily limit the scope of this application to any single
invention or inventive
concept if more than one is in fact disclosed. Thus, although specific
embodiments have
been illustrated and described herein, it should be appreciated that any
arrangement
calculated to achieve the same purpose may be substituted for the specific
embodiments
shown. This disclosure is intended to cover any and all adaptations or
variations of various
embodiments. Combinations of the above embodiments, and other embodiments not
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specifically described herein, will be apparent to those of skill in the art
upon reviewing the
above description.
