Note: Descriptions are shown in the official language in which they were submitted.
An Electronic Toolset for Use With Multiple Generations of Implantable
Programmable
Valves With or Without Orientation Functionality Based on a Fixed Reference
Magnet
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a system and method for an implantable
drainage
valve for drainage of a bodily fluid (e.g., cerebrospinal fluid). In
particular, the present
inventive system and method is directed to an electronic toolset for
indicating and adjusting
with automatic switching between multiple generations of implantable bodily
fluid drainage
valves with and without orientation functionality.
Description of Related Art
[0002] Hydrocephalus is the accumulation of cerebrospinal fluid in the brain,
resulting from
increased production, or more commonly, pathway obstruction or decreased
absorption of the
fluid. Cerebrospinal fluid (CSF) shunts have been used for decades for the
treatment of
hydrocephalus. A CSF shunt involves establishing an accessory pathway for the
movement of
CSF to bypass an obstruction of the natural pathways.
[0003] The shunt is positioned to enable the CSF to be drained from the
cerebral ventricles or
sub-arachnoid spaces into another absorption site (e.g., the right atrium of
the heart or the
peritoneal cavity) through a system of small catheters. A regulatory device,
such as a valve,
may be inserted into the pathway of the catheters. In general, the valve keeps
the CSF
flowing away from the brain and moderates the pressure or flow rate. The
drainage system
using catheters and valves enables the excess CSF within the brain to be
evacuated and,
thereby, the pressure within the cranium to be reduced.
[0004] Some implantable valves are fixed pressure valves (i.e., monopressure
valves) while
others have adjustable or programmable settings. Programmable or adjustable
implantable
valves are desirable in that the valve pressure setting may be varied non-
invasively via an
1
CA 3019405 2018-10-02
external control device over the course of treatment without requiring
explantation. One such
conventional adjustable or programmable implantable valve using magnets is the
CODMAN HAKIMO Programmable Valve (CHPV), as disclosed in US Patent No.
4,595,390, which is assigned to DePuy Orthopedics, a J&J company related to
that of the
present assignee, and herein incorporated by reference in its entirety.
Another programmable
implantable drainage valve is the CODMANO CERTAS or CERTASO Plus Programmable
Valve, as disclosed in US Patent No. 8,322,365, also assigned to DePuy
Orthopedics, a J&J
company related to that of the present assignee, and which is herein
incorporated by reference
in its entirety. Medtronic also has a programmable implantable shunt valve
Strata
controlled using magnets. The pressure setting in these aforementioned
conventional
programmable implantable valves may be non-invasively adjusted post
implantation in the
body using a rotating construct or rotor with a pair of magnets.
[0005] Each programmable implantable valve is controlled using an associated
external
toolset comprising one or more devices used to locate the valve, read the
current valve setting
and adjust the valve setting. With each improved generation or version of the
programmable
implantable valve an associated toolset may be required. However, often the
electronic
toolset used for indicating and adjusting the latest generation of the
programmable
implantable valve is inoperable on an earlier generation or version of the
programmable
implantable valve. As a result, medical personnel are required to store
multiple versions of
,0 the electronic toolset (i.e., not just the latest improved version, but
previous versions also) as
well as properly use each electronic toolset only with the applicable
programmable
implantable valve. Furthermore, it is not always clear from the patient
records or x-ray
identification, what generation of valve is implanted in the patient based on
which the
appropriate toolset is selected.
,5
[0006] It is therefore desirable to develop a universal or interchangeable
electronic toolset for
use in indicating and adjusting multiple generations or versions of
programmable implantable
valves that can automatically switch without additional input from the
clinician between
generations of valves with or without orientation functionality.
Summary of the Invention
2
CA 3019405 2018-10-02
[0007] An aspect of the present invention is directed to a universal or
interchangeable
electronic toolset for use in indicating and adjusting multiple generations or
versions of
programmable implantable valves that can automatically switch without
additional input from
the clinician between generations of valves with or without orientation
functionality.
[0008] Another aspect of the present invention relates to a method for using a
universal
electronic toolset for indicating and adjusting of an implantable programmable
bodily fluid
drainage valve whether the implantable programmable bodily fluid drainage
valve includes a
fixed reference magnet used to determine an angle of orientation of the
implantable
programmable bodily fluid drainage valve or not, wherein the implantable
programmable
bodily fluid drainage valve includes an adjustable valve unit having a pair of
primary
magnetic elements. Using a magnetic field detection sensor array in an
indicator tool of the
electronic toolset it is determined whether the fixed reference magnet is
present in the
implantable programmable bodily fluid drainage valve. If the presence of the
fixed reference
magnet in the implantable bodily fluid drainage valve is detected then: a
center of the
adjustable valve unit is located using the indicator tool of the electronic
toolset; a direction of
flow of the adjustable valve unit is ascertained based exclusively on
electronic feedback
provided by the indicator tool of the electronic toolset, without requiring
manual physical
palpation; the indicator tool of the electronic toolset is aligned with the
located center and the
0 direction of flow of the adjustable valve unit; and a current valve setting
is read using the
indicator tool of the electronic toolset. Otherwise, if the presence of the
fixed reference
magnet is in the implantable programmable bodily fluid drainage valve is not
detected then:
the center of the adjustable valve unit is located using the indicator tool of
the electronic
toolset; the direction of flow of the adjustable valve unit is established
exclusively by manual
physical palpation, without electronic feedback from the indicator tool of the
electronic
toolset; the indicator tool of the electronic toolset is aligned with the
located center and the
direction of flow of the adjustable valve unit; and the current valve setting
is read using the
indicator tool of the electronic toolset.
: 0 [0009] Yet
another aspect of the present invention is directed to an implantable
programmable bodily fluid drainage valve system including an implantable
programmable
bodily fluid drainage valve having an adjustable valve unit including a pair
of primary
3
CA 3019405 2018-10-02
magnetic elements for programming the implantable programmable bodily fluid
drainage
valve to a desired valve setting. The system also includes a universal
electronic toolset for
indicating and adjusting the implantable programmable bodily fluid drainage
valve. In that,
the universal electronic toolset includes an indicator tool having a magnetic
field detection
sensor array for: (i) detecting the pair of primary magnetic elements; and
(ii) determining the
presence or absence of a fixed reference magnet in the implantable
programmable bodily fluid
drainage valve. Circuitry is provided for determining a center of the
adjustable valve unit
based on the detected pair of primary magnetic elements. Such circuitry
determines
exclusively by electronic feedback from the toolset an angular orientation of
the implantable
programmable bodily fluid drainage valve, when the fixed reference magnet is
present;
whereas the circuitry generates on a display of the implantable programmable
bodily fluid
drainage valve steps for determining exclusively by manual physical palpation
the angular
orientation and/or center of the implantable programmable bodily fluid
drainage valve, when
the fixed reference magnet is absent.
Brief Description of the Drawing
[0010] The foregoing and other features of the present invention will be more
readily
apparent from the following detailed description and drawings of illustrative
of the invention
wherein like reference numbers refer to similar elements throughout the
several views and in
0 which:
[0011] Figure 1 is a schematic perspective exploded view of a programmable
implantable
valve device having a fixed reference magnet in addition to the rotational
primary magnets
associated with the adjustable valve unit;
[0012] Figure 2 is an exploded perspective view of the adjustable valve unit
of Figure 1;
[0013] Figure 3 is a top view of the adjustable valve unit of Figure 2;
A) [0014] Figure 4 is a side cross-sectional view of the adjustable valve
unit of Figure 3 along
lines 4-4;
4
CA 3019405 2018-10-02
[0015] Figure 4A is a side view of a single rotor tooth in engagement with a
single lock stop;
[0016] Figure 5 is a cross-sectional view of the adjustable valve unit of
figure 3 along lines 5-
5;
[0017] Figure 6 is a partial cross-sectional view of the adjustable valve unit
of Figure 4
approximately along lines 6-6 at a first pressure setting;
[0018] Figure 6A is a deeper cross-sectional view of the adjustable valve unit
of Figure 4
approximately along lines 6A-6A at a first pressure setting;
[0019] Figures 6B-6H are partial cross-sectional view of the adjustable valve
unit of Figure 4
at different, successive pressure settings;
[0020] Figure 61 is a partial cross-sectional view of the adjustable valve
unit of Figure 4 at an
exemplary first pressure setting illustrating the arrow marking on the
programmable valve
device denoting a direction of fluid flow therethrough and the fixed reference
magnet;
[0021] Figure 6J is a top view of the programmable valve device of Figure 1
wherein the
adjustable valve unit is at the same first pressure setting illustrated in
Figure 61 and also
showing the direction of flow arrow marking and positioning of the fixed
reference magnet;
[0022] Figure 7 is a deeper cross-sectional view of the adjustable valve unit
of Figure 4 along
lines 7-7;
[0023] Figure 8 is a cross-sectional view of the adjustable valve unit of
Figure 7 showing the
transition to a different pressure setting;
[0024] Figure 9 is a perspective view of the spring arm unit with optional
torsion spring;
'30
[0025] Figure 9A is a top plan view of the element of Figure 9;
5
CA 3019405 2018-10-02
[0026] Figure 10 is a side cross-sectional view of the adjustable valve unit
of Figure 8 along
lines 10-10 showing axial lifting of the rotatable construct;
[0027] Figure 11 is a shallower partial top cross-sectional view of the
adjustable valve unit of
Figure 6H showing the "virtual off' position in an unconstrained condition;
[0028] Figure 12 is a side view along lines 12-12 of Figure 11;
[0029] Figure 13 is a side cross-sectional view along lines 13-13 of Figure
11;
[0030] Figure 13A is a partial cross-sectional view along lines 13A-13A of
Figure 13;
[0031] Figure 14 is a perspective view of a tool set including an integrated
locator/indicator
tool, an adjustment tool and a screwdriver;
[0032] Figure 14A is a top perspective view of the integrated
locator/indicator tool and
adjustment tool of Figure 14, prior to the adjustment tool being inserted into
the integrated
locator/indicator tool;
[0033] Figure 14B is a top perspective view of the integrated
locator/indicator tool and
adjustment tool of Figure 14, with the adjustment tool inserted into a
complementary cavity in
the integrated locator/indicator tool;
[0034] Figure 15 is an exploded perspective view of the integrated
locator/indicator tool of
Figure 14;
[0035] Figure 16 is an exploded perspective view of the adjustment tool of
Figure 14;
[0036] Figure 16A is a perspective view of the placement of the half round
magnets on either
side of the magnet shield comprising part of the magnet assembly of Figure 16;
[0037] Figure 16B is a perspective view of the assembled magnet assembly of
Figure 16;
6
CA 3019405 2018-10-02
[0038] Figure 16C is a top view of the assembled bottom and middle housing
sections of the
adjustment tool of Figure 16 showing the internal vertical ribs;
[0039] Figure 16D is a perspective view of the assembled adjustment tool of
Figure 14
without the outer housing section to illustrate the magnet assembly;
[0040] Figures 17A-17I are sequential illustrations of the steps for operating
the electronic
toolset in accordance with the present invention; and
[0041] Figure 18 is a flow chart of the method for ascertain whether the
implanted valve is a
current valve with orientation functionality (i.e., employs a fixed reference
magnet) in
accordance with the present invention or a previous version of the implanted
valve without
orientation functionality (i.e., does not employ a fixed reference magnet).
is
Detailed Description of the Invention
[0042] Figure 1 illustrates a programmable shunt valve device 10 having a
shunt housing 12,
preferably formed of a translucent material such as silicone, with proximal
connector 14 and
distal connector 16. A ventricular catheter or other proximal catheter is
connectable to
connector 14 to bring fluid into shunt housing 12. Fluid passes into sampling
or pumping
chamber 18 and then through a valve mechanism in inlet 102 into adjustable
valve unit 100,
which is shown and described in more detail below in relation to Figures 2-
13A. Adjustable
valve unit 100, Figure 1, includes a casing 103 formed as upper casing 104 and
lower casing
106 which are joined by sonic welding in this construction. A needle guard 20,
preferably
formed of a rigid polymeric material, and lower casing 106 are secured within
housing 12 by
a backing plate 22, preferably formed of silicone reinforced with a polymeric
mesh, which is
bonded to housing 12 by a medical grade epoxy. A fixed reference magnet 800,
as described
in detail further below, is preferably seated in a bump or projection 801 on
the needle guard
20.
[0043] When fluid pressure at inlet 102 exceeds a selected pressure setting
within adjustable
valve unit 100, fluid is admitted past a valve mechanism and then flows
through valve unit
7
CA 3019405 2018-10-02
outlet 110 into passage 30 of housing 12. Ultimately, fluid exits from housing
12 through
distal connector 16 into a peritoneal catheter or other distal catheter.
[0044] Adjustable valve unit 100, Figure 2, includes a rotor 120, spring arm
unit 130, valve
mechanism 140, and a rotor retention spring 150. Rotor 120, also referred to
as a rotating
construct, is formed of a lower cam structure 122 having a plurality of
radially flat cam
surfaces, as shown and described in more detail below, and an upper, magnet
housing 124
carrying magnetic elements 123 and 125, N and S pole magnets, respectively.
Housing 124
also defines a finger 127 which engages a stop in upper casing 104 when rotor
120 is moved
to an unconstrained condition as described below. Rotor 120 rotates about axle
126 which
defines a substantially fixed axis of rotation R at a first location in casing
103.
[0045] Preferably, rotor 120 is also capable of moving along the axis of
rotation, in a
translational motion, to an unconstrained condition when an adjustment tool
from an
electronic toolset is applied to it, as described in more detail below.
Retention spring 150
biases rotor 120 to a downward, normally constrained condition. Preferably,
spring 150 is a
coil spring having sufficient bias to resist the effect of gravity, regardless
of the position of the
adjustable valve unit 100, and to resist magnetic or ferrous objects, such as
magnets in an
integrated locator/indicator tool from the electronic toolset, as described in
more detail below.
However, spring 150 is insufficient to resist the effects of the adjustment
tool, also described
below. Lower cam section 122 has a sufficient height to ensure that cam
follower 132
remains in contact with a cam surface in both the constrained and
unconstrained conditions.
[0046] Spring arm unit 130 includes cam follower 132, a resilient spring
element 134 as well
:5 as upper and lower axles 136, 138 at a second location in casing 103.
Axle 138 turns about a
bearing 139 formed of a relatively low-friction, relatively hard material such
as synthetic
ruby. It is desirable for casing 103, rotor 120 and spring arm unit 130 to be
formed of
polyethersulfone, while all spring components are formed of medical grade non-
ferromagnetic
stainless steel.
[0047] Valve mechanism 140 includes seat 142 and movable valve member 144.
Preferably,
seat 142 and valve member 144, such as a ball, are formed of the same non-
ferromagnetic
8
CA 3019405 2018-10-02
material such as synthetic ruby. In other constructions, the movable valve
member 144 may
be a disc, a cone, or other type of plug. A spherical ball is currently
preferred as the moveable
valve member because that shape enables tight, precise tolerances, assembly
and control
relative to the valve seat. Also, the position of the seat within a port can
be adjusted during
assembly of the valve unit to alter the actual performance value achieved at
each setting,
using a force versus displacement relationship. First, a mandrel checks the
position of the ball,
and the seat is inserted to an estimated desirable location within the port.
Ball displacement is
tested at one or more settings to confirm that desired performance will be
achieved.
[0048] Adjustable valve unit 100 is shown assembled in Figures 3-5 and
positioned at a
second pressure setting, as described in more detail below. Rotor housing 124
carries
downwardly projecting teeth 160 and 162 with cooperate with four lock stops
170, 172, 174,
176 projecting upwardly from lower casing 106 in this construction. Lock stop
172 is shown
in partial cross-section in Figure 4 and lock stops 170 and 176 are visible in
Figure 5.
5 Preferably, the lower surfaces 161 of rotor teeth 160 and 162 are rounded
and the upper
surfaces of casing lock stops 170, 172, 174 and 176 each have a plurality of
facets 163 to
create a chisel-like, lead-in topography which encourages the rotor teeth to
return to a
constrained position, as illustrated in the side view in Figure 4A. However,
the vertical
surfaces of the rotor teeth 160, 162 and of lock stops 170-176 abut when
engaged and do not
"lead out", that is, relative translational movement is discouraged, once
again illustrated in
Figure 4A. Pure vertical lift must therefore be provided by an adjustment
tool, as described in
more detail below, to overcome the rotor teeth-to-lock stop abutment and
change the
performance setting.
[0049] A limiter 180, Figure 4, restricts travel of spring 134 away from seat
142 so that ball
144 does not become misaligned or dislodged relative to seat 142. A gasket 182
of epoxy is
shown in Figures 4 & 5 as an optional, redundant seal between upper casing 104
and lower
casing 106 in this construction.
[0050] The operation of adjustable valve unit 100 is illustrated in Figures 6-
8 with identical
reference numerals identifying identical components and features. Not all such
components
and features are labelled in each drawing for the sake of visual clarity.
Figures 6 & 6A show
9
CA 3019405 2018-10-02
different levels of top partial cross-sectional views for adjustable valve
unit 100 at a first
pressure setting. Cam follower 132 slidably contacts only a first cam surface
191, which has
an arc length bounded by points 190 and 192, because rotor housing tooth 162
is captured
between casing lock stops 170 and 172 in the normal, constrained condition.
First cam
surface 191 has a first, preferably shortest radial distance 210 relative to
the axis of rotation of
rotor 120. By comparison, outermost cam surface 205 has a greatest radial
distance 218. An
optional torsion spring 220 is shown in greater detail in Figure 9.
[0051] When rotor 120 is translated upwardly by magnets using an adjustment
tool rotor
0 tooth 162 is lifted so that subsequent clockwise or counter-clockwise
rotation of the
adjustment tool rotates rotor tooth 162 up and over casing lock stop 172.
After the adjustment
tool is removed and when the second pressure setting has been selected as
shown in Figure
6B, rotor 120 is biased downwardly by spring 150, Figures 2, 4 & 5.
5 [0052] Rotor tooth 160 is illustrated as not being in contact with any
stop in Figures 4 & 6B,
for example, because in the constrained condition rotor tooth 162 is now
captured between a
pair of adjacent lock stops 172 and 174, Figure 6B, which is sufficient to
prevent rotation of
rotor 120 relative to the cam follower 132 beyond points 192 and 194 on the
cam structure of
rotor 120. Points 192 and 194 represent a second arc length for second cam
surface 193.
20 Surface 193 is at a second radial distance 212 which is greater than
distance 210 and is less
than distance 218, Figures 6A & 6H. The arc length of second cam surface 193,
Figure 6B,
can be the same or different than the arc length of first cam surface 191 but,
preferably, is
substantially the same length.
[0053] The outward radial motion of cam follower 132 as it slidably travels
from first cam
surface 191, Figure 6A, to second cam surface 193, Figure 6B, increases the
biasing force by
valve spring 134 on ball 144 as increased torque is applied by cam follower
132 to the
remainder of spring arm unit 130. Improved precision in pressure control is
achieved by
having a stiff cam follower 132 in contact with the selected cam surface and a
flexible
30 element, spring 134, in contact with the valve ball 144. The enhanced
result is opening of the
ball 144 from the valve seat 142 by requiring only the resilient spring
element 134 to bend,
which provides a constant spring force to the ball 144. The opening pressure,
and overall
CA 3019405 2018-10-02
valve performance, is not reliant on axial pivoting of the spring arm unit
130.
[0054] A third opening pressure setting is shown in Figure 6C with rotor tooth
162 positioned
between casing stops 174 and 176 such that cam follower 132 experiences only
third cam
surface 195 between points 194 and 196 at a third radial distance 214. To
achieve a fourth
pressure setting, Figure 6D, both rotor teeth 160 and 162 are utilized
relative to casing stops
170 and 176, respectively. Cam follower 132 is restricted thereby to fourth
cam surface 197
between points 196 and 198.
[0055] Fifth through seventh pressure settings are illustrated in Figures 6E-
6G as rotor tooth
160 is successively captured between casing adjacent lock stop pairs 170-172,
172-174, and
174-176, respectively. Cam follower 132 is restricted thereby to fifth cam
surface 199
between points 198 and 200, Figure 6E, sixth cam surface 201 between points
200 and 202,
Figure 6F, and seventh cam surface 203 between points 202 and 204, Figure 6G.
5
[0056] Preferred opening pressure settings currently range from approximately
30 mm to 210
mm water (294 Pa to 2,059 Pa) in seven increments of 30 mm (294 Pa), with a
final, "virtual
off" setting described in more detail below. Preferably, each valve unit is
calibrated and
tested at the time of manufacture at one or more flow rates. Actual opening
pressure for each
setting tends to vary according to flow rate, typically measured in
milliliters per hour. Also,
when tested with a 120 cm long distal catheter having an inner diameter of 1
mm, the average
opening pressure typically will increase by 9 mm water or more at flow rates
of 5 ml/h or
more.
[0057] The final setting, Figure 6H, of approximately at least 400 mm water
(3,920 Pa)
minimizes flow as a "virtual off" setting, that is, as substantially closed.
This final setting is
achieved by exposing cam follower 132 to outermost cam surface 205, defined by
points 204
and 206, having greatest radial distance 218. This greatest cam setting forces
stiffener
element 133 of spring arm unit 130 against valve spring 134 to shorten its
active, effective
:4) length and thereby dramatically increase the biasing force applied
against ball 144. The final
opening pressure is increased by more than fifty percent over the prior
setting. In other
constructions, a stiffener element is forced against a valve spring during two
or more final
11
CA 3019405 2018-10-02
cam settings at desired pressure increments.
[0058] Spring arm unit 130 is shown in greater detail in Figures 9 and 9A with
cam follower
132, stiffener element 133, and valve spring 134. Cam follower 132 terminates
in a triangular
head 233 with rounded or chamfered edges, one of which serves as a bearing
surface 235. In a
preferred construction, spring element 134 is formed from stainless steel
having a thickness of
0.020 inches and terminates in an enlarged pad 230 for contacting the valve
ball or other
movable valve member. In one construction, spring element 134 is attached to
the remainder
of spring arm unit 130 by a post 232 and rivet 234 which are secured by
ultrasonic welding.
Torsion spring 220 has a first leg 221 which is retained in recess 236 of
projection 238.
Second spring leg 223 rests against an inner surface of the casing.
[0059] Use of torsion spring 220 is optional, and is possible because only
spring element 134
contacts the movable valve member. As a result, additional spring force from
torsion spring
220 can be utilized to force bearing surface 235 of cam follower 132 against a
cam surface of
the rotor. This biasing force provided by torsion spring 220 augments
rotational position of
the spring arm reflective of the intended cam displacement without otherwise
impacting the
force applied to the ball or other movable valve member. This provides for a
more accurate
and repeatable opening pressure and a more manufacturable and robust design as
it reduces
the need to maintain minimal friction such as when the valve spring element
solely provides
the force needed to maintain the cam follower on the cam surface.
[0060] The position of the components and features within adjustable valve
unit 100 at the
first pressure setting shown in Figure 6A is illustrated at a deeper partial
cross-sectional view
in Figure 7. Opening 222 into the lower cam portion of rotor 120 inhibits
negative pressure
from developing under rotor 120, that is, opening 222 ensures pressure
equalization as
cerebrospinal fluid passes through valve unit 100.
[0061] The transition from the first pressure setting to the second pressure
setting is
illustrated in Figures 8 & 10 as rotor 120 is translated upwardly by magnetic
attraction with
an adjustment tool so that rotor tooth 162 is able to clear casing lock stop
172. Cam follower
132 is shown in FIG. 8 at point 192 passing from first cam surface 191 to
second cam surface
12
CA 3019405 2018-10-02
193. Lower cam section 122 has a sufficient height relative to cam follower
bearing surface
235 to ensure that cam follower 132 remains in contact with a cam surface of
cam portion 122
in both the constrained and unconstrained conditions. Rotor retention spring
150, Figure 10,
has been compressed, its biasing force being overcome by magnetic attraction
between rotor
120 and the adjustment tool while it is positioned over valve unit 100. Also
illustrated in
Figure 10 are upper and lower synthetic ruby bearings 242 and 139 for upper
and lower axles
136 and 138, respectively, of spring arm unit 130. Synthetic ruby bearing 240
rotatably
supports rotor axle 126.
[0062] The position of the components and features within valve unit 100 at
the final, "virtual
off" or substantially closed setting shown in Figure 6H is depicted at a
shallower cross-
sectional view in Figure 11 in an unconstrained condition. Further clockwise
rotation of rotor
120 is prevented by rotation stop or limiter 250 which projects downwardly
from upper casing
104 to contact finger 127. Rotation stop 250 contacts the opposite surface of
finger 127 when
rotor 120 is turned fully counter-clockwise in an unconstrained condition. The
actual position
of rotation stop 250 may be shifted to the right of the position shown in
Figure 11 so that cam
follower 132 is able to track nearly the entire portion of cam surface 205.
Preferably, one side
of stop 250 prevents rotor movement from the lowest setting directly to the
highest setting,
and also prevents the cam follower from touching the cam projection for the
highest setting
when the rotor is at its lowest setting. The other side of stop 250 prevents
movement from the
highest setting directly to the lowest setting. A side, partial cross-
sectional view of rotation
stop 250 blocking rotor housing 124, as well as spring 150 compressed between
rotor 120 and
upper casing 104, is shown in Figure 12 for this unconstrained condition.
[0063] Further detailed views of selected features and components of rotor 120
in one
construction are illustrated in Figures 13 & 13A. In particular, the housing
portion 124 is
shown as integral with cam portion 122, similar to monolithic rotor 120a of
Figure 1A.
Pocket cavity 260, Figure 13, contains magnet 123 and tantalum reference ball
129 which is
readily visible during imaging of the valve unit 100 after implantation in a
patient to confirm
:10 the actual pressure setting. Pocket cavity 262 holds magnet 125. A
partial end view of
housing portion 124 through magnet 125, pocket 262 and rotor tooth 160 is
provided in
Figure 13A.
13
CA 3019405 2018-10-02
[0064] It is therefore the particular design of the abutting rotor-tooth-to-
lock-stop vertical
surfaces requiring purely vertical lift by an adjustment tool to overcome the
rotor-tooth-to-
lock-stop abutment in order to change the pressure setting that provides the
resistance to
change of valve settings even during exposure to external foreign magnetic
fields. The rotor
tooth-to-lock stop abutment mechanically prevents rotational movement from a
given
performance setting as the vertical surfaces provide no lead in to facilitate
travel up and over
the lock stops made of a sufficiently rigid material (such as a moldable
plastic, for example,
polyethersulfone (PES), polysulfone (PSU), polyphenylsulfone (PPSU)) and
sufficient wall
thickness (greater than 0.2 mm) to prevent flexure. Axial movement is
restricted due to the
orientation of the rotating construct magnets inducing a combined attraction
and repulsion
when interacting with a strong north or south magnet. Furthermore, the
interference between
the axle and the bushing surface of the rotating construct mechanically limit
tilt associated
with attraction/repulsion to an external magnetic field.
[0065] However, it is only when the downward projecting rotor teeth 160, 162
of the rotor
housing 124 are properly locked, engaged or seated in corresponding setting
pockets 171,
171', 171", 171" defined by at least one of the lock stops 170, 172, 174, 176
projecting
upwardly from the lower casing 106 that the programmable implantable bodily
fluid drainage
valve is resistant to magnetic fields. It is mechanically possible for the
downward projecting
teeth 160, 162 when vertically lowered to undesirably rest on the lock stops
170, 172, 174,
176, as depicted in Figure 8 wherein rotor tooth 162 is resting on lock stop
172. When the
rotor teeth 160, 162 are resting on the lock stops 170,172, 174, 176 (i.e.,
not properly seated
in the respective setting pockets defined by the lock stops) the programmable
implantable
bodily fluid drainage valve is at risk of possible unwanted change to the
valve setting when
exposed to magnetic fields such as during an MRI procedure. Heretofore,
conventional
programming valves are not able to verify whether the rotor teeth 160, 162 are
properly seated
in the setting pockets 171, 171', 171", 171". Experimental testing has
confirmed that the
valve setting remains unchanged when subject to magnetic fields up to
approximately 3T if
:0 .. the rotor teeth are properly locked, engaged or seated in the respective
setting pockets. To be
certain, prior to being exposed to a magnetic field (e.g., prior to undergoing
an MRI
procedure, the programmed valve setting must once again be verified by medical
personnel
14
CA 3019405 2018-10-02
using the indicator tool from the associated toolset or alternatively the
medical personnel
would have to use a tool to confirm proper engagement. The possibility of a
change in valve
setting if the rotor teeth are not properly seated in a setting pocket during
exposure to
magnetic fields, despite its relative small probability of occurrence, is
still particularly
problematic since the implantable programmable bodily fluid drainage valve
cannot be
guaranteed as being resistant to magnetic fields in such circumstances.
[0066] The present inventive improved implantable valve drainage system
eliminates this
uncertainty by verifying whether the downward projecting rotor teeth 160, 162
are properly
seated in the respective seating pockets 171, 171', 171", 171', that is,
confirm whether the
magnetic field resistance mechanism is properly engaged to carry out its
intended
functionality.
[0067] This is realized by configuring the programmable shunt valve 10 to
include a fixed
reference magnet 800, in addition to the primary magnetic elements 123, 125
disposed in the
housing 124 of the rotor 120 of the adjustable valve unit, as illustrated in
Figure 61. Referring
to Figure 6J, preferably, the fixed reference magnet 800 is located between
the proximal
connector 14 and the sampling/pumping chamber 18 within the direction of flow
of the shunt
valve. Preferably, fixed reference magnet 800 has a different magnetic
strength from the
'Al primary magnetic elements 123, 125 and a different nominal distance
between magnets (i.e.,
distance between reference magnet 800 and primary magnet 123 compared to
distance
between primary magnets 123 and 125) for proper identification. Nominal
distance between
primary magnetic elements 123, 125 is approximately 5.48mm as measured from
bottom
inner corner to bottom inner corner. Fixed reference magnet 800 nominal
distance is 17.5mm
25 from RC axle to leading edge of reference magnet 800. The fixed
reference magnet 800 is
aligned with an arrow indicia or marking "A" on the programmable shunt valve
10 itself
denoting the direction of flow of fluid therethrough and a center point "C"
midway between
the magnetic elements 123, 125. A line passing through these three points
(referred to as a
direction of flow line) is the basis for determining the orientation of the
programmable shunt
:0 valve 10 using an integrated locator/indicator tool 1405 from the
exemplary tool set 1400 in a
case, as illustrated in Figure 14. Also included in the tool set is an
adjustment tool 1415, a
screwdriver 1410 and spare batteries 1408. It is noted that the locator and
indicator tools
CA 3019405 2018-10-02
described herein and illustrated in the accompanying drawings have been
integrated into a
single device for simplicity of operation. It is, however, contemplated and
within the intended
scope of the present invention for none, some, or all of the tools in the
toolset to be integrated.
[0068] A top perspective view of the integrated locator/indicator tool 1405
and adjustment
tool 1415 of Figure 14, prior to the adjustment tool 1415 being inserted into
a cavity 1420 of
the integrated locator/indicator tool 1405, is shown in Figure 14A. While
Figure 14B shows
the adjustment tool 1415 following insertion into the cavity 1420.
[0069] Figure 15 is an exploded perspective view of the integrated
locator/indicator tool 1405
of Figure 14 which includes a housing 1500. In the illustrated example,
housing 1500
comprises a bottom housing section 1505, a middle housing section 1510 and a
top housing
section 1515, each separate from one another. A cylindrical shaped section
1530 of the
middle housing section 1510 defines a passageway or channel 1535 extending
longitudinally
therethrough. Top housing section 1515 has a chimney 1525 complementary in
size and
shape to be received within the passageway or channel 1535 of the cylindrical
shaped section
1530 of the middle housing section 1510. Chimney 1525 is closed at one end and
open at an
opposite end. The open end of the chimney 1525 receiving therein the
adjustment tool 1415,
as described in detail below. An exterior surface of the bottom housing
section 1505 has a
recess 1520 defined therein that is complementary in shape and size to the
outer contour of
the programmable implantable bodily fluid drainage valve. In
use, the integrated
location/indication tool 1405 is positioned with the exterior surface of the
bottom housing
section 1505 against the skin of the patient and the implantable bodily fluid
drainage valve
seated within the recess 1520. A top covering or layer 1540 may be mounted to
the top of the
assembled housing. Such covering or layer 1540 has a complementary size and
shape
opening 1542 to that of the chimney 1525. Disposed about the perimeter of the
opening 1542
are a series of markings representing the different valve settings in
predetermined increments
(e.g., 1, 2, 3õ5, 6, 7, 8). A second opening 1550 in the top covering or layer
1540 permits
viewing therethrough of a display 1555, such as a Liquid Crystal Display
(LCD). The
integrated locator/indicator tool 1405 is powered by one or more batteries and
turned ON/OFF
by a button 1560. The batteries are housed within a battery enclosure assembly
1565 that
includes a tray with electronic contact terminals between which the batteries
are inserted.
16
CA 3019405 2018-10-02
Access to the battery enclosure assembly 1565 for insertion/removal of the
batteries therefrom
is via a removeable battery door assembly 1575. A two-dimensional array of 3-
axis magneto-
resistive sensors 1570 printed on a circuit board detects the magnetic field
pattern produced
by the magnetic elements 123, 125 disposed in the housing 124 of the rotor 120
and the fixed
reference magnet 800. It is within the intended scope of the present invention
to substitute
other types of sensor arrays capable of detecting magnetic fields, such as
Hall sensors, for the
3-axis magneto-resistive sensors 1570. Another printed circuit board 1573
includes a
processor/controller and memory device.
[0070] Figure 16 is an exploded perspective view of the adjustment tool 1415
of Figure 14.
In the illustrated example, housing 1600 comprises an outer housing section
1610 and a top
housing section 1615, each separate from one another. A magnet assembly 1620
is disposed
in the outer housing section 1610. In particular, the magnet assembly 1620 in
Figure 16A is a
Halbach array comprising two half round magnets 1630, 1635 connected by a yoke
1650 and
separated by a shield magnet 1640 that redirects the magnetic field allowing
deeper
5 penetration. The strength of the half round magnets 1630, 1635 selected
for use in the
adjustment tool 1415 depends on one or more factors, such as distance from the
valve and the
design of the sensor array. In the magnet assembly 1620, the two half round
magnets 1630,
1635 are rotated until their flat side lays flush against the shield magnet
1640, as depicted in
Figure 16A. The orientation of the magnets 1640, 1630, 1635 should preferably
be as shown
in Figure 16 with the magnet north side of the shield magnet 1640 in contact
with the half
round magnet 1630, 1635 with a magnetic north pointed toward the bottom of the
outer
housing section 1610. One of the two half round magnets 1630, 1635 faces the
tantalum
reference ball 129 (Figure 13). The shield magnet 1640 is partially repelled
by the half round
magnets 130, 1635 and thus is held down by a yoke 1650 mounted on top of the
shield
magnet 1640 that, when assembled, is also in contact with the two half round
magnets 1630,
1635. It is these components of the magnet assembly 1620 that when assembled
together are
inserted into the outer housing section 1610 so that the two half round
magnets 1630, 1635 are
received in respective recesses 1655 defined in an interior surface of the
outer housing section
1610 with the half round magnet facing the tantalum ball 129 facing towards
the '1 to 8 stop'.
As is visible in the top view in Figure 16C, the outer housing section 1610
includes a plurality
of vertical ribs 1655 with which the half round magnets 1630, 1635 connect. A
cylindrical
shaped spacer 1625 is positioned above the yoke 1650 (Figure 16D). The top
housing section
17
CA 3019405 2018-10-02
1615 with a marking indicator is secured to the outer housing section 1610
forming the
assembled adjustment tool 1415.
[0071] The magnetic field pattern produced by the magnetic elements 123, 125
disposed in
the housing 124 of the rotor 120 and the fixed reference magnet 800 is
detected by the two-
dimensional array of 3-axis magneto-resistive sensors 1570 of the integrated
locator/indicator
tool 1405. Once these three magnets are detected, the center point "C" midway
between the
two detected magnetic elements 123, 125 is located. The detected fixed
reference magnet 800
is connected with the arrow indicia or marking "A" denoting the direction of
flow on the
implantable valve and the center point "C" midway between the two detected
magnetic
elements 123, 125 to define a direction flow line as a reference line for
aligning the integrated
locator/indicator tool 1405 with the direction of flow line on the valve. Once
the user has
centered and oriented the toolset over the valve mechanism the toolset will
provide an
indication of valve setting based on the angle of north/south poles and
facilitate adjustment of
5 the valve setting.
[0072] Figures 18A-181 are sequential steps in operation of the improved
electronic toolset of
Figure 14 in accordance with the present invention. In Figure 18A the
integrated
locator/indictor tool 1405 is powered on by pressing the power button 1560.
Holding the
power button 1560 for a predetermined period of time, e.g., approximately 3
seconds,
calibrates, clears or zeros out the integrated locator/indicator tool 1405, as
illustrated in Figure
18B. Then a bottom surface (sensor floor) of the integrated locator/indicator
tool 1405 is
positioned against the skin above the implantable valve system such that the
implantable
valve is received in the complementary size and shaped recess 1520 defined in
the exterior
surface of the bottom housing section 1505, as illustrated in Figure 18C. The
integrated
location/indication tool 1405 is moved in the appropriate direction (as
indicated by the four
arrows pointing in different directions) until the two circular visual images
viewed on the
LCD display 1555 are aligned with one another, indicating that the center of
the adjustable
valve unit 100 has been aligned with the center of the adjustable valve unit
100. Having
centered the locator/indictor tool 1405 above the adjustable valve unit 100,
then in Figure
18D, the integrated locator/indicator tool 1405 is rotated until the two
visual icons
(complementary in shape (key hole shaped) to the implantable valve) displayed
within the two
18
CA 3019405 2018-10-02
circular visual images are aligned with one another to orient the integrated
location/indication
tool 1405 in the proper direction of flow of the implantable valve. It is now
that the integrated
location/indication tool 1405 has been centered and oriented in a direction of
flow of the
implantable valve, that the current indication or valve setting is read and
visually displayed on
the LCD (Figure 18E). If the current valve setting is to be changed or
programmed to a new
valve setting, then in Figure 18F the adjustment tool 1415 is inserted into
the cavity 1420 of
the integrated location/indication tool 1405 and rotated until the reference
marking 1619 on
the adjustment tool 1415 is aligned with the marking on the top lens 1540
corresponding to
the read current valve setting. In Figure 18G the adjustment tool 1415 is
rotated
clockwise/counterclockwise to the marking on the top lens corresponding to the
new valve
setting. Once set to the new valve setting, in Figure 18H the adjustment tool
1415 is removed
from the integrated locator/indicator tool 1405 (while the integrated
location/indication tool
1405 remains stationary in place) and this new valve setting is now
automatically detected by
the integrated location/indication tool 1405 and visibly displayed on the LCD
1555 (Figure
181). It is noted that the positioning of the integrated location/indication
tool 1405 remains
unchanged in steps 18E-181. The improved electronic toolset eliminates the
requirement or
need to have to once again locate the center of the valve and then confirm the
new valve
setting following adjustment by the adjustment tool 1415.
[0073] The present inventive electronic toolset, as illustrated in Figure 14,
is suitable for use
with a latest version or generation of the programmable implantable valve
(Figure 1) having a
fixed reference magnet 800 separate from and in addition to the pair of
primary magnets 123,
125 in the adjustable valve unit 100. As discussed above, the fixed reference
magnet is used
to determine the angular orientation of the valve. Other, possibly older,
generations or
versions of the programmable implantable valve not employing a reference
magnet separate
from and in addition to the pair of primary magnets in the adjustable valve
unit, may still be in
use. Then the angular orientation of the valve cannot be ascertained using the
electronic
toolset. Of course, a generation or version of the programmable implantable
valve not
employing a reference magnet may still be programmed using its corresponding
older version
or generation of toolset (i.e., one that is not adapted to detect the fixed
reference magnet and
based on such determine electronically the angle of orientation). However,
this would require
medical personnel to have available on site different versions or generations
of electronic
19
CA 3019405 2018-10-02
toolsets corresponding to whether the fixed reference magnet is present in the
programmable
implantable valve or not. Selecting the appropriate generation or version of
toolset would
first require the user to identify which version or generation of the
implantable programmable
valve was implanted. This may be accomplished via X-ray imaging (e.g.,
identifying the
presence or absence of a reference magnet), however, such exposure has
deleterious health
effects and thus is to be avoided, whenever possible. Another drawback is that
medical
facilities would require an allocation of space for storing of the different
versions or
generations of toolsets. However, by far one of the most relevant risks is the
possible
selection and use by medical personnel of an incompatible generation or
version of toolset
with the implanted valve. These risks and drawbacks are reduced or overcome by
using the
present inventive universal electronic toolset that may be interchangeably
used with both
programmable implantable valves employing a fixed reference magnet as well as
with earlier
generations or versions of programmable implantable valves that do not include
a fixed
reference magnet.
[0074] Specifically, the present inventive locator/indicator tool 1405
includes circuitry for
determining whether the fixed reference magnet 800 associated with the
adjustable valve unit
100 is detected by the 2-dimensional array of 3-axis magneto-resistive sensors
1570. If the
fixed reference magnet 800 is not detected (i.e., not present) the system
classifies the magnets
based on the historical valve mechanism and facilitates guidance for locating
the valve but
requires the user to determine orientation without electronic assistance or
feedback, such as
through palpation. Once the user has manually oriented the toolset over the
valve mechanism
the toolset will provide an indication of valve setting based on the angle of
north/south poles
and facilitate adjustment of the valve setting.
[0075] Figure 18 is an exemplary flow chart of the specific steps taken to
ascertain whether
the implanted valve 10 is a generation or version that includes a fixed
reference magnet 800
or not and associated operational steps taken in either case. Specifically, in
step 2005 the
presence of the fixed reference magnet 800 in the implanted valve 10 is
ascertained using the
two-dimensional array of 3-axis magneto-resistive sensors 1570 in the
integrated
locator/indicator tool 1405. If the fixed reference magnet 800 in the
implanted valve 10 is
detected in step 2010, then the center of adjustable valve unit 100 is located
in step 2015.
CA 3019405 2018-10-02
Specifically, locating the center of the adjustable valve unit 100 is achieved
by first detecting
the primary magnets 123, 125 associated with the adjustable valve unit 100
using the two-
dimensional array of 3-axis magneto-resistive sensors 1570 in the integrated
locator/indicator
tool 1405. Once the primary magnets 123, 125 have been detected, the center of
the
adjustable valve unit 100 is located midway therebetween representing the
center of the
adjustable valve unit 100. Next, in step 2020 the direction of flow of the
valve is determined
based on the located center of the adjustable valve unit 100 (in step 2015)
and the detected
fixed reference magnet 800 (in step 2005). The integrated location/indication
tool 1405 is
moved until aligned with the identified center of the adjustable valve unit
100 and then the
tool is rotated to the proper orientation aligned with the identified
direction of flow of the
valve. Preferably, this is accomplished visually on a display screen 1555 on
which are
displayed two separate icons (one fixed valve location icon illustrative of
the implanted valve
and one movable locator/indicator tool icon representing the integrated
location/indication
tool 1405). Note that a single icon can be used to denote more than one
parameter (e.g.,
centering and direction of flow) hereinafter referred to as a "dual parameter
icon." For
example, the dual parameter icon may be an outer circle with a key-hole shape
within the
outer circle complementary to the outline of the programmable shunt valve
device 10 in
Figure 1. In this exemplary dual parameter icon, the outer circle is
representative of the
centering parameter, whereas the key-hole shape within the outer circle
denoting the direction
:0 of flow parameter. Integrated locator/indicator tool 1405 is moved and
rotated appropriately
until the two icons visible on the display screen 1555 are aligned relative to
both the center
(outer circles aligned) and direction of flow of the valve (key-hole shape).
Now that the
integrated location/indication tool 1405 is properly centered and the angle of
orientation
aligned with the direction of flow of the valve, the operation advances to
step 2025 wherein
the indication of the current valve setting is read by the integrated
locator/indicator tool 1405
based on the angle of north/south poles of the primary magnets 123, 125 and
facilitate
adjustment of the valve setting, if desired.
[0076] If the new electronic toolset is being used with a previous generation
or version of an
implanted valve not employing a fixed reference magnet, then the presence of
such fixed
reference magnet will not be detected by the two-dimensional array of 3-axis
magneto-
resistive sensors 1570 in step 2010. The processing advances to step 2030
wherein the center
21
CA 3019405 2018-10-02
of adjustable valve unit 100 is located in a manner similar to the processing
discussed above
with respect to step 2015. Specifically, locating the center of the adjustable
valve unit 100 is
achieved by first detecting the primary magnets 123, 125 associated with the
adjustable valve
unit 100 using the two-dimensional array of 3-axis magneto-resistive sensors
1570 in the
integrated locator/indicator tool 1405. Once the primary magnets 123, 125 have
been
detected, the center of the adjustable valve unit 100 is located midway
therebetween. The
integrated location/indication tool 1405 is moved until aligned with the
identified center of the
adjustable valve unit 100. Once again this is preferably accomplished visually
on the display
screen 1555 on which are displayed two separate icons (one fixed valve
location icon
illustrative of the implanted valve and one movable locator/indicator tool
icon representing
the integrated location/indication tool 1405). When the presence of the fixed
reference
magnet is not detected, the icon displayed (e.g., the outer circle only)
represents a single
parameter (e.g., centering). There is no key-hole shape within the outer
circle denoting the
direction of flow parameter since such parameter is not detectable
electronically with the
assistance and feedback of the integrated locator/indicator tool 1405 in the
absence of the
fixed reference magnet 800. Integrated locator/indicator tool 1405 is moved
appropriately
until the two icons visible on the display screen 1555 are aligned relative to
the center (outer
circles aligned). Since no fixed reference magnet has been detected and thus
no electronic
assistance or feedback information regarding the direction of flow line of the
implanted valve
0 is provided by the integrated locator/indicator tool 1405, instead the
operator is informed (via
one or more senses such as visually, audibly and/or tactile) that the center
and direction of
flow, i.e., angle of orientation, of the adjustable valve unit must be
determined manually
without any electronic assistance or feedback information from any tool in the
electronic
toolset. Preferably, the user is guided step-by-step how to manually orient
the toolset over the
implanted valve, that is manually determine the center and direction of flow
of the implanted
valve (step 2035), without any electronic assistance or feedback information
provided by the
electronic toolset. By way of illustrative example based on the adjustable
valve unit 100
configuration illustrated, the user may be instructed to palpate the area of
interest until the
adjustable valve unit 100 is located and then the center is marked (i.e., the
hard portion of the
valve distal to the reservoir). The position of the inlet and outlet connector
barbs on the
respective catheters may also be determined through palpation and marked
accordingly. A
straight line passing through the three markings then represents the direction
of flow line.
22
CA 3019405 2018-10-02
Once the direction of flow line has been ascertained manually (without any
electronic
assistance or feedback information from any tool in the electronic toolset)
the integrated
locator/indicator tool 1405 is manually oriented to align with the direction
of flow line. Now
that the center of the adjustable valve unit 100 has been located and the
integrated
.. location/indication tool 1405 has been manually aligned with the manually
detected
orientation of the direction of flow of the implanted valve, the operation
advances to step
2040 wherein the indication of the current valve setting is read by the
integrated
locator/indicator tool 1405 based on the angle of north/south poles of the
primary magnets
123, 125 and facilitate adjustment of the valve setting, if desired. As
previously mentioned,
.. with other valve configurations the steps for locating the center and
direction of flow of the
valve may vary from those described above using other fixed reference points
on the valve.
[0077] Thus, while there have been shown, described, and pointed out
fundamental novel
features of the invention as applied to a preferred embodiment thereof, it
will be understood
that various omissions, substitutions, and changes in the form and details of
the devices
illustrated, and in their operation, may be made by those skilled in the art
without departing
from the spirit and scope of the invention. For example, it is expressly
intended that all
combinations of those elements and/or steps that perform substantially the
same function, in
substantially the same way, to achieve the same results be within the scope of
the invention.
0 Substitutions of elements from one described embodiment to another are
also fully intended
and contemplated. It is also to be understood that the drawings are not
necessarily drawn to
scale, but that they are merely conceptual in nature. It is the intention,
therefore, to be limited
only as indicated by the scope of the claims appended hereto.
[0078] Every issued patent, pending patent application, publication, journal
article, book or
any other reference cited herein is each incorporated by reference in their
entirety.
23
CA 3019405 2018-10-02
