Note: Descriptions are shown in the official language in which they were submitted.
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FOOT MEASUREMENT APPARATUS
FIELD OF THE INVENTION
The present invention generally relates to foot measurement and the analysis
of foot
measurement data.
BACKGROUND
= - Many people require footcare products. Footcare products may be
placed inside
footwear products to provide support, cushioning, to improve fit or comfort,
etc.
Examples of footcare products include orthotic products (hereinafter referred
to as
"orthotics"), insoles, foot cushions, heel cups, etc. Examples of footwear
products
include sneakers, loafers, dress shoes, high heels, etc.
Footcare products are currently made available in two different ways, namely
as a limited range of pre-manufactured footcare products which may be
purchased
from retail displays in shops, and as custom-made footcare products, which are
individually made to match the particular requirements of a customer.
Both of these ways of purchasing footcare products suffer from a number of
problems, however.
In the case of pre-manufactured footcare products, although packaging may
provide some guidance, customers may have to guess which products are
appropriate, e.g., the customers' size, foot characteristics, and other
attributes.
However, even if a customer were given the opportunity to try on a product,
the
customer may not know the best type of support or size of footcare product for
their
particular foot characteristics. This practice may result in the customer
buying
multiple products before the customer finally finds a product that meets the
customer's needs. Retailers therefore want to be able to provide a service to
help
customers select the correct product without having to employ a person that
has
specialized training and/or knowledge of all possible products, footcare or
footwear,
and foot types.
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In the case of custom-made footcare products, significant expertise and time
is required to measure a customer's feet, determine the required footcare
product
and manufacture the footcare product to the specification of the customer's
feet. As
. a
result, custom-made footcare products are typically more expensive than pre-
manufactured footcare products. Furthermore, creating a custom-made footcare
product generally requires a trained professional that measures the customer
and
makes or orders the footcare product.
There is therefore a requirement for an apparatus and automated technique
for making measurements of a person's feet to assist in the selection of a
footcare
product or to select automatically the footcare product.
However, the present inventors have found that there are a number of
technical problems when implementing such an apparatus/technique. For example,
the apparatus must be low-cost, reliable and simple to use. In addition:
(1) Before making measurements of a person's feet, it is important to ensure
that the person is standing correctly for the type of measurement sensor
being used, otherwise the measurements may be inaccurate and variable.
(2) Even if a person is standing correctly, inaccuracies may occur in the foot
measurements, and the apparatus/automated technique should therefore
identify and address the cause of these errors.
(3) One measurement which often needs to be taken of a person's foot is a
measure of the arch of the foot. However, a problem arises as to how to
measure such a three-dimensional feature using a sensor which makes
measurements in a two-dimensional plane, such as a two-dimensional
pressure sensor.
(4) For some types of footcare products it is necessary to make dynamic
measurements of a person's foot (that is, measurements while the person
is walking, for example to analyse the person's gait). Accordingly, an
apparatus which can make this type of measurements is necessary.
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However, the apparatus must not occupy a large volume otherwise it will
take up too much float- space in a shop.
(5) The number of different types and sizes of footcare products is very
large,
and hence the number of foot measurements that need to be made to
select a product for a customer is also very large. Accordingly, an
apparatus/automated technique which reduces the number of
measurements to be made, and therefore the measurements time and
opportunity of inaccuracies, is required.
The present invention has been made with these technical problems in mind.
SUMMARY OF THE INVENTION
To address problem (1) above, the present invention provides an apparatus
and method in which a plurality of pressure sensors are used to make pressure
measurements of a person's foot on a surface. Signals from the pressure
sensors
are processed to calculate a point of force on the surface for the person
(preferable a
centre of force point comprising the point on the surface through which the
person's
weight acts) and to compare this point of force for the person with a
previously
determined target zone on the surface for correct measurements using the
sensors.
A display is presented to the user showing the difference in location of the
person's
current point of force and the target zone in order to assist the user to move
(and
therefore change the point through which his weight acts) and bring his point
of force
into the target zone. Measurements of the person's foot are not taken until
the
person's point of force is within the target zone.
The use of pressure sensors, as opposed to optical, gauge, or other
previously proposed approaches to measuring feet solves the problem of
providing a
low-cost, robust measurement system suitable for use in an unattended retail
environment. In addition, the apparatus and method ensure that the user is
standing
in such a way that accurate and reliable measurements can be taken using the
pressure sensors.
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With reference to problem (2) above. The present inventors have recognized
that many measurement errors occur because a person is not using the
measurement apparatus correctly. In particular, the present inventors have
recognized that many people wear an item of footwear such as a shoe or sock
when
measurements are taken, whereas measurements should be taken when the user is
not wearing any such item. The present invention therefore provides an
apparatus
and method in which signals from the foot measurement sensor(s) are first
processed to determine a plurality of different foot dimensions, to calculate
one or
more ratios of the measured dimensions, and to compare the calculated ratio(s)
with
one or more reference values to determine if the person is wearing an item of
footwear. In this way, further measurements of the person's foot can be
delayed until
the person has removed any item of footwear, thereby avoiding inaccurate
measurement results.
To address problem (3) above, the present inventors have devised a new
technique to characterize the arch of a persons foot using measurements taken
on a
two-dimensional plane on which the foot is placed. More particularly, the
present
invention provides an apparatus and method in which a plurality of pressure
sensors
are used to generate a pressure map of the sole of the person's foot when it
is
placed on a two-dimensional surface and the pressure map is processed to
determine a measure of the arch of the foot. Preferably, the pressure map is
processed to determine the portion thereof relating to the arch of the
person's foot,
and the ratio of the area of the arch portion to the foot area is determined.
This ratio
is referred to herein as the "arch index" and the inventors have found that
this index
is particularly useful for characterizing the arch of a person's foot to
enable a suitable
footcare product to be selected to match the foot.
To address problem (4) above, the present inventors have realized that
dynamic measurements when a person is walking can be replaced with static
measurements taken when the person is standing in a position which simulates
movement (such measurements being referred to herein as "quasi-dynamic"
measurements). In particular, the present inventors have realised that foot
measurements taken while a person stands on only one foot can be used to
replace
measurements taken while the person is walking. Furthermore, the present
inventors
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5 have realized that the accuracy and reliability of measurements taken
while a person
is standing on one foot can be increased by using pressure sensors to make the
measurements.
According to the present invention, there is provided an apparatus and
method in which signals from a plurality of sensors associated with a surface
are
processed to determine if a person is standing on the surface on one foot
only. In
this way, incorrect measurements taken when the person is standing on two feet
can
be avoided. Preferably, the determination of whether the person is standing on
only
one foot is based upon the weight applied to pressure sensors in an area of
the
surface (the area corresponding to one foot) and/or whether a centre of force
for the
person on the surface (such as the point through which the person's centre of
gravity
acts on the surface) falls within a predetermined area on the surface.
The present inventors have also realised that a person's foot can be better
characterized if two sets of foot measurements are used, namely one set of
measurements taken while the user stands on two feet and one set of
measurements taken while the user stand on only one foot.
The present invention provides an apparatus and method in which one or
more sensors associated with a surface are used to generate a set of
measurement
signals while a person stands on two feet on the surface and a set of
measurement
signals while the person stands on the surface on only one foot. The sets of
signals
are processed to determine a property of the person's foot, thereby improving
accuracy.
With reference to problem (5) above, the present inventors have devised a
technique for accurately and reliably characterizing a person's foot to allow
a
footcare product to be matched to the foot which requires only a small number
of foot
measurements, requires only a small amount of data storage and which can be
performed quickly.
According to the present invention, there is provided an apparatus and
method in which a foot is characterized and a footcare product is selected
based
upon foot length, a measure of the foot arch (such as arch index) and body
weight.
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Other features may be used as well, but these add to the complexity of the
measurements and product selection, and the inventors have found that just the
three
features provide extremely accurate and reliable foot characterization and
product
selection. Data is pre-stored defining a plurality of foot length ranges and a
plurality of
ranges for the measure of foot arch. For each foot length range, a respective
plurality
of weight ranges is also stored so that the weight ranges are different for
each foot
length range. Measurements of a person's foot length and foot arch are taken.
The
person's weight may be measured or input by the person. The foot length, arch
measure and weight are compared against the pre-stored values and a pre-
manufactured footcare product is selected in dependence upon the comparison
results.
The present invention also provides a computer program product, such as a
signal carrying a computer program or a storage medium storing a computer
program,
for implementing the methods.
According to a broad aspect of the present invention, there is provided an
apparatus, comprising: a surface, wherein the surface is configured to allow a
person to
stand upon the surface; a plurality of pressure sensors located under the
surface; a
processor in communication with the plurality of pressure sensors, the
processor
configured to receive a plurality of pressure measurements from at least a
subset of
the plurality of pressure sensors while the person stands upon the surface,
the
processor configured to take quasi-dynamic pressure measurements and determine
an
arch index while the person stands on one foot, the processor further
configured to
select a recommended product for a foot from among a set of pre-manufactured
candidate products for feet based at least in part upon the plurality of
pressure
measurements; and an output device to display information received from the
processor, the information identifying the recommended product to the person.
According to a further broad aspect of the present invention, there is
provided
an apparatus, comprising: surface, wherein the surface is configured to allow
a person
to stand upon the surface; a plurality of pressure sensors located under the
surface; a
processor in communication with the plurality of pressure sensors, the
processor
configured to receive a plurality of pressure measurements from at least a
subset of
the plurality of pressure sensors while the person stands upon the surface,
the
processor further configured to select a recommended product for a foot from
among a
set of pre-manufactured candidate products for feet based at least in part
upon the
plurality of pressure measurements; and an
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7
output device to display information received from the processor and to
recommend
selection of a candidate product from a merchandise display area, wherein the
information identifies the recommended product to the person.
According to a still further broad aspect of the present invention, there is
provided a method, comprising: standing by a person on a surface, a plurality
of
pressure sensors being located under the surface; receiving, by a processor in
communication with the plurality of pressure sensors, a plurality of pressure
measurements from at least a subset of the plurality of pressure sensors while
the
person stands on the surface, the processor configured to take quasi-dynamic
pressure
measurements and determine an arch index while the person stands on one foot;
selecting by the processor a recommended product for a foot from among a set
of pre-
manufactured candidate products for feet based at least in part upon the
plurality of
pressure measurements; and displaying information received from the processor,
the
information identifying the recommended product to the person.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a functional block diagram of an example kiosk, according
to
an example embodiment of the present invention.
FIG. 2 illustrates several example foot dimensions.
FIG. 3a illustrates an example of the locations of alignment marks that may be
displayed on a pressure mat.
FIG. 3b illustrates measurements that may be derived from pressure
measurements on a pressure mat.
FIG. 4 illustrates a flowchart of an example procedure for characterizing a
person's feet based on pressure measurements and selecting a recommended
footcare
product, according to an example embodiment of the present invention.
FIG. 5 illustrates an example pressure map showing foot dimensions that may
be used to determine if a foot on a sensor is unshod, according to an example
embodiment of the present invention.
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FIG. 6 illustrates an example procedure using foot dimensions from FIG. 5 to
determine whether an unshod foot is on a pressure mat, according to an example
embodiment of the present invention.
FIG. 7 illustrates an example procedure to take pressure measurements to
calculate biomechanical data estimates, such as those in FIG. 2, according to
an
example embodiment of the present invention.
FIG. 8a illustrates an example decision matrix, according to an example
embodiment of the present invention.
FIG. 8b illustrates an example procedure for selecting a footcare product from
a decision matrix, such as in FIG. 8a, based on pressure measurements,
according
to an example embodiment of the present invention.
HG. 9a illustrates an example kiosk selecting pre-manufactured orthotics,
according to an example embodiment of the present invention.
FIG. 9b illustrates an example internal structure of a pressure pad, according
to an example embodiment of the present invention.
FIG. 9c illustrates an example layer-by-layer internal structure of a pressure
pad, according to an example embodiment of the present invention.
FIG. 10a illustrates an example screen that may display footcare products,
according to an example embodiment of the present invention.
FIG. 10b illustrates an example screen that may display a footcare product
and its various components, according to an example embodiment of the present
invention.
FIG. 11 illustrates any number of example screens that display information,
instructions, or that provide a language option, according to an example
embodiment
of the present invention.
FIG. 12 illustrates an example instruction screen directing a person to take
off
his or her shoes, according to an example embodiment of the present invention.
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FIG. 13a illustrates an example screen that may be displayed to a person. to
help achieve proper foot alignment and weight distribution, according to an
example
embodiment of the present invention.
FIG. 13b illustrates an alternative example screen that may be displayed to a
person to help achieve proper foot alignment and weight distribution,
according to an
example embodiment of the present invention.
FIG. 14 illustrates an example screen that may be displayed to a person when
the person has his or her weight balanced on both feet, according to an
example
embodiment of the present invention.
FIG. 15 illustrates an example screen containing instructions that may be
displayed to a person regarding taking quasi-dynamic foot measurements,
according
to an example embodiment of the present invention.
FIG. 16a illustrates an example screen that may be displayed after
measurements of a single planting foot are taken, according to an example
embodiment of the present invention.
FIG. 16b illustrates an alternative example screen that may be displayed after
measurements of a single planting foot are taken, according to an example
embodiment of the present invention.
FIG. 17a illustrates an example screen containing instructions that may be
displayed to a person regarding taking pressure measurements of the person
while
the person stands on the right foot, according to an example embodiment of the
present invention.
FIG. 17b illustrates an alternative example screen containing instructions
that
may be displayed to a person regarding taking pressure measurements of the
person while the person stands on the right foot, according to an example
embodiment of the present invention.
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5 FIG.
18 illustrates an example screen that may be displayed after
measurements of a single planting foot are taken, according to an example
embodiment of the present invention.
FIG. 19 illustrates an example screen that may display a selected
recommended footcare product, in this example, an orthotic.
10 FIG.
20 illustrates an example screen displaying other information that may be
displayed to a person, according to an example embodiment of the present
invention.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
FIG. 1 illustrates a functional block diagram of an example kiosk, according
to
an example embodiment of the present invention. The example kiosk 100 may be
used to take a person's foot measurements, and based on the measurements,
select
a recommended footcare product. The kiosk 100 may include a foot measurement
subsystem 114, e.g., a plurality of pressure sensors 101. The pressure sensors
101
may be provided by using a pad having an array of pressure sensors made from
pressure sensitive conductive inks, e.g., sensors from Tekscan, Inc. (307 West
First
Street., South Boston, MA. 02127-1309, USA), and/or sensors described in U.S.
Patents 5,989,700 and 6,964,205. Other measurement technologies may also be
employed, e.g., force plates, piezoelectric sensors, digital air pressure
sensors,
optical measurements, gauges, thermal sensors, etc.
The pressure sensors 101 may be arranged to obtain pressure
measurements at different points of a person's foot. For example, the pressure
sensors may be arranged as a 2-D grid or a 3-D grid of multiple sensor layers.
SenseIs of up to 7.5 mm by 7.5 mm arranged in an array provide adequate detail
to
characterize feet up to men's size 15. The sensing element may provide the
measurements needed to provide an accurate pressure map of the foot. For
example, in one example embodiment, given the square footage of the pressure
pad, a minimum of 1144 number of pressure sensors per foot area with a size of
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11
6.86 mm x 6.65 mm provides an accurate pressure map of a foot. Thus, for two
feet
there would be 2288 pressure sensors. However, with a varying range of sensor
sizes, the number of sensors that may be needed to accurately capture a
pressure
map of the foot may vary. The foot area, and correspondingly the number
sensors,
may also vary depending on the target population. For example, an example
embodiment of the kiosk may contain pressure pads underlying the feet that are
capable of measuring children to adults, and the pads underlying would be
large
enough to capture the foot area of an adult.
The pressure measurements taken from the plurality of pressure sensors 101
may, but need not, be the only measurements of the foot collected to select a
recommended footcare product. For example, in alternative embodiments, a scale
113 may also be employed in the foot measurement subsystem 101 to provide
greater accuracy in estimating a person's weight. It will be appreciated that
measurement approaches that produce a relative pressure distribution, without
producing absolute pressure values, may also be employed in place of absolute
numerical pressure measurements.
The example kiosk 100 may also contain an output device 102, such as a
video screen or LCD screen, and an input device 103, such as a keyboard,
mouse,
etc. An alternative embodiment may contain a touch-screen as a combination of
the
input device 103 and the output device 102. The output device 102 may display
informatibn received from a processor 104. Such information may include a
recommended footcare product in the form of a picture or a model number,
instructions on how to use the kiosk, biomechanical data estimates, data
containing
kiosk transaction information, etc. The output device 102 may display foot
pressure
in real-time as soon as a user steps onto the pressure sensors. If the output
device
is a digital display, the pressure may be displayed in pixel format or
contoured
format, i.e. a real-time smoothed version of the pixilated format for
aesthetic display
purposes. The display may also show in real-time a pressure map and changes in
the pressure map of a person's feet while the person stands on the pressure
sensors.
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The output device 102 may also display a final peak pressure map to a
person. The peak pressure map is the combination of the peak at each specific
point. A dynamic pressure display may use a fixed color legend while a peak
pressure generated after data collection may use a floating (variable) legend
based
on the range of peak pressure. The various pressure maps, such as the peak
pressure map, may be used by other embodiments of a kiosk to detect hot spots
and
recommend therapeutic products or pads. For example, hot spots may be used to
detect where the peak pressure is applied in various areas of the foot. Pads
or other
cushioning foot products may then be recommended to apply to those areas.
While a person, such as a customer 109, may use the input device 103 to
perform a procedure 108 to select a recommended footcare product based on the
pressure measurements of a person's foot, another person, such as an
administrator
110, may use the input device 103 to configure 111 the processor 104.
Configuring
111 may involve adjusting the parameters used to select a recommended footcare
product, calibrating the pressure sensors, providing new product listings,
etc.
An administrator 110 may calibrate the processor 104 to ensure the accuracy
of the pressure measurements taken from the pressure sensors 101. Two methods
may be employed by an administrator 110: a Force Calibration (FC) or a Multi-
Level
Pressure Calibration (MPC). Using a Force Calibration method, an administrator
110 measures a testers body weight on a calibrated weight scale and
subsequently
measures the tester's body standing on the pressure mat 114. The body weight
of
the tester is entered into the processor and the tester would stand still on
the
pressure mat for a fixed duration before starting the calibration process. The
fixed
duration may range from as low as 1 second to 15 seconds. A system that could
collect data or frames at higher rates could decrease the time needed.
Using a Multi-level Pressure Calibration method, an automatic sensitivity
adjustment may be executed. In the calibration window, a "sensitivity setting"
button
may be added. A tester may insert the pressure mat in the calibration mat in
the
calibration device and load the pressure mat at a fixed known pressure, such
as 15
pounds per square inch (psi). The process may involve adjusting sensitivity
based
on raw digital readings. To conduct the multi-level pressure calibration, the
entire
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13
pressure platform may be placed in a pressure calibration device. The pressure
mat
may then be loaded at various pressure levels, such as 5 psi, 10 psi, 15 psi,
20 psi,
30 psi, etc. A load-output curve is generated for each sensel on the pressure
mat,
the sensel being an independent sensing cell. Moreover, in order to ensure
proper
calibration, the processor may perform a test calibration of the pressure
sensors in
order to offset long-term drifting.
The example kiosk 100 may also contain a storage device 105, e.g., RAM, a
hard drive, flash drive, etc. that may transfer 120 information to be stored
or sent,
such as the instructions or software upgrades 115 needed to operate the kiosk,
a
mapping or decision matrix 116 of footcare products to classified subgroups,
an
inventory list 117, demographic information 118 of people that use the kiosk,
parameters 122 of the kiosk that are pre-configured and which may be set by an
administrator, records of kiosk transactions 119, demographic information 118
relating types of footcare products selected for foot types, etc. The
inventory list 117
may store information of the types of products and also current availability
in stock of
those products. This information may also be transferred across a
communication
medium 107, e.g. a modem, DSL, cable, Ethernet, etc., to network servers 106
which may transfer 121 the stored kiosk information from a plurality of kiosks
100.
The network servers 106 or databases may store the corresponding
information from a plurality of kiosks 100, including instructions or software
upgrades
123, mappings or decision matrices 124, inventory 125 or product lists,
demographic
information 126, transactional information 127, and parameters 128. It may
appreciated that the operation of the networked kiosks may alternatively be
controlled through instructions or software upgrades 123 located only on the
network
servers 106. Alternatively, networked kiosks may share instructions and
operational
control with the server 106. An administrator 110, may collect and analyze 112
data
from the network servers 106 to adjust parameters used to select a recommended
footcare product or to adjust shipment of certain models of footcare products.
Moreover, the inventory 125 may be analyzed, as will be explained later, to
track the
sales statistics of inventory or to register whether certain kiosks need to be
restocked
or more products need to be manufactured.
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A processor 104 in the example kiosk 100 may be configured to perform a
variety of tasks, such as taking pressure measurements from the pressure
sensors
101. The processor may be able to calculate biomechanical data estimates of a
person's foot based on the pressure measurements. Biomechanical data estimates
may include estimated foot dimensions, estimated foot type, and estimated body
weight. Foot types may indicate whether the person has flat feet, supination,
pronation, etc.
At the end of kiosk use, or before it is used during the day, an administrator
110 may initiate a checkup, or alternatively, the kiosk may initiate a self-
check-up. A
self-check-up may involve a pressure mat condition check-up (sensel misfiring
when
there is no load), handle-sensor, handle-computer check-up, touch screen check-
up,
system memory clean-up, calibrating the pressure mat, calibrating a scale,
accounting for daylight savings time, etc.
Prior to the start of the kiosk, or while the kiosk is not in use, an
administrator
110 may access the processor 104 using the input device 103 or the output
device
102 that can act as an input, such as a touch screen interface. Or, if there
is an error
while the kiosk is in use, the error may prompt administrator 110 action. An
administrator may set parameters for error-checking, such as a weight range
limit,
equation coefficients to calculate biomechanical data estimates or to select a
footcare product. An administrator may also download from a network 107 or
upload
into the storage device 105 new product lists, inventory 117, video clips,
language
templates, etc.
FIG. 2 illustrates several example foot dimensions. The example estimated
foot dimensions may be calculated based on pressure measurements taken by the
example kiosk described previously. A foot dimension may be a longitudinal
line 200
that runs from the lateral center of a heel to the lateral center of a second
toe. Foot
length 201 may be the distance between the most posterior point, i.e. the
point
towards the heel, of the foot 204 and the most anterior point 213, i.e. the
point
farthest toward the toes, on the foot pressure map on the longitudinal line.
Foot
width 202 may be the projection of distance between the most medial point 206
and
most lateral point 207 of the foot pressure map, the projected foot width
shown in the
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5 figure being perpendicular to the longitudinal line 200. An arch index is
an estimate
which may be used to characterize the arch. An arch index may be defined as
the
ratio of the area of the middle third of the toeless footprint to the total
toeless
footprint area, known as the foot body. The division of the three segments is
along a
line L 205 that is drawn between the lateral center point of the second toe
211 at the
10 level of the toe line 203 and the lateral center of the heel 212 on the
level of the most
posterior point of the heel 204. The foot is thus divided into thirds, A 208,
B 209, and
C 210, with each third being of length L divided by 3. The Arch Index is equal
to the
areas of B / (A + B + C), which is equal to the area of B divided by the Foot
Body
Area. It may be appreciated that foot dimensions may be estimated using
alternative
15 methods or based on alternative points of measurement.
FIG. 3a illustrates an example of the locations of alignment marks that are
displayed on a pressure mat. When a person stands on a pressure mat his feet
should be located at the approximate angle of the two feet-shaped outlines
311. An
alignment border 310 marks the furthest posterior boundary capable of
receiving
measurements. Internally the sensor array grid may detect features of the
foot. As
long as some part of the region of measurement can be taken it can be
determined
whether a person being measured is standing outside the measurement grid. The
person would them be instructed in how to move his feet in order to be within
the
measurement area. For example, one way of determining whether a foot is in a
measurement region is to determine whether a part of a foot is on one side of
the
measurement grid, e.g., whether measurements can be taken on the sensor grid
outside the measurement grid. Thus, a measurement grid 312 may be defined
within a larger actual sensor grid 313 array boundary. If sensors detected
measurements within 312 and also within 313 near that same area, then the
system
would recognize that a foot was outside the boundary and direct the person to
adjust
his foot.
FIG. 3b illustrates measurements that may be derived from pressure
measurements on a pressure mat. In this alternative method of determining
alignment, a person may stand within a designated area like in FIG. 3a. A
longitudinal line 307 may be calculated to provide prospective of the location
of a line
connecting the center of the heel 305 and the center of the second toe 306.
The
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16
outline 308 of the foot may be the general measurable boundaries for a person
to
place his or her foot. The outline may be large enough to fit a majority of
people.
For example, in one embodiment, a little more than 6 inches may be provided
for
toes. A grid 309 may be provided in order to provide uniform measurement units
and they may, but need not, be provided to the person standing on the pressure
mat.
Three Alignment Marks, X 301, Y 302, and Z 303 are designated across the
width of the outline 308. Alignment Mark X 301 may be derived by taking the
100%
multiplied by the ratio of the Average First Metatarsal Length over the
Average First
Toe Length. Average lengths may be derived by studying the mean foot lengths
tailored to groups of people based on race, gender, foot type, or an overall
population. Alignment Mark Z 303 may be derived by taking 100% multiplied by
the
ratio of the Average Fifth Metatarsal Length over the Average Fifth Toe Length
minus a predefined number of grids. Alignment Mark Y 302 may be derived by
taking an average length differential between the second and first metatarsal
heads
in the longitudinal direction. A generally hyperbolic fitted curve may be
drawn over
the three points to represent a toe line 304. It may be appreciated that the
average
lengths may have some variation, and thus, the exact location of the Alignment
Marks may deviate slightly.
In one embodiment, Alignment Mark X 301 may be estimated to be 73% of
the pressure mat length (=100% * 19.29/26.32 ¨38 grids; 19.29 = average
Canadian
first metatarsal length; 26.32 = average Canadian first toe length). Alignment
Mark Z
303 may be estimated to be 64% of the pressure mat length (= 100% *
16.9/21.69;
16.9 = average Canadian fifth metatarsal length; 21.69 = average Canadian
fifth toe
length). Each grid may be equal to 6.73 mm. One average length differential
between the second and first metatarsal heads in the longitudinal direction is
3.4 mm
while another average is 3.2 mm. Taking the average of the two averages would
derive an average of 3.35 mm. Assuming an average foot length of 26.32 cm, the
location of the second metatarsal head location may be moved up by 4.45 mm (=
3.35 * 35/26.32). If each grid is equal to 6.73 mm, the location of Alignment
Mark Y
302 may be moved approximately 2/3 of the distance of a single grid. The
location
of center of the heel 305 and the center of the second toe 306 may be derived
from
CA 02811132 2013-03-28
17
averages, but in this example embodiment, it is defined to be between the
ninth and
tenth grid in the lateral direction.
FIG. 4 illustrates a flowchart of an example procedure for characterizing a
person's feet based on pressure measurements and selecting a recommended
footcare product, according to an example embodiment of the present invention.
The example procedure may be implemented by a kiosk, such as the example kiosk
described in FIG. 1. In 400, the example procedure may be initiated by an
administrator. In 401, an output device may display an attract screen, e.g.,
pictures
of products that may be sold in a merchandise display area of an example
kiosk, and
awaits a person's input 402. While there is no input, the attract screen may
continue
to display footcare products 401 or other images to attract a person. In an
alternative embodiment, a dispensing mechanism may replace a merchandise
display area, and the dispensing mechanism may automatically, or at the
request of
the person, begin the procedure to dispense the recommended footcare product.
Intermittent audio and video clips may accompany the display of the footcare
products.
When a person responds to the attract screen, e.g. by touching a touch
screen or pressing a start button, the procedure may indicate that various
language
options 403 may be available, e.g., English or Spanish. The person may
indicate a
language preference and an error-check may be performed 404. While pressure
measurements are taken, while a person's feet is grouped into a classified
subgroup,
or while a recommended footcare product is being selected, various screens may
be
displayed. At each of these screens, errors may occur or the user may
voluntarily
abort the procedure. These errors or aborts and the corresponding screen that
it
occurred may be tracked, e.g. by storing in the kiosk storage device or
sending over
a network to be tracked at a server 106. If an error or abort occurs, the
procedure
may restart 405 and return to its waiting mode by displaying footcare products
401.
If an error did not occur in 403, at 406, the procedure may re-display the
instructions or display more detailed instructions. The person may place his
feet on
the pressure mat, if the person had not done so already. In 407, the display
may
provide a person with feedback, e.g., showing a real-time display of a
pressure map
CA 02811132 2013-03-28
18
of the person's feet. In 408, a person may be instructed to align the person's
feet,
for example using with alignment marks such as those in FIG. 3b. Alignment
marks
may be displayed that match the exact pressure map locations. Alignment marks
may include toelines and longitudinal lines for the left and right foot and
may be
illustrated by different zones of color. The center of the heel and the center
of the
second toe may automatically be detected. If it is not, a longitudinal line
may be
displayed and a person may be asked to adjust the foot until the feet are
aligned with
the longitudinal line. Alternatively, as in Fig. 3a, the user may be prompted
to move
his feet within the boundaries as detected by pressure sensors. The kiosk may
determine if the feet are out of bounds of the pressure mat, whether the
person's
body weight is out of a pre-determined range, or whether a person's feet are
unshod.
In 409, whether a person has unshod feet while standing on the pressure mat
may
be verified.
In 410, multiple error checks may be performed.
Based on prior
determinations, errors are flagged if the issues may not be resolved. These
errors
may include: (1) if it cannot be recognized that a person is standing on the
pressure
with unshod feet (even if the person is); (2) if the person is standing out of
the
bounds of the pressure mat; (3) if the person has their feet misaligned; or
(4) if the
person's weight is not placed evenly on the pressure mat. Moreover, other
error
checks may be determined. For example, a minimum and maximum limit for a
person's weight may be determined. It may be required that a person weigh
between 70 and 400 pounds. It may be appreciated that a weight range may vary
and also be represented in other metrics. As a result of the errors, the
procedure
may attempt to re-display the instructions 406 in order to help the person
resolve any
issues. The procedure may reach a threshold where the issues may not be easily
resolved and thus restart the entire procedure 405.
If there are no errors, the procedure continues to 411. In 411, measurements
of the feet may be obtained, e.g. pressure measurements from an array of
pressure
sensors. Throughout the measuring process, the person being measured may abort
the procedure, e.g., by stepping off the pressure mat. The procedure may be
also
be aborted if there are problems in the measurement process, such as by the
user
shifting his weight unevenly. In 412, any measuring errors or aborts may be
CA 02811132 2013-03-28
19
detected. If the issue cannot be resolved, the procedure may be re-started
405. In
413, based on the pressure measurements and biomechanical data estimates, a
person may be grouped into a classified subgroup. In 414, a recommended
footcare
product is selected for the person based on a decision matrix or a mapping.
For
example, a product may be selected for a person based on physical
characteristics
such as arch index, weight, or foot length.
In one embodiment, the footcare product may be a pre-manufactured orthotic.
In alternative embodiments, the processor or pressure sensors may be
configured to
collect pressure measurements to select another footcare product, e.g. a heel
cup, a
pressure pad, etc. The same pressure measurements may be implemented in the
selection and recommendation procedures for different types of footcare
products.
However, alternative points may be taken from a pressure mat to recommend
different types of footcare products. For example, while the same pressure
measurements may be used to recommend an orthotic and a heel cup, alternative
points of measurements concentrated in the heel may be more accurate to
determine a heel cup fit. Both methods may be used and the processor and
pressure sensors need only be configured to accommodate both footcare
products.
Alternatively, in 414, multiple footcare products may be selected for a person
to choose from. The person may also be prompted to answer questions providing
additional information, for example, in order to provide the procedure with
accuracy
factors that can adjust parameters to search for a more accurate match. Such
accuracy factors may use preferences, types of activities that the person
frequently
engages in, the type of shoes that the footcare product may be used with,
gender of
the person, etc. in order to further narrow the list of selected orthotics.
Alternative
questions may be asked earlier in the procedure, such as before the pressure
measurements are taken. Alternative factors may change the recommended
footcare product from one type of footcare product to another, e.g. an
orthotic versus
a heel cup.
In 415, several types of information may be displayed, e.g. to the person
using the kiosk described above. lndicia identifying the model of the
recommended
footcare product may be displayed. These indicia may help the person locate a
CA 02811132 2013-03-28
5 corresponding footcare product that is located in a merchandise display
area.
Moreover, along with the real-time pressure measurements that a person may
already view, a peak pressure map may be displayed to show the pressure
measurements taken by the kiosk. Information regarding any of the
biomechanical
data estimates, such as estimated weight, foot type, or others may also be
10 displayed. Examples of biomechanical data estimates that may be
displayed include
foot length, foot width, body weight, arch index, outline of the foot and
toeline, a
longitudinal line (drawn on the peak pressure map), or the intersection of the
longitudinal line and foot body, Le. the area of the foot excluding the toes.
In 416, after the person has completed the measurements and received
15 information about the recommended footcare product, the person can choose
to
restart the process or the person can step off the measuring device, which
would
automatically restart the procedure to display foot care products, in 401,
while
waiting for a new person to initiate the procedure.
If a person were to use the procedure with the example kiosk of FIG. 1, values
20 may be stored or sent over a network regarding kiosk transactions that were
performed. Examples of kiosk transaction information that may be stored are
the
number of times the kiosk has been used, the number of times the system was
used
to completion of selecting a footcare product to a person, if a person aborted
use of
the kiosk and at which screen the person was viewing at the time of aborting,
a count
of which products have been recommended, and a total count of persons that
used
the kiosk and the time of day that the kiosk was used as well as the length of
time
spent using the kiosk per person. If the kiosk is not activated for a
significant period
or if the kiosk is scheduled to operate during only certain times of the day,
the last
person may be measured and the kiosk may automatically shutdown or go to sleep
in 417.
Measurements of a person's foot vary significantly if the foot is not unshod.
Accordingly procedures may be provided to automatically detect whether a
footwear
is worn by a person whose foot is being measured. FIG. 5 illustrates an
example
pressure map showing foot dimensions that may be used to determine if a foot
on a
sensor is unshod, according to an example embodiment of the present invention.
CA 02811132 2013-03-28
21
The pressure map may be generated after collecting a static pressure for a
prescribed period of time, for example, 2 seconds. On the pressure map, a
longitudinal line 500 connects the lateral center of the heel 502 and the
lateral center
of the second toe 501. The center of the heel and the center of the second toe
(and
any other point of interest) may be determined by comparing the measured foot
profile with general foot templates. Generalized foot templates may be created
by
taking samples of actual feet measurements or averaging many foot types. Based
on the pressure map, a geometric center of the feet may be determined. The
general foot templates may expand or shrink depending on the size or length of
the
foot and the general foot template may be compared to that of the pressure map
outline using the geometric center as a reference point. A matching method,
such as
best fit, may then be used to determine the most comparable general foot
template.
Using the most comparable general foot template, all other points of the foot
may be
estimated, including the center of the heel and center of the second toe.
For the purpose of clarity and explanation, in FIG. 5, the most anterior point
and the most posterior point along the longitudinal line are projected out as
the most
posterior point line 503 and the most anterior point line 504, which are
perpendicular
to the longitudinal line. The projection of the line between the most
posterior point
and most anterior point is the Foot Length (FL) line 505, which is equal to
the
distance between the most posterior point and the most anterior point. Three
points
are identified along the longitudinal line measured in relation to the foot
length.
These are point A 506, measured at 16% of the FL line 505 from the posterior
end,
point B 507, measured at 50% of the FL line 505 from the posterior end, and
point C
508, measured at 75% of the FL line from the posterior end. It may be
appreciated
that these points may vary, and these points may derived from trial runs on
the feet
of approximately 30 test subjects.
Line A 509, is perpendicular to the longitudinal line and is drawn through
point
A 506. Line A 509 intersects with the boundaries of the pressure map, and the
length of Line A 509 may be truncated within the outline of the pressure map.
The
outline of the pressure map indicates the outermost pressure points that are
reflected in a real-time pressure measurement. The length of Line A 509
represents
the Heel Width (HW). Line B 510, is perpendicular to the longitudinal line and
is
CA 02811132 2013-03-28
22
drawn through point B 507. Line B 510 intersects with the boundaries of the
pressure map in the midfoot area and the length is truncated within the
outline of the
pressure map. The length of Line B 510 represents an estimate of the Arch
Width
(AW). Line C 511, is perpendicular to the longitudinal line and is drawn
through point
C 508. The widest points between Line B 510 and Line C 511 are projected out
as
lines, parallel to the foot, on the medial side 512 and the lateral side 513.
The
longest width of the pressure map between Line B 510 and Line C 511, i.e. the
distance between lines 512 and 513, represents an estimate of the Forefoot
Width
(FVV).
FIG. 6 illustrates an example procedure using foot dimensions from FIG. 5 to
determine whether an unshod foot is on a pressure mat, according to an example
embodiment of the present invention. In 600, a pressure map may be generated
at
the start of the unshod foot detection. As explained previously, the pressure
map
may be generated from collecting a static pressure for a prescribed period of
time.
In 601, the longitudinal line 500 is identified. In 602, key points are
identified, in
particular point A 506, point B 507, and point C 508. In 603, the estimated
Heel
Width may be determined, as explained in FIG. 5 relating to deriving Line A
509. In
604, the estimated Arch Width may be determined, as explained in FIG. 5
relating to
deriving Line B 510. In 605, if there is no intersection with the pressure
map, then in
607, the Arch Width is assigned a pre-determined number, e.g. some constant
that is
not zero to avoid the situation where a number could be divided by zero. If
the Arch
Width does have a value, then in 606, the Arch Width is assigned that value.
In 608,
the Forefoot Width may be determined, as explained in FIG. 5 relating to
deriving
Line C 511. In 609, the values previously recorded are compared with pre-
determined values. The pre-determined values can be derived by recording and
comparing values of actual test subjects wearing shoes and comparing them to
measurements while standing unshod. For both feet, an example condition is:
(FL/HW > FL low) & (FL/HW < FL high) & (FW/HW > &
(AW/HW > AW_
In this example, FL low = 3.5; FL high = 6.0; FW_Jimit = 1.2; AW_Iimit = 0.1.
CA 02811132 2013-03-28
23
In 610, after the condition is determined, if the condition is "true" then, in
611,
the person is recognized as being unshod. If the condition is false, then in
612, the
user is recognized as wearing Shoes. It may be appreciated that values can be
added to the condition range to have the option to determine if a person is
wearing
socks. The procedure to determine if an unshod foot is on a pressure sensor
ends in
613.
The target ratios and constant values may be derived by comparing the ratios
to actual test subjects and calculating whether the ratios and constants
match, on
average, the ratios for those test subjects. However, it the ratios may also
be altered
by adjusting the point of Line A 509, Line B 510, or Line C 511 on varying
degrees
along the foot length line. The locations of these varying lines are derived
from
testing multiple subjects and calculating ranges with the least errors.
Alternative
measurements may allow the lines to vary or in fact to add further lines. For
example, a Line D may be added between Line A 509 and Line B. Ratios of Line D
compared to the other widths and lengths may also create a new constant with
which
to compare the ratio. This new constant may be a floor or minimum or a ceiling
or
maximum constant when compared to the ratio of Line D to a measurement of the
length, width, arch width, some other newly derived line, etc.
FIG. 7 illustrates an example procedure to take pressure measurements to
calculate biomechanical data estimates, such as those in FIG. 2, according to
an
example embodiment of the present invention. In 700, the procedure may begin
after a person's feet are on pressure measurement sensors. At the start,
various
other checks may also be performed to interact with a person that is being
measured. For example, an output may display a real-time pressure map as soon
as a person steps on a pressure mat; a person may be prompted to remove their
shoes and step on the pressure mat at designated areas on the pressure mat
with
their weight balanced between the left and right, front and back; the person
may be
prompted to indicate whether or not the person is ready for measurement, such
as
by clicking on a "Start" button. Several error checks may have been performed
at
the pressure measurement collection time, such as to determine whether an
unshod
foot is actually on the sensor as in FIG. 6, or whether there are other errors
with foot
alignment, weight, etc. as in 408 or 410 in FIG. 4.
CA 02811132 2013-03-28
24
In 701, a target zone may be defined. The target zone may be the geometric
center of the pressure print of both feet, but may also be another geometric
pressure
point of reference. In determining the target zone, the target zone may be
shifted
10% distally to force the user to lean forward slight, and consequentially,
allow the
person's toes to have direct contact with the pressure mat. In 702, a person
may be
prompted to match the person's center of force (COF) into the target zone. The
center of force may be determined by calculating the moment of torque for each
sensor point and taking the centroid weighted by the force at each point to
create an
overall representation of the force of both magnitude and location of the
various
forces. The center of force may be used to indicate the body's center of
gravity.
In 703, if the length of the foot pressure map changes by more than 15 mm,
approximately a 2 sensel element difference, 701 is repeated and the target
zone
may be re-calculated and displayed to the person on an output device. The
length of
pressure map change that would trigger a re-calculation of defining a target
zone
may depend on the use of the measurement. A 15 mm threshold is approximately 2
shoe sizes and may justify a re-calculation. The person may be prompted to
continue to match the person's COF into the new target zone.. If in 703, there
is no
significant increase of foot pressure length, the initial target zone may not
be re-
calculated. In 704, the final target zone may be located at a fixed location
unless the
person moves or lifts his feet. In alternative embodiments, the target zone
may also
be determined dynamically, wherein the COF matches a dynamic target zone,
which
may be defined as the center of area.
In 705, a static pressure measurement may be initiated. Frames may be
collected at different rates. Pressure data may be collected at a rate of 10
frames
per second. While frames are taken, the target zone may be displayed on an
output
device. In 706, frames of pressure data may be collected. Depending on the
desired accuracy of pressure measurements, a minimum number of frames may be
needed, such as 20 frames of pressure data. Twenty frames of pressure data at
10
frames per second may require a person to hold a target zone for 2 seconds.
Among the frames collected, some of the frames may have be poor. Some
frames may be eliminated for use through a qualifying process. The qualifying
CA 02811132 2013-03-28
5 process may use any number of different methods. For example, the method
described in FIG. 6 for determining whether a foot is unshod may also be used
to
determine whether a frame is a qualifying frame. If a foot is determined to be
unshod, the frame would be qualified. If the frame would not be qualified as
unshod,
it is likely that the collected frame was poor or that there was an error and
would thus
10 be eliminated. Another example method may be to determine whether the
balance
of weight between the front and back and the sides are properly distributed
based on
the COF.
In 707, based on the pressure measurements taken, a static foot outline
(SFO) may be derived from the pressure measurements. In 708, after static
15 pressure measurements have been taken, the person may be informed that the
static pressure measurement has been completed.
In 709, the quasi-dynamic pressure measurement process may commence.
Generally, dynamic measurements are taken during ambulation in order to
determine pressure on various parts of the person based on his or her gait.
20 However, a quasi-dynamic process estimates the types of pressures
created without
a need for ambulation. Rather, a quasi-dynamic process may allow for pressure
measurements to be taken while a person is standing on one foot in order to
simulate pressure that may be generated during ambulation.
In 710, the person may be prompted to hold a balance, such as by holding a
25 balance bar or to keep their balance on their own, and then to gently
and slowly lift
one foot while balancing and standing on a first planting foot. In 711, a
target zone
may be defined for the first planting foot based in part on the static foot
outline
previously determined in 707. The location of the target zone may be slightly
modified according to the one-foot pressure map. The user may be prompted to
match the target zone for the first planting foot.
In 712, the biomechanical status of the person may be monitored and different
triggers for pressure frame collection may be implemented. For example, one
trigger
to start collecting pressure frames may be when the COF enters the target zone
and
is stable for a short pre-defined period, such as one second. Again varying
number
CA 02811132 2013-03-28
26
of frames may be collected; for example, 20 frames at 10 frames per second may
be
collected. An alternative trigger may be to collect frames when the load on
the
planting foot reaches 90% bodyweight. It may be appreciated that variations
and
combinations of biomechanical status may trigger the collection of frames. For
example, frame collection may be triggered when a person's COF matches the
target zone and at least 95% of static weight is achieved. In 713, once the
measurement collection is completed, a person may be instructed place replace
the
raised foot back onto the pressure mat.
In 714, if both feet have been measured individually, parameters may be
calculated in 715. If not, 710 to 713 may be repeated to collect frames for
the
second planting foot. The order of the frame collection of the individually
feet may
be altered. During the second round of 710, when measuring the second planting
foot, the SFO may need to be rotated to match the pressure print of the second
planting foot. In 711, a new target zone may also be defined based on the SFO.
The location may also be slightly modified according to the one-foot pressure
map.
In 715, based on the static or quasi-dynamic pressure measurements from
the collected frames, biomechanical data estimates of the foot may be
calculated.
Only the qualifying frames are used to calculate biomechanical data estimates.
Determining qualifying frames may involve methods previously mentioned, such
as
using the method of determining whether a foot is unshod. The qualifying
process is
generally performed before the biomechanical data estimate calculations are
performed because otherwise the processing would be wasted if a frame were
discarded in the qualifying process. Nevertheless, the order of qualifying and
calculating biomechanical data estimates may be altered. For example,
qualifying
may be done for all frames and then calculations of biomechanical data
estimates
may be done for remaining frames, or vice versa. Alternatively, the
combination of
the qualifying process and calculation of biomechanical data estimate may be
done
for each frame at a time.
Using FIG. 2 as a reference for the calculation of biomechanical data
estimates, a foot length 201 may be determined by searching along the
longitudinal
axis and determining the lowest and highest points. The distance between the
most
CA 02811132 2013-03-28
27
posterior point of the heel 204 and the most anterior point 213 may be
calculated as
the foot length 201. A general foot profile may be used to match the pressure
map,
similar to the methods described in FIG. 5. A lateral center point of the
second toe
211 and a lateral center of the heel 212 may be derived from the foot template
and a
longitudinal line may be derived which is a line between the two points. The
longitudinal line becomes the axis of the searching direction. Using the
pressure
maps, the toe line 203 may be determined by searching for the peaks and
valleys of
pressure. For example, the big toe is known to have a large peak in pressure
and
valleys in pressure exist between the toes. The distance between the toe line
203
and the most posterior point of the heel 204 is the distance of line L 205.
The total
area of the foot within line L of the foot is the foot body, consisting of the
sums of the
areas of sections A 208, B 209, and C 210. Based on the location of pressure,
the
area of A 208, 8 209, and C 210 may be calculated. The Arch Index is equal to
B
divided by the area of the foot body. The arch index of a person's foot may
then be
the average arch index of all the qualified frames for each foot.
The biomechanical data estimates may include foot dimensions, estimated
foot type, and estimated body weight. For example, biomechanical data
estimates
that may be calculated may include peak pressure maps of both static and quasi-
dynamic pressure, an artificial double-footed peak pressure map derived from
the
combined left and right foot quasi-dynamic foot pressure measurements, foot
length,
foot width, body weight, a longitudinal line, an arch index, etc. The
biomechanical
data estimates may be stored in the kiosk storage area or sent over a network
to be
stored. Demographic information, for example, information relating a user id
number
associated with corresponding biomechanical data estimates and a recommended
footcare product, may be stored in a storage device or relayed over a network
for
storage in a central database or server.
FIG. 8a illustrates an example decision matrix, according to an example
embodiment of the present invention. A decision matrix module is used to
correlate
classified subgroups with a footcare product model. The decision may, in part,
be
derived from the various footcare products available, and may thus vary based
on
the product specification list that is stored in the storage area. The
classified
subgroups may be based on biomechanical data estimates or directly on the
CA 02811132 2013-03-28
28
pressure measurements themselves. Another example of selecting a footcare
product is a mapping between a classified subgroup and footcare products.
A set of 14 pre-manufactured orthotics may be provided as described in
concurrently filed application titled, "Cushioned Orthotic", filed U.S.
Application No.
11/524,979 filed September 21, 2006, assigned to Schering-Plough Healthcare
Products, Inc. the assignee of the present application. These orthotics
include 4
lengths/size, 2 different levels of arch support and 2 different levels of
cushioning.
However, only one level of cushioning is provided for the largest size. This
may be
because people of the largest size feet require the maximal cushioning.
The particular matrix in FIG. 8a is divided into bands and indexed by weight
of
the person and arch index. The bands represent the foot length of the person.
For
example, in the example matrix there are four bands: Band A 850 for foot
lengths
below 244 mm, Band B for foot lengths greater than and including 244 and less
than
255 mm, Band C for foot lengths greater than 255 mm and less than 270 mm, and
Band D for foot lengths greater than and equal to 270 mm. Each band contains a
cross-reference between a weight and an arch index.
In the example matrix the weights are divided between low weight and high
weight, although with more product models and weights tested the weight
categories
within a band may increase. The dividing weight between low and high weight is
the
median weight. The determination of the median weight is the median weight
that is
expected for people of a particular foot length. The type of support may
require
more cushioning for people of a certain foot length but heavier than the
median
weight for that foot length. The median weight would thus vary between the
different
bands. As foot length increased, a median weight would also be expected to
increase.
In the example matrix the arch index is divided between low, medium or
normal, and high, although with more product models the arch index may
increase in
categories. The low arch index range 853 may be defined as greater than 0.257.
The medium arch index range 859 may be greater than 0.173 and less than or
equal
to 0.257. The high arch index range 860 may be less than or equal to 0.173. In
CA 02811132 2013-03-28
29
these examples, there is an inverse relationship between the arch index and
the
arch, e.g., the higher the arch index the lower the arch. It is possible for
the foot care
products to be sold individually for the left and the right foot because it is
possible
that the right and the left foot will have differing arch indexes. Presumably,
the foot
length and body weight will not differ. If the footcare product were only sold
in pairs,
then the low or high arch index would dominate over the medium/normal arch
index.
For example, if the right foot was a high arch index and the left foot was a
normal
arch index, the selected model would be for the high arch index. Between the
high
arch index and the low arch index the more conservative product may be
selected,
e.g. the medium arch index may be selected.
Using the foot length, arch index, and weight of a person a product model
may be selected and then recommended to that person. For example, if a person
had a foot length of 220 mm, weighed 120 pounds, and an arch index of 0.261. A
length of 220 mm would mean the person would fall within Band A 850. Band A
850
has a median weight 855 of 135 pounds, thus a person weighing 120 pounds would
be classified in the low weight 851. An arch index of 0.261 would place the
person in
the low arch 854 of Band A. A low arch 854 within Band A 850 of low weight 851
would recommend "Product 1" 856. As another example, suppose a person had a
foot length of 220 mm, weighed 150 pounds, and had an arch index of 0.205. The
foot length as before would fall into Band A 850. Band A 850 has a median
weight
855 of 135 pounds, thus a person of 150 pounds would be classified in the high
weight 852. An arch index of 0.205 would place the person in the medium or
normal
arch 858 of Band A. A medium arch 858 within Band A 850 of high weight 852
would recommend "Product 4" 857.
It may be appreciated that while this decision matrix is displayed in this
example as a spreadsheet, the organization of the products and biomechanical
data
estimates may be organized, searched, and accessed in the kiosk storage using
other methods, such as an array, linked list, database table, etc.
FIG. 8b illustrates an example procedure for selecting a footcare product from
a decision matrix, such as in FIG. 8a, based on pressure measurements,
according
to an example embodiment of the present invention. The procedure may be used
in
CA 02811132 2013-03-28
5 selecting a recommended footcare product 414 as in FIG. 4. In 800, when the
procedure has started, the person's weight, arch index, and foot length will
have
already been determined, from the pressure measurements, the scale, or the
person's input. In 801, the person is classified into a Band. In 802, if the
person's
foot length is less than 244 mm the person is classified into Band A in 806.
If not, in
10 803, if the person's foot length is greater than or equal to 244 mm or
less than 255
mm the person is classified into Band B in 807. If not, in 804, if the
person's foot
length is greater than or equal to 255 mm or less than 270 mm the person is
classified into Band C in 808. If not, in 805, if the person's foot length is
greater than
or equal to 270 mm the person is classified into Band D in 809.
15 After the Band is determined, in 810 the person's arch index may be
cross-
referenced with an arch index range. In 811, if the person's arch index is
greater
than 0.257, the person is classified as having a low arch in 814. If not, in
812, if the
arch index is greater than 0.173 or less than or equal to 0.257, the person is
classified as having a medium arch in 815. If not, in 813, if the arch index
is less
20 than or equal to 0.173, the person is classified as having a high arch
in 816.
After the person is classified into a Band and Arch Index, in 817 the person
is
classified into a weight range. In 818, if the person's weight is less than
the median
weight, the person is into a low weight for the particular band 820. If not,
in 819, and
by default, if the person's weight is greater than or equal to the median
weight, the
25 person is classified into a high weight for the particular band 821. As
in Figure 8a,
the median weight may vary depending on the particular band. The order of the
designation of the arch index range, weight range, and Band may also vary. For
example, depending on how the data is stored or how the software is written,
the
weight range may be determined before arch index range. After a person is
30 classified based on selection criteria, the selection criteria may be
cross-referenced
in 822 to determine the recommended product model. This product model is
returned in 823 to be recommended to the person.
FIG. 9a illustrates an example kiosk selecting pre-manufactured orthotics,
according to an example embodiment of the present invention. A pressure mat
900
which may be removably attached to the kiosk is located on the bottom of the
kiosk.
CA 02811132 2013-03-28
31
On the surface 904 of the pressure mat 900, alignment marks may be displayed
that
match the exact pressure map locations. The foam template mat may overlay the
pressure sensors in order to guide a person using the kiosk in the placement
of the
person's feet, and the entire pressure sensor and foam template mat
combination
may form a pressure mat 900. A set of candidate footcare products, in this
example
orthotics, may be displayed on or near the kiosk in a merchandise display area
901
located on the sides of the kiosk, e.g. stored in clear plastic shelves that
allow
removal. Other forms of removable attachments may be used to display products.
It
may be appreciated that the merchandise display area may be located on the
kiosk
or near the kiosk_ Alternatively, footcare products may be dispensed like that
of a
vending machine. Handlebars 903 which a person may use to balance while
standing on one foot during a pressure measurement procedure may be vertical
bars, but in alternative kiosks, handlebars 903 may be located on the sides.
An
output device 902, such as a touch screen device, may be located at eye-level
or
where a person standing on the pressure mat 900 may easily access and view the
touch screen.
FIG. 9b illustrates an example internal structure of a pressure pad, such as
the pressure pad 900 in FIG. 9a, according to an example embodiment of the
present invention. A sensor grid array for the left foot 906 and right foot
907 is
separated 908 by 10 cm at the lower-right corner of the left foot sensor grid
906 and
the lower-left corner of the right foot sensor grid 907. The angle of
separation 905
between the two sensor grids is 17.5 degrees. The layout of the grid is
developed
for the comfort of the user and is not necessary for measurement. The pressure
pad
also contains a handle 909. The pressure pad itself is sloped upward at an
angle
where the point at 915 is at a vertical height lower than the point at 916.
While the
system in theory could be calibrated to work with any angle of the pressure
pad, or a
flat pressure pad, having angled pressure pad reduced the likelihood of the
device
being overridden by shopping carts in an unattended retail environment. The
reason
for this is because people naturally tend to stand without as much pressure on
their
toes, and the angle forces the person to create a pressure image. The actual
degree
of the slope may vary, but a lean of approximately 10% is recommended. The
importance of the sensors receiving proper contact from the toes is to ensure
a
CA 02811132 2013-03-28
32
proper reading of the foot length. The width 916 of the pressure mat may be 24
inches and the length 917 is 21.5 inches.
FIG. 9c illustrates an example layer-by-layer internal structure of a pressure
pad, such as the pressure pad 900 in FIG. 9a and 9b, according to an example
embodiment of the present invention. The first layer 909 is the top of the
pressure
mat and contains an image of the foot outline and boundaries of the foot
measurement area, as viewable by a person using the pressure mat. This is also
the layer that is in direct contact with the person's feet. The second layer
910 may
be a foam sheet that may provide padding for the feet. A third layer 911 may
be a
Teflon sheet, or other non-conductive material. A fourth layer 912 may be the
sensor mat containing pressure sensors. Extending from the sensor mat may be a
set of leads 915 attached to a handle 914. The bottom layer 913 hard layer
supporting the pressure mat and may be made of acrylonitrile-butadiene-styrene
(abs). The various layers of the pressure mat may be altered, either in order
or in
material, depending on various factors, such as the sensitivity of the
pressure,
comfort level, or height of the pressure mat.
Figs. 10 through 20 illustrate example screens that may be displayed on an
output device while performing the example procedures of Figs. 4, 7, and 813,
according to an example embodiment of the present invention. FIG. 10a
illustrates
an example screen that may display footcare products, according to example 401
in
FIG. 4, while the system is not in use, according to an example embodiment of
the
present invention. An example image 1000 of a footcare product, e.g. a cushion
orthotic, in the set of available footcare products may be displayed.
Alternatively, a
video clip or a rotating image of the product may be displayed. Audio may also
be
provided along with the image or video. Descriptions 1002 of the displayed
footcare
product may also accompany the video or image 1000. An instruction 1001 to
initiate the kiosk may be displayed as well, e.g. a button reading "Touch
Screen to
Begin." FIG. 10b illustrates an example screen that may display a footcare
product
and its various components, according to an example embodiment of the present
invention. For example, a cover layer 1003, cushioning layers 1004 and 1005,
and a
bottom shell layer 1006 of a footcare product, like that shown in FIG. 10a,
may be
displayed on a page with an instruction 1001 to initiate the kiosk.
CA 02811132 2013-03-28
33
FIG. 11 illustrates any number of example screens that display information,
instructions, or that provide a language option, according to examples 403 and
406
in FIG. 4, according to an example embodiment of the present invention. For
=
example, a title 1100, which may contain the name of the system or the name or
trademark of the company employing the kiosk, may be listed on the screen.
Instructions 1102 on how to generally use the kiosk may also be displayed. A
language option may be presented, e.g. the user may choose English language
= 1101 or Spanish language 1103 instructions. Alternatively, a "switch to
Spanish"
option may be displayed where the default may be English language
instructions, or
vice versa. It may be appreciated that other languages may be accommodated by
adding language files to the kiosk.
FIG. 12 illustrates an example instruction screen directing a person to take
off
his or her shoes, according to an example embodiment of the present invention.
The
screen may show a real-time pressure map 1200 of the person's feet.
Instructions
1201 may be displayed on another side of the screen. At the direction of the
instruction screen, a person may take off his shoes and step back onto the
pressure
mat. An error check may be performed using a procedure to determine whether an
unshod foot is on the pressure mat, such as the example procedure of FIG. 7.
Moreover, error checks may be performed, such as those described in 410 of
FIG. 4.
Subsequent error checks may be performed on any subsequent screens as well. If
an error is detected, the person may be prompted to restart the procedure, or
further
instructions or more detailed instructions may be displayed to help the person
rectify
any errors.
FIG. 13a illustrates an example screen that may be displayed to a person to
help achieve proper foot alignment and weight distribution, according to an
example
embodiment of the present invention. Foot alignment may be determined
according
to analysis of foot measurements, e.g. analysis of foot pressure measurements
as
described above in example 408 in FIG. 4. A person may be asked to position
his or
her toes at a line 1300, and a corresponding line may also appear on the
pressure
mat to guide the person to stand in the appropriate position. A target Center
of
Force 1303 and a current Center of Force 1304 oval may be displayed on the
screen. Further instruction may request that the person balance his or her
weight
CA 02811132 2013-03-28
34
evenly on both feet by aligning two displayed ovals 1301 (in alternative
embodiments
circles or other shapes may be displayed). As the person shifts his or her
weight,
the COF is recalculated and the COF oval moves on the screen. While the weight
is
unbalanced, the person may be unable to proceed to the next step because a
"proceed" button 1302 may not be active.
FIG. 13b illustrates an alternative example screen that may be displayed to a
person to help achieve proper foot alignment and weight distribution,
according to an
example embodiment of the present invention. Alignment marks in the anterior
of
the feet may be replicated on the screen as the anterior limit 1308 of the
measurement boundary. A foot pressure gauge 1307 may be displayed to allow the
user to interpret the pressure results. The person may be instructed 1309 to
move a
yellow circle 1306 into a red target circle 1305, similar to the example in
FIG. 13a
where a person may be asked to move a current COF to a target COF.
FIG. 14 illustrates an example screen that may be displayed to a person when
the person has his or her weight balanced on both feet, according to an
example
embodiment of the present invention. An active "proceed" button 1400 may be
highlighted as active after the weight is balanced. This may be indicated if
the
Current COF and Target COF oval become an overlapping balanced COF 1401.
Measurements may be obtained, for example, in a procedure described in 411 of
FIG. 4, or illustrated in more detail in 705 to 708 of FIG. 7.
FIG. 15 illustrates an example screen containing instructions that may be
displayed to a person regarding taking quasi-dynamic foot measurements, e.g.
pressure measurements of the person while the person stands on the left foot,
according to an example embodiment of the present invention. Instructions 1500
may be displayed in one section and various steps may be highlighted as they
are
performed. A first instruction 1502 may request that the person place his or
her
hands on a bar for balance and safety purposes. The person may hold onto bars,
such as those of 903 of the example kiosk illustrated in FIG. 9. The bars may
contains sensors that may register contact in order for a kiosk to determine
when this
step has been performed. A second instruction 1503 may instruct the person to
5
slowly raise the right foot completely off the pressure mat. A third
instruction 1504
CA 02811132 2013-03-28
5 may instruct the person to balance his or her weight on the remaining
left foot, in this
case the first planting foot. These three instructions may be implemented
according
to example 707 to 709 of FIG. 7. Pressure measurements may be taken while the
person is standing on the left foot. While pressure measurements are
collected, a
pressure map of the first planting foot 1501, in this case the left foot, may
be
10 displayed on the screen.
FIG. 16a illustrates an example screen that may be displayed after
measurements of a single planting foot are taken, according to an example
embodiment of the present invention. An instruction 1600 may be highlighted
after
measurements have been taken to indicate that the person's foot may be placed
15 back onto the pressure mat. When the person's foot is detected on the
pressure
mat, the real-time pressure map 1602 may display the foot that was previously
lifted
off the mat, in this example the right foot. This may be done according to
example
710 in FIG. 7. When measurements are completed and the foot is replaced, a
"proceed" button 1601 may be activated to indicate to a person that the
20 measurements of the left foot were taken.
FIG. 16b illustrates an alternative example screen that may be displayed after
measurements of a single planting foot are taken, according to an example
embodiment of the present invention. In the example screen, after the foot is
placed
back on the mat the person may be prompted for a weight input 1603 asking
whether
25 the person weighs less than a pre-defined weight. The pre-defined weight
may be
derived from a median weight of a particular band, for example, of a band as
shown
in FIG. 8a. The screen at which the user is asked to input weight may be
displayed
at any point of the measurement process. For example, the prompt for a weight
input may be shown after both feet have been measured individually, before any
feet
30 have been measured, etc. Alternatively, the prompt may not be displayed
at all if the
pressure measurements are deemed accurate enough to calculate the weight, or
if
an optional scale is used to verify the pressure measurement's weight
calculation.
FIG. 17a illustrates an example screen containing instructions that may be
displayed to a person regarding taking pressure measurements of the person
while
35 the person stands on the right foot, according to an example embodiment of
the
CA 02811132 2013-03-28
36
present invention. Instructions 1700 may be displayed in one section and
various
steps may be highlighted as they are performed. A first instruction 1702 may
request that the person place his or her hands on a bar for balance and safety
purposes. The person may hold onto bars, such as those of 903 of the example
kiosk illustrated in FIG. 9. The bars may contains sensors that may register
contact
in order for a kiosk to determine when this step has been performed. A second
instruction 1703 may instruct the person to slowly raise the right foot
completely off
the pressure mat. A third instruction 1704 may instruct the person to balance
his or
her weight on the remaining right foot, in this case the planting foot, by
aligning the
ovals, for example, a current COF oval 1706 with that of a target COF oval
1705.
These three instructions may be implemented through the repeated 707 to 709 of
FIG. 7. Foot measurements, e.g. pressure measurements, may be taken while the
person is standing on the right foot, in this example the second planting
foot. While
measurements are collected, a pressure map of the second planting foot 1701,
in
this case the right foot, may be displayed on the screen. It will be
appreciated that
foot order may be reversed, or only one foot might be measured.
FIG. 17b illustrates an alternative example screen containing instructions
that
may be displayed to a person regarding taking pressure measurements of the
person while the person stands on the right foot, according to an example
embodiment of the present invention. Instructions for measuring on one foot
1712
may be displayed and highlighted. The person may be instructed to move a
yellow
circle 1710 into a red circle 1711 in order to balance the COF.
FIG. 18 illustrates an example screen that may be displayed after
measurements of a single planting foot are taken, according to an example
embodiment of the present invention. This screen is similar to FIG. 16,
although the
instruction to replace the foot onto the pressure map may be integrated with
an
activated button 1800 instructing the person that he or she may proceed. This
may
be done according to example 710 in FIG. 7. A real-time pressure map 1801 of
the
feet may be displayed on the screen as the raised foot is placed back onto the
pressure mat. ,When measurements have been completed and the person is ready
to proceed, as indicated in pressing 1800, biomechanical data estimates may be
calculated behind-the-scenes according to example 712 in FIG. 7.
CA 02811132 2013-03-28
37
FIG. 19 illustrates an example screen that may display a selected
recommended footcare product, in this example, an orthotic. An image 1900 of
the
footcare product may be displayed that a person may use to recognize the
footcare
product displayed in the merchandise display area, like that of 901 of FIG. 9.
It may
be appreciated that other indicia identifying a recommended footcare product
may
also be displayed, such as a rotating image, or an image that a person may
manipulate through a touch screen, or a video clip containing an audio
description,
etc. It may be advantageous to color code various products so that a customer
can
more easily locate a recommended product.
FIG. 20 illustrates an example screen displaying other information that may be
displayed to a person, according to an example embodiment of the present
invention. For example, the screen may display further indicia of the
recommended
footcare product that was selected, such as a model number 2000. The packaging
2002 of the footcare product as it would appear on a merchandise display area
901,
such as that of FIG. 9a, may also be displayed_ A restart button 2001, in
order to
maneuver through various pages to view the person's own biomechanical data
estimates.
In alternative embodiments, when the selection process is complete, the kiosk
may display several recommended footcare products. The person may then, from
these few selected footcare products, narrow the range of products down,
either by
CA 02811132 2013-03-28
38
choices may be asked prior to the last page and the kiosk may automatically
eliminate choices for the person.
It will be understood form the description above that the inventors of the
present application have recognized an unmet need to provide an economic and
efficient method and apparatus, which provides recommendations from a wide,
but
not unlimited range of pre-manufactured orthotics including different amounts
of
support, different sizes, and different cushioning. Using a limited number of
measurements, the inventors have found that a large proportion of the
population
can then be guided to one of these pre-manufactured orthotics, achieving at
least
part of the benefit of a custom approach without the associated cost.
Moreover, the
inventors of the present application have recognized a need for and developed
a
solution which allows the measurement and mapping to be conducted using an
unattended kiosk located in a retail environment.
Some prior devices have been proposed which use measurement approaches
including optical measurements using two-dimensional or three-dimensions
optical
or laser scanners, thermal imaging, ink-blot measurement of the foot, and
physical
measurement with gauges. However, none of these types of devices has been
found to be cost-effective or reliable enough to use in a device widely
deployed in a
mass-market retail environment. Moreover, many of these measurements require
careful supervision by an operator and may not be suitable for use in an
unattended
measurement kiosk application. In contrast, the inventors of the present
application
have recognized the unmet need for a device which can reliably and accurately
characterize a customer's foot for the purpose of choosing a footcare product,
e.g.,
an. orthotic, where the measurement device is inexpensive and relatively
robust,
making it suitable for use in a mass-market retail environment. As disclosed
in the
present application, the inventors of the present application have identified
pressure
measurement devices, e.g., using a piezoelectric mat, as particularly suited
to use in
this environment.
When a podiatrist or other trained person fits a custom orthotic to a patient,
the podiatrist may make a large number of different types of observations and
measurements. In particular, the podiatrist, in addition to static
measurements of the
CA 02811132 2013-03-28
39
foot, may observe and/or measure the patient's dynamic gait. While instruments
for
gait analysis exist, they are not suitable for use in an unattended retail
device.
Accordingly, the inventors of the present application have recognized the
unmet
need for methods and apparatus that can characterize a person's foot and
identify
an appropriate footcare product, e.g., an orthotic. The inventors have
developed
methods and system that incorporate elements of dynamic gait analysis in a
manner
which is suitable for use in a relatively simple and inexpensive, unattended
measurement kiosk. These methods and systems include quasi-dynamic
measurement of the foot, to provide some of the advantages of dynamic gate
analysis using a simple, automated tool. In particular, the inventors of the
present
application have developed methods and systems for characterizing the foot
based
on pressure measurements of a person standing on only one foot, which can be
used to add a dynamic element to a static two-footed measurement. This
solution
may allow a more accurate characterization of the foot and a better
recommendation
of a footcare product, e.g., an orthotic, without the need for additional more
complicated and expensive measurements and/or measurement devices.
To provide a device that can accurately characterize a user's foot and
recommend a foot care product that is suitable for use in an unattended retail
environment, several other problems had to be solved. First, the inventors of
the
present application have observed that, without proper supervision, users may
use a
measurement device improperly. For example, users may wear shoes when they
should be unshod, and users may lean on the device rather than standing.
Accordingly, the inventors have recognized an unmet need for systems and
methods
which automatically determine if a user is making proper user of the
measurement
device, e.g., .by detecting if the user is shod, wearing socks, or unshod, by
determining if the user is leaning on the device or placing their full weight
on the
measurement system, for determining if the user's weight is properly centered
on the
measurement device, for determining if the user's feet are properly positioned
on the
measurement device. Moreover, there is a further unmet need, once pressure
sensors are adopted, for solving these problems using only pressure
measurements,
or with pressure measurements plus a limited range of easy to obtain
information
CA 02811132 2013-03-28
5 that does not add greatly to the cost of the measurement device (e.g., a
simple
weight measurement or query of the user).
In some example embodiments of the present invention, a kiosk measures a
person's feet and determines a recommended footcare product, e.g., a pre-
manufactured orthotic, for the person and the recommended product may be
10 dispensed or may be selected by the person from a display. The measurements
may be taken with a surface containing pressure sensors to measure a person's
feet. A processor may correlate footcare products to the person's foot
measurements. In one example embodiment, the kiosk may contain a video screen
that provides instructions to the person. The system selects a recommended
15 footcare product from among a set of candidate footcare products based
at least in
part upon a plurality of pressure measurements received from the pressure
sensors.
The set of candidate footcare products may be displayed on or near the kiosk
in a
merchandise display area, and the person would be provided with an indicia of
the
recommended footcare product, such as a picture of the footcare product, the
model
20 number of the footcare product, a color or symbol, etc. The person may
then easily
locate the footcare product that will provide the best calculated fit and
support for the
person's needs. Alternatively, products may be dispensed from a kiosk, for
example,
the kiosk may be configured as a vending machine. The footcare product sold
may
be a pre-manufactured orthotic, and the set of candidate footcare products may
be a
25 set of different models of pre-manufactured orthotics of varying
attributes, such as
size, arch support levels, arch index, cushioning levels (i.e. foam density,
cushioning
material used, etc.), etc. The range of models provided are chosen to address
the
most common conditions needing a footcare product, while coming in a range of
sizes and models needed to fit and provide an appropriate support level for
the vast
30 majority of the potential user population.
One example embodiment of the present invention may be a system including
a surface, wherein the surface is configured to allow a person to stand upon
the
surface; a plurality of pressure sensors located under the surface forming a 2-
D
array of sensors; a measurement system configured to obtain measurements from
a
35 customer's feet; a processor in communication with the plurality of
pressure sensors,
the processor configured to receive a plurality of pressure measurements from
at
=
CA 02811132 2013-03-28
41
least a subset of the plurality of pressure sensors while the person stands
upon the
surface, the processor further configured to select a recommended footcare
product
from among a set of candidate footcare products based at least in part upon
the
plurality of pressure measurements, wherein the processor is configured to
receive
at least a first subset of the plurality of pressure measurements while the
person
stands on one foot; an output device to display information received from the
processor, the information identifying the recommended footcare product to the
person; an input device configured to receive a person's input in selection of
a
recommended product; and a merchandise display area, the merchandise display
area configured to display the set of candidate footcare products.
The use of pressure sensors, as opposed to optical, gauge, or other
previously proposed approaches to characterizing the foot solves the problem
providing a low-cost, robust measurement system suitable for use in an
unattended
retail environment.
Moreover, the use of pressure measurements allows
measurement approximating the results that would be obtained from a dynamic
gait
An alternative example embodiment of the present invention may be a
method of selecting a recommended orthotic, including determining if a foot on
a
sensor is unshod; collecting a first set of pressure measurements of a foot of
a
person while the person stands stationary on one foot, wherein a plurality of
CA 02811132 2013-03-28
42
measurements, wherein biomechanical data comprises foot length, foot width,
body
weight, arch index, outline of the foot and toeline, a peak pressure map, a
longitudinal line drawn on a peak pressure map, or an intersection of a
longitudinal
line and a foot body; comparing the biomechanical data with values from a
decision
matrix of orthotics and classified subgroups; and selecting an orthotic based
on the
comparison.
The use of pressure sensors may provide superior results to optical
measurements. Moreover, the use of pressure sensors solves the problem of
providing a robust solution suitable for use in an unattended retail kiosk.
However,
because the pressure data is much more limited than full range of data used by
a
podiatrist in a foot analysis, the systems and methods presented herein solve
the
problem of providing a broad range of biomechanical characteristics of the
user's
foot, using only pressure data, or pressure data plus a limited amount of
other data,
e.g., the customer's weight on a scale or in response to a query. This may
solve the
problem of how to accurately characterize the user's foot with only a limited
amount
of data.
The use of a decision matrix mapping orthotics and classified subgroups of
measurements solves the problem of how to map a customer's feet to recommended
products using only limited data. These mappings have been developed based on
testing and mapping of actual users.
Because the example embodiments described herein are intended for use in
an unattended retail environment, customers will use them without supervision.
If a
customer uses the system while wearing shoes, this will alter the measurements
and
may produce an unsatisfactory product recommendation. The system and method
for determining whether a customer is shod or unshod solves the problem, which
will
always potentially be present in an unattended system, of automatically
identifying a
customer who is using the system improperly, so that proper use of the kiosk
can be
encouraged.
An alternative example embodiment of the present invention may be an
apparatus with a surface, multiple pressure sensors located under the surface,
and a
CA 02811132 2013-03-28
43
= 5 processor in communication with the plurality of pressure sensors, the
processor
configured to receive multiple pressure measurements from a subset of the
multiple
pressure sensors while the person stands upon the surface. The process may
also
be configured to select a recommended footcare product from among a set of
candidate footcare products based at least in part upon the multiple pressure
measurements. The surface may be configured to allow a person to stand upon
the
surface. Footcare products may include orthotics. The set of candidate
footcare
products includes a set of orthotics, the set including pre-manufactured
orthotics with
a plurality of different sizes and a plurality of different support levels.
The pressure
sensors may be a grid of pressure sensors, possibly formed of a 2-D array.
There
may be 1144 sensors in an array for a single foot. The sensors may be 7.5 mm x
7.5 mm or smaller. The pressure sensors may include a pressure-sensitive
conductive ink, a piezoelectric, sensor, etc.
The apparatus may select a
recommended footcare product and the selection may be made without other foot
measurements being taken other than the pressure measurements. In alternative
embodiments, a scale may be used to provide a weight measurement of the
person.
The example embodiment of the apparatus may also contain input and output
features. The apparatus may contain an output device to display information
received from the processor, the information identifying the recommended
footcare
product to the person. The output device may be a video screen configured to
display an image of the recommended footcare product, a biomechanical data
estimate, or display instructions, the instructions directing the person to
stand on one
foot. Biomechanical data may include at least one of the foot length, foot
width,
body weight, arch index, outline of the foot and toeline, a peak pressure map,
a
longitudinal line drawn on a peak pressure map, or an intersection of a
longitudinal
line and a foot body. The video screen may also be a touch screen,
configurable to
receive both input and output. A separate input device may also receive input
to
configure the processor.
Displaying measured data to the system may help solve the problem of
getting the user of an unattended kiosk to properly use the system, and be
engaged
with its use. For example, systems and methods are presented for encouraging
the
user to properly center their weight on the machine, particularly when one-
footed
CA 02811132 2013-03-28
44
measurements are taken, so that proper characterization of the user's foot can
be
achieved.
The apparatus may also be configured to receive and calculate pressure
measurements with a processor. The processor may be configured to take
pressure
measurements while the person stands on only one foot or may be configured to
receive at least a first subset of the plurality of pressure measurements
while the
person stands on only one foot. The processor may be configured to receive at
least
a second subset of the plurality pressure measurements while the person stands
on
both feet. The processor may be configured receive demographic information.
Taking one-footed or "quasi-dynamic" measurements may provide more
accurate characterization of the user's foot, as compared to a single two-
footed static
measurement. This enables a more accurate recommendation of an appropriate
footcare product using a relatively simple and robust measurement system,
without
the cost of a full custom examination.
To select a recommended footcare product, a storage device may store a
mapping of footcare products to classified subgroups. The storage device may
also
store a storage record containing an apparatus transaction. The processor may
be
configured to calculate biomechanical data estimates based on the plurality of
pressure measurements. The categories of biomechanical data estimates include
estimated foot dimensions, estimated foot type, and estimated body weight.
Foot
dimensions may be a longitudinal line that runs from the center of a heel to
the
center of a second toe, a toe line that is a fitted curve through three
alignment marks,
a foot length that is the projection of the distance between the most anterior
point
and most posterior point of foot pressure map on the longitudinal line, a foot
width
that is the projection of distance between the most medial point and most
lateral
point of foot pressure map on the perpendicular line of the longitudinal line,
the arch
index that is the ratio of the area of the middle third of the toeless
footprint to the
toeless footprint area, etc. The processor may be configured to select a
recommended footcare product based on the biomechanical data estimates. The
processor of the apparatus may also be configured to determine whether an
unshod
foot, a shoe, or a sock is on the pressure sensors. The processor may use some
of
CA 02811132 2013-03-28
5 the biomechanical data estimates or pressure measurements to make this
determination.
As stated above, the apparatus may select a recommended footcare product
from a set of candidate footcare products. The set of candidate footcare
products
may include a set of different pre-manufactured orthotics. The set of
different pre-
10 manufactured orthotics may include orthotics that differ in size, arch
support levels,
and cushioning levels. The set of different pre-manufactured orthotics
variations
may be calculated to fit the majority of the population. The processor may be
configured to receive accuracy factors from a person. The accuracy factors may
be
received before making the recommendation or after making a recommendation.
15 The accuracy factors may be integrated with the calculations and procedures
performed for selection of the recommended footcare product but may also be a
complete separate procedure. The apparatus may also include a merchandise
display area configured to display the set of candidate footcare products.
The collection of accuracy factors, for example queries about the customer's
20 body type, weight, height, etc., solves the problem of how to make accurate
characterizations and recommendations using only relatively simple and robust
measurement systems, such as the pressure sensors described herein. Moreover,
because some of the example embodiments described herein are intended for
unattended use in a retail environment, they are provided with bars for a
customer to
25 support themselves, e.g., while standing on one foot. Accordingly, there
is a
problem that customers may lean or overly support themselves while
measurements
are being taken, possibly resulting inaccurate characterizations of the foot
or product
recommendations. The use of additional confirmation information from
the
customer helps validate that the measurements have been taken accurately. They
30 also allow demographic data to be collected for improving the system
over time.
An example embodiment of the present invention may be a point-of-sale
system for selling orthotics including a set of pre-manufactured orthotics of
different
types, a measurement system configured to obtain measurements from a
customer's
feet, and a processor configured to receive the measurements and to recommend
an
35 orthotic to the customer from the set of pre-manufactured orthotics
based at least in
CA 02811132 2013-03-28
46
part on the measurements. The measurement system may contain a plurality of
pressure sensors. The processor may be configured to derive biomechanical data
from measurements collected by the measurement system. The biomechanical data
may be selected from the foot length, foot width, body weight, arch index,
outline of
the foot and toeline, a peak pressure map, a longitudinal line drawn on a peak
pressure map, and an intersection of a longitudinal line and a foot body,
among
others. A dispensing mechanism may provide an orthotic from the set of pre-
manufactured orthotics to the person.
An example embodiment of the present invention may also perform a method
of characterizing a foot. The method may collect a first set of pressure
measurements of a foot of a person while the person stands stationary on one
foot
and characterize the foot based on the first set of pressure measurements.
Selection of a footcare product may then be based on the characterization of
at least
the one foot. The method may collect a second set of pressure measurements
from
both feet of a person while the person stands on both feet and characterize
the foot
based on the first set and second set of pressure measurements. Alternatively,
the
method may only collect pressure measurements from both feet as the first set
of
pressure measurement of a person and characterize the foot based on the first
set,
in this example, the pressure measurements of both feet. The method may also
calculate a biomechanical data estimate of the foot using the pressure
measurements. The method may compare the biomechanical data with values from
a decision matrix of orthotics and classified subgroups, wherein a classified
subgroup may include the weight of the person, the band of the person (i.e. a
band
based on a person's foot length), a person's arch index, etc. The method may
involve calibrating a plurality of pressure sensors and a processor using a
Force
Calibration method or a Multi-level Pressure Calibration method. The method
may
involve adjusting coefficients in a processor change the accuracy factors to
recommend an orthotic. The decision matrix may be created based on a product
specification list.
An example embodiment of the present invention may also perform a method
of selecting an orthotic. The method may include collecting a plurality of
pressure
measurements at different points of the foot of a person and selecting an
orthotic
CA 02811132 2013-03-28
47
based on the pressure measurements. The method may perform a combination of
grouping a person into one of a plurality of classified subgroups based on the
pressure measurements; recommending a footcare product based on a person's
classified subgroup; deriving biomechanical data estimates from the pressure
measurements of at least one of the both feet of a person, the left foot of a
person,
or the right foot of a person; estimating the biomechanical data of the
person's feet
using the first set of pressure measurements and the second set of pressure
measurements; confirming the person is balanced based on the received pressure
measurements; confirming the person is not wearing a footwear based on the
pressure measurements; confirming the person is not wearing a footwear based
on
the biomechanical data estimates; receiving the second set of pressure
measurements when the load on the individual planting foot reaches a pre-
determined bodyweight percentage; receiving the second set of pressure
measurements when the person's Center of Force enters a target zone, wherein a
target zone is a pressure reference point; receiving the second set of
pressure
measurements when the Center of Force matches a target zone and at least 95%
of
static weight, weight calculated by the sum of forces created by the feet when
relatively still, is achieved; or generating a static foot outline based on
pressure
measurements. Biomechanical data may include foot length, foot width, body
weight, arch index, outline of the foot and toeline, a peak pressure map, a
longitudinal line drawn on a peak pressure map, or an intersection of a
longitudinal
line and a foot body. A specified bodyweight percentage may be between the
range
of 90 to 95 percent of bodyweight.
Calculating the various biomechanical data based on pressure
measurements, solves the problem of obtaining an adequate characterization of
the
user's foot to make a product recommendation using only a relatively simple,
inexpensive measurement system in an unattended system. Mapping the data into
subgroups based on empirical analysis solves the problem of automatically
recommending a good solution for the vast majority of customers using only a
limited
range of pre-manufactured products and a limited amount of measurement data.
Getting the customer to match a center of force, solves of the problem of
having a customer correctly use an unattended kiosk. The target center of
force can
CA 02811132 2013-03-28
48
be shown on the screen, which helps the customer to properly balance and
position
their weight on the measurement apparatus so that accurate measurements can be
made. Similarly, tracking the bodyweight percentage helps verify the user is
properly balanced on the system when a one-footed measurement is taken,
solving
the problem of how to take an accurate measurement in an unattended system,
particularly given that user's are inclined to lean or improperly balance when
standing on one foot.
Generating the various foot characterization measures described, solves the
problem of providing a sufficient characterization of the user's foot to make
accurate
product recommendations using only a pressure measurement map, or a pressure
measurement map with small amounts of supplemental information.
An example embodiment of the present invention may also perform a method
of determining if a foot on a sensor is unshod. The method may include
determining
plurality of foot dimensions, calculating a plurality of foot dimension
ratios, and
comparing the foot dimension ratios to pre-determined values (e.g. 3.5, 6.0,
1.2, and
0.1). The foot dimensions may be selected from the group consisting of foot
length,
heel width, arch width, and forefoot width, although it will be appreciated
that other
dimensions may also be used. Foot dimension ratios may include foot length
(e.g.
the length of the line between the most posterior and most anterior points of
each
foot pressure print) over the heel width (e.g. the length of a first tine that
is
perpendicular to a second line, wherein the second line is a line between the
center
of the heel and the center of the second toe, and the first line is located at
16%,
though it may range between 5 to 20%), forefoot width/heel width, and arch
width/heel width.
Several example embodiments of the present invention are specifically
illustrated and described herein. However, it will be appreciated that
modifications
and variations of these embodiments are possible.
