U.S. patent application number 15/684511 was filed with the patent office on 2018-03-01 for systems and methods for portable powered stretching exosuit.
The applicant listed for this patent is Superflex, Inc.. Invention is credited to Melinda J. Cromie, Louis Calvin Fielding, Megan Grant, Mary Elizabeth Hogue, Nicole Ida Kernbaum, Richard Mahoney, Violet Riggs, Erik Shahoian, Mallory L. Tayson-Frederick, Katherine Goss Witherspoon.
Application Number | 20180055713 15/684511 |
Document ID | / |
Family ID | 61240286 |
Filed Date | 2018-03-01 |
United States Patent
Application |
20180055713 |
Kind Code |
A1 |
Cromie; Melinda J. ; et
al. |
March 1, 2018 |
SYSTEMS AND METHODS FOR PORTABLE POWERED STRETCHING EXOSUIT
Abstract
Portable powered stretching exosuit (PPSE) systems and methods
according to various embodiments are described herein. The PPSE can
be used to facilitate stretching routines for athletics,
rehabilitation, or for therapeutic purposes such as maintaining
mobility for DMD patients. The PPSE is comfortable, relatively easy
to don and doff, and in a form factor such that the PPSE can be
worn during the wearer's normal activities. The PPSE may be
self-powered, and automatically perform or assist with specific
stretching routines. PPSEs may be optimized for one or more
specific stretches, whether for athletic performance, medical
purposes or rehabilitation following surgery or injury.
Inventors: |
Cromie; Melinda J.; (Menlo
Park, CA) ; Witherspoon; Katherine Goss; (Redwood
City, CA) ; Grant; Megan; (San Francisco, CA)
; Kernbaum; Nicole Ida; (Sunnyvale, CA) ; Mahoney;
Richard; (Los Altos, CA) ; Tayson-Frederick; Mallory
L.; (Oakland, CA) ; Fielding; Louis Calvin;
(San Carlos, CA) ; Riggs; Violet; (San Francisco,
CA) ; Shahoian; Erik; (Sonoma, CA) ; Hogue;
Mary Elizabeth; (San Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Superflex, Inc. |
Menlo Park |
CA |
US |
|
|
Family ID: |
61240286 |
Appl. No.: |
15/684511 |
Filed: |
August 23, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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62378471 |
Aug 23, 2016 |
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62378555 |
Aug 23, 2016 |
|
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62431779 |
Dec 8, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A63B 21/00178 20130101;
A63B 2220/40 20130101; A63B 21/4007 20151001; A63B 21/4013
20151001; A63B 21/4011 20151001; A61H 2201/165 20130101; A63B
2230/60 20130101; A61H 1/02 20130101; A63B 21/4025 20151001; A63B
23/03541 20130101; A61H 2201/1238 20130101; A61H 2201/5061
20130101; A61H 1/0266 20130101; A61H 2201/1253 20130101; A63B
21/4039 20151001; A63B 21/00181 20130101; A63B 21/4047 20151001;
A63B 2209/00 20130101; A63B 2209/10 20130101; A61H 2201/1215
20130101; A61H 2201/5097 20130101; A63B 2225/096 20130101; A63B
2220/51 20130101; A63B 21/4043 20151001; A61H 2201/5048 20130101;
A63B 2220/803 20130101; A61H 2201/5064 20130101; B25J 9/0006
20130101; A61H 2201/1642 20130101; A61H 2201/501 20130101; A63B
2230/605 20130101; A61H 2230/60 20130101; A61H 2201/5043 20130101;
A61H 2201/5084 20130101; A63B 21/4015 20151001; A61H 3/00 20130101;
A61H 2201/1676 20130101; A63B 21/0004 20130101; A63B 2225/20
20130101; A61H 2201/1647 20130101; A63B 21/152 20130101; A63B
2220/24 20130101; A61H 2201/123 20130101; A63B 2225/50 20130101;
A61H 2201/164 20130101; A63B 24/0087 20130101; A63B 2220/801
20130101 |
International
Class: |
A61H 1/02 20060101
A61H001/02; B25J 9/00 20060101 B25J009/00 |
Claims
1. A portable powered stretching exosuit (PPSE) system for use with
a human body joint, the PPSE system comprising: a support plate
having inside, outside, and lateral attachment points; a load
distributing and flexible grip elements (Flexgrip) configured to
enshroud a portion of the human body adjacent to the joint; first,
second, and third flexible linear actuators (FLAs), each of which
are coupled to the support plate and the Flexgrip; at least one
muscle activity detection sensor; at least one pressure sensor
coupled to the plate; and control circuitry electrically coupled to
the first, second, and third FLAs, the at least one muscle activity
detection sensor, and the at least one pressure sensor, the control
circuitry operative to execute a control scheme to stretch the
joint, wherein the control scheme selectively activates the first,
second, and third FLAs to apply to one or more stretching forces to
the joint.
2. The system of claim 1, wherein the control scheme is a position
and time controlled stretching scheme for the joint, wherein the
stretching scheme comprises a series of stretch segments, each of
which are followed by a holding position of a fixed period of
time.
3. The system of claim 1, wherein the stretching scheme comprises:
a first stretch segment that pulls the joint to a first stretch
position; a first hold period that holds the joint in the first
stretch position for a first period of time; a second stretch
segment that pulls the joint to a second stretch position; and a
second hold period that holds the joint in the second stretch
position for a second period of time.
4. The system of claim 3, wherein the stretching scheme further
comprises a release segment that releases the joint from the second
stretch position.
5. The system of claim 3, wherein the FLAs are used to place the
joint in the first and second stretch positions, and wherein
clutches are activated in each FLA to hold the joint in the first
and second stretch positions
6. The system of claim 1, wherein the control scheme is a
viscoelastic-controlled stretching scheme.
7. The system of claim 6, wherein the viscoelastic-controlled
stretching scheme comprises: a first stretch segment that pulls the
joint to a first stretch position defined by the stretch force
produced at least one of the first, second, and third FLAs or by a
measured position of the joint; a first hold period that holds the
joint in the first stretch position until a measured force drops to
a first threshold; a second stretch segment that pulls the joint to
a second stretch position in response to the measured force
dropping below the first threshold, wherein the second stretch
position is defined by the stretch force produced at least one of
the first, second, and third FLAs or by a measured position of the
joint; a second hold period that holds the joint in the second
stretch position until the measured force drops to second
threshold; and a release segment that releases the joint from the
second stretch position in response to the measured force dropping
below the second threshold.
8. The system of claim 1, wherein the control scheme is an active
stretching scheme in which the user is provided with instructions
to activate his or her muscles.
9. The system of claim 8, wherein the joint is a foot, wherein
during the active stretching scheme, the control circuitry is
operative to: issue a first dorsiflexion stretch command to be
received by a user; monitor motion of the user's voluntary
dorsiflexion of the foot; and activate at least one of the first,
second, and third FLAs to match the monitored user's voluntary
dorsiflexion motion and to balance foot rotation and ankle eversion
in conjunction with the user's voluntary dorsiflexion.
10. The system of claim 9, wherein the control circuitry is
operative to: detect that the user's voluntary dorsiflexion of the
foot has reached a first stretch position; and further activate at
least one of the first, second, and third FLAs to apply increased
force to maintain the foot in the first stretch position.
11. The system of claim 10, wherein the control circuitry is
operative to: detect that the user is moving the foot after having
reached the first stretch position; and activate at least one of
the first, second, and third FLAs to match the monitored user's
voluntary dorsiflexion motion and to balance foot rotation and
ankle eversion in conjunction with the user's voluntary
dorsiflexion of the foot to a second stretch position; detect that
the user's voluntary dorsiflexion of the foot has reached the first
stretch position; and further activate at least one of the first,
second, and third FLAs to apply increased force to maintain the
foot in the second stretch position
12. The system of claim 1, wherein the control circuitry is
operative to execute an assistive stretch regimen that selectively
activates the first, second, and third FLAs in response muscle
activity detected by the at least one muscle activity detection
sensor such that when the control circuitry processes a user
activated joint movement via the at least one muscle activity
detection sensor and the at least one pressure sensor, the control
circuitry is further operative to assist the user in performing
his/her own dorsiflexion or eversion stretch.
13.-27. (canceled)
28. The system of claim 1, wherein the joint is a foot and wherein
the support plate comprises: a first set of contour blocks that
supports instep and front of an ankle of the foot; a second set of
contour blocks that that supports a plantar surface of the foot; a
third set of contour blocks that support a heel of the foot; and a
tensioning cable coupled to each contour block in the first,
second, and third sets, wherein when the support plate is in a
release state, the tensioning cable is slack, and wherein when the
support plate in a tightened state, the tensioning cable is
taught.
29. The system of claim 28, wherein when the tensioning cable is
taught, the first set of contour blocks apply force to the front of
the ankle, the second set of contour blocks apply force to a
metatarsal-phalangeal joint of the foot, and the third set of
contour blocks apply force to a back portion of the heel.
30. The system of claim 1, wherein the support plate comprises: a
strap configured to be wrapped around the foot; a first pulley
coupled to the strap; a first set of contour blocks that that
supports a plantar surface of the joint; a second pulley coupled to
an end of the first set of contour blocks; a second set of contour
blocks that support a second portion of the joint; and a tensioning
cable coupled to the first and second sets and to the first and
second pulleys, wherein when the support plate is in a release
state, the tensioning cable is slack, and wherein when the support
plate in a tightened state, the tensioning cable is taught, which
enables the strap to apply a force to the front of the ankle, the
first set of contour blocks to apply a force to a
metatarsal-phalangeal joint, and the second set of contour blocks
to apply a force to the heel, of which the combined forces generate
a torque about the ankle to rotate the foot in dorsiflexion.
31.-38. (canceled)
39. The system of claim 38, wherein the support plate is relatively
more rigid along the longitudinal axis than it is along the
transverse axis.
40.-42. (canceled)
43. The system of claim 1, wherein the support plate comprises: a
heel strap; an FLA anchor strap having first and second FLA
attachment members; and a cable coupled to the first and second FLA
attachment members and to the heel strap such that cable loops
around the heel strap and crosses below the support plate.
44.-48. (canceled)
49. A method implemented in a portable powered stretching exosuit
(PPSE) system for use with a human foot, the method comprising:
conducting first programming in which a person performs a manual
stretching routine on a user foot that has the PPSE donned thereon,
the conducting comprising recording sensor data during execution of
the manual stretching routine; and generating second programming
based on the recorded sensor data, wherein the second programming
controls operation of the PPSE to execute an automated stretching
routine that emulates the manual stretching routine.
50. The method of claim 49, wherein the recorded sensor data
comprises pressure sensor data and goniometer data.
51. The method of claim 50, wherein the recorded sensor data
comprises electromyogram (EMG) sensor data.
52. The method of claim 49, further comprising: determining forces
applied during the manual stretching routine based on the recorded
data; and reproducing the applied forces determined during the
manual stretching routine during execution of automated stretching
routine.
53. The method of claim 49, further comprising recording the sensor
data during execution of the automated stretching routine.
54. The method of claim 53, further comprising transmitting the
sensor data recording during execution of the automated stretching
routine to a remote server.
55. The method of claim 49, further comprising updating the second
programming that causes the PPSE to execute an adjusted automated
stretching routine.
56. A portable powered stretching exosuit (PPSE) system for use
with a human foot, comprising: a base layer comprising an ankle
region and a calf region; first load distribution member secured to
the calf region; second load distribution member secured to the
ankle region; a footplate constructed to interface with a planar
surface of the foot and is coupled to the second load distribution
member, the footplate comprising first and second attachment
points; first flexible linear actuator (FLA) coupled to the first
load distribution member and the first attachment point; second FLA
coupled to the first load distribution member and the second
attachment point; a plurality of sensors; and control circuitry
electrically coupled to the first and second FLAs and the plurality
of sensors, the control circuitry operative to control operation of
the first and second FLAs to apply a stretch routine to the
foot.
57. The system of claim 56, wherein the control circuitry is
operative to instruct the first and second FLAs to increase tension
between the footplate and the first load distribution member,
wherein the increase in tension between the footplate and the first
load distribution member causes the foot to pivot in dorsiflexion
about the ankle.
58. The system of claim 57, wherein the coupling between the second
load distribution member and the footplate enables the foot to
pivot in dorsiflexion about the ankle.
59. The system of claim 58, further comprising a cable that is
coupled to the first and second attachments points and the second
distribution member.
60. The system of claim 56, wherein the footplate comprises at
least one adjustable strap that is constructed to secure the
footplate to the foot, wherein the first and second attachment
points are included on the at least one adjustable strap.
61. The system of claim 56, wherein the footplate further comprises
a third attachment point, the system further comprising: a third
FLA coupled to the first load distributing member and the third
attachment point; and wherein the control circuitry is operative to
instruct the third FLA to increase tension between the third
attachment point of the footplate and the first load distribution
member to cause the foot to undergo an eversion stretch.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 62/378,471, filed Aug. 23, 2016, U.S. Provisional
Patent Application No. 62/378,555, filed Aug. 23, 2016, and U.S.
Provisional Patent Application No. 62/431,779, filed Dec. 8, 2016,
the disclosures of which are incorporated by reference in their
entireties.
BACKGROUND
[0002] Stretching activities have been shown to be beneficial for
mobility, athletic performance, rehabilitation, and general health.
Stretching is most commonly performed as a series of exercises,
often incorporated into an exercise or rehabilitation routine; or
as its own activity such as yoga.
[0003] Due to the viscoelastic nature of the tissues to be
stretched, recommended durations for a single stretch often range
from 30 seconds to several minutes. When a stretching routine
involves multiple stretches or repetitions, stretching can become
very time-consuming and tedious, resulting in low compliance to a
given routine. Non-compliance may be particularly problematic in
medical, athletic or rehabilitation settings, where prescribed
stretches may be critical to avoid injury, attain recovery or
mitigate effects of disease progression. In the case of patients
with Duchenne Muscular Dystrophy (DMD), stretching is important to
maintain joint mobility for as much function as possible due to the
progressive nature of the disease and associated contractures.
Currently, prescriptions for stretching regimens are communicated,
prescribed, and reproduced based on therapist and caregiver feel.
The subjective nature of this method leads to variability across
stretch sessions, patients, and stretch providers.
[0004] Orthoses are commonly available to facilitate stretching.
Ankle foot orthoses (AFOs) such as those from Ultraflex Systems
(Pottstown, Pa.) and Cascade Dafo (Ferndale, Wash.) are commonly
prescribed for DMD patients to facilitate ankle stretching. The
AFOs may utilize an elastic or spring-loaded stirrup to pull upward
on the forefoot to assist with dorsiflexion stretching of the ankle
joint. Because these AFOs utilize passive elastic components, they
must be manually engaged or disengaged to apply the stretching
force, making repetitions of a particular stretch cumbersome.
Additionally, the rigid elements of AFOs render the device bulky,
which may discourage patient use and result in decreased stretching
regimen compliance. AFOs worn at night are not well tolerated by
some users, and users often remove the AFOs. Some complain of not
being able to walk to the bathroom at night while wearing them.
There is currently no documentation of how long or how often they
are used. The toe strap or stirrup that induces ankle dorsiflexion
typically has an elastic section to allow the foot to release and
reset into the stretch. There is currently no documentation of how
often or how long the foot is pressing against the elastic
portion.
[0005] Powered devices for stretching assistance are known, such as
the Intellistretch developed by Rehabtek LLC (Wilmette, Ill.).
These systems typically comprise large, stationary frames,
computers and equipment. The size of these devices typically
requires that they remain in one location and that the wearer
transfer into and out of the system in order to use it. In some
cases, the patient may be required to travel to a clinical setting
where such a system is provided.
[0006] The passive range of motion (ROM) of a joint is often
reduced as a consequence of injury, surgery or degenerative
changes. Stretching exercise regimens are often prescribed to
restore ROM, sometimes in conjunction with therapy. As described
above, stretching regimens can be tedious and compliance is often
poor. In the case of reduced ROM secondary to surgery, a continuous
passive motion (CPM) machine is commonly prescribed. CPM machines
are typically large, utilize wall power, and are generally not
indicated to be worn while sleeping or performing any other
activities. CPM machines also typically operate through a specified
range of motion, without any capability of sensing the actual ROM
of the joint or progress being made. An improved system would be
portable, with an integral battery or power supply, would be able
to be worn while sleeping or performing other activities, and be
able to sense and measure the range of motion or kinematics of the
joint to properly stretch the joint and increase ROM as
prescribed.
SUMMARY
[0007] Portable powered stretching exosuit (PPSE) systems and
methods according to various embodiments are described herein. The
PPSE can be used to facilitate stretching routines for athletics,
rehabilitation, or for therapeutic purposes such as maintaining
mobility for DMD patients. The PPSE is comfortable, easy to don and
doff, and in a form factor such that the PPSE can be worn during
the wearer's normal activities. The PPSE may be battery-powered,
and automatically perform or assist with specific stretching
routines. PPSEs may be optimized for one or more specific
stretches, whether for athletic performance, medical purposes or
rehabilitation following surgery or injury. One example includes
ankle dorsiflexion and eversion stretches, which are commonly
prescribed for DMD patients.
[0008] The PPSE can "learn" the stretch prescribed by a therapist
to an individual by measuring and recording the biomechanics of the
stretch and parameters of the stretch regimen performed by the
therapist on the patient. The PPSE can reproduce the stretch
biomechanics across stretch sessions. The PPSE can communicate the
parameters of the stretch biomechanics and stretch regimen with a
central database. The PPSE may use the stored data to suggest
stretching regimens during the programming step, and enable the
user and therapist to access the database to explore successful
treatment regimens for similar users. The PPSE may be used to
record and share innovations in therapy quantitatively to guide
individual therapy, capture innovations in prescribed therapy,
outcome measures to evaluate the impact of drug, gene, or manual
therapy treatments, and document improvement in joint health to
guide practitioners and inform insurance reimbursement.
[0009] In one embodiment, a portable powered stretching exosuit
(PPSE) system for use with a human body joint is provided. The PPSE
system can include a support plate having inside, outside, and
lateral attachment points, a load distributing and flexible grip
elements (Flexgrip) configured to enshroud a portion of the human
body adjacent to the joint, first, second, and third flexible
linear actuators (FLAs), each of which are coupled to the support
plate and the Flexgrip. The system can include at least one muscle
activity detection sensor, at least one pressure sensor coupled to
the plate, and control circuitry electrically coupled to the first,
second, and third FLAs, the at least one muscle activity detection
sensor, and the at least one pressure sensor, the control circuitry
operative to execute a control scheme to stretch the joint, wherein
the control scheme selectively activates the first, second, and
third FLAs to apply to one or more stretching forces to the
joint.
[0010] In another embodiment, a method implemented in a portable
powered stretching exosuit (PPSE) system for use with a human foot
is provided. The method includes conducting first programming in
which a person performs a manual stretching routine on a user foot
that has the PPSE donned thereon, the conducting comprising
recording sensor data during execution of the manual stretching
routine, and generating second programming based on the recorded
sensor data, wherein the second programming controls operation of
the PPSE to execute an automated stretching routine that emulates
the manual stretching routine.
[0011] In yet another embodiment, a portable powered stretching
exosuit (PPSE) system for use with a human foot is provided. The
system can include a base layer comprising an ankle region and a
calf region, first load distribution member secured to the calf
region, second load distribution member secured to the ankle
region, a footplate constructed to interface with a planar surface
of the foot and is coupled to the second load distribution member,
the footplate including first and second attachment points. The
system can include first flexible linear actuator (FLA) coupled to
the first load distribution member and the first attachment point,
second FLA coupled to the first load distribution member and the
second attachment point, a plurality of sensors, and control
circuitry electrically coupled to the first and second FLAs and the
plurality of sensors, the control circuitry operative to control
operation of the first and second FLAs to apply a stretch routine
to the foot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Various objects, features, and advantages of the disclosed
subject matter can be more fully appreciated with reference to the
following detailed description of the disclosed subject matter when
considered in connection with the following drawings, in which like
reference numerals identify like elements.
[0013] FIGS. 1A-1C illustrate terms related to kinematics and
movements of the foot that are used in descriptions of a PPSE.
[0014] FIGS. 2A-2F illustrate a concept for a PPSE to assist with
ankle stretches according to certain embodiments of the present
disclosure.
[0015] FIGS. 3A-3C illustrate the elements of actuation control of
an ankle stretching PPSE according to certain embodiments of the
present disclosure.
[0016] FIGS. 4A-4C illustrate a system of contour blocks that can
form a desired profile when actuated, and relax to allow
flexibility when not actuated according to certain embodiments of
the present disclosure.
[0017] FIGS. 5A-5J illustrate concepts for a cable-supported
footplate for use in an ankle stretching PPSE according to certain
embodiments of the present disclosure.
[0018] FIGS. 6A-6B illustrate footplate with Contour Blocks and
electrolaminate clutch according to certain embodiments of the
present disclosure.
[0019] FIG. 7 provides a flowchart of an exemplary usage model of a
PPSE according to certain embodiments of the present
disclosure.
[0020] FIG. 8 illustrates the PPSE "learning" a stretch according
to certain embodiments of the present disclosure.
[0021] FIGS. 9A-9H illustrate a cuff for applying traction to the
ankle joint to facilitate ankle stretches according to certain
embodiments of the present disclosure.
[0022] FIGS. 10A-10C illustrate a pressure sensor array integrated
into semi-rigid assembly to sense distribution of load on foot to
control stretch biomechanics according to certain embodiments of
the present disclosure.
[0023] FIGS. 11A-11F illustrate the design parameters for contour
blocks, which are cable-actuated 3D structures according to certain
embodiments of the present disclosure.
[0024] FIGS. 12A-12D illustrate a fully and rapidly configurable
system for rapidly prototyping and fitting PPSE according to
certain embodiments of the present disclosure.
[0025] FIGS. 13A-13B describe the data measured by, calculated by,
or entered into the PPSE during the programming and use of the
PPSE, and the use of these data according to certain embodiments of
the present disclosure.
[0026] FIG. 14 illustrates a PPSE and system configured to
communicate with the PPSE according to various embodiments.
[0027] FIG. 15 illustrates a schematic of a control scheme for a
PPSE according to various embodiments.
DETAILED DESCRIPTION
[0028] In the following description, numerous specific details are
set forth regarding the systems, methods and media of the disclosed
subject matter and the environment in which such systems, methods
and media may operate, etc., in order to provide a thorough
understanding of the disclosed subject matter. It will be apparent
to one skilled in the art, however, that the disclosed subject
matter may be practiced without such specific details, and that
certain features, which are well known in the art, are not
described in detail in order to avoid complication of the disclosed
subject matter. In addition, it will be understood that the
examples provided below are exemplary, and that it is contemplated
that there are other systems, methods and media that are within the
scope of the disclosed subject matter.
[0029] A PPSE can typically include elements of an assistive
exosuit, as described in U.S. patent application Ser. No. ______,
titled "Systems and Methods for Assistive Exosuit System," filed
______, the contents of which are incorporated by reference. A PPSE
typically includes one or more flexible linear actuators (FLAs). An
FLA is a powered actuator capable of generating a contractile force
between two attachment points, over a given stroke length. An FLA
is flexible, such that it can follow a contour, for example around
a body surface, and therefore the forces at the attachment points
are not necessarily aligned. In some embodiments, one or more FLAs
comprise one or more twisted string actuators or Flexdrives, as
described in further detail in U.S. Pat. No. 9,266,233, the
contents of which are incorporated herein by reference. In the
descriptions that follow, FLA refers to a flexible linear actuator
that exerts a contractile force, contracts or shortens when
actuated. The FLA may be used in conjuction with a mechanical
clutch that lock the tension force generated by the FLA in place so
that the FLA motor does not have to consume power to maintain the
desired tension force. Examples of such mechanical clutches are
discussed below. FLA may also be used in connection with
electrolaminate clutches, which are described in the U.S. Pat. No.
9,266,233. The electrolaminate clutch (e.g., clutches configured to
use electrostatic attraction to generate controllable forces
between clutching elements) may provide power savings by locking a
tension force without requiring the FLA to maintain the same
force.
[0030] In some embodiments, a PPSE can be adapted to be both
comfortable and unobtrusive, as well as to comfortably and
efficiently transmit loads from one or more FLAs to the wearer's
body in order to provide the desired assistance. The PPSE can
include one or more different material types to achieve these
purposes. Elastic materials may provide compliance to conform to
the wearer's body and allow for ranges of movement. The innermost
layer is typically adapted to grip the wearer's skin, undergarments
or clothing so that the PPSE does not slip as stretching loads are
applied. Substantially inextensible materials are preferably used
to transfer loads from the to the wearer's body. These materials
may be substantially inextensible in one axis, yet flexible or
extensible in other axes such that the load transmission is along
preferred paths. The load transmission paths can be optimized to
distribute the loads across regions of the wearer's body to
minimize the forces felt by the wearer, while providing efficient
load transfer with minimal loss and not causing the PPSE to slip.
Collectively, this load transmission configuration may be referred
to as a Flexgrip. Further details and embodiments are described in
International Application PCT/US16/19565, titled "Flexgrip," the
contents of which are incorporated herein by reference. Flexgrips
refer to elements that distribute loads across a region of the
wearer's body and may sometimes be referred to as a load
distribution member.
Foot Kinematics
[0031] FIGS. 1A-1C illustrate terms related to kinematics and
movements of the foot that are used in descriptions of a PPSE. The
foot illustrated in FIGS. 1A-1C is a right foot for illustration
purpose. It is also understood by someone familiar with the art
that other instances of this PPSE are possible for all joints of
the body and that the PPSE may be customized according to the
unique biomechanics of each joint, and that this description of the
foot is an exemplar.
FIG. 1A: Inversion and Eversion
[0032] FIG. 1A illustrates inversion and eversion of the foot.
Inversion refers to inward rotation (101) of the foot (102) about
the ankle (103) or heel. Eversion refers to outward rotation (104)
of the foot (102) about the ankle (103) or heel. The inversion and
eversion about the ankle may be referred to herein as ankle
eversion and ankle inversion.
FIG. 1B: Midfoot Rotation, Pronation and Supination
[0033] FIG. 1B illustrates rotation of the midfoot (105). Pronation
refers to inward rotation (106) of the midfoot (105), typically
corresponding to flattening the arch (107). Supination refers to
outward rotation (108) of the midfoot (105), typically
corresponding to raising the arch (107).
FIG. 1C: Dorsiflexion
[0034] FIG. 1C illustrates dorsiflexion of the foot. Dorsiflexion
refers to upward, or dorsal, movement of the foot (102) toward the
tibia (109) or shin. Dorsiflexion involves rotation (110) of the
foot about the ankle (103), as well as anterior or forward
translation (111) of the foot (102) relative to the ankle (103) due
to the location of the center of rotation (112) within the tibia
(109). The forward translation (111) can represent a stretching of
the achillies tendon. Thus, dorsiflexon rotation can stretch the
achillies tendon as the foot rotates about the ankle (103).
Foot Stretch PPSE Concept
[0035] FIGS. 2A-2F illustrate a concept for a PPSE to assist with
ankle/foot stretches, including dorsiflexion and eversion,
according to certain embodiments of the present disclosure. Three
"layers" of the ankle stretching PPSE concept are shown: a power
layer, a sensors and controls layer, and a base layer. Though these
layers are shown in separate images, they form an integrated
system.
FIGS. 2A-2B: Power Layer, Ankle PPSE
[0036] FIG. 2A shows a lateral or outside view of an ankle
stretching PPSE. FIG. 2B shows a medial or inside view of an ankle
stretching PPSE. The power layer comprises three FLAs. A first FLA
(201) is operably coupled at a first end to a Flexgrip (202) on the
outside of the upper calf and at the other end to a footplate (206)
at the inside of the foot (203) near the head of the first
metatarsal. A second FLA (204) is operably coupled at a first end
to a Flexgrip (202) on the inside of the upper calf and at the
other end to a footplate (206) at the outside of the foot (205)
near the head of the fifth metatarsal. When actuated together, the
first and second FLAs (201, 204) draw the foot upward into a
dorsiflexion stretch. The first and second FLAs cross (207) in
front of the leg, providing stability when actuated. Differential
actuation of these drives allows control and balance of the forces
applied to the foot such that the stretch is applied safely and as
intended.
[0037] A third FLA (208) is operably coupled at a first end to the
medial side of a Flexgrip (202) at the upper calf and at the
opposite end to a footplate (206) at the lateral side of the
midfoot (209). Actuating the third FLA (208) pulls on the outside
of the foot to perform an eversion stretch. The Flexgrips (202)
around the upper calf support the loads of the FLAs (201, 204,
208), distributing forces generated by the FLAs evenly around the
calf, while the Flexgrip resists sliding down the leg.
[0038] The footplate (206) distributes forces generated by the FLAs
about the plantar surface of the foot. Stiffness or rigidity of the
footplate distributes these loads across the foot both for comfort,
and to ensure that the forces generate a dorsiflexion torque that
stretches the ankle, as opposed to stretching the plantar fascia of
the foot. That is, the footplate (206) may support the arch of the
foot and is sufficiently stiff such that it does not stretch the
plantar fascia when a dorsiflexion or eversion stretch is applied
to the foot. A strut (214) connects the footplate (206) to a
Flexgrip (215) at the lower ankle so that the footplate is securely
coupled to the foot. The coupling between footplate (206) and
Flexgrip (215) can ensure that the ankle is pulled forward towards
the front of the foot (in the direction of the toes) when the PPSE
subjects the foot to a dorsiflexion stretch. Many other mechanisms
for securing the back of the foot or the region above the
calceaneus bone to the footplate (206) are possible and are
discussed in more detail below.
[0039] It should be appreciated that additional FLAs may be added
to the PPSE of FIGS. 2A-2D. For example, one or more FLAs may be
added to provide midfoot pronation and/or supination. As another
example, an additional FLA may placed in parallel with one or more
of FLAs 201, 204, or 208 to provided additional force tension to
perform a desired stretch (e.g., dorisflexin or eversion).
FIGS. 2C-2D: Sensors and Controls Layer, Ankle PPSE
[0040] FIGS. 2C-2D illustrate elements of the sensors and controls
layer of a PPSE for performing ankle stretches. Electromyogram
(EMG) sensors (210) detect muscle activity in the gastrocnemius,
soleus and tibialis muscles. Pressure sensors (211) distributed
under the foot to detect pressure distributions applied to the foot
by the FLAs. The pressure sensors can include pairs of force
sensing resistors (FSRs) on the medial and lateral sides of the
foot to sense the balance of forces applied during stretching.
Force sensors (212) integrated in the FLAs detect the forces
generated by the FLAs. Goniometers (213) detect motions of the
ankle joint. Collectively, these sensors enable controlled
actuation of the FLAs to safely apply the desired stretch.
[0041] In one example, first and second FLAs (201, 204) are
simultaneously actuated to perform a dorsiflexion stretch. Based on
the prescribed stretch, the FLAs apply a specified total force
corresponding to the sum of the forces measured by the force
sensors (212) integrated in the first and second FLAs. The control
hardware monitors the pressure sensors (211) on the bottom of the
foot to ensure that the forces applied by the FLAs are
appropriately balanced, adjusting each FLA as needed. The output of
the goniometers (213) is monitored to measure the actual range of
motion and amount of stretch that was achieved. In another example,
a wearer initiates a dorsiflexion or eversion stretch to the best
of their ability, using their own muscles. The EMG sensors (210)
detect this activity, and the FLAs are actuated to support the
wearer-initiated stretch, maintain balance and help prevent
fatigue. In yet another example, first, second, and third FLAs
(201, 204, and 208) are simultaneously actuated to perform a
combination dorsiflexion and heel eversion stretch. The control
hardware can monitor pressure sensors (211) and goniometers (213)
to ensure the stretches are being applied with adequate force and
sufficient range of motion.
FIGS. 2E-2F: Base Layer, Ankle PPSE
[0042] FIGS. 2E-2F illustrate elements of a base layer of an ankle
stretching PPSE. The base layer can include a sock (216) extending
from the foot to the upper calf. The sock can be constructed made
from a breathable, elastic material and may be seamless for
comfort. In some embodiments, the base layer may have a coefficient
of friction that provides relatively good adherence to human skin.
The Flexgrips at the upper calf and lower ankle (202, 215) are
attached to the sock and integrated with the base layer, to
comfortably and efficiently transmit loads to the wearer's body
during stretching activities. Closure elements (217) are provided
to facilitate donning and doffing the PPSE. The closure elements
may include hook-and-loop fasteners, snaps, zippers, buttons or the
like. Alternatively, the base layer may have enough elastic
compliance that the wearer can simply pull the PPSE on and off
without specific closure elements. The nature of the closure
elements may be selected based on the disability or manual
dexterity of the wearer. For example, a wearer with good dexterity
may be able to pull the PPSE on and off without any closure
elements, whereas a patient with limited dexterity may require a
zipper with large, looped pulls to don and doff the PPSE
independently.
Stretch Profiles
FIGS. 3A-3C: Actuation Control for Stretching
[0043] FIGS. 3A-3C illustrate the elements of actuation control of
an ankle stretching PPSE according to certain embodiments of the
present disclosure. Each control scheme has a two-stage stretch and
hold scheme, in order to maximize the amount of plastic deformation
in the connective tissue, which leads to increased range of motion.
Each control scheme is described in terms of numbered segments of
time (the horizontal axis in all graphs). The stretch and hold
actions are actuated by FLAs and held by clutches, with controls
enabled by measurements of time, actuator force, foot reaction
force, ankle joint position, and muscle electromyography (See FIG.
2). Specific force and joint position levels are pre-set in the
programming step (See FIG. 7), as indicated in the descriptions
below. The PPSE controls three biomechanical degrees of freedom of
the foot and ankle (see FIG. 1 and FIG. 2), and for clarity the
joint position here is representative of stretch in all three
degrees of freedom, which will be controlled simultaneously.
Throughout each stretch segment, the joint position will not exceed
a safety threshold position (307) set at programming.
FIG. 3A: Control Scheme for Position-Controlled Stretch
[0044] FIG. 3A illustrates one control system, a
position-controlled stretch. The vertical axis (301) is the
relative ankle joint position, with a resting position indicated as
the starting position (302). In users with joint contracture, the
resting position can be dorsiflexed to varying degrees. The
positive direction (303) indicates relative dorsiflexion, or
toe-up, and the negative direction (304) indicates relative
plantarflexion, or toe-down. The first stretch segment (320) is a
slow ramp in position actuated by the FLAs, from the resting
position (302) to the Stretch 1 position (305). The time duration
of the stretch ramp time may be such that it does not trigger a
stretch reflex in the muscles of the person being stretched. If
desired, the EMG sensors may be used to monitor the muscles to
ensure no stretch reflex has occurred. The control hardware
responsible for controlling the stretch may record the speed of the
tensile force ramp up and alter that speed depending on whether a
stretch reflex is detected. For example, if a stretch reflex is
detected, the control hardware may adjust the ramp up time such
that the increase in force occurs over a longer period of time.
Stretch1 position (305) is set during programming. The second
stretch segment (321) is a hold of position Stretch (305) for a set
period of time. The set period of time for hold position (305) may
be any suitable period of time. In some embodiments, the set period
of time can be long enough to ensure sufficient stretch of the
tissue in the foot. For example, it has been found that time
periods of at least four or five minutes are required to ensure
that the tissue within the foot has been sufficiently stretched.
Thus, an advantage of the PPSE is that it is able to maintain the
necessary stretch force throughout the entire stretch duration. By
contrast, a therapist or the human receiving stretch treatment is
unable to match the PPSE in its ability to provide a constant force
for an extended period of time. The hold may be actuated by the
motor in the FLA, mechanical clutching, or electrolaminate
clutching. The third stretch segment (322) may be a slow ramp in
joint position actuated by the FLAs, at which point, the clutch (if
any) is release. The joint position Stretch2 (306) may be set
during programming and may be greater than Stretch2 (306). The
fourth stretch segment (323) is a hold of position Stretch2 (306),
and may be actuated by mechanical clutching or electrolaminate
clutching. Duration of hold is set during programming, and the
duration hold can be any suitable period of time (e.g., 20-30
seconds, a few minutes, or five minutes or more). The fifth stretch
segment (324) can be a slow ramp of position back to the resting
posture (302). This can be actuated by slow reverse or controlled
release of the actuators. If desired, the release segment 324 can
be relatively fast in that an instant step change to the resting
posture (302) may be achieved. It should be appreciated that
anytime during the stretch routine, the user can instruct the PPSE
to disengage so that the foot returns to the resting posture (302).
Moreover, the user may also be provided with the opportunity adjust
the force tension and hold duration, as desired.
FIG. 3B: Control Scheme for Viscoelastic-Triggered Stretch
[0045] FIG. 3B illustrates a stretch control system based on
measuring stress relaxation in the joint with force sensors, and
determining the time to hold a stretch based on the measured stress
relaxation. This control scheme enables the stretch from day to day
to be determined by the same force, so on days when a user's joint
is tighter, a smaller distance of stretch is applied. This control
scheme also enables the stretch to be performed in such a way that
it is maximizing the viscoelastic, or plastic, deformations which
are thought to best increase range of motion. In the top graph, as
in FIG. 3A, the vertical axis (301) is the relative ankle joint
position, with a resting position indicated as the starting
position (302). The positive direction (303) indicates relative
dorsiflexion, or toe-up, and the negative direction (304) indicates
relative plantarflexion, or toe-down. In the bottom graph, the
vertical axis (310) is the relative stretch force in the joint,
with rest position at zero (311).
[0046] The first stretch segment (340) is a slow ramp in position
actuated by the FLAs, from the resting position (302) to an end
position (312) that is defined by the position at which the stretch
force reaches a specified level (313), as programmed. The stretch
force can be determined by the contactor force applied by FLAs or
can be measured using a sensor. In one embodiment, the specified
level (313) can set on-the-fly by the user. For example, the
stretch force may increase at constant rate and the user can
instruct the PPSE to cease increasing the stretch force by
providing an input to a user interface. The first stretch segment
can also be a ramp in force up to a defined force level, because
the force is expected to raise exponentially with a ramp in
position. The second stretch segment (341) is a hold of position
(312). During this position hold, the joint is expected to relax
viscoelastically. Once the force relaxes to a programmed level
(314) set in the programming step, the third stretch segment (342)
begins. The third stretch segment is a ramp in position up to the
position at which the same force level (313) programmed for the
first stretch segment occurs. Due to viscoelastic relaxation during
the second stretch segment, the force level (313) is expected to
occur at a more dorsiflexed joint position (315) as compared to
joint position (312) reached during the first stretch segment
(340). The fourth stretch segment (343) is a hold at the position
(315) defined by the programmed force level (313), with measurement
of force relaxation. When the measured stress reaches the
programmed level (314), the fifth segment (344) begins. In the
fifth segment, the joint is slowly released back to the resting
position, by releasing the clutching and reversing or releasing the
actuators. The viscoelastic time constant of collagen is around 100
seconds. Therefore, the approximate time of the stretch can be
predicted by the ratio of the max stretched force and the target
relaxation force level (314) according to standard exponential
relationship:
t = - .tau. ln ( F target F max ) ##EQU00001##
A reduction to 61% of max force can occur over 50 seconds, to 36%
of F.sub.max can occur over 100 seconds, and to 13% of F.sub.max
can occur over 200 seconds. Thus this control mode can result in
stretch sequences lasting several minutes to a half hour.
[0047] If desired, the stretch and hold segments can be repeated as
many times as desired during a stretch session. The stretch forces,
positions, hold segments are selected to target the viscoelastic
parameters of the joint (e.g., foot) and tissue.
FIG. 3C: Control Scheme for Active Stretch with EMG
[0048] FIG. 3C illustrates a stretch control system based on the
above system with actuated stretch and hold, measurement of
viscoelastic relaxation, with the addition of muscle activation at
the joint by the user to assist the stretch. The active stretch may
pull the joint into a deeper stretch by means of mechanical
assistance (muscle pulling in parallel with the actuators) and
neural reciprocal inhibition. In reciprocal inhibition, the
activation of muscles with one action at the joint inhibits
activation of the muscles with opposing action at the joint
(antagonists). In the case of the ankle, the activation of the
tibialis anterior and other dorsiflexors can inhibit the action of
the gastrocnemius, soleus, and other plantarflexors. The user can
be instructed when to activate the muscles through the phone/tablet
application (346), and activation can be measured with EMG sensors
in the device (see FIG. 2C-2D). Reciprocal inhibition may be
verified by EMG measurement of the muscles to be stretched, in this
example the gastrocnemius and soleus (See FIG. 2C-2D).
[0049] As in FIGS. 3A and 3B, the top graph shows relative joint
position. The vertical axis (301) is the relative ankle joint
position, with the resting position indicated as the starting
position (302). In the middle graph, as in FIG. 3B, the vertical
axis (310) is the relative stretching force (torque) in the joint,
with the no-load rest position at zero (311). The vertical axis on
the bottom graph shows the relative force in the actuators
(340).
[0050] In the first stretch segment (361), the user activates
muscles that are agonists to (work in the same direction as) the
direction of the stretch (at the ankle, the tibialis anterior and
other dorsiflexors) to near-maximal effort or level of tolerance,
at the cue of the tablet/phone application. The actuators match the
voluntary dorsiflexion motion, and provide actuation forces to
balance the foot rotation and ankle eversion (See FIG. 2A-2B).
These two degrees of freedom are more difficult for users with
neuromuscular disease to control voluntarily. The actuation of the
separate degrees of freedom are not represented separately in the
graph. The first stretch segment (361) ends when the maximum
voluntary position (342) is reached, defined by either a preset
level or no further increase over a small time range, for example
300 milliseconds. At the end of the first stretch segment (361),
the stretch force in the joint is high (343) even though the
actuator force is low (341) because the muscles are pulling in
parallel with the actuators. In the second stretch segment (362),
the joint position (342) is held by the actuators, such as with
mechanical clutching, with the continued activation of the
dorsiflexion muscles. In the third stretch segment (363), the same
joint position is held (342), and the dorsiflexion muscles are
relaxed, with the device providing increased force (344). In the
fourth stretch segment (364), similar to the first stretch segment
(361), the dorsiflexors are activated voluntarily to reach the
maximum possible stretched position (345). This stretch position
may or may not be above the previously held position (342). The
motors again match the dorsiflexion position and provide balancing
forces to control the rotational degrees of freedom of the foot and
ankle. The stretch force in the joint increases (343), while the
actuation force remains low (341). In stretch segment (365), as in
segment (362), the device holds the joint position, for example
with clutching, while the user continues to voluntarily activate
the agonist muscles. The stretch force decreases with viscoelastic
relaxation (347). In stretch segment (366), as in segment (363),
the user relaxes the dorsiflexion muscles and the device holds the
joint position, with increased actuation force (344). The end of
segments (363) and (366) may be triggered by joint force level
(347), similar to segments (341) and (343) in FIG. 3B or by time,
similar to segments (321) and (323) in FIG. 3A. In the final
segment (367), the joint is slowly released back to the resting
position.
Contour Blocks (Ankle)
[0051] FIGS. 4A-4C illustrate a system of contour blocks that can
form a desired profile when actuated, and relax to allow
flexibility when not actuated according to certain embodiments of
the present disclosure. The system of contour blocks may be used in
a PPSE application to adequately support anatomical structures such
as the plantar surface of the foot, while allowing flexibility for
donning and doffing.
FIG. 4A: Contour Blocks (Released)
[0052] FIG. 4A illustrates a system of contour blocks. A plurality
of blocks (401) are strung on a cable (402). The cable is initially
slack, such that the system of contour blocks is loose and
flexible. This permits the system to be easily pulled on or off the
body, for example a foot, without significant resistance. The
contour blocks may be constructed from any suitable material. For
example, the blocks may be constructed from a foam material or a
material that can compress under load. As another example, the
contour blocks can be constructed from plastic, metal, fabric,
wood, foam, or any combination thereof. The blocks may be
constructed to have different densities such that higher density
blocks provide more stability or rigidity than lower density
blocks.
FIG. 4B: Contour Blocks (Tightened)
[0053] FIG. 4B illustrates the system of contour blocks of FIG. 4A
when tightened. Applying tension (T) to the cable (402) pulls the
blocks (401) together in such a way that the blocks together form
contoured surfaces that support the wearer's anatomy. In this
example, a first contour (403) supports the instep and front of the
ankle, a second contour (404) supports the plantar surface of the
foot, and a third contour (405) supports the heel or calcaneous
bone. Applying the tension (T) to the cable (402) may be
accomplished with an FLA. When the FLA is actuated, the cable (402)
is tightened, which simultaneously draws the blocks (401) together
to form the contoured surfaces (403, 404, 405) and draws the foot
into dorsiflexion for the stretch. In this example the cable is
continuous, passing around a pully (406) at the front of the foot,
and extending back to the blocks that support the contour at the
heel (405). Thus, as when the FLA is actuated, in addition to
pulling the blocks together, compressive forces (410, 411, 412) are
generated at the front of the ankle, under the
metatarsal-phalangeal (MTP) joint and on the back of the heel,
which together generate a torque about the center of rotation of
the ankle (408) to rotate the foot in dorsiflexion (407). Although
not shown in FIG. 4B, additional contour blocks can be added and
connected to another FLA to provide a heel eversion stretch.
FIG. 4C: Contour Blocks
[0054] FIG. 4C illustrates an alternative embodiment utilizing
contour blocks in an ankle PPSE. As in FIG. 4B, contour blocks
(401) create contoured surfaces (404, 405) that support the plantar
surface and calcaneous or heel. As above, the cable loops around a
pully (406) at the front of the foot. The cable additionally loops
around a second pulley (409) near the heel, passing forward to
either a strap or contour blocks on the front of the ankle (413).
As in the example of FIG. 4B, tension in the cable (402) draws the
contour blocks together to create the contoured surfaces (404, 405)
and generates compressive forces (410, 411, 412) on the front of
the ankle, under the MTP joint and on the back of the heel, which
together generate a torque about the center of rotation of the
ankle (408) to rotate the foot in dorsiflexion (407).
Footplate, Cable-Supported
[0055] FIGS. 5A-5J illustrate concepts for a cable-supported
footplate for use in an ankle stretching PPSE according to certain
embodiments of the present disclosure.
FIG. 5A: Top-Front View of Foot and Cable-Supported Footplate
[0056] FIG. 5A illustrates the top-front view of a foot and
cable-supported footplate for use in an ankle stretching PPSE. The
footplate (501) is seen extending just beyond the sides of the
widest point of the foot. The five MTPs are the joints between the
metatarsals (MT) and phalanges (P), approximately along the dotted
line (502). The footplate (501) is constructed to have a built in
spring bias that applies an upward force at the center (550) of the
footplate (501) and downward forces at the ends (560 and 570). A
cable (503) is attached to end (560) and the same cable (503) is
attached to the other end (570). A first FLA (not shown) may be
coupled to the end (560) and a second FLA (not shown) may be
coupled to end (570).
FIGS. 5B-5C: Unloaded Cable-Supported Foolplate
[0057] FIGS. 5B-5C illustrate the front view of the cable-supported
footplate in an unloaded state, through a cross-section of the MTP
joints (MTP). The cable (503) supporting the footplate (501) is
loose or slack such that the footplate (501) exerts minimal
pressure against the plantar surface of the foot (504) such that
the MTPs (MTP) and connective tissue (CT) between the MTPs is in a
relaxed or free state.
FIGS. 5D-5E: Loaded Cable-Supported Footplate
[0058] FIGS. 5D-5E illustrate the front view of the cable-supported
footplate in a loaded state, through a cross-section of the MTP
joints (MTP). The cable (503) supporting the footplate (501) is now
tightened such that the footplate (501) presses against the plantar
surface of the foot (504) such that the connective tissue (CT)
between the MTPs (MTP) is stretched. Applying tension to the cable
thus stretches the connective tissue between the MTPs, and
depending on the placement of the cable may also stretch the ankle
in dorsiflexion or eversion. The upward bias force 550 is still
applied even though cable (503) is pulling up on ends (560 and
570). This combination of forces ensures that the MTP joints of the
foot are stretched across a width of the footplate (501), and
prevents the outer MTP joints (e.g., MTP joints 1 and 5) from
rotating too far around a center MTP joint (e.g., MTP joint 1) in a
manner that creates discomfort for the owner of the foot. Thus,
under tension by footplate (501), the MTP joints are spreadout
across the footplate (501), thereby placing the foot in an balanced
loading position ideal for dorsiflexion and heel eversion
stretches.
FIGS. 5F-5G: Plantar Vs. Ankle Stretch
[0059] FIGS. 5F and 5G illustrate how an upward force applied to
the front of the foot can stretch either the plantar fascia (5F) or
stretch the ankle in dorsiflexion (5G). In both FIGS. 5F and 5G, an
upward force (F) is applied to the front portion of the foot in the
region of the MTPs. In FIG. 5F the plantar surface (504) is
unsupported, such that the upward force (F) causes the foot itself
to flex upward (505), affecting the arch (506) of the foot and
stretching the plantar fascia. In FIG. 5G, the plantar surface
(504) is supported, such as with a footplate or contour blocks,
such that the upward force (F) causes the ankle to rotate (507)
into dorsiflexion about its center of rotation (508), while the
arch (506) is substantially unaffected. As the ankle rotates (507),
the heel (509) also moves forward (which assists in stretching the
Achilles tendon).
FIGS. 5H-5I: Footplate Properties
[0060] FIG. 5H shows a footplate (510) with a longitudinal axis
(511) and a transverse axis (512). The footplate is designed such
that it has different bending and torsional stiffnesses in the
different axes. The different stiffnesses may be achieved through
material selection or properties such as embedded fiber
orientation, or through design geometry. In this ankle stretching
PPSE example, the footplate (510) has torsional flexibility (513)
about the long axis (511), which may facilitate eversion stretches,
as well as allow balanced loading across the foot. The footplate
(510) is more rigid to provide resistance in flexing (514) along
the longitudinal axis (511) or bending (515) about the transverse
axis (512). This rigidity along the longitudinal axis (511)
provides support to the plantar surface in order to stretch the
ankle in dorsiflexion vs. stretching the plantar fascia, as
described above. In some embodiments, the footplate (501) need not
span the entire length of the foot and may span from the toes to
the beginning of the calcaneous bone.
[0061] FIG. 5I illustrates the footplate (510) of FIG. 5H in situ
on a foot. A cable (516) is threaded under the footplate (510). An
upward force (F) applied to the cable, typically by one or more
FLAs, creates the dorsiflexion torque about the center of rotation
(508) of the ankle, such that the ankle rotates (507) in
dorsiflexion for the stretch. In this example, the cable (516) is a
continuous loop that passes underneath the footplate (510), looping
behind the heel through a heel strap (517). Thus the tension in the
cable generated by the upward force (F) also creates a compressive
force (518) against the heel, assisting with the ankle dorsiflexion
stretch. The FLAs may pull on attachment points (not shown)
existing on the footplate (501), which causes the upward force (F)
and also translates to the compressive force (518).
FIG. 5J: Coupling of FLA to Footplate and Cable
[0062] FIG. 5J illustrates the coupling of an FLA (521) to the
footplate (510) and cable (516) of FIG. 5I. The FLA action can
depend on the rotation of a twisted string. The anchor point (522)
for the rotation is provided by a strap (523). The cable (516) is
attached to the anchor point (522), which may be a Chicago screw
that is anchored through the strap (522). Strap (523) may include
first and second FLA anchor points or attachment members (only one
of which is shown in FIG. 5J). A first FLA may be coupled to the
first FLA anchor point (522) and a second FLA may be coupled to the
second anchor point (not shown). The linear tension in the FLA
(521) is transferred to the cable (516) via the anchor point (522)
by making the relative lengths of the strap and cable such that the
FLA (521) tension pulls the cable (516) taut, but the strap (523)
is still slightly loose. The linear tension in the second FLA (not
shown) is transferred to the cable (516) via the second anchor
point by making the relative lengths of the strap and cable such
that the second FLA tension pulls the cable (516) taut, but the
strap (523) is still slightly loose. When both FLAs are engaged,
footplate 510 may perform a dorsiflexion stretch. When only a first
FLA is activated (e.g., such as FLA attached to the anchor point on
the inside part of the foot), footplate 510 may perform an eversion
stretch. When only a second FLA is activated (e.g., such as the FLA
attached to the anchor point on the outside part of the foot),
footplate 510 may perform a peroneals stretch.
Footplate with Contour Blocks and Electrolaminate Clutch
[0063] FIGS. 6A-6B illustrate footplate with Contour Blocks and
electrolaminate clutch according to certain embodiments of the
present disclosure.
FIG. 6A: Loose/Relaxed Footplate with Contour Blocks and
Electrolaminate Clutch
[0064] FIG. 6A illustrates a footplate (601) with contour blocks
(602) in its loose or relaxed state. A cable (603) threaded through
the contour blocks is loose or slack. The electrolaminate clutch
(604) in the footplate is disengaged such that the contour blocks
are free to separate along the cable. This facilitates donning and
doffing the PPSE, as well as wearer comfort by not applying
pressure to the bottom of the foot when a stretch is not being
performed.
FIG. 6B: Tightened/Actuated Footplate with Contour Blocks and
Electrolaminate Clutch
[0065] FIG. 6B illustrates the footplate with contour blocks and
electrolaminate clutch in its actuated or tightened state. A force
(F) is applied to the cable (603). The force (F) may be the upward
force on the front of the foot that assists with the dorsiflexion
stretch, or an independent force. The force (F) tightens the cable
(603), drawing the contour blocks (602) together and against the
bottom of the footplate (601). The pressure of the contour blocks
(602) against the footplate (601) causes the footplate to bend
(605) away from its undeformed contour (606) to conform to the
profile of the contour blocks (601). Engaging the electrolaminate
clutch (604) in this state can maintain the contour blocks in this
configuration even if tension in the cable (602) is released.
Usage Model
FIG. 7: Example Usage Model Flowchart
[0066] FIG. 7 provides a flowchart of an exemplary usage model of a
PPSE according to certain embodiments of the present disclosure.
The PPSE can be prescribed by a referring provider such as a
clinician, physical therapist or physician (701). The PPSE can then
be fit (702) to the individual wearer, typically by an orthotist
who can assess the wearer for parameters such as size, required
forces or specific stretches that have been prescribed. The PPSE is
then prepared (703) for the individual wearer, either by the
orthotist from a standard set of components, or at a fabrication
facility for example if custom components are required.
[0067] The PPSE is then programmed for the specific stretches
prescribed for the wearer. In a first programming step (704), the
PPSE "learns" stretches as they are performed by a therapist. For
example, a therapist may manually perform a dorsiflexion ankle
stretch, applying the appropriate amount of force or resistance
based on their training and familiarity with the wearer's needs.
The PPSE can detect the forces applied during the stretch, for
example with pressure sensors in the footplate, goniometers at the
ankle joint, or other elements of the sensors and controls layer.
This enables the PPSE to reproduce the stretch as performed by the
therapist via the sensors and controls layer. In a second
programming step (705), the stretching regimen or routine is
programmed, including the stretch duration and frequency. The
wearer is then trained (706) in use of the PPSE, for example how to
don and doff the system, clean and care for the device, and any
specific guidelines or techniques for the stretching regimen with
the PPSE.
[0068] The wearer is then released to use the PPSE for independent
stretch assistance at home (707). Depending on the prescribed
stretches and wearer's capabilities, the PPSE may be worn for
stretching while asleep, during leisure time or other appropriate
settings for a given stretch sequence. While at use in the home,
the sensors and controls layer of the PPSE logs data pertaining to
the stretching regimen, including wearer compliance with the
regimen, PPSE status, and analytics related to the stretches such
as range of motion and joint stiffness. These data are logged and
reported to a clinician, therapist, caregiver or other individual
or service (708). Based on these data, the stretch regimen
programming is adjusted, as necessary (709).
FIG. 8: PPSE Learning
[0069] FIG. 8 illustrates the PPSE "learning" a stretch according
to certain embodiments of the present disclosure. A therapist (801)
is manually performing an ankle dorsiflexion stretch for a patient
(802) who is wearing an ankle-stretching PPSE (803). The sensors
and controls layer of the PPSE (803) detects parameters of the
stretch such as range of motion via a goniometer; foot pressure
distribution via pressure sensors in the footplate, or other forces
or motions in the PPSE. The PPSE is then able to reproduce this
stretch by actuating power layer components such as FLAs (804)
controlled by the sensors and controls layer.
Ankle Traction Cuff
[0070] Traction typically increases the range of motion of a joint,
which facilitates stretching and may increase the effectiveness of
a stretch. FIGS. 9A-9H illustrate a cuff for applying traction to
the ankle joint to facilitate ankle stretches according to certain
embodiments of the present disclosure.
FIG. 9A: Ankle Traction Cuff on Ankle
[0071] FIG. 9A illustrates an ankle traction cuff (901) on an ankle
(902). The ankle cuff is generally barrel-shaped, with a larger
diameter in its central section (903) than its end sections (904).
One or more cables (905) encircle the ankle, typically embedded or
laced through the body of the cuff (906) in a generally
circumferential arrangement around the cuff. Applying tension to
the one or more cables constricts the central, barrel portion of
the cuff, causing the entire cuff to elongate and apply traction to
the ankle joint.
FIG. 9B-9E: Cuff Body
[0072] FIG. 9B illustrates the cuff body (906). The cuff has an
upper opening (907), lower opening (908) and central channel (909).
The cuff is made from a deformable material with substantially
elastic properties such that it will return to its undeformed
state. In its undeformed state, the cuff has the barrel-shaped
configuration as described above. When tension is applied to the
one or more cables, the cuff is constricted to a deformed profile
(910) with reduced diameter along the central section.
[0073] FIG. 9C illustrates a cross section of the cuff body (906)
and the compressive forces (911) applied by the one or more cables
to constrict and deform the cuff body. FIG. 9D illustrates the cuff
body (906) in both its deformed profile (910) and undeformed
profile (912). As the larger, undeformed diameter (D.sub.0) is
constricted to the smaller, deformed diameter (D.sub.1), the
shorter, undeformed length (L.sub.0) elongates to the longer,
deformed length (L.sub.1) to generate the traction. FIG. 9E
illustrates the contact areas (913, 914).
FIGS. 9F-9H: Cuff Cable Configurations
[0074] FIGS. 9F and 9G illustrate possible configurations of the
one or more cables. FIG. 9F illustrates one or more cables (905) in
a generally parallel, circumferential configuration. FIG. 9F
illustrates the one or more cables (905) in a crossing
configuration, in this example crossing at a point (915) on the
side of the ankle. The crossing configuration may permit more range
of motion for the cuff to bend when the ankle flexes, as well as
permit optimization of the stiffness or deformation pattern of the
cuff. FIG. 9H illustrates an automated tightening mechanism (916)
to tighten and release all cables, to enable automatically
programmed sequences of traction and release.
FIG. 10: Pressure Sensor Array Integrated into Semi-Rigid Assembly
to Sense Distribution of Load on Foot to Control Stretch
Biomechanics
[0075] FIGS. 10A-10C illustrate a pressure sensor array integrated
into a soft and semi-rigid assembly, which is used to sense
distribution of load on the foot or ankle for the purposes of (1)
measuring the stretch biomechanics during a calibration step and
(2) controlling the actuation load and balance of load during
application of stretch according to certain embodiments of the
present disclosure.
[0076] FIG. 10A illustrates a single pressure sensing area (force
sensitive resistor, FSR) (1001) integrated into a strap (1000). The
strap can be used to integrate the sensor into the PPSE and for
load application, and can be made of nonconductive webbing or
similar narrow fabric with low extensibility. The pressure sensing
material changes electrical resistance with applied pressure to
make a force sensitive resistor (FSR). The FSR (1001) is stitched
in place using a combination of conductive and nonconductive thread
to make mechanical contact around all 4 sides and electrical
connections (1002) along 2 opposite sides. The electrical
connections (1002) are made by stitching the FSR with conductive
thread on the side that contacts the FSR and nonconductive thread
on the opposite side (1003). The remainder of the FSR perimeter
(1004) is stitched with nonconductive thread (NCT), to provide
mechanical connection between the FSR and the strap without making
electrical contact between the conductive threads. The conductive
thread (1003) stitching continues from each contact with the FSR
out to the location at which electrical contacts are to be made
(1005), in this case the ends of the strap. The FSR area (1001) and
the conductive threads (1003) are electrically insulated by
lamination (1010). The lamination layer (1007) leaves some of the
conductive thread exposed to make electrical contact (1005). The
force sensitive resistor assembly can be integrated into the
wearable device at a specific location on the foot or leg, and the
resulting resistance used as a readout sensor, for example using a
voltage divider circuit.
[0077] FIG. 10B illustrates a spatial array of pressure sensors
integrated into an assembly with a semirigid plate (1007) and strap
(1008) to measure the relative pressure across different areas of
the foot for the purpose of controlling the loads applied to ankle
inversion/eversion and midfoot rotation. In this example, there are
two pressure sensor areas (FSRs) (1001). By sensing the difference
in pressure between the medial and lateral sides of the arch of the
foot, or the medial and lateral sides of the ball of the foot, the
device can sense and control the desired amount of ankle eversion
and midfoot rotation, respectively. The FSRs are in an assembly of
a padded (1015) semirigid plate (1011) which is shaped to the
desired contour and strap (1008) for integration with the PPSE and
load application. The plate serves to balance heterogeneity in the
local stiffness of the foot to more repeatably measure the
difference in force across the array, in this example medially and
laterally. The plate can be shaped to the desired surface contours
as described above (e.g. see FIGS. 5A-J, 6A-6B).
[0078] The FSRs (1001) are stitched with one common conductive
thread connecting them electrically (1006), to be used as a common
ground. Each FSR has a separate electrical contact with the
conductive thread (1009), which is not connected to the other FSR.
As in FIG. 10A, The FSRs are stitched using a combination of
conductive and nonconductive thread to make mechanical contact
around the full perimeter and electrical connections (1002) along
two opposite sides. The conductive thread (1003) is only on the
side of the substrate that is contacting the FSR. The opposite side
of the substrate has the nonconductive thread. The side of the
strap with the FSR and conductive thread is laminated (1010) for
electrical isolation, leaving the ends of the conductive threads
open for electrical contact (1005).
[0079] FIG. 10C illustrates and embodiment of the layers of the
assembly in FIG. 10B. The plate (1011) is shaped to the desired
profile and covered in a padded sleeve (1015). This padded plate is
against the surface of the foot (1017). The FSR (1001) is stitched
onto the strap (1008) with conductive thread (1003) contacting the
FSR and nonconductive thread (1016) on the opposite side.
Electrical isolation is achieved with the laminate (1010). In this
example, the FSRs sense the relative load applied by the straps on
either side of the foot. It can be appreciated that the layers may
be ordered in different combinations if beneficial. For example,
positioning the FSRs (1001) between the foot surface (1017) and
plate (1011) may provide more sensitive detection of pressures on
either side of the foot.
FIG. 11. Contour Blocks: Cable-Actuated 3D Structures for Joint
Mobilization, Stabilization, and Compression
[0080] FIGS. 11A-11F illustrates the design parameters for contour
blocks, which are cable-actuated 3D structures according to certain
embodiments of the present disclosure. Contour blocks may be used
for joint mobilization, stabilization, and compression. Separated
blocks (FIG. 11F) or connected block trains (FIG. 11A-11E) have
cables located in channels passing through the blocks.
Three-dimensional features are designed into the blocks such that
the final conformation under cable tension is defined. Cable
tension may be achieved with actuators such as FLAs or remote
actuators connected for example via Bowden cables. When cable
tension is applied to achieve the intended conformation,
arrangements of contour blocks can be used to control the pressure
distribution and grip points on the body as described above (e.g.
see FIGS. 4A-4C, 6A-6B). Materials are envisioned to be rigid
(separated blocks) to semi-rigid (block trains), such as silicones
or stiff foams, with possible heterogeneous material
properties.
[0081] FIG. 11A illustrates the mechanism of action of
cable-actuated contour blocks operating in a single curvature
motion. The figure shows a block train (1101) with the cable (1102)
not under load. The cable runs through a channel (1103) in the
block train positioned within the cross section such that it passes
through the voids (1104) in the train. To enable the compression
force to be generated, the edge of the block train is held with a
reaction force at one end (1105), and the cable kept from slipping
through the block by a clamp (1106) at the other end of the
train.
[0082] FIG. 11B illustrates the block train (1101) in FIG. 11A with
the cable (1102) under load. The voids (1104) close and the narrow
parts of the train cross section (1107) bend along the desired
contour due to the tension in the cable and the reaction forces
(1105, 1106).
[0083] FIG. 11C illustrates a block train with features in opposing
directions (1121) to generate more complex curvatures. This example
has four actuation voids, two on one side (1122) and two on the
opposite side (1123), with a cable (1101) passing through a channel
(1124) in the blocks and crossing all four voids. The reaction
points (1105, 1106) on the train and cable are needed, but omitted
in the figure for clarity.
[0084] FIG. 11D illustrates the block train in FIG. 11C with the
cable under tension, demonstrating an S-curve. As in FIG. 11B, the
cable tension causes the voids (1122,1123) to close and the small
cross sectional areas on opposing sides (1125) to bend along the
desired contour. The geometry and location of the voids control the
resulting shape of the bend and the load-displacement relationship
(stiffness). The reaction points (1105, 1106) on the train and
cable are needed, but omitted in the figure for clarity.
[0085] FIG. 11E illustrates the parameters for design of contour
block chains (1131) for controlled curvature in one plane. The
narrow part of the train (1132) can be modeled as a bending beam.
For longer void length L (1133), the resulting angle between the
consecutive blocks under full tension increases and the bending
stiffness decreases. For shorter void depth D (1134), the curve
radius shortens and the resulting angle between the consecutive
blocks under full tension is increased. For increased distance S
(1135) from beam bending axis (1136) to string position (1137), the
tension required to bend the train decreases and the stroke length
required to bend the structure increases.
[0086] FIG. 11F illustrates contour blocks with features to
generate curvature in 3 dimensions. The x axis of each block is
defined to be the channel. In this example, one block (1141) is
shaped such that the mating surface (1142) is rotated slightly
about the z axis. The adjacent block (1143) has a mating surface
(1144) with an angle rotated slightly about its y axis. Thus, when
the cable is under tension, the x axis of block (1143) can be
rotated relative to the x axis of block (1141) about both the y and
z axes of block (1141).
[0087] In this example the blocks are separated for clarity in the
illustration, but can be connected by narrow segments with
arbitrary shapes and angles to control effective bending stiffness
and position of the structure under no-load condition. Blocks can
also be combined with multiple channels in different directions to
create networks of contour blocks with controllable contours and
pressure distributions.
FIGS. 12A-12D Configurable System for Rapid Prototyping and Fitting
of PPSE
[0088] FIGS. 12A-12D illustrate a fully and rapidly configurable
system for rapidly prototyping and fitting PPSE according to
certain embodiments of the present disclosure. FIG. 12A is a
lateral view, FIG. 12B is a top view, and FIG. 12C is a medial view
of the configurable system in use. A sock (1201) and leg wrap
(1202) are made of fabric with nonslip surface worn towards the
skin and a surface on the outside that allows the hook side of
hook-and-loop closures to adhere. FLAs (1203) are attached by
hook-and-loop based "fern tape" (1204) to prototype Flexgrips, as
described in International Patent Application PCT/US16/19565,
titled "Flexgrip" and U.S. Provisional Patent Application No.
62/378,471, titled "Systems and Methods for Assistive Exosuit
System."
[0089] FIG. 12D illustrates the graded pattern for the sock. The
pattern pieces include the toe (1205), graded midfoot (1206), heel
bottom (1207), heel back (1208), inner ankle wrap (1209), and outer
ankle wrap (1210).
FIG. 13. Table of Measured and Derived Data
[0090] FIG. 13 describes the data measured by, calculated by, or
entered into the PPSE during the programming and use of the PPSE,
and the use of these data according to certain embodiments of the
present disclosure. These data may include the biomechanical and
programming details of the stretching regimens, and be connected to
a database which stores these data for multiple uses.
[0091] Several direct measurements are made by embedded sensors
integrated into the PPSE as described above, including but not
limited to: skin stretch (1301), joint position (1302), FLA force
(1304), foot pressure (1305), and muscle activity (1307). Several
derived values are calculated from the measurements, including but
not limited to joint position (1302, which may be either directly
measured or calculated), joint velocity (1303), joint torque
(1306). At the programming step, the joint stiffness (1309) and
desired stretch position and torque (1310) are measured, and the
stretch regimen parameters (1311) are entered and recorded locally
in the PPSE and also in the database. The measured, derived, and
entered values can be used to control the position, force, and
duration of the segments of the stretch regimen (for example, as in
FIG. 3). The ability to control the PPSE to perform repeatable
stretch is an improvement over the current standard of
reproducibility based on the feel of the stretch biomechanics and
stretch duration by the person performing the stretch.
[0092] If desired, some or all of the derived data can be reported
to the user and therapist to track disease progression or therapy
effects. The primary readout to track progression is the joint
stiffness (1309), and may also include changes over time in any of
the other measured or derived data, including stretch reflex or
reciprocal inhibition (1307). The PPSE may store the parameters
describing the stretch regimen and the user biomechanics.
[0093] Events that may be detected from the collective sensors
include user effort against the device (1308) and stretch reflex or
reciprocal inhibition in the muscles (1307). Detection of user
effort against the device (1308) or a stretch reflex (1312) may
indicate that the speed or force of the stretch should be
decreased, and/or the duration of the stretch increased, while
detection of reciprocal inhibition (1313) may indicate a beneficial
neuromuscular response to the stretch regimen. These events can be
reported to the therapist and user, along with suggestions to alter
the stretch regimen based on the collected experience stored in the
database.
[0094] The PPSE may use these stored data to suggest stretching
regimens during the programming step, and enable the user and
therapist to access the database to explore successful treatment
regimens for similar users. The collected data may be used to guide
individual therapy, capture innovations in prescribed therapy,
evaluate the impact of drug, gene, or manual therapy treatments,
and document improvement in joint health to guide practitioners and
inform insurance reimbursement.
Methods for Controlling and Applications of a PPSE
[0095] A PPSE can be operated by electronic controllers disposed on
or within the PPSE or in wireless or wired communication with the
PPSE. The electronic controllers can be configured in a variety of
ways to operate the PPSE and to enable functions of the PPSE. The
electronic controllers can access and execute computer-readable
programs that are stored in elements of the PPSE or in other
systems that are in direct or indirect communications with the
PPSE. The computer-readable programs can describe methods for
operating the PPSE or can describe other operations relating to a
PPSE or to a wearer of a PPSE.
[0096] FIG. 14 illustrates an example PPSE 1400 that includes
actuators 1401, sensors 1403, and a controller configured to
operate elements of the PPSE 1400 (e.g., 1401, 1403) to enable
functions of the PPSE 1400. The controller 1405 is configured to
communicate wirelessly with a user interface 1410. The user
interface 1410 is configured to present information to a user
(e.g., a wearer of the PPSE 1400) and to the controller 1405 of the
flexible exosuit or to other systems. The user interface 1410 can
be involved in controlling and/or accessing information from
elements of the PPSE 1400. For example, an application being
executed by the user interface 1410 can access data from the
sensors 1403, calculate an operation (e.g., to apply dorsiflexion
stretch) of the actuators 1401, and transmit the calculated
operation to the PPSE 1400. The user interface 1410 can
additionally be configured to enable other functions; for example,
the user interface 1410 can be configured to be used as a cellular
telephone, a portable computer, an entertainment device, or to
operate according to other applications.
[0097] The user interface 1410 can be configured to be removably
mounted to the PPSE 1400 (e.g., by straps, magnets, Velcro,
charging and/or data cables). Alternatively, the user interface
1410 can be configured as a part of the PPSE 1400 and not to be
removed during normal operation. In some examples, a user interface
can be incorporated as part of the PPSE 1400 (e.g., a touchscreen
integrated into a sleeve of the PPSE 1400) and can be used to
control and/or access information about the PPSE 1400 in addition
to using the user interface 1810 to control and/or access
information about the PPSE 1400. In some examples, the controller
1805 or other elements of the PPSE 1400 are configured to enable
wireless or wired communication according to a standard protocol
(e.g., Bluetooth, ZigBee, WiFi, LTE or other cellular standards,
IRdA, Ethernet) such that a variety of systems and devices can be
made to operate as the user interface 1410 when configured with
complementary communications elements and computer-readable
programs to enable such functionality.
[0098] The PPSE 1400 can be configured as described in example
embodiments herein or in other ways according to an application.
The PPSE 1400 can be operated to enable a variety of applications.
The PPSE 1400 can be operated to enhance the strength of a wearer
by detecting motions of the wearer (e.g., using sensors 1403) and
responsively applying torques and/or forces to the body of the
wearer (e.g., using actuators 1401) to increase the forces the
wearer is able to apply to his/her body and/or environment. The
PPSE 1400 can be operated to train a wearer to perform certain
physical activities. For example, the PPSE 1400 can be operated to
enable rehabilitative therapy of a wearer. The PPSE 1400 can
operate to amplify motions and/or forces produced by a wearer
undergoing therapy in order to enable the wearer to successfully
complete a program of rehabilitative therapy. Additionally or
alternatively, the PPSE 1400 can be operated to prohibit disordered
movements of the wearer and/or to use the actuators 1801 and/or
other elements (e.g., haptic feedback elements) to indicate to the
wearer a motion or action to perform and/or motions or actions that
should not be performed or that should be terminated. Similarly,
other programs of physical training (e.g., dancing, skating, other
athletic activities, vocational training) can be enabled by
operation of the PPSE 1400 to detect motions, torques, or forces
generated by a wearer and/or to apply forces, torques, or other
haptic feedback to the wearer. Other applications of the PPSE 1400
and/or user interface 1410 are anticipated.
[0099] The user interface 1410 can additionally communicate with
communications network(s) 1420. For example, the user interface
1410 can include a WiFi radio, an LTE transceiver or other cellular
communications equipment, a wired modem, or some other elements to
enable the user interface 1410 and PPSE 1400 to communicate with
the Internet. The user interface 1410 can communicate through the
communications network 1420 with a server 1430. Communication with
the server 1430 can enable functions of the user interface 1410 and
PPSE 1400. In some examples, the user interface 1410 can upload
telemetry data (e.g., location, configuration of elements 1401,
1403 of the PPSE 1400, physiological data about a wearer of the
PPSE 1400) to the server 1430.
[0100] In some examples, the server 1430 can be configured to
control and/or access information from elements of the PPSE 1400
(e.g., 1401, 1403) to enable some application of the PPSE 1400. For
example, the server 1430 can operate elements of the PPSE 1400 to
move a wearer out of a dangerous situation if the wearer was
injured, unconscious, or otherwise unable to move themselves and/or
operate the PPSE 1400 and user interface 1410 to move themselves
out of the dangerous situation. Other applications of a server in
communications with a PPSE are anticipated.
[0101] The user interface 1410 can be configured to communicate
with a second user interface 1445 in communication with and
configured to operate a second flexible exosuit 1440. Such
communication can be direct (e.g., using radio transceivers or
other elements to transmit and receive information over a direct
wireless or wired link between the user interface 1410 and the
second user interface 1445). Additionally or alternatively,
communication between the user interface 1410 and the second user
interface 1445 can be facilitated by communications network(s) 1420
and/or a server 1430 configured to communicate with the user
interface 1410 and the second user interface 1445 through the
communications network(s) 1420.
[0102] Communication between the user interface 1410 and the second
user interface 1445 can enable applications of the PPSE 1400 and
second PPSE 1440. In some examples, actions of the PPSE 1400 and
second flexible exosuit 1440 and/or of wearers of the PPSE 1400 and
second PPSE 1440 can be coordinated. For example, the PPSE 1400 and
second PPSE 1440 can be operated to coordinate the lifting of a
heavy object by the wearers. The timing of the lift, and the degree
of support provided by each of the wearers and/or the PPSE 1400 and
second PPSE 1440 can be controlled to increase the stability with
which the heavy object was carried, to reduce the risk of injury of
the wearers, or according to some other consideration. Coordination
of actions of the PPSE 1400 and second PPSE 1440 and/or of wearers
thereof can include applying coordinated (in time, amplitude, or
other properties) forces and/or torques to the wearers and/or
elements of the environment of the wearers and/or applying haptic
feedback (though actuators of the exosuits 1400, 1440, through
dedicated haptic feedback elements, or through other methods) to
the wearers to guide the wearers toward acting in a coordinated
manner.
[0103] Coordinated operation of the PPSE 1400 and second PPSE 1440
can be implemented in a variety of ways. In some examples, one PPSE
(and the wearer thereof) can act as a master, providing commands or
other information to the other PPSE such that operations of the
PPSE 1400, 1440 are coordinated. For example, the PPSE 1400, 1440
can be operated to enable the wearers to dance (or to engage in
some other athletic activity) in a coordinated manner. One of the
PPSEs can act as the `lead`, transmitting timing or other
information about the actions performed by the `lead` wearer to the
other PPSE, enabling coordinated dancing motions to be executed by
the other wearer. In some examples, a first wearer of a first
exosuit can act as a trainer, modeling motions or other physical
activities that a second wearer of a second exosuit can learn to
perform. The first exosuit can detect motions, torques, forces, or
other physical activities executed by the first wearer and can send
information related to the detected activities to the second
exosuit. The second exosuit can then apply forces, torques, haptic
feedback, or other information to the body of the second wearer to
enable the second wearer to learn the motions or other physical
activities modeled by the first wearer. In some examples, the
server 1430 can send commands or other information to the PPSEs
1400, 1440 to enable coordinated operation of the PPSEs 1400,
1440.
[0104] The PPSE 1400 can be operated to transmit and/or record
information about the actions of a wearer, the environment of the
wearer, or other information about a wearer of the PPSE 1400. In
some examples, kinematics related to motions and actions of the
wearer can be recorded and/or sent to the server 1430. These data
can be collected for medical, scientific, entertainment, social
media, or other applications. The data can be used to operate a
system. For example, the PPSE 1400 can be configured to transmit
motions, forces, and/or torques generated by a user to a robotic
system (e.g., a robotic arm, leg, torso, humanoid body, or some
other robotic system) and the robotic system can be configured to
mimic the activity of the wearer and/or to map the activity of the
wearer into motions, forces, or torques of elements of the robotic
system. In another example, the data can be used to operate a
virtual avatar of the wearer, such that the motions of the avatar
mirrored or were somehow related to the motions of the wearer. The
virtual avatar can be instantiated in a virtual environment,
presented to an individual or system with which the wearer is
communicating, or configured and operated according to some other
application.
[0105] Conversely, the PPSE 1400 can be operated to present haptic
or other data to the wearer. In some examples, the actuators 1401
(e.g., twisted string actuators, exotendons) and/or haptic feedback
elements (e.g., EPAM haptic elements) can be operated to apply
and/or modulate forces applied to the body of the wearer to
indicate mechanical or other information to the wearer. For
example, the activation in a certain pattern of a haptic element of
the PPSE 1400 disposed in a certain location of the PPSE 1400 can
indicate that the wearer had received a call, email, or other
communications. In another example, a robotic system can be
operated using motions, forces, and/or torques generated by the
wearer and transmitted to the robotic system by the PPSE 1400.
Forces, moments, and other aspects of the environment and operation
of the robotic system can be transmitted to the PPSE 1400 and
presented (using actuators 1401 or other haptic feedback elements)
to the wearer to enable the wearer to experience force-feedback or
other haptic sensations related to the wearer's operation of the
robotic system. In another example, haptic data presented to a
wearer can be generated by a virtual environment, e.g., an
environment containing an avatar of the wearer that is being
operated based on motions or other data related to the wearer that
is being detected by the PPSE 1400.
[0106] Note that the PPSE 1400 illustrated in FIG. 14 is only one
example of a PPSE that can be operated by control electronics,
software, or algorithms described herein. Control electronics,
software, or algorithms as described herein can be configured to
control flexible exosuits or other mechatronic and/or robotic
system having more, fewer, or different actuators, sensors or other
elements. Further, control electronics, software, or algorithms as
described herein can be configured to control PPSEs configured
similarly to or differently from the illustrated PPSE 1400.
Further, control electronics, software, or algorithms as described
herein can be configured to control flexible exosuits having
reconfigurable hardware (i.e., exosuits that are able to have
actuators, sensors, or other elements added or removed) and/or to
detect a current hardware configuration of the flexible exosuits
using a variety of methods.
Software Hierarchy for Control of a PPSE
[0107] A controller of a PPSE and/or computer-readable programs
executed by the controller can be configured to provide
encapsulation of functions and/or components of the flexible
exosuit. That is, some elements of the controller (e.g.,
subroutines, drivers, services, daemons, functions) can be
configured to operate specific elements of the PPSE (e.g., a
twisted string actuator, a haptic feedback element) and to allow
other elements of the controller (e.g., other programs) to operate
the specific elements and/or to provide abstracted access to the
specific elements (e.g., to translate a command to orient an
actuator in a commanded direction into a set of commands sufficient
to orient the actuator in the commanded direction). This
encapsulation can allow a variety of services, drivers, daemons, or
other computer-readable programs to be developed for a variety of
applications of a flexible exosuits. Further, by providing
encapsulation of functions of a flexible exosuit in a generic,
accessible manner (e.g., by specifying and implementing an
application programming interface (API) or other interface
standard), computer-readable programs can be created to interface
with the generic, encapsulated functions such that the
computer-readable programs can enable operating modes or functions
for a variety of differently-configured PPSE, rather than for a
single type or model of flexible exosuit. For example, a virtual
avatar communications program can access information about the
posture of a wearer of a flexible exosuit by accessing a standard
exosuit API. Differently-configured exosuits can include different
sensors, actuators, and other elements, but can provide posture
information in the same format according to the API. Other
functions and features of a flexible exosuit, or other robotic,
exoskeletal, assistive, haptic, or other mechatronic system, can be
encapsulated by APIs or according to some other standardized
computer access and control interface scheme.
[0108] FIG. 15 is a schematic illustrating elements of a PPSE 1500
and a hierarchy of control or operating the PPSE 1500. The flexible
exosuit includes actuators 1520 and sensors 1530 configured to
apply forces and/or torques to and detect one or more properties
of, respectively, the PPSE 1500, a wearer of the PPSE 1500, and/or
the environment of the wearer. The PPSE 1500 additionally includes
a controller 1510 configured to operate the actuators 1520 and
sensors 1530 by using hardware interface electronics 1540. The
hardware electronics interface 1540 includes electronics configured
to interface signals from and to the controller 1510 with signals
used to operate the actuators 1520 and sensors 1530. For example,
the actuators 1520 can include exotendons, and the hardware
interface electronics 1540 can include high-voltage generators,
high-voltage switches, and high-voltage capacitance meters to
clutch and un-clutch the exotendons and to report the length of the
exotendons. The hardware interface electronics 1540 can include
voltage regulators, high voltage generators, amplifiers, current
detectors, encoders, magnetometers, switches, controlled-current
sources, DACs, ADCs, feedback controllers, brushless motor
controllers, or other electronic and mechatronic elements.
[0109] The controller 1510 additionally operates a user interface
1550 that is configured to present information to a user and/or
wearer of the PPSE 1500 and a communications interface 1560 that is
configured to facilitate the transfer of information between the
controller 1510 and some other system (e.g., by transmitting a
wireless signal). Additionally or alternatively, the user interface
1550 can be part of a separate system that is configured to
transmit and receive user interface information to/from the
controller 1510 using the communications interface 1560 (e.g., the
user interface 1550 can be part of a cellphone).
[0110] The controller 1510 is configured to execute
computer-readable programs describing functions of the flexible
exosuit 1512. Among the computer-readable programs executed by the
controller 1510 are an operating system 1512, applications 1514 a,
1514 b, 1514 c, and a calibration service 1516. The operating
system 1512 manages hardware resources of the controller 1510
(e.g., I/O ports, registers, timers, interrupts, peripherals,
memory management units, serial and/or parallel communications
units) and, by extension, manages the hardware resources of the
PPSE 1500. The operating system 1512 is the only computer-readable
program executed by the controller 1510 that has direct access to
the hardware interface electronics 1540 and, by extension, the
actuators 1520 and sensors 1530 of the PPSE 1500.
[0111] The applications 1514 a, 1514 b, 1514 are computer-readable
programs that describe some function, functions, operating mode, or
operating modes of the PPSE 1500. For example, application 1514 a
can describe a process for transmitting information about the
wearer's posture to update a virtual avatar of the wearer that
includes accessing information on a wearer's posture from the
operating system 1512, maintaining communications with a remote
system using the communications interface 1560, formatting the
posture information, and sending the posture information to the
remote system. The calibration service 1516 is a computer-readable
program describing processes to store parameters describing
properties of wearers, actuators 1520, and/or sensors 1530 of the
PPSE 1500, to update those parameters based on operation of the
actuators 1520, and/or sensors 1530 when a wearer is using the PPSE
1500, to make the parameters available to the operating system 1512
and/or applications 1514 a, 1514 b, 1514 c, and other functions
relating to the parameters. Note that applications 1514 a, 1514 b,
1514 and calibration service 1516 are intended as examples of
computer-readable programs that can be run by the operating system
1512 of the controller 1510 to enable functions or operating modes
of a PPSE 1500.
[0112] The operating system 1512 can provide for low-level control
and maintenance of the hardware (e.g., 1520, 1530, 1540). In some
examples, the operating system 1512 and/or hardware interface
electronics 1540 can detect information about the PPSE 1500, the
wearer, and/or the wearer's environment from one or more sensors
1530 at a constant specified rate. The operating system 1512 can
generate an estimate of one or more states or properties of the
PPSE 1500 or components thereof using the detected information. The
operating system 1512 can update the generated estimate at the same
rate as the constant specified rate or at a lower rate. The
generated estimate can be generated from the detected information
using a filter to remove noise, generate an estimate of an
indirectly-detected property, or according to some other
application. For example, the operating system 1512 can generate
the estimate from the detected information using a Kalman filter to
remove noise and to generate an estimate of a single directly or
indirectly measured property of the PPSE 1500, the wearer, and/or
the wearer's environment using more than one sensor. In some
examples, the operating system can determine information about the
wearer and/or PPSE 1500 based on detected information from multiple
points in time. For example, the operating system 1500 can
determine an eversion stretch and dorsiflexion stretch.
[0113] In some examples, the operating system 1512 and/or hardware
interface electronics 1540 can operate and/or provide services
related to operation of the actuators 1520. That is, in case where
operation of the actuators 1520 requires the generation of control
signals over a period of time, knowledge about a state or states of
the actuators 1520, or other considerations, the operating system
1512 and/or hardware interface electronics 1540 can translate
simple commands to operate the actuators 1520 (e.g., a command to
generate a specified level of force using a twisted string actuator
(TSA) of the actuators 1520) into the complex and/or state-based
commands to the hardware interface electronics 1540 and/or
actuators 1520 necessary to effect the simple command (e.g., a
sequence of currents applied to windings of a motor of a TSA, based
on a starting position of a rotor determined and stored by the
operating system 1510, a relative position of the motor detected
using an encoder, and a force generated by the TSA detected using a
load cell).
[0114] In some examples, the operating system 1512 can further
encapsulate the operation of the PPSE 1500 by translating a
system-level simple command (e.g., a commanded level of force
tension applied to the footplate) into commands for multiple
actuators, according to the configuration of the PPSE 1500. This
encapsulation can enable the creation of general-purpose
applications that can effect a function of an PPSE (e.g., allowing
a wearer of the PPSE to stretch his foot) without being configured
to operate a specific model or type of PPSE (e.g., by being
configured to generate a simple force production profile that the
operating system 1512 and hardware interface electronics 1540 can
translate into actuator commands sufficient to cause the actuators
1520 to apply the commanded force production profile to the
footplate).
[0115] The operating system 1512 can act as a standard,
multi-purpose platform to enable the use of a variety of PPSEs
having a variety of different hardware configurations to enable a
variety of mechatronic, biomedical, human interface, training,
rehabilitative, communications, and other applications. The
operating system 1512 can make sensors 1530, actuators 1520, or
other elements or functions of the PPSE 1500 available to remote
systems in communication with the PPSE 1500 (e.g., using the
communications interface 1560) and/or a variety of applications,
daemons, services, or other computer-readable programs being
executed by operating system 1512. The operating system 1512 can
make the actuators, sensors, or other elements or functions
available in a standard way (e.g., through an API, communications
protocol, or other programmatic interface) such that applications,
daemons, services, or other computer-readable programs can be
created to be installed on, executed by, and operated to enable
functions or operating modes of a variety of flexible exosuits
having a variety of different configurations. The API,
communications protocol, or other programmatic interface made
available by the operating system 1512 can encapsulate, translate,
or otherwise abstract the operation of the PPSE 1500 to enable the
creation of such computer-readable programs that are able to
operate to enable functions of a wide variety of
differently-configured flexible exosuits.
[0116] Additionally or alternatively, the operating system 1512 can
be configured to operate a modular flexible exosuit system (i.e., a
flexible exosuit system wherein actuators, sensors, or other
elements can be added or subtracted from a flexible exosuit to
enable operating modes or functions of the flexible exosuit). In
some examples, the operating system 1512 can determine the hardware
configuration of the PPSE 1500 dynamically and can adjust the
operation of the PPSE 1500 relative to the determined current
hardware configuration of the PPSE 1500. This operation can be
performed in a way that was `invisible` to computer-readable
programs (e.g., 1514 a, 1514 b, 1514 c) accessing the functionality
of the PPSE 1500 through a standardized programmatic interface
presented by the operating system 1512. For example, the
computer-readable program can indicate to the operating system
1512, through the standardized programmatic interface, that a
specified level of torque was to be applied to an ankle of a wearer
of the PPSE 1500. The operating system 1512 can responsively
determine a pattern of operation of the actuators 1520, based on
the determined hardware configuration of the PPSE 1500, sufficient
to apply the specified level of torque to the ankle of the
wearer.
[0117] In some examples, the operating system 1512 and/or hardware
interface electronics 1540 can operate the actuators 1520 to ensure
that the PPSE 1500 does not operate to directly cause the wearer to
be injured and/or elements of the PPSE 1500 to be damaged. In some
examples, this can include not operating the actuators 1520 to
apply forces and/or torques to the body of the wearer that exceeded
some maximum threshold. This can be implemented as a watchdog
process or some other computer-readable program that can be
configured (when executed by the controller 1510) to monitor the
forces being applied by the actuators 1520 (e.g., by monitoring
commands sent to the actuators 1520 and/or monitoring measurements
of forces or other properties detected using the sensors 1530) and
to disable and/or change the operation of the actuators 1520 to
prevent injury of the wearer. Additionally or alternatively, the
hardware interface electronics 1540 can be configured to include
circuitry to prevent excessive forces and/or torques from being
applied to the wearer (e.g., by channeling to a comparator the
output of a load cell that is configured to measure the force
generated by a TSA, and configuring the comparator to cut the power
to the motor of the TSA when the force exceeded a specified
level).
[0118] In some examples, operating the actuators 1520 to ensure
that the PPSE 1500 does not damage itself can include a watchdog
process or circuitry configured to prevent over-current, over-load,
over-rotation, or other conditions from occurring that can result
in damage to elements of the PPSE 1500. For example, the hardware
interface electronics 1540 can include a metal oxide varistor,
breaker, shunt diode, or other element configured to limit the
voltage and/or current applied to a winding of a motor.
[0119] Note that the above functions described as being enabled by
the operating system 1512 can additionally or alternatively be
implemented by applications 1514 a, 1514 b, 1514 c, services,
drivers, daemons, or other computer-readable programs executed by
the controller 1500. The applications, drivers, services, daemons,
or other computer-readable programs can have special security
privileges or other properties to facilitate their use to enable
the above functions.
[0120] The operating system 1512 can encapsulate the functions of
the hardware interface electronics 1540, actuators 1520, and
sensors 1530 for use by other computer-readable programs (e.g.,
applications 1514 a, 1514 b, 1514 c, calibration service 1516), by
the user (through the user interface 1550), and/or by some other
system (i.e., a system configured to communicate with the
controller 1510 through the communications interface 1560). The
encapsulation of functions of the PPSE 1500 can take the form of
application programming interfaces (APIs), i.e., sets of function
calls and procedures that an application running on the controller
1510 can use to access the functionality of elements of the PPSE
1500. In some examples, the operating system 1512 can make
available a standard `exosuit API` to applications being executed
by the controller 1510. The `exosuit API` can enable applications
1514 a, 1514 b, 1514 c to access functions of the exosuit 1500
without requiring those applications 1514 a, 1514 b, 1514 c to be
configured to generate whatever complex, time-dependent signals are
necessary to operate elements of the PPSE 1500 (e.g., actuators
1520, sensors 1530).
[0121] The `PPSE API` can allow applications 1514 a, 1514 b, 1514 c
to send simple commands to the operating system 1512 (e.g., `begin
storing mechanical energy from the ankle of the wearer when the
foot of the wearer contacts the ground`) in such that the operating
system 1512 can interpret those commands and generate the command
signals to the hardware interface electronics 1540 or other
elements of the PPSE 1500 that are sufficient to effect the simple
commands generated by the applications 1514 a, 1514 b, 1514 c
(e.g., determining whether the foot of the wearer has contacted the
ground based on information detected by the sensors 1530,
responsively applying high voltage to an exotendon that crosses the
user's ankle).
[0122] The `PPSE API` can be an industry standard (e.g., an ISO
standard), a proprietary standard, an open-source standard, or
otherwise made available to individuals that can then produce
applications for PPSEs. The `PPSE API` can allow applications,
drivers, services, daemons, or other computer-readable programs to
be created that are able to operate a variety of different types
and configurations of PPSEs by being configured to interface with
the standard `PPSE API` that is implemented by the variety of
different types and configurations of PPSEs. Additionally or
alternatively, the `PPSE API` can provide a standard encapsulation
of individual exosuit-specific actuators (i.e., actuators that
apply forces to specific body segments, where
differently-configured exosuits may not include an actuator that
applies forces to the same specific body segments) and can provide
a standard interface for accessing information on the configuration
of whatever PPSE is providing the `PPSE API`. An application or
other program that accesses the `PPSE API` can access data about
the configuration of the PPSE (e.g., locations and forces between
body segments generated by actuators, specifications of actuators,
locations and specifications of sensors) and can generate simple
commands for individual actuators (e.g., generate a force of 30
newtons for 50 milliseconds) based on a model of the PPSE generated
by the application and based on the information on the accessed
data about the configuration of the PPSE. Additional or alternate
functionality can be encapsulated by an `PPSE API` according to an
application.
[0123] Applications 1514 a, 1514 b, 1514 c can individually enable
all or parts of the functions and operating modes of a flexible
exosuit described herein. For example, an application can enable
haptic control of a robotic system by transmitting postures,
forces, torques, and other information about the activity of a
wearer of the PPSE 1500 and by translating received forces and
torques from the robotic system into haptic feedback applied to the
wearer (i.e., forces and torques applied to the body of the wearer
by actuators 1520 and/or haptic feedback elements). In another
example, an application can enable a wearer to locomote more
efficiently by submitting commands to and receiving data from the
operating system 1512 (e.g., through an API) such that actuators
1520 of the PPSE 1500 assist the movement of the user, extract
negative work from phases of the wearer's locomotion and inject the
stored work to other phases of the wearer's locomotion, or other
methods of operating the PPSE 1500. Applications can be installed
on the controller 1510 and/or on a computer-readable storage medium
included in the PPSE 1500 by a variety of methods. Applications can
be installed from a removable computer-readable storage medium or
from a system in communication with the controller 1510 through the
communications interface 1560. In some examples, the applications
can be installed from a web site, a repository of compiled or
un-compiled programs on the Internet, an online store (e.g., Google
Play, iTunes App Store), or some other source. Further, functions
of the applications can be contingent upon the controller 1510
being in continuous or periodic communication with a remote system
(e.g., to receive updates, authenticate the application, to provide
information about current environmental conditions).
[0124] The PPSE 1500 illustrated in FIG. 15 is intended as an
illustrative example. Other configurations of flexible exosuits and
of operating systems, kernels, applications, drivers, services,
daemons, or other computer-readable programs are anticipated. For
example, an operating system configured to operate a PPSE can
include a real-time operating system component configured to
generate low-level commands to operate elements of the PPSE and a
non-real-time component to enable less time-sensitive functions,
like a clock on a user interface, updating computer-readable
programs stored in the PPSE, or other functions. A PPSE can include
more than one controller; further, some of those controllers can be
configured to execute real-time applications, operating systems,
drivers, or other computer-readable programs (e.g., those
controllers were configured to have very short interrupt servicing
routines, very fast thread switching, or other properties and
functions relating to latency-sensitive computations) while other
controllers are configured to enable less time-sensitive functions
of a flexible exosuit. Additional configurations and operating
modes of a PPSE are anticipated. Further, control systems
configured as described herein can additionally or alternatively be
configured to enable the operation of devices and systems other
than PPSE; for example, control systems as described herein can be
configured to operate robots, rigid exosuits or exoskeletons,
assistive devices, prosthetics, or other mechatronic devices.
Controllers of Mechanical Operation of a PPSE
[0125] Control of actuators of a PPSE can be implemented in a
variety of ways according to a variety of control schemes.
Generally, one or more hardware and/or software controllers can
receive information about the state of the flexible exosuit, a
wearer of the PPSE, and/or the environment of the PPSE from sensors
disposed on or within the PPSE and/or a remote system in
communication with the PPSE. The one or more hardware and/or
software controllers can then generate a control output that can be
executed by actuators of the PPSE to effect a commanded state of
the PPSE and/or to enable some other application. One or more
software controllers can be implemented as part of an operating
system, kernel, driver, application, service, daemon, or other
computer-readable program executed by a processor included in the
PPSE.
Alternative Applications and Embodiments
[0126] The PPSE embodiments described above generally relate to an
ankle-stretching PPSE, typically to improve ankle flexibility by
performing stretches prescribed for patients with DMD. However, it
can be easily appreciated that the application for PPSEs is not
limited to ankle stretches for DMD patients. In one alternative
embodiment, a PPSE may be used during injury rehabilitation in
place of a continuous passive motion (CPM) machine. The system
described above may be used to restore ROM of the ankle, for
example in the case of surgery or arthritis. An ankle ROM PPSE may
additionally include FLAs approximating calf muscles to induce
plantar-flexion of the ankle. Whereas a CPM machine simply cycles
through a pre-set ROM, a PPSE can adaptively accommodate changes in
a joints ROM. ROM of the ankle may be sensed by the sensors and
controls layer, for example via one or more goniometers or force
sensors, such that the PPSE applies a regimen that gradually
increases ROM over time.
[0127] PPSEs may be optimized to other joints and muscle groups as
well. For example, a PPSE may be adapted to pronate or supinate the
forearm and wrist, in order to increase rotational range of motion
of the joints, or muscles in the case of contractures. A PPSE
adapted to flex and extend the knee can be used as an alternative
to a CPM machine, in order to increase the range of motion of the
knee after surgery such as anterior cruciate ligament (ACL)
reconstruction or total joint replacement.
[0128] In addition to performing stretching regimens, embodiments
of a PPSE can be adapted to perform assistive functions as well.
For example, the ankle-stretching PPSE described above can be used
to assist patients with foot-drop. The sensors and controls layer
of a system like the ankle-stretching PPSE can detect the phases of
the wearer's gait cycle, for example via one or more inertial
measurement units (IMUs). Using that information, the PPSE can
initiate dorsiflexion of the ankle during the swing phase, to
assist with walking for wearers with foot drop.
[0129] In some embodiments, a powered assistive exosuit intended
primarily for assistive functions can also be adapted to perform
PPSE functions. In one embodiment, an assistive exosuit similar to
the embodiments described in U.S. patent application Ser. No.
______, titled "Systems and Methods for Assistive Exosuit System,"
filed ______, that is used for assistive functions may be adapted
to perform PPSE functions. Embodiments of such an assistive exosuit
typically include FLAs approximating muscle groups such as hip
flexors, gluteal/hip extensors, spinal extensors, or abdominal
muscles. In the assistive modes of these exosuits, these FLAs
provide assistance for activities such as moving between standing
and seated positions, walking, and postural stability. Actuation of
specific FLAs within such an exosuit system may also provide
stretching assistance. Typically, activation of one or more FLAs
approximating a muscle group can stretch the antagonist muscles.
For example, activation of one or more FLAs approximating the
abdominal muscles might stretch the spinal extensors, or activation
of one or more FLAs approximating gluteal/hip extensor muscles can
stretch the hip flexors. The exosuit may be adapted to detect when
the wearer is ready to initiate a stretch and perform an automated
stretching regimen; or the wearer may indicate to the suit to
initiate a stretching regimen.
[0130] It is to be understood that the disclosed subject matter is
not limited in its application to the details of construction and
to the arrangements of the components set forth in the following
description or illustrated in the drawings. The disclosed subject
matter is capable of other embodiments and of being practiced and
carried out in various ways. Also, it is to be understood that the
phraseology and terminology employed herein are for the purpose of
description and should not be regarded as limiting.
[0131] As such, those skilled in the art will appreciate that the
conception, upon which this disclosure is based, may readily be
utilized as a basis for the designing of other structures, systems,
methods and media for carrying out the several purposes of the
disclosed subject matter. Although the disclosed subject matter has
been described and illustrated in the foregoing exemplary
embodiments, it is understood that the present disclosure has been
made only by way of example, and that numerous changes in the
details of implementation of the disclosed subject matter may be
made without departing from the spirit and scope of the disclosed
subject matter.
* * * * *