# US 8,308,665 B2 · Method and apparatus for improving human balance and gait and preventing foot injury > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,308,665 B2 - Document ID: US8308665B2 - Status: Granted - Kind: B2 - Application number: 10/793,729 - Filed: 2004-03-08 - Published: 2004-09-09 - Granted: 2012-11-13 - Earliest claimed: 2003-03-06 - Assignees: Trustees of Boston University - Inventors: Jason D. Harry; James J. Collins; James B. Niemi; Atilla A. Priplata; Stephen J. Kleshinski - Web page: https://patentgrep.com/patent/US8308665B2 ## CPC - A61N 1/36003: {of motor muscles, e.g. for walking assistance} - A43B 3/34: with electrical or electronic arrangements - A43B 7/00: Footwear with health or hygienic arrangements - A43B 7/1464: with adjustable pads to allow custom fit - A43B 13/00: Soles; Sole-and-heel integral units - A43B 17/00: Insoles for insertion, e.g. footbeds or inlays, for attachment to the shoe after the upper has been joined - A43B 19/00: Shoe-shaped inserts; Inserts covering the instep - A61F 5/0111: {for the feet or ankles} - A61F 5/14: Special medical insertions for shoes for flat-feet, club-feet or the like - A61H 1/00: Apparatus for passive exercising (A61H5/00 takes precedence); Vibrating apparatus; Chiropractic devices, e.g. body impacting devices, external devices for briefly extending or aligning unbroken bones - A61H 39/002: {Using electric currents (electrotherapy A61N1/32)} - A61N 1/0456: {Specially adapted for transcutaneous electrical nerve stimulation [TENS]} - A61N 1/0484: {Garment electrodes worn by the patient} - A61N 1/0492: {Patch electrodes (A61N1/0412, A61N1/0428 take precedence)} - A61N 1/20: continuous direct currents - A61N 1/32: alternating or intermittent currents {(applying electric fields by inductive or capacitive coupling A61N1/40; microwave apparatus A61N5/02)} - A61N 2/06: using magnetic fields produced by permanent magnets (A61N2/12 takes precedence) - A61H 2205/125: Foot reflex zones - A61N 1/0468: {Specially adapted for promoting wound healing} - A61N 1/0476: {Array electrodes (including any electrode arrangement with more than one electrode for at least one of the polarities)} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - A43B: CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61H: PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY (electrotherapy, magnetotherapy, radiation therapy or ultrasound therapy A61N) ## Abstract A method and wearable system and for enhancing human balance and gait and preventing foot injury through neurological stimulation of the foot and the ankle. Subthreshold stimulation for neurosensory enhancement is provided via electrodes or vibrational actuators, or combination thereof, disposed in or on a wearable a platform, such as an insole, sock shoe, removable shoe insert, or applied without the support of a platform, to the skin surface of an individual. Suprathreshold stimulation for therapeutic purposes, such as improving blood flow, is also provided by the vibrational actuators. The actuators and electrodes are driven by bias signals generated by a bias signal generator that is coupled to a controller. The signal generator under the control of the controller is adapted to generate a non-deterministic random signal, a repetitive pattern or series of patterns. The controller optionally includes a communication port for interfacing with an external computer for purposes of optimizing and programming the controller. The wearable system is powered by a power source. ## Claims ### Claim 1 A wearable system for neurological stimulation of a human foot, the system comprising: a platform having at least one stimulator adapted to apply a stimulation to mechanoreceptors in the foot; a controller including at least one bias signal generator providing a driving signal to the at least one stimulator, the at least one stimulator providing a subthreshold bias signal to target cells in response to receiving the driving signal, the subthreshold bias signal having a magnitude that is below a threshold where the target cells are activated by a stimulus; and a power source providing electrical energy to the controller, including the at least one bias signal generator. ### Claim 2 (depends on 1) The wearable system of claim 1, wherein the platform is a removable insole insert of a shoe. ### Claim 3 (depends on 2) The wearable system of claim 2, wherein the power source and the controller, including the at least one bias signal generator, are disposed on the removable insole insert. ### Claim 4 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator is positioned such that stimulation is applied to the sides of the foot. ### Claim 5 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator is positioned such that stimulation is applied to the plantar surface of the foot. ### Claim 6 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator is positioned such that stimulation is applied to a combination of locations including the sides of the foot, the top of the foot, and the plantar surface of the foot. ### Claim 7 (depends on 6) The wearable system of claim 6, wherein the platform is a flexible disposable pad having a form of a foot with an underside coated with adhesive for removably attaching to an insole of a shoe. ### Claim 8 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator is positioned on the platform to contact non-pressure point areas of the foot, so as to minimize discomfort to an individual wearing the platform, and to contact non-bending areas of the foot, so as to allow the flexing of the platform during foot movement without additional or uncomfortable stress being placed on the foot. ### Claim 9 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator comprises at least one electrode placed on or near the foot that provides electrical stimulation to the mechanoreceptors of the foot. ### Claim 10 (depends on 9) The wearable system of claim 9, wherein the at least one stimulator further comprises at least one reference electrode placed on the body wearing the system. ### Claim 11 (depends on 9) The wearable system of claim 9, wherein the at least one stimulator is positioned such that stimulation is applied to the sides of the foot. ### Claim 12 (depends on 9) The wearable system of claim 9, wherein the at least one stimulator is positioned such that stimulation is applied to the plantar surface of the foot. ### Claim 13 (depends on 9) The wearable system of claim 9, wherein the at least one stimulator is positioned such that stimulation is applied to a combination of locations including the sides of the foot, the top of the foot, and the plantar surface of the foot. ### Claim 14 (depends on 9) The wearable system of claim 9, wherein the at least one stimulator is positioned on the platform to contact non-pressure point areas, so as to minimize discomfort to an individual wearing the platform, and to contact non-bending areas of the foot, so as to allow the flexing of the platform during foot movement without additional or uncomfortable stress being placed on the foot. ### Claim 15 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator comprises at least one of a stick-slip electrode, a disposable electrode, and a reusable electrode. ### Claim 16 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator is a vibrational actuator providing stimulating vibration to the mechanoreceptors of the foot. ### Claim 17 (depends on 16) The wearable system of claim 16, wherein the vibrational actuator is an active vibrational actuator. ### Claim 18 (depends on 17) The wearable system of claim 17, wherein the active vibrational actuator comprises at least one of an electromagnetic actuator, an electro-mechanical actuator, a solid-state actuator, a hydraulic actuator, a pneumatic actuator, a ferro-fluidic actuator, and an electroactive polymeric actuator. ### Claim 19 (depends on 18) The wearable system of claim 18, wherein the at least one electromagnetic actuator comprises at least one of a rotary motor and a linear motor. ### Claim 20 (depends on 18) The wearable system of claim 18, wherein the at least one solid-state actuator comprises at least one of a shape memory alloy, piezoelectric materials, and microelectromechanical actuator. ### Claim 21 (depends on 16) The wearable system of claim 16, wherein the platform is a flexible disposable pad having a form of a foot with an underside coated with adhesive for removably attaching to a sole of a shoe. ### Claim 22 (depends on 16) The wearable system of claim 16, wherein the platform comprises a flexible matrix material enclosing a vibration transmitting structure and at least one of the actuators, and the platform is optimized for transmitting vibration to surfaces of the foot. ### Claim 23 (depends on 22) The wearable system of claim 22, wherein the vibration transmitting material comprises at least one of polymeric gel and a viscoelastic foam. ### Claim 24 (depends on 22) The wearable system of claim 22, wherein the vibration transmitting material comprises at least one of rigid beads, polymeric gel, viscoelastic foam, a metallic structural element, and a composite structural element. ### Claim 25 (depends on 22) The wearable system of claim 22, wherein the at least one actuator is encapsulated within the flexible matrix material such that the matrix is optimized for transmitting vibration to the surface of the foot. ### Claim 26 (depends on 22) The wearable system of claim 22, wherein the flexible matrix material has a form factor of a shoe insert. ### Claim 27 (depends on 22) The wearable system of claim 22, wherein the vibration transmitting material comprises at least one of rigid beads, polymeric gel, a viscoelastic foam, a metallic structural element, and a composite structural element and is arranged in such a way as to effect adjustable vibration propagation. ### Claim 28 (depends on 22) The wearable system of claim 22, wherein the vibration transmitting material comprises at least one of rigid beads, polymeric gel, a viscoelastic foam, a metallic structural element, and a composite structural element and is arranged in such a way as to effect adjustable vibration propagation, and the at least one actuator is a plurality of actuators positioned at a predetermined spatial separation between the plurality of actuators to optimize the vibration propagation characteristics of the platform. ### Claim 29 (depends on 16) The wearable system of claim 16, wherein the at least one stimulator comprises one or more actuators positioned such that stimulation is applied to the sides of the foot. ### Claim 30 (depends on 16) The wearable system of claim 16, wherein the at least one stimulator comprises at least one actuator positioned such that stimulation is applied to the plantar surface of the foot. ### Claim 31 (depends on 16) The wearable system of claim 16, wherein the at least one stimulator comprises one or more actuators such that stimulation is applied to a combination of locations including the sides of the foot, the top of the foot, and the plantar surface of the foot. ### Claim 32 (depends on 16) The wearable system of claim 16, wherein the at least one stimulator comprises one or more actuators positioned on the platform to contact non-pressure point areas, so as to minimize discomfort to an individual wearing the platform, and to contact non-bending areas of the foot, so as to allow the flexing of the platform during foot movement without additional or uncomfortable stress being placed on the foot. ### Claim 33 (depends on 16) The wearable system of claim 16, wherein the at least one stimulator comprises a plurality of vibrational actuators adapted to create a vibration when being electrically biased, and wherein the at least one bias signal generator is adapted to generate stepped driving signals, wherein the duration of each step of the driving signals is of a time duration sufficient to avoid placing the actuators in its natural frequency of vibration. ### Claim 34 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator comprises a combination of at least one vibrational actuator and at least one electrode pair for a delivery of mechanical and electrical stimulation to the mechanoreceptors of the foot. ### Claim 35 (depends on 34) The wearable system of claim 34, wherein the at least one stimulator is applied to the sides of the foot. ### Claim 36 (depends on 34) The wearable system of claim 34, wherein the at least one stimulator is positioned such that stimulation is applied to the plantar surface of the foot. ### Claim 37 (depends on 34) The wearable system of claim 34, wherein the at least one stimulator is positioned such that stimulation is applied to a combination of locations including the sides of the foot, the top of the foot, and the plantar surface of the foot. ### Claim 38 (depends on 34) The wearable system of claim 34, wherein the at least one stimulator is positioned on the platform to contact non-pressure point areas, so as to minimize discomfort to an individual wearing the platform, and to contact non-bending areas of the foot, so as to allow the flexing of the platform during foot movement without additional or uncomfortable stress being placed on the foot. ### Claim 39 (depends on 1) The wearable system of claim 1, wherein the power source and the controller, including the at least one bias signal generator, are integrated into a housing that is positioned remotely from the platform and is coupled to the platform. ### Claim 40 (depends on 39) The wearable system of claim 39, wherein the housing is securable onto a shoe. ### Claim 41 (depends on 39) The wearable system of claim 39, where the housing can be secured to a garment. ### Claim 42 (depends on 39) The wearable system of claim 39, wherein the platform further comprises a platform coupling means, and the controller further comprises a controller coupling means for coupling with the platform coupling means for transmitting the driving signal to the platform coupling means. ### Claim 43 (depends on 42) The wearable system of claim 42, wherein the platform coupling means and the controller coupling means are wireless communication means, comprising optical means, RF means, and induction means, or wired serial or parallel communication means. ### Claim 44 (depends on 43) The wearable system of claim 43, wherein the time duration is in a range of 2 to 8 msec. ### Claim 45 (depends on 1) The wearable system of claim 1, wherein the at least one stimulator comprises a plurality of vibrational actuators disposed on the platform at a predetermined spatial separation between the plurality of actuators to induce a vibration having a desirable amplitude by manipulating phase and amplitude of the driving signal of each vibrational actuator. ### Claim 46 (depends on 1) The wearable system of claim 1, wherein the controller is adapted to detect a stance phase and a swing phase, and to provide sub-threshold stimulation for sensory enhancement during a stance phase and to provide supra-threshold stimulation for improving blood flow during a swing phase. ### Claim 47 (depends on 1) The wearable system of claim 1, wherein the controller comprises means for detecting pressure exerted on the platform so as to detect to what degree the foot is bearing weight. ### Claim 48 (depends on 47) The wearable system of claim 47, wherein the controller further comprises power management means for placing the system in a power conservation mode when the foot is not substantially bearing weight. ### Claim 49 (depends on 1) The wearable system of claim 1, wherein the platform comprises means for detecting pressure exerted on the platform so as to detect what degree the foot is bearing weight. ### Claim 50 (depends on 1) The wearable system of claim 1, wherein the controller comprises means for determining gait cycles so as to place the system under a power conservation mode during predetermined phases of a predetermined gait cycle. ### Claim 51 (depends on 1) The wearable system of claim 1, further comprising a power recovery means for harnessing energy from gait cycles and means for recharging the power source from the harnessed energy. ### Claim 52 (depends on 51) The wearable system of claim 51, wherein the power recovery means comprises converting means for converting mechanical energy into electrical energy. ### Claim 53 (depends on 52) The wearable system of claim 52, wherein the converting means comprises at least one of a piezo-electric means, a linear electro-mechanical generator means, hydraulic generator means, and a electro-active polymer means. ### Claim 54 (depends on 1) The wearable system of claim 1, wherein the controller means further controls the power source to switch the power source on and off and to an activate power conservation mode based the detection of motion of the wearable system. ### Claim 55 (depends on 1) The wearable system of claim 1, wherein the power source comprises a recharging means. ### Claim 56 (depends on 55) The wearable system of claim 55, wherein the recharging means is an inductive coupling. ### Claim 57 (depends on 55) The wearable system of claim 55, wherein the recharging means is a electrical socket for receiving an electrical connector providing electrical energy to recharge the power source. ### Claim 58 (depends on 1) The wearable system of claim 1, wherein the power source and the controller, including the at least one bias signal generator, are disposed in the sole of the shoe. ### Claim 59 (depends on 1) The wearable system of claim 1, further comprising a thermal radiation source controlled by the control means for providing heating to the foot. ### Claim 60 (depends on 59) The wearable system of claim 59, wherein the thermal radiation source is an infrared light source. ### Claim 61 (depends on 59) The wearable system of claim 59, wherein the thermal radiation source is a heating filament. ### Claim 62 (depends on 1) The wearable system of claim 1, further comprising adjusting means for a wearer to adjust the amplitude of the bias signal, including threshold and therapeutic levels of one or more of the at least one stimulator. ### Claim 63 (depends on 1) The wearable system of claim 1, further comprising external power coupling means for recharging the power source, interface means for interfacing the controller with an external device for diagnostic, optimization, calibrating and programming the wearable system and recharging the power source. ### Claim 64 (depends on 1) The wearable system of claim 1, wherein the power source is at least one of a rechargeable lithium-ion battery, polymer battery, gel battery, and nickel metal hydride. ### Claim 65 (depends on 64) The wearable system of claim 64, wherein the power source is removably disposed in the sole of a shoe. ### Claim 66 (depends on 64) The wearable system of claim 64, wherein the power source is located separately from the platform. ### Claim 67 (depends on 1, 24) The wearable system of claim 1 or 24, wherein the signal generator provides a signal of controllable signal amplitude, frequency content, waveform shape, and repetition. ### Claim 68 (depends on 1, 24) The wearable system of claim 1 or 24, wherein the controller is adapted to control each individual stimulator so as to effect individually controllable amplitude, frequency content, waveform shape, and repetition of the bias signal. ### Claim 69 A wearable system for neurological stimulation of a human foot, the system comprising: a platform having at least one passive vibrational mechanical actuator, the at least one passive vibrational mechanical actuator providing a subthreshold bias signal to target cells in response to a compression or a decompression, the subthreshold bias signal having a magnitude that is below a threshold where the target cells are activated by a stimulus. ### Claim 70 (depends on 69) The wearable system of claim 69, wherein the passive vibrational actuator comprises at least one of ratcheting system and hook-and-eye filaments. ### Claim 71 A system for optimizing neurological stimulation, comprising: a platform having at least one stimulator adapted to apply a stimulation to a skin surface area of a test subject; a controller including at least one bias signal generator providing a driving signal to the at least one stimulator, the at least one stimulator providing a subthreshold bias signal to target cells in response to receiving the driving signal, the subthreshold bias signal having a magnitude that is below a threshold where the target cells are activated by a stimulus; a remote external computer for effecting the control of the controller during an optimization procedure; a communication means between the remote external computer and the controller; and a measurement means for measuring the responses of the test subject as stimulation is adjusted, wherein the remote external computer is adapted to communicate with the controller to effect varying driving signals inputted into the at least one stimulator, while responses from a subject in contact with the platform and executing a prescribed task are observed and measured, wherein the remote computer is adapted to determine the optimal driving signal parameters suitable for the subject based on the observed responses of the subject. ### Claim 72 (depends on 71) The system of claim 71, wherein the remote external computer communicates optimal bias signal parameters to a wearable system for neurological stimulation. ### Claim 73 (depends on 71) The system of claim 71, wherein the remote external computer selects bias signal parameters to test based on responses of the subject. ### Claim 74 (depends on 71) The system of claim 71, wherein the platform comprises means to provide test stimuli as well as a bias signal to the subject. ### Claim 75 (depends on 74) The system of claim 74, wherein the remote external computer comprises means for receiving and recording responses from the subject for each bias signal used and each test stimulus applied. ### Claim 76 (depends on 71) The system of claim 71, wherein the remote external computer comprises means for receiving and recording responses from the subject for each bias signal applied. ### Claim 77 (depends on 76) The system of claim 76, wherein the means for receiving subject responses is a wired means. ### Claim 78 (depends on 76) The system of claim 76, wherein the means for receiving subject responses is a wireless means. ### Claim 79 (depends on 76) The system of claim 76, wherein the remote computer is adapted to communicate with the controller to generate a test stimulation directed at a specific actuator and hence a specific region so as to observe and measure localized responses, whereby the response of the subject is recorded and adjustments in stimulation can be made to optimize performance. ### Claim 80 (depends on 76) The system of claim 76, wherein the remote computer is adapted to measure responses from the subject performing a prescribed task demonstrating balance or gait. ### Claim 81 (depends on 71) The system of claim 71, wherein the remote external computer is adapted to communicate with the controller to effect the generation of a bias signal of a predetermined one or more frequencies, amplitude, repetition, waveform shape, and pattern. ### Claim 82 (depends on 71) The system of claim 71, wherein the communication means is comprised of at least one of a wired or optical serial communication link, a wired or optical parallel communication link, a wireless RF communication link, and a wireless optical communication link. ### Claim 83 A method for providing neurological stimulation in a wearable system, comprising: providing a wearable platform having one or more stimulators a controller including at least one signal generator coupled to the one or more stimulators, and a power supply source for powering the controller; adjusting or programming the controller to produce a sensory enhancement bias signal at a subthreshold level via the bias signal generator, the subthreshold level having a magnitude that is below a threshold where target cells are activated by a stimulus; and activating the signal generator and supplying the subthreshold bias signal to the one or more sources of stimulation to stimulate mechanoreceptors based on a determined therapeutic need of an individual. ### Claim 84 (depends on 83) The method according to claim 83, further comprising measuring an individual's threshold level of sensation in an area to receive stimulation. ### Claim 85 (depends on 84) The method according to claim 84, wherein adjusting or programming the controller to control the bias signal generator comprises producing a therapeutic level relative to the measured threshold level. ### Claim 86 (depends on 84) The method according to claim 84, wherein the subthreshold level is between 10 and 30% below the measured threshold level. ### Claim 87 (depends on 84) The method according to claim 84, wherein the measuring of a threshold level comprises inputting a minimal bias signal to the one or more actuators and progressively increasing the amplitude of the bias signal until an individual wearing the platform detects stimulations from the one or more of the actuators. ### Claim 88 (depends on 84) The method according to claim 84, wherein the measuring of a threshold level comprises a tracking procedure which begins with a minimal or maximal signal and makes incremental changes towards the final threshold based on an individual's response. ### Claim 89 (depends on 84) The method according to claim 84, wherein the measuring of a threshold level comprises monitoring activity of sensory neurons emanating from the test area. ### Claim 90 (depends on 84) The method according to claim 84, wherein the measuring of threshold comprises monitoring brain function using tools including EEG or fMRI. ### Claim 91 (depends on 83) The method according to claim 83, further comprising determining an optimal level of stimulation. ### Claim 92 (depends on 91) The method according to claim 91, wherein adjusting or programming the bias signal generator comprises producing a therapeutic level relative to the optimal level of stimulation. ### Claim 93 (depends on 91) The method according to claim 91 wherein determining an optimal level of stimulation comprises repeatedly measuring the performance of an individual in a directed sensory or sensorimotor task and selecting the stimulation so as to optimize the measured performance. ### Claim 94 (depends on 91) The method according to claim 91, wherein determining an optimal level of stimulation comprises monitoring activity of sensory neurons emanating from the test area. ### Claim 95 (depends on 91) The method according to claim 91, wherein determining an optimal level of stimulation comprises monitoring brain function using tools including EEG or fMRI. ### Claim 96 (depends on 83) The method of claim 83, wherein programming the controller further comprises adapting the controller to activate a power conservation mode during a predetermined gait cycle. ### Claim 97 (depends on 83) The method of claim 83, wherein programming the controller further comprises adapting the controller to alternately provide subthreshold stimulation for sensory enhancement and suprathreshold stimulation for improving blood flow. ### Claim 98 (depends on 83) The method of claim 83, wherein programming the controller further comprises adapting the controller to detect a stance phase and a swing phase, and providing a subthreshold stimulation for sensory enhancement during a stance phase and a suprathreshold stimulation for improving blood flow during a swing phase.