Treadmill training device adapted to provide targeted resistance to leg movement

Patent metadata

Field	Value
Publication number	US-9713439-B1
Application number	US-53613609-A
Country	US
Kind code	B1
Filing date	Aug 5, 2009
Priority date	Aug 6, 2008
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A system and method are provided for targeted training of a person walking on a powered backward moving surface. Kinematic information of motor performance, such as ankle position and velocity, is measured throughout one or more phases of a gait cycle with a detector. The gait phase is determined, and a resistive/assistive force is applied to the leg that differs depending upon the gait phase and the measured kinematic information.

First claim

What is claimed is:

1. A method for providing training to a person volitionally moving their legs while walking on a powered backward moving surface over a plurality of gait cycles, comprising:
using at least one position detector to determine at least one of the horizontal position and horizontal velocity of a person's leg throughout the plurality of gait cycles to obtain kinematic information of motor performance of the leg;
for each gait cycle in the plurality of gait cycles:
determining a phase of the gait cycle; and
in a swing phase of the gait cycle, applying a resistive force to the leg for the physical rehabilitation of the person, such resistive force resisting a forward swing movement of the leg, in an amount that differs depending upon the obtained kinematic information;

wherein the resistive force is applied by a cable, wherein a proximal portion of the cable is attached to a holding element attached to the leg and a distal portion of the cable is attached to a drive system.

2. The method according to claim 1 in which the obtained kinematic information is ankle horizontal position and horizontal velocity and the kinematic information is obtained using three dimensional position detectors.

3. The method according to claim 2 , further comprising:
determining and saving in a memory desired kinematic information comprising a desired measure of horizontal position as a function of time or gait cycle (x d (t)), and a desired measure of horizontal velocity as a function of time or gait cycle ({dot over (x)} d (t)); and
utilizing the obtained kinematic information and the desired kinematic information in determining an amount of the resistive force that is applied to the leg.

4. The method according to claim 3 , further comprising:
setting preset threshold values for position errors e t and velocity errors ė t that are used in determining the amount of resistive force that is applied to the leg.

5. The method according to claim 4 , wherein the resistive force is applied to the leg according to the following equation:
F r ( t )= k P ( e t −( x d ( t )− x ( t )))+ k D ( ė t −( {dot over (x)} d ( t )−{dot over ( x )}( t )))

where
t is time;
F r (t) is the applied resistive force as a function of time;
k P is the position gain (e.g., k P =0.1 N/mm nominal);
k D is the velocity gain (e.g., k D =0.05 N/mm/s nominal);
x(t) is the measured ankle horizontal position during the swing phase;
{dot over (x)}(t) is the measured ankle horizontal velocity during the swing phase;
x d (t) is the desired ankle horizontal position during the swing phase;
{dot over (x)} d (t) is the desired ankle horizontal velocity during the swing phase;
e t is the preset threshold value for the position errors: e t =280 mm nominal; and
ė t is the preset threshold value for the velocity errors: ė t =25 mm/s nominal.

6. The method according to claim 1 , wherein the drive system comprises a motor and a cable spool, and the motor is arranged to actuate the cable spool.

7. The method according to claim 1 , wherein the drive system is positioned directly behind the leg during a therapy session.

8. The method according to claim 1 , further comprising providing side support to the patient through the use of a harness.

9. The method according to claim 6 , wherein the cable applies the resistive force by being wound around the cable spool during actuation of the motor.

10. The method according to claim 1 , further comprising:
measuring the resistive force with a reaction torque load cell.

11. The method according to claim 1 , wherein the gait phase during which the resistive force is applied is only about 10% of the gait cycle prior to toe off through mid swing.

12. The method according to claim 1 , further comprising providing partial or full body weight support to the person walking on the moving surface.

13. The method according to claim 12 , further comprising providing a counterbalance as the partial or full body weight support.

14. The method according to claim 1 , further comprising:
varying the resistive force across the plurality of gait cycles to maintain predefined values for step kinematics.

15. The method according to claim 14 , wherein the predefined values for step kinematics include stride length and step height.

16. The method according to claim 1 , further comprising providing ankle position detectors that determine an ankle position of the person, wherein the determining of the gait phase comprises reading information from the ankle position detectors.

17. The method according to claim 1 , further comprising providing motor feedback to the person related to the motor performance of the person.

18. The method according to claim 17 , wherein the providing of motor feedback comprises displaying parameters related to the motor performance of the person on a monitor visible to the person.

19. The method according to claim 1 , wherein measuring kinematic information of motor performance comprises measuring EMG data from muscle groups associated with at least one of hip, knee, and ankle muscles.

Assignees

• Wu Ming
• Schmit Brian D
• Hornby T George
• Chicago Rehabilitation Inst

Inventors

• Wu Ming
• Schmit Brian D
• Hornby T George

Classifications

• A61B5/1121

  Determining geometric values, e.g. centre of rotation or angular range of movement · CPC title

• A61B5/11 Primary

  Measuring movement of the entire body or parts thereof, e.g. head or hand tremor or mobility of a limb {(A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721)} · CPC title

• A61B2505/09

  Rehabilitation or training · CPC title

• A61B5/6829

  Foot or ankle · CPC title

• A61B5/221

  Ergometry, e.g. by using bicycle type apparatus · CPC title