Muscle stimulation systems

Abstract

A control system for controlled exercise controls a functional electrical stimulation (FES) system which applies electrical signals to muscle groups of a user such as a user having a disability; the user exercises on a motor driven exercise machine such that substantially isokinetic exercise during a movement is obtained as the user's body part moves with a motor driven displaceable element of the machine. This element provides resistance to applied displacement load from the user's stimulated muscles. A feedback control system receives signals indicative of the user's performance and a control arrangement controls electrical stimulation to the user's muscles to achieve a desired exercise regime.

1 . A system including: 
 (a) an exercise machine having displaceable means for moving with a body part of a user;    (b) a motor arranged to drive the displaceable means at a selected but normally substantially constant speed and providing a resistance for resisting displacement load from the user's body part applied to the displacement means;    (c) a functional electrical stimulation (FES) system for selected muscle groups of the user corresponding to the body part to be exercised on the exercise machine;    (d) a feedback control system that receives signals indicative of the user's performance during exercise; and    (e) means for controlling the FES system, by controlling the electrical stimulation to the user's muscles to control the exercise regime.    
   
   
       2 . A system as claimed in  claim 1 , wherein the FES system has means for eliciting muscle contractions via controlling the amplitude of electrical stimulation for a paretic or paraplegic user.  
   
   
       3 . A system as claimed in  claim 1  and wherein the FES system has means adapted to assist muscle contraction to select muscles of a user having impaired or voluntary muscle control.  
   
   
       4 . A system as claimed in  claim 1  and further comprising means to measure and provide output data for recording the muscle performance of the user.  
   
   
       5 . A system as claimed in  claim 4  and including means for controlling an exercise regime for the user with means responsive to the data relating to the user's muscle performance to select different speeds for the motor and different corresponding timings for stimulation through the FES to vary the work load.  
   
   
       6 . A system as claimed in  claim 5  wherein during an exercise session the system initially establishes a relatively low speed of exercise and subsequently adopts a higher speed or speeds, whereby early fatiguing of the user's muscles is obviated and longer exercise training sessions are provided.  
   
   
       7 . A system as claimed in  claim 6  and wherein an initial exercise speed for a user not having voluntary muscle control or with impaired muscle control is at about 5-25 rev·min −1  and subsequently during the exercise session the speed is increased to of the order of 40-60 rev·min −1 .  
   
   
       8 . A system as defined in  claim 4  wherein the system includes an adaptive control loop to adjust the motor to maintain constant velocity motion in the machine and/or to regulate FES pulses to the user's muscles to maintain a user-selected average power and/or average torque output during exercise irrespective of any voluntary muscle contractions of the user additional to those generated by the electrical stimulation.  
   
   
       9 . A system as claimed in  claim 1  when the controlling means has means allowing the user to utilise substantially isokinetic exercise at different velocities of limb movement to elicit different patient outcomes suitable for promoting muscular strength, muscle fatigue-resistance or cardiorespiratory fitness via FES muscle recruitment or voluntary muscle activation.  
   
   
       10 . A system as claimed in  claim 9 , and comprising means to control an exercise regime and having means to maintain a relatively slow speed for an initial exercise segment followed by a relatively high speed segment.  
   
   
       11 .- 27 . (canceled)