Modified Elliptical Machine Motor-Drive Design for Assistive Gait Rehabilitation

Treadmill rehabilitation with PBWS (Madonna Rehabilitation Hospital's Institute for Rehabilitation Science and Engineering)

Kinematic and electromyographic evaluation of existing elliptical machine (Madonna Rehabilitation Hospital’s Institute for Rehabilitation Science and Engineering)

View of installed pulleys to motor with flat belt

View of the right foot pedal attached to the roller on the curved portion of the main coupler

Layout of pulley dimensions (in inches; 0.5 in.=1.3 cm, 1 in.=2.5 cm, 1.25 in.=3.2 cm, 4.05 in.=10.3 cm, 6 in.=15.2 cm, 6.75 in.=17.1 cm, 10.5 in.=26.7 cm, 14 in.=35.6 cm, 58 in.=147.3 cm)

Kinematic schematic of elliptical machine. Approximate dimensions in inches (cm): rocker (full) 36 (91), rocker (to upper coupler) adjustable, fixed-center distance 63 (160), crank 10.5 (27), foot pedal link 18 (46), and coupler 58 (147). Note the flat foot pedal and the curved cam below it.

Circle highlights control-box remote used for speed manipulation

Circle highlights the initial safety switch design

Circle highlights the final safety switch design

Motor current output as a function of time when a participant without known disability trains at 25 rpm. Numbered phases in the movement cycle: (1) left midstance (pedal most inferior) and right midswing (pedal most superior), (2) right initial contact/loading response (pedal most anterior) and left preswing (pedal most posterior), (3) right midstance (pedal most inferior) and left midswing (pedal most superior), and (4) left initial contact/loading response (pedal most anterior) and right preswing (pedal most posterior).

Single-sided amplitude spectrum of motor current output when a participant without known disability trains at 25 rpm

Motor current output as a function of time when a participant with bilateral weakness and greater right-side involvement due to Parkinson's disease trains at 25 rpm. Numbered gait markers are same as in Fig. 1.

Single-sided amplitude spectrum of motor current output when a participant with bilateral weakness and greater right-side involvement due to Parkinson's disease trains at 25 rpm. Spectrum for a healthy participant shown for comparison.

Motor current output as a function of time when a participant with left-side weakness due to traumatic brain injury trains at 25 rpm. Numbered gait markers are same as in Fig. 1.

Single-sided amplitude spectrum of motor current output when a participant with left-side weakness due to traumatic brain injury trains at 25 rpm. Spectrum for a healthy participant shown for comparison.

Motor current output as a function of time when a healthy participant of Fig. 1 trains at 60 rpm. Numbered gait markers are same as in Fig. 1.

Single-sided amplitude spectrum of motor current output for healthy participant of Fig. 1 at 60 rpm, showing smaller peak at higher frequency. Spectrum for 25 rpm operation shown for comparison.