Muscle activity recorder

Claim 1

Means for providing a visual indication of muscular activity comprising: resilient collapsible bellows means positioned adjacent the area of interest of the subject to be observed and making physical contact therewith; said bellows means including means having an output opening adapted to emit a stream of air of negative and positive pressure related respectively to expansion and contraction of the musculature being observed; piston means coupled to said output opening for converting the incoming air stream into reciprocating mechanical movement; mechanical amplifier means coupled to the output of said piston means for amplifying the linear movement produced by said piston means; said mechanical amplifier being comprised of a rotatable shaft; a disc secured to and rotated by said shaft; a linking arm having a first end pivotally coupled to the output of said piston means and a second end secured to said shaft for rotating said disc in a direction controlled by the direction of linear movement of said piston means; second conversion means; said mechanical amplifier means further comprising an output arm having a first end pivotally coupled to said disc near the periphery of said disc and a second end coupled to the input of said second conversion means; said second conversion means including a variable impedance whose impedance value is adapted to change with movement of said output arm; meter means coupled to said variable impedance for providing a visually observable output.