Manually controllable medical aid oscillator instrument

Claim 1

A medical aid instrument in the form of an electronic pacer easily carried externally on a patient for producing an audible rhythmical cadence for initiating and sustaining a walking pattern by providing a steady beat to be sensed by said patient comprising a relaxation oscillator producing periodic beats in the range substantially of 30 to 120 beats per minute, a manual switch under control of said patient for turning said relaxation oscillator on and off, and a transducer coupled to said relaxation oscillator for attachment to said patient, said relaxation oscillator having a relay in its output which is energized at the beat rate of said relaxation oscillator, said relay having a pair of contacts, a battery connected to said switch and to one of said contacts, a phase shift audio oscillator coupled between the other contact of said relay, said battery and said transducer, said audio oscillator having a twin T network, a plurality of differently valued resistors associated with said twin T network for providing selectable phase shift and hence selectable frequencies, and a selector switch for effectively selecting and connecting any one of said resistors into said audio oscillator, whereby said audio oscillator produces spaced pulses of selectable audio frequencies, an audio amplifier in the output of said audio oscillator and located between said audio oscillator and said transducer, said selector switch being provided with a movable arm connected to ground and with a contact connected to the output of said audio oscillator, whereby movement of said arm to engage said last contact disables said audio oscillator.