GB654823A - Artificial respiration by electronic stimulation - Google Patents

Abstract

654,823. Artificial respiration. SARNOFF, S. J. Dec. 15, 1948, No. 32449. Convention date, Jan. 3. [Class 81 (ii)] Apparatus for inducing respiration comprises means for applying a cyclically varying electric potential to a nerve trunk, the cycle comprising a rise to a peak value followed by a sudden decrease to an insensible value, means being also provided to vary the length of the rising portion independently of the length of the cycle. In the form described a valve V1 connected as an oscillator feeds into a square wave generator G, the output of which passes through leads 17, 18 and tapping arm S to a potentiometer 16. A variable tapping contact 13 is continuously rotated by a motor M and the voltage thus tapped off is passed through a rectifier V2 to probe contacts P. These consist of two conducting segments set in an insulating trough in which the phrenic nerve may be placed. As the arm 13 is rotated the amplitude of the series of square pulses received from G increases from zero to a maximum at the point selected by switch S and thereafter it rapidly drops to zero, remaining at zero until the starting end of the potentiometer is again reached.