APPARATUS FOR DETECTING HUMAN PULSE WAVE AND BREATHING CYCLE SIGNALS Russian patent published in 2014 - IPC A61B5/205 A61B5/295 A61B5/53 

FIELD: physics.

SUBSTANCE: apparatus (1) for detecting pulse wave and breathing cycle signals of a person has two current-conducting electrodes (2, 3) to be attached to the human body, a first (4) and a second (6) operational amplifier, an amplitude detector (5), a switched frequency-dependent voltage divider (8) and a microcontroller (7). The electrodes (2, 3) are connected in the negative feedback circuit of the first operational amplifier (4). The microcontroller (7) is configured to generate a high-frequency carrier signal at the output of a first input/output port (L). The upper (10) and lower (11) arms of the voltage divider (8) are formed by two circuits, having a common end at the mid-point of the voltage divider and two separate ends. The second operational amplifier (6) and the voltage divider (8) form an active band-pass filter with upper and lower cut-off frequencies defined by parameters of the upper (10) and lower (11) arms of the voltage divider (8), respectively. The frequency response of such a filter when the second input/output port (M) of the microcontroller (7) is connected to zero potential enables signal detection in a frequency band which corresponds to the frequency band the pulse wave signal, and enables signal detection in the frequency band corresponding to the frequency band of the breathing cycle signal when the third input/output port (N) of the microcontroller (7) is connected to zero potential.

EFFECT: detecting pulse wave and breathing cycle signals of a person based on measuring the impedance of a body area using a simple non-adjustable electrical circuit.

14 cl, 12 dwg