DEVICE FOR MEASURING OXYGENATION LEVEL AND PULSE FREQUENCY Russian patent published in 2007 - IPC A61B5/145 A61B5/02 

FIELD: medical engineering.

SUBSTANCE: device has pulse- and oxymetric transducer to be put on patient finger. The transducer has photodiode and two back-to-back connected light-emitting diodes. One of light-emitting diodes operates in red and the other in infrared radiation bandwidth. Measuring circuit has amplifying tract, the first and the second high frequency filters and reference voltage source. Measuring circuit signal input is connected to pulse- and oxymetric transducer photodiode leads. Microprocessor unit has computing unit for calculating heart beat rate and blood oxygenation indexes and showing the readings on electronic device, two analog-to-digital converters and control microcontroller unit which outputs are connected to corresponding computing unit input units, the first and the second units for controlling reset operation, light-emitting diode glow time control unit and unit for controlling high frequency filters commutation. The first and the second high frequency filters have commutation inputs connectable to and disconnectable from the measuring circuit. The first integrator unit having reset option, differential amplifier and the second integrator unit having reset option belong to the amplifying tract. The microcontroller unit has five additional outputs. The first one is connected to light-emitting diode glow time control unit one of current leads of which is connected to its another current lead via the back-to-back connected light-emitting diodes of the pulse- and oxymetric transducer. The second additional controlling microcontroller unit output is connected to control input of the first integrator unit having reset option. The third additional output is connected to the second integrator unit having reset option via the second reset control unit. The fourth and the fifth additional outputs are connected to commutation inputs of the first and the second high frequency filters via the unit for controlling high frequency filter commutation, respectively. Potential outlet lead of the inverting input of the differential amplifier is connected to potential outlet lead of its non-inverting input via the commutation inputs of the first and the second high frequency filters. The inverting input of the differential amplifier is connected to output of the first integrator unit having reset option and its output to input of the second integrator unit having reset option. Reference voltage source output is connected to reference input of the differential amplifier and to non-inverting input of the second integrator unit having reset option. Input signal leads of the first integrator unit having reset option make measuring circuit input for processing signals. Output of the first integrator unit having reset option is connected to the first analog-to-digital converter input and output of the second integrator unit having reset option is connected to the second analog-to-digital converter input.

EFFECT: simplified amplifying tract control; high degree of operation characteristics linearity; low noise level; broad amplification bandwidth; high accuracy and reliability of operation.

6 cl, 6 dwg