RU2259161C1 - Pulsating oxymeter - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device has red-light-radiator unit, infrared-light-radiator unit, light-sensitive cell unit, pulse shaper, three synchronous detectors, two subtracters computation and indication unit.

EFFECT: high measurement accuracy.

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Description

The invention relates to medical equipment and can be used for non-invasive measurement of oxygen saturation of arterial blood.

Known pulse oximeter [1], containing blocks of red and infrared emitters, an antiphase pulse shaper, a photodetector block, two synchronous detectors, blocks of formation, calculation and indication, a calibration block. The disadvantage of this device is the limited measurement accuracy due to the neglect of external light illumination.

A device for monitoring a pulse oximeter [2], containing blocks of red and infrared emitters, an antiphase pulse generator, a photodetector unit, two synchronous detectors, units for generating, calculating and indicating, a calibration unit and a switch. The disadvantage of this device is the limited measurement accuracy due to the neglect of external light illumination.

The closest in technical essence is a pulse oximeter [3], containing blocks of red and infrared emitters, an antiphase pulse shaper, a photodetector block, two synchronous detectors, blocks of formation, calculation and indication. The disadvantage of this device is the limited measurement accuracy due to the neglect of external light illumination.

The technical result of the proposed solution is to provide increased measurement accuracy by compensating for the interference component of external light exposure.

The technical result is ensured by the fact that in a pulse oximeter containing a red emitter unit, an infrared emitter unit, a pulse shaper, a photodetector unit, first and second synchronous detectors, the inputs of which are connected to the output of the photodetector unit, the control input of the first synchronous detector connected to the input of the red unit the emitter and the first output of the pulse shaper, the second output of which is connected to the input of the infrared emitter unit and the control input of the second synchronous detector and the calculation and indication unit, the pulse shaper is capable of cyclically sequentially generating three pulses at the respective outputs, and the first and second subtractors and the third synchronous detector are introduced, the input of which is connected to the output of the photodetector block, the control input is connected to the third output of the pulse shaper, and the output is connected to the corresponding inputs of the subtractors, the other inputs of which are connected to the outputs of the corresponding synchronous detectors, and the outputs are connected to the corresponding their inputs of the unit of calculation and indication.

The drawing shows a structural diagram of a pulse oximeter.

The device comprises a red emitter unit 1, an infrared emitter unit 2, a pulse shaper 3, a photodetector unit 4, first, second and third synchronous detectors 5, 6 and 7, first and second subtractors 8 and 9, and a calculation and indication unit 10.

Pulse oximeter works as follows.

The red emitter unit 1, the infrared emitter unit 2, and the photodetector unit 4 are mounted on a finger or earlobe using known devices. When the pulse is cycled from the first output of the 3 pulse shaper to the control inputs of the red emitter unit 1 and the first synchronous detector 5, the red light signal transmitted through the object under investigation passes to the input of the photodetector unit 4 and the interference light flux of the external light exposure, which is output from the first synchronous detector 5 form an additive composition, the level of which is maintained during the duration of the cycle.

Upon receipt of the next pulse from the second output of the pulse shaper 3 to the control inputs of the infrared emitter unit 2 and the second synchronous detector 6, the signal light flux passing through the object under investigation in the infrared range and the interfering light flux of the external light illumination, which are output from the second synchronous detector 6 form an additive composition, the level of which is maintained during the duration of the cycle.

Upon receipt of the next pulse from the third output of the pulse shaper 3 to the control input of the third synchronous detector 7, the input of the photodetector unit 4 receives only the interfering light flux of external light exposure, which at the output of the third synchronous detector 7 forms a level that persists for the duration of the cycle and is subtracted from the considered compositions in subtractors 8 and 9, as a result of which only signal light fluxes at the edges are formed and stored over the duration of the cycle sleep and infrared ranges received in block 10 calculation and indication of the degree of saturation of arterial blood with oxygen.

The pulse oximeter can be made of standard modules and on an accessible element base. The structural implementation of a number of blocks may coincide with the structures of the same functional purpose of the prototype. For example, blocks 1, 2, and 4 may include structures of blocks 1-7 of the prototype, blocks 5-7 are identical to blocks 8 and 11 of the prototype, block 10 may include structures of blocks 9, 10, 12, 13, 15, and 16 of the prototype, and calculations are carried out according to the same well-known formulas as in the prototype. The execution of the blocks as a whole is determined by their functional purpose in the device and is known or obvious from the prior art in the applicable time and frequency ranges.

Bibliographic list

1. Patent No. 2194445 (RU). Pulse Oximeter / K.M. Matus et al. // BI. 12/20/2002.

2. Patent No. 2201139 (RU). A device for monitoring a pulse oximeter / K.M. Matus et al. // BI. 03/27/2003.

3. Patent No. 2152030 (RU). Pulse oximeter (options) / K.M. Matus // BI. 06/27/2000.

Claims (1)

A pulse oximeter comprising a red emitter unit, an infrared emitter unit, a pulse shaper, a photodetector unit, first and second synchronous detectors, the inputs of which are connected to the output of the photodetector unit, the control input of the first synchronous detector being connected to the input of the red emitter unit and the first output of the pulse former, the second output of which is connected to the input of the infrared emitter unit and the control input of the second synchronous detector, the calculation and indication unit, characterized in that then the pulse shaper is configured to cyclically sequentially generate three pulses at the respective outputs, as well as by introducing the first and second subtractors and the third synchronous detector, the input of which is connected to the output of the photodetector block, the control input is connected to the third output of the pulse shaper, and the output is connected to the corresponding inputs subtractors, the other inputs of which are connected to the outputs of the corresponding synchronous detectors, and the outputs are connected to the corresponding inputs of the block in Numerical and display.