CN201033073Y - Sphygmus blood oxygen test apparatus - Google Patents

Abstract

The utility model provides a pulse oximetry checkout gear not only being able to measure oxygen saturation of blood and pulse rate, but also being able to measure the hemoperfusion index (PI), which comprises a light source, a sensor for transforming light frequency, a microprocessor and an exterior device. The sensor for transforming light frequency is used for receiving the signal of measured light with the light source weakened by the object tested, and transforming the measured light into the tested digital signal which can be output to the microprocessor; the microprocessor is used for processing the tested digital signal received and making the testing result output to the exterior device to display. The pulse oximetry checkout gear adopting the digital chip integrating without analog device reduces the number of electronic components and improves stability, reliability, sensitivity and measurement precision of the system as well as the consistency of the mass production.

Description

A kind of pulse blood oxygen checkout gear

Technical field

This utility model relates to medical apparatus and instruments, the pulse blood oxygen checkout gear of particularly a kind of not only energy measurement blood oxygen saturation and pulse frequency but also energy measurement blood perfusion index (PI).

Background technology

According to youth primary-Bill (Lamber-Beer) law, material is directly proportional at the absorbance at certain wavelength place and his concentration, when the illumination of constant wavelength is mapped on the tissue, reflected the architectural feature of illuminated position tissue to a certain extent by the light intensity that measures behind tissue absorption, the reflection loss.Because (600nm～1000nm) unique absorption spectrum is arranged utilizes these characteristics, just can measure the human body blood oxygen saturation in HONGGUANG, infrared light district for HbO2 Oxyhemoglobin (HbO2) and reduced hemoglobin in the blood.

In existing pulse blood oxygen detector, the main mode of analog circuit that adopts designs, the scheme block diagram is seen Fig. 1, and system mainly is made up of photoelectric sensor, signal conditioning circuit (analog circuit), A/D conversion (analog/digital conversion) circuit, microprocessor, memorizer and external equipment; Work process is: photoelectric sensor receives the optical signal after the decay, and be converted into current signal, because weak output signal and have interference such as power frequency, then needing to carry out filtering through signal conditioning circuit amplifies, afterwards again by A/D converter, analog electrical signal is converted to digital signal, delivers to microprocessor processes.Conventional blood oxygen checkout gear is based on Analog Circuit Design, Devices Characteristics directly affects the quality of system, the influence of lot of simulation device property makes system stability and reliability relatively poor, and certainty of measurement is also lower, and the secondary reflection light that causes in measuring process.In addition, Chang Gui blood oxygen checkout gear is only measured blood oxygen saturation SpO₂, (Pulse Rate PR.), does not have the function of measurement and demonstration blood perfusion indices P I value (Perfusion Index) to pulse frequency.Product awaits improving and development.

The utility model content

The purpose of this utility model is, the defective that exists at above-mentioned prior art provides a kind of full digital pulse blood oxygen checkout gear, and this pulse blood oxygen checkout gear can reduce measurement error, improves certainty of measurement.

The technical solution of the utility model is as follows:

A kind of pulse blood oxygen checkout gear, comprise a light source, the light frequency conversion sensor, microprocessor and external equipment, described light frequency conversion sensor is used to receive the tested optical signal after light source is decayed by testee, and convert tested optical signal to the measured number signal and export to described microprocessor, described microprocessor is used for the measured number signal that receives is handled, and the measurement result that obtains is exported to described external equipment shows.Wherein said light frequency conversion sensor comprises light sensitive diode and current frequency converter, described light sensitive diode is used for the tested optical signal after the receiving attenuation, convert tested optical signal to tested electric signals and export described current frequency converter to, described current frequency converter is used to export described measured number signal; Also comprise a low-pass filtering module in the described microprocessor, an one high-pass filtering module and a computing module, described low-pass filtering module is used for the high-frequency interferencing signal of the tested optical signal of filtering, described high-pass filtering module is used for obtaining the AC compounent of tested optical signal, the outfan of described low-pass filtering module and described high pass filter all is connected to computing module, obtains DC component and blood perfusion index in the tested optical signal by described computing module computing; Described light source, light frequency conversion sensor and described microprocessor are wholely set, and are encapsulated into a blood oxygen detection module, are used to measure blood oxygen saturation, pulse frequency and blood perfusion index.Also comprise a regulated power supply, be used for to described light source, light frequency conversion sensor and described microprocessor power supply; The described light frequency conversion sensor end that links to each other with described regulated power supply also comprises a ground capacity, is used to filter power supply input clutter, stabilized power source.

Described light source and light frequency conversion sensor be arranged on one the probe on, described probe have one with the suitable groove in the tested position of health, described light source and light frequency conversion sensor are separately positioned on corresponding two medial walls of described groove; Described groove internal layer surface scribbles light absorbent, is used to reduce the interference of secondary reflection light.

Described light source adopts light emitting diode, and described light emitting diode comprises at least two, is set up in parallel on the sidewall in described groove, is used for red-emitting or infrared light.

Full digital pulse blood oxygen checkout gear provided by the utility model, adopt the measuring system of the full digital of light frequency change type pick off, microprocessor composition, pulse by monitoring health outer peripheral portion (as finger tip or ear-lobe) changes, and can detect blood oxygen saturation (SpO noinvasive₂) and pulse frequency (Pulse Rate, PR), energy measurement blood perfusion index (Perfusion Index also, PI), the pulse blood oxygen checkout gear of this digit chip integrated form has reduced the components and parts number, thereby has improved system stability owing to no analog device, reliability, the concordance of sensitivity and certainty of measurement and batch process.

Description of drawings

Fig. 1 is the pulse blood oxygen detector theory diagram of prior art;

Fig. 2 is this utility model pulse blood oxygen detector theory diagram;

Fig. 3 is this utility model PI value sampling module theory diagram;

Fig. 4 measures the probe sketch map of blood oxygen for this utility model;

Fig. 5 is the pulse blood oxygen detection module after this utility model encapsulation;

Fig. 6 divides spirogram for the AC and DC of this utility model absorbing amount.

The specific embodiment

Below preferred embodiment of the present utility model is described in detail.

A kind of pulse blood oxygen checkout gear, comprise a light source, it is luminous tube, the light frequency conversion sensor, microprocessor, regulated power supply and external equipment see for details shown in the accompanying drawing 2, described light frequency conversion sensor is used to receive the tested optical signal of light source after by the testee decay, and converts tested optical signal to the measured number signal and export to described microprocessor; Regulated power supply is used for to described luminous tube, described light frequency conversion sensor and described microprocessor power supply.

Described light frequency conversion sensor comprises light sensitive diode and current frequency converter, described light sensitive diode and described luminous tube electric property coupling, be used for the tested optical signal after the receiving attenuation, the outfan of described light sensitive diode is connected to the input of described current frequency converter, convert tested optical signal to tested electric signals and export to described current frequency converter, the outfan of described current frequency converter links to each other with the input of described microprocessor, exports described measured number signal and gives described microprocessor; Described microprocessor is used for the measured number signal that receives is handled, and the measurement result that obtains is exported to described external equipment shows.External equipment described here can comprise LCD display, keyboard etc.

As shown in Figure 3, blood perfusion indices P I value sampling module is in described microprocessor, described PI value sampling module comprises a low-pass filtering module, an one high-pass filtering module and a computing module, PI value sampling module obtains the light decrement primary signal from described microprocessor, remove High-frequency Interference through low pass filter, obtain AC compounent through high pass filter, the outfan of low-pass filtering module and high pass filter all is connected to described computing module, by described computing module computing, deduct AC compounent and obtain DC component with total light decrement, and will exchange to compare by described internalarithmetic and obtain the PI value with direct current, after the PI value is carried out signal processing by described microprocessor the most at last, the measurement result that obtains is exported to LCD display.

Be a probe sketch map that monitoring health outer peripheral portion (as finger tip or ear-lobe) pulse changes of the present utility model as shown in Figure 4, luminous tube is corresponding with described light frequency conversion sensor to be arranged in the groove, be used to monitor the pulse variation of health outer peripheral portion, described groove can be designed to the cavity with the suitable end opening of finger or ear-lobe, probe sheath is at the outer peripheral portion (as finger tip or ear-lobe) of health during use, upper wall has been fixed two light emitting diodes of placing side by side, emission wavelength is respectively 660nm HONGGUANG and 940nm infrared light, and lower wall has a receiving tube (light frequency conversion sensor); The measuring method of detecting sphygmus and blood oxygen saturation is the periphery position (as finger or ear-lobe) that the redness sent of the light emitting diode with two kinds of wavelength and infrared light see through health, detect the optical signal of transmission by the light sensor of offside, different with the absorbance of reduced hemoglobin according to HONGGUANG and infrared light again characteristics to HbO2 Oxyhemoglobin, the testing circuit variation waveform that light that artery blood flow caused absorbs that obtains earlier pulsing calculates detecting sphygmus and blood oxygen saturation and pulse frequency value then in view of the above.

In order to reduce the influence that surround lighting is measured pulse signal, consider the convenience that pick off uses simultaneously, adopt the finger cot type manner of packing of sealing, whole casing adopts lighttight medium and color, reduce the influence of external environment light as far as possible, the influence of the secondary reflection light in the measuring process is coated one deck light absorbent on the internal layer surface of finger cot type pick off, can effectively reduce the interference of secondary reflection light like this.

This utility model is with luminous tube, light frequency conversion sensor and microprocessor are wholely set, be encapsulated into a blood oxygen detection module, as shown in Figure 5, its outfan can connect the I/O interface, RAM memorizer etc., this blood oxygen detection module can place in the multiple parameter measurement instrument, as can be applicable to refer to that the formula pulse blood oxygen detects, the hand-held pulse blood oxygen detects, in the instruments such as blood oxygen detection of multi-parameter monitor, the integrated module design has improved the integrated level of system.

This utility model can be measured blood perfusion indices P I index (PI=Perfusion Index), and the PI index has reflected the blood perfusion situation of tested position under current physiological status; Show according to PI, adjust measuring point and placement situation,, can reduce measurement error in the higher position measurement of PI value to obtain good signal intensity.

Definition, measurement and clinical meaning about the PI value are described below: during measurement, see through systemic light decrement as shown in Figure 6, should comprise the composition (arterial blood, venous blood) and the non-blood composition (skin, skeleton, connective tissue etc.) of blood.Non-blood composition does not change with the pulsation process, and the blood that the composition of blood causes with the pulsation process flows into and the volume change of outflow vascular bed changes, therefore the former (non-blood composition) is constant (being called direct current) to the absorbtivity of light, and the latter is (being called interchange) of pulsation to the absorbtivity of light.The variation of light decrement be since arterial volume beat caused, thereby just can from the overall attenuation of light, remove the direct current composition, with the remainder Alternating Component analyze, calculate the oxygen saturation of arterial blood.

Blood perfusion indices P I value then is exactly above AC compounent and DC component ground ratio, has reflected the perfusion ability of arterial blood.Calculating by the PI value can be found out: under the constant situation of another one component (DC component), DC component is low more or AC compounent is high more, and the PI value is then big more.Therefore, measuring point (influences such as skin, fingernail, skeleton) and patient's blood perfusion situation (mobility status of arterial blood) itself all will influence the PI value.Because sympathetic nerve can influence heart rate and arteriotony (influencing the pulse artery blood flow), so the neural modulation system of human body or the mental status also can remote-effects PI values.Thereby under the state of different anesthesia, its PI value also can be different.

Should be understood that, for those of ordinary skills, can be improved according to the above description or conversion, and all these improvement and conversion all should belong to the protection domain of claims of the present invention.

Claims (9)

1. pulse blood oxygen checkout gear, comprise a light source, microprocessor and external equipment, it is characterized in that: also comprise the light frequency conversion sensor, described light frequency conversion sensor is used to receive the tested optical signal after light source is decayed by testee, and convert tested optical signal to the measured number signal and export to described microprocessor, described microprocessor is used for the measured number signal that receives is handled, and the measurement result that obtains is exported to described external equipment shows.

2. pulse blood oxygen checkout gear according to claim 1, it is characterized in that, described light frequency conversion sensor comprises light sensitive diode and current frequency converter, described light sensitive diode is used for the tested optical signal after the receiving attenuation, convert tested optical signal to tested electric signals and export described current frequency converter to, described current frequency converter is used to export described measured number signal.

3. pulse blood oxygen checkout gear according to claim 1, it is characterized in that, also comprise a low-pass filtering module in the described microprocessor, an one high-pass filtering module and a computing module, described low-pass filtering module is used for the high-frequency interferencing signal of the tested optical signal of filtering, described high-pass filtering module is used for obtaining the AC compounent of tested optical signal, the outfan of described low-pass filtering module and described high pass filter all is connected to computing module, obtains direct current, AC compounent and blood perfusion index in the tested optical signal by described computing module computing.

4. pulse blood oxygen checkout gear according to claim 1, it is characterized in that described light source, light frequency conversion sensor and described microprocessor are wholely set, be encapsulated into a blood oxygen detection module, be used to measure blood oxygen saturation, pulse frequency and blood perfusion index.

5. pulse blood oxygen checkout gear according to claim 1 is characterized in that, also comprises a regulated power supply, is used for to described light source, light frequency conversion sensor and described microprocessor power supply.

6. pulse blood oxygen checkout gear according to claim 5 is characterized in that, the described light frequency conversion sensor end that links to each other with described regulated power supply also comprises a ground capacity, is used to filter power supply input clutter, stabilized power source.

7. pulse blood oxygen checkout gear according to claim 4, it is characterized in that, described light source and light frequency conversion sensor are arranged on the probe, described probe have one with the suitable groove in the tested position of health, described light source and light frequency conversion sensor are separately positioned on corresponding two medial walls of described groove.

8. pulse blood oxygen checkout gear according to claim 7 is characterized in that, described groove internal layer surface scribbles light absorbent, is used to reduce the interference of secondary reflection light.

9. pulse blood oxygen checkout gear according to claim 7 is characterized in that, described light source adopts light emitting diode, and described light emitting diode comprises at least two, is set up in parallel on the sidewall in described groove, is used for red-emitting or infrared light.

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