CN203693603U - Environment-light-interference-resisting blood oxygen measuring equipment - Google Patents
Environment-light-interference-resisting blood oxygen measuring equipment Download PDFInfo
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- CN203693603U CN203693603U CN201420012141.0U CN201420012141U CN203693603U CN 203693603 U CN203693603 U CN 203693603U CN 201420012141 U CN201420012141 U CN 201420012141U CN 203693603 U CN203693603 U CN 203693603U
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- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 229910052760 oxygen Inorganic materials 0.000 title claims abstract description 32
- 239000001301 oxygen Substances 0.000 title claims abstract description 32
- 239000008280 blood Substances 0.000 title claims abstract description 29
- 210000004369 blood Anatomy 0.000 title claims abstract description 29
- 238000012545 processing Methods 0.000 claims abstract description 34
- 238000006243 chemical reaction Methods 0.000 claims description 41
- 230000003287 optical effect Effects 0.000 claims description 35
- 230000003750 conditioning effect Effects 0.000 claims description 17
- 238000002347 injection Methods 0.000 claims description 13
- 239000007924 injection Substances 0.000 claims description 13
- 238000001914 filtration Methods 0.000 abstract description 15
- 238000000034 method Methods 0.000 description 7
- 238000002496 oximetry Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 230000003321 amplification Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 230000002452 interceptive effect Effects 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 238000013519 translation Methods 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000001795 light effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000011514 reflex Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
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- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
The utility model discloses environment-light-interference-resisting blood oxygen measuring equipment which is provided with a light-emitting module, a light receiving module, a current-voltage converting module, an analog-digital converting module, a signal processing module and a compensation module. The compensation module is arranged between the light receiving module and the current-voltage converting module and is connected with the light receiving module, the current-voltage converting module and the signal processing module respectively. The compensation module is used for filtering out interference light current output by the light receiving module according to signals output by the signal processing module. The compensation module is directly connected with the light receiving module, the interference light current output by the light receiving module can be directly filtered out, mixing of the interference light current can be avoided at the source, and the signal to noise ratio of the measuring equipment is effectively improved.
Description
Technical field
This utility model relates to a kind of noinvasive Oximetry equipment, relates in particular to a kind of blood oxygen measuring device of anti-ambient light interference.
Background technology
Blood oxygen is again blood oxygen saturation, and blood oxygen saturation is to weigh blood of human body to carry the important parameter of the ability of oxygen, by the measurement of blood oxygen saturation, can understand in time patient's oxygen content, has epochmaking clinical value.
Noinvasive Oximetry mainly adopts photoelectric technology, conventionally has two kinds of methods: projective method and bounce technique.Photoelectric technology is by exposing to the specific part of human body by transmitting light beam, light is by transmission or reflex to Optical Receivers, the photo-signal intensity that different blood oxygen saturations and different pulse frequencies all can cause Optical Receivers to produce is different, can detect accordingly blood oxygen saturation and pulse frequency.
The testing circuit of blood oxygen all comprises current/voltage conversion (being that electric current turns voltage) circuit, the common way of this conversion is to adopt operational amplifier to realize, for realizing high signal to noise ratio, we wish that this circuit has large as far as possible signal gain conventionally,, while receiving maximum photoelectric current, the voltage of current/voltage modular converter output should approach the maximum output voltage of operational amplifier.But under practical situation, because the spectrum of external environment light (sunlight, houselights, for medical light source of disease treatment etc.) and the receiving spectrum of Optical Receivers have overlapping part, so in the time that these illumination are mapped to Optical Receivers, will inevitably produce photoelectric current, the photoelectric current generation aliasing that in these photoelectric currents and measurement, light emitting module produces, when significantly promoting, photoelectric current intensity also increases the error of measuring circuit, when the most serious, can cause the operational amplifier in current/voltage modular converter saturated, cause Oximetry to lose efficacy.
And at present ambient light rejection unit is that mode based on voltage is carried out interference filtering, this must be provided with current/voltage modular converter before this ambient light rejection unit, is its conversion and processes optical signal.When easily making current/voltage modular converter saturated, also inevitably some light interfering signals are treated to useful signal, thereby cause Oximetry equipment error large, signal to noise ratio is low, even measures and loses efficacy.
Summary of the invention
It is relatively simple that the technical problems to be solved in the utility model is to provide a kind of structure, signal to noise ratio high blood oxygen measuring device.
Carry the device that the anti-surround lighting of high oxygen pressure is measured, be provided with: for the light emitting module of efficient light sources is provided; The Optical Receivers that irradiates refracted light and the reflected light after measured body and be converted to photoelectric current for receiving described light emitting module; Be connected with described Optical Receivers, for the photoelectric current of its output being converted to the current/voltage modular converter of photovoltage; Be connected with described current/voltage modular converter, for the analogue signal of its output being converted to the analog-to-digital conversion module of digital signal; Be connected with described analog-to-digital conversion module, for the digital signal of its output being carried out to the signal processing module of respective algorithms processing;
Also be provided with compensating module, this compensating module is arranged between described Optical Receivers and described current/voltage modular converter, and be connected with described Optical Receivers, described current/voltage modular converter, described signal processing module respectively, for according to the signal of described signal processing module output, the stray light electric current of Optical Receivers output described in filtering.
Further, described compensating module includes D/A converting circuit, signal conditioning circuit, electric current injection circuit;
Described D/A converting circuit is connected with described signal processing module, described signal conditioning circuit respectively, for the compensating signal of described signal processing module input is converted to analog signal output to described signal conditioning circuit;
Described signal conditioning circuit comprises: the first operational amplifier, the first electric capacity, the second electric capacity, the 3rd electric capacity, the 4th electric capacity, the first resistance, the second resistance, the 3rd resistance, ground terminal, output voltage terminal Vref;
Described first resistance one end is connected to described D/A converting circuit, and the other end is connected serially to the first operational amplifier reverse input end; Described the first operational amplifier output terminal is connected with described the 3rd resistance, described Vref lead-out terminal, described the 3rd electric capacity, described ground terminal order; Described the 4th Capacitance parallel connection is in described the 3rd electric capacity two ends; Described the second Capacitance parallel connection is in reverse input end and the outfan of described the first operational amplifier; Described the second resistance is parallel to described the first operational amplifier reverse input end and described output voltage terminal Vref; Described the first Capacitance parallel connection is in described the second resistance two ends; Described the first operational amplifier non-inverting input is connected with described ground wire terminal;
Described electric current injection circuit is provided with the 8th resistance, and described the 8th resistance one end is connected to described output voltage terminal Vref, the node between other end access Optical Receivers and current/voltage modular converter; For exporting offset current according to the signal of described D/A converting circuit input to described current/voltage modular converter.
Further, described current/voltage modular converter also comprises auxiliary current voltage conversion unit; Described auxiliary current voltage conversion unit is connected with described Optical Receivers, described signal processing module respectively, for many one group of translation interfaces are provided;
Described electric current injection circuit is also provided with the 9th resistance, for many electric current grouting sockets are provided.
Improve as one, described compensating module also comprises signal inversion circuit;
Described signals reverse circuit comprises the 4th resistance, the 5th resistance, the second operational amplifier, the common-mode voltage terminal Vcom of described current/voltage modular converter;
Described the 4th resistance one end is connected to described output voltage terminal Vref, and the other end is connected to the second operational amplifier reverse input end; Described the 5th resistance is connected in parallel between described the second operational amplifier reverse input end and the second operational amplifier output terminal; Described common-mode voltage connecting terminals is connected to described the second operational amplifier non-inverting input; Described the 9th resistance one end is connected to the second operational amplifier output terminal, node between other end access Optical Receivers and auxiliary current voltage conversion unit, anti-phase for the voltage of described output voltage terminal Vref output is carried out centered by the common-mode voltage Vcom of described current/voltage modular converter, produce a pair of voltage symmetrical centered by the common-mode voltage Vcom of described current/voltage modular converter.
Moreover described the 8th resistance and described the 9th resistance are set to trimmable resistance.
Further, between described current/voltage modular converter and described analog-to-digital conversion module, be also provided with signal condition module, described signal condition module is connected with described current/voltage modular converter, described analog-to-digital conversion module respectively, for when analog-to-digital conversion module is not when integrated filtering and amplifying circuit, photoelectric signal to described current/voltage modular converter output amplifies and/or filtering operation, and exports to described analog-to-digital conversion circuit.
The blood oxygen measuring device of a kind of anti-ambient light interference of this utility model is by adopting the compensating module while based on adjusting electric current, avoided increasing signal conversion unit before compensating module, and avoid the processing of measurement device to interfering signal from source and the error that causes, improve and measured accurately, make the blood oxygen measuring device of a kind of anti-ambient light interference of this utility model there is the scope of application widely, overcome deficiency of the prior art.
Accompanying drawing explanation
For ease of explanation, this utility model is described in detail by the following specific embodiment and accompanying drawing.
Fig. 1 is the basic structure schematic diagram of the blood oxygen measuring device of a kind of anti-ambient light interference of this utility model;
Fig. 2 is the improvement structural representation of the blood oxygen measuring device of a kind of anti-ambient light interference of this utility model;
Fig. 3 is the circuit diagram of the compensating module of the blood oxygen measuring device of a kind of anti-ambient light interference of this utility model;
Fig. 4 is the improvement circuit diagram of the compensating module of the blood oxygen measuring device of a kind of anti-ambient light interference of this utility model.
The specific embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, this utility model is further elaborated.
As shown in accompanying drawing 1-4, a kind of device of proposing the anti-surround lighting measurement of high oxygen pressure, is provided with: for the light emitting module 101 of efficient light sources is provided; For receiving the Optical Receivers 102 that described light emitting module 101 irradiates refracted light and the reflected light after measured body and is converted to photoelectric current; Be connected with described Optical Receivers 102, for the photoelectric current of its output being converted to the current/voltage modular converter 104 of photovoltage; Be connected with described current/voltage modular converter 104, for the analogue signal of its output being converted to the analog-to-digital conversion module 106 of digital signal; Be connected with described analog-to-digital conversion module 106, for the digital signal of its output being carried out to the signal processing module 107 of respective algorithms processing.
Also be provided with compensating module 103, this compensating module 103 is arranged between described Optical Receivers 102 and described current/voltage modular converter 104, and be connected with described Optical Receivers 102, described current/voltage modular converter 104, described signal processing module 107 respectively, for the signal exported according to described signal processing module 107, the stray light electric current that Optical Receivers 102 is exported described in filtering.
Further, described compensating module 103 includes D/A converting circuit 301, signal conditioning circuit 302, electric current injection circuit 304.
Described D/A converting circuit 301 is connected with described signal processing module 107, described signal conditioning circuit 302 respectively, is converted to analog signal output to described signal conditioning circuit 302 for the compensating signal that described signal processing module 107 is inputted.
Described signal conditioning circuit 302 comprises: the first operational amplifier opa1, the first electric capacity c1, the second electric capacity c2, the 3rd electric capacity c3, the 4th electric capacity c4, the first resistance r1, the second resistance r2, the 3rd resistance r3, ground terminal, output voltage terminal Vref lead-out terminal 0.
Described first resistance r1 one end is connected to D/A converting circuit 301, and the other end is connected serially to the reverse input end of the first operational amplifier opa1; Described the first operational amplifier output terminal is connected with described the 3rd resistance r3, described output voltage terminal Vref, described the 3rd electric capacity c3, described ground terminal 0 order; Described the 4th electric capacity c4 is parallel to described the 3rd electric capacity c3 two ends; Described the second electric capacity c2 is parallel to reverse input end and the outfan of described the first operational amplifier opa1; Described the second resistance r2 is parallel to described the first operational amplifier reverse input end and described output voltage terminal Vref; Described the first electric capacity c1 is parallel to described the second resistance r2 two ends; The non-inverting input of described the first operational amplifier opa1 is connected with described ground wire terminal 0.
Described electric current injection circuit 304 is provided with the 8th resistance r8, and described the 8th resistance r8 one end is connected to described output voltage terminal Vref, the node between other end access Optical Receivers 102 and current/voltage modular converter 104; Export offset current for the signal of inputting according to described D/A converting circuit 301 to described current/voltage modular converter 104.
Further, described current/voltage modular converter 104 also comprises auxiliary current voltage conversion unit 1041; Described auxiliary current voltage conversion unit 1041 is connected with described Optical Receivers 102, described signal processing module 107 respectively, for many one group of translation interfaces are provided.
Described electric current injection circuit 304 is also provided with the 9th resistance r9, for many electric current grouting sockets are provided.
Improve as one, described compensating module 103 also comprises signals reverse circuit 303.
Described signals reverse circuit 303 comprises the 4th resistance r4, the 5th resistance r5, the second operational amplifier opa2, the common-mode voltage terminal Vcom of described current/voltage modular converter 104.
Described the 4th resistance r4 one end is connected to described output voltage terminal Vref, and the other end is connected to the reverse input end of the second operational amplifier opa2; Described the 5th resistance r5 is parallel between the reverse input end of described the second operational amplifier opa2 and the outfan of the second operational amplifier opa2; Described common-mode voltage terminal Vcom is connected to the non-inverting input of described the second operational amplifier opa2; The 9th resistance r9 one end is connected to the outfan of the second operational amplifier opa2, node between other end access Optical Receivers 102 and auxiliary current voltage conversion unit 1041, anti-phase for the electric current of described output voltage terminal Vref output is carried out centered by the common-mode voltage of described current/voltage modular converter 104, produce a pair of voltage symmetrical centered by the common-mode voltage of described current/voltage modular converter 104.
Moreover described the 8th resistance r8 and described the 9th resistance r9 are set to trimmable resistance.
Another step, between described current/voltage modular converter 104 and described analog-to-digital conversion module 106, be also provided with signal condition module 105, described signal condition module 105 is connected with described current/voltage modular converter 104, described analog-to-digital conversion module 106 respectively, for in the time of the not integrated filtering and amplifying circuit PGA of analog-to-digital conversion module 106, the photoelectric signal that described current/voltage modular converter 104 is exported amplifies and/or filtering operation, and exports described analog-to-digital conversion circuit 106 to.
Specifically, as shown in Figure 1, 2:
Light source.This light source is that light and the surround lighting that light emitting module 101 sends is stray light.
Optical Receivers 102.Receive the light that light emitting module 101 sends, also can receive part external environment light simultaneously; And convert the optical signal receiving to current signal, the current signal that this part current signal has comprised light emitting module generation and the disturbance current signal of surround lighting.
Compensating module 103.Compensating module 103 is a constant-current source circuit that output current is adjustable, the stray light electric current producing for offsetting surround lighting.Compensating circuit comprises D/A converting circuit 301, signal conditioning circuit 302, signal inversion circuit 303,304 4 element circuits of electric current injection circuit.
Current/voltage modular converter 104.Convert the photoelectric current after compensation to voltage signal, if the current compensation that surround lighting produces is insufficient, the voltage signal of output will contain certain flip-flop, because of its amplitude very low, can not cause measuring circuit saturated, and signal processing module 107 can be processed this part interfering signal easily, can ignore in its impact of event.
Signal condition module 105.This part circuit can amplify and/or filtering operation signal.According to concrete application, if the inner integrated amplifier of analog-to-digital conversion module (ADC), filtering can be carried out hardware filtering or/and carry out digital filtering in signal processing module 107 in current/voltage modular converter 104, and signal condition module 105 can be omitted so.
Analog-to-digital conversion module 106.Analog digital conversion is that the analogue signal that signal condition module 105 is exported converts digital signal to (if signal condition module 105 is omitted, the signal of directly current/voltage modular converter 104 being exported converts digital signal to), for the Digital Signal Processing of signal processing module 107 is prepared.
Digital Signal Processing 107.The digital signal that analog digital conversion is obtained carries out algorithm process, and algorithm process comprises that control and compensation module 103 exports calculating of required offset current and blood oxygen, pulse frequency etc.
Optical Receivers 102 receives all light sources within the scope of its receiving spectrum, is electric energy by transform light energy, converts current signal to.
The photoelectric current that the current signal that Optical Receivers 102 is exported has comprised light emitting module generation is or/and the stray light electric current that surround lighting produces.
Only a kind of light with certain size of current, certain frequency, certain dutycycle that light emitting module 101 is launched, after seeing through human body specific part, Optical Receivers 102 converts the light of reception to current signal, and this electric current is square wave, crest has certain amplitude, and trough is 0.
In the measuring process of blood oxygen, surround lighting converts electric current to after being received by Optical Receivers 102, but slow because of surround lighting conversion, can think that this part electric current is DC current.So, in the situation that there is ambient light effects, the electric current that Optical Receivers 102 is exported is the square wave current signal with certain biasing, the trough of its square wave is the photoelectric current that surround lighting produces, and crest to trough electric current is that the light of light emitting module 102 sees through the photoelectric current producing after human body specific part.
Compensating module 103 is an adjustable constant-current source circuit for generating, the feature that the electric current that has utilized surround lighting to produce is direct current, according to signal processing module output signal, export an electric current equating with surround lighting and offset, so remaining electric current just only the light of remaining light emitting module see through the photoelectric current producing after human body specific part.
This utility model has designed a closed-loop control system, the disturbance current signal receiving by signal processing module 107, calculate the interference DC component of this photoelectric current, then by offset current export one with it corresponding compensating direct current component offset, so just, realize the compensation under different ambient light photographs, improved accuracy and the reliability of Oximetry.
After compensation, only the light of remaining light emitting module sees through the photoelectric current that human body specific part produces, and the trough of square wave current is 0.In actual control, the electric current that surround lighting produces has allowed a small amount of residue, and remainder is processed by 107.
Embodiment mono-
As shown in Figure 3, compensating circuit comprises D/A converting circuit (DAC) 301, signal conditioning circuit 302,304 3 element circuits of electric current injection circuit, current/voltage modular converter 104 is comparatively general current-to-voltage converting circuit, signal condition module 105 is carried out program control amplification to meet the demand of unlike signal intensity to signal, and directly signal is carried out to analog digital conversion.This embodiment does not have specialized designs signal condition module 105, only by C5 in figure, signal is carried out to simple filtering.This scheme is for one-terminal current change-over circuit, and it is single-ended that so-called one-terminal current conversion is that current/voltage modular converter 104 is input as.Offset current formula is:
.
D/A converting circuit (DAC) 301, output adjustable voltage.A reference source, figure place that analog-digital converter uses have determined output voltage precision and voltage-regulation step-length.For example, the analog-digital converter of 12, a reference source is 2.5V, so,
Adjustable digital quantity is:
Output voltage precision is:
Adjusting step-length is:
Therefore, need according to the concrete suitable analog-digital converter of Oximetry application choice, conventionally use the inner integrated analog-digital converter of microcontroller (107) to meet the demands.
Signal conditioning circuit 302, amplifies and Filtering Processing 301 output voltages, and to reduce signal noise, this circuit output voltage represents with Vref.If 301 output noises are very low, this part circuit can be removed so.
Electric current injection circuit 304, is also referred to as electric current and voltage (being V-I voltage transitions electric current) change-over circuit.This circuit is realized by the identical resistance R 8 of one or two resistance or R8, R9, and the voltage that R8, R9 resistance and signal conditioning circuit 302 are exported has determined the size of offset current jointly, can derive offset current formula by circuit diagram:
,
,
,
determined by concrete application,
maximum at least can be designed into 15uA, and this design circuit still can obtain high signal to noise ratio, can meet again the measurement of blood oxygen under surround lighting.
Current/voltage modular converter 104, this circuit converts current signal to voltage signal, and this is current detecting common practice.The photoelectric current surround lighting having been produced due to front stage circuits compensates, therefore current conversion multiple can be improved, improve the resistance of R10, R11, realize higher signal to noise ratio by the amplification that improves first order circuit, this is also the object that this utility model patent will reach.
Analog to digital conversion circuit 106, analog-digital converter device that this circuit uses is inner integrated gain-programmed amplifier (PGA), realizes unlike signal gain, to meet the application under blood oxygen different measuring environment by this circuit of software control.Signal amplifies afterwards and carries out analog digital conversion, for Digital Signal Processing (107) is prepared.
Microcontroller 107, realizes Digital Signal Processing and peripheral circuit control.
Embodiment bis-
As shown in Figure 4, compensating circuit comprises D/A converting circuit (DAC) 301, signal conditioning circuit 302, signal inversion circuit 303,304 4 element circuits of electric current injection circuit.Consistent with embodiment, current/voltage modular converter 104 is comparatively general current-to-voltage converting circuit, and 106 pairs of signals carry out program control amplification to meet the demand of unlike signal intensity, and directly signal are carried out to analog digital conversion.This embodiment does not have specialized designs signal conditioning circuit, only by C5, C8 in figure, signal is carried out to simple filtering.This embodiment is for both-end current mode change-over circuit, and so-called both-end current mode conversion 104 is input as both-end.
Signal inversion circuit 303, circuit carries out anti-phase centered by common-mode voltage Vcom to the signal after 302 processing, be intended to produce a pair of voltage symmetrical centered by common-mode voltage Vcom.Wherein common-mode voltage terminal Vcom is the common-mode voltage of current/voltage modular converter 104.
The foregoing is only preferred embodiment of the present utility model; not in order to limit this utility model; all interior done any modifications in spirit of the present utility model and principle, be equal to and replace and improvement etc., all should be included in protection domain of the present utility model in.
Claims (6)
1. a blood oxygen measuring device for anti-ambient light interference, is provided with: for the light emitting module of efficient light sources is provided; The Optical Receivers that irradiates refracted light and the reflected light after measured body and be converted to photoelectric current for receiving described light emitting module; Be connected with described Optical Receivers, for the photoelectric current of its output being converted to the current/voltage modular converter of photovoltage; Be connected with described current/voltage modular converter, for the analogue signal of its output being converted to the analog-to-digital conversion module of digital signal; Be connected with described analog-to-digital conversion module, for the digital signal of its output being carried out to the signal processing module of respective algorithms processing;
It is characterized in that, be also provided with compensating module, this compensating module is arranged between described Optical Receivers and described current/voltage modular converter, and is connected with described Optical Receivers, described current/voltage modular converter, described signal processing module respectively.
2. a kind of blood oxygen measuring device of anti-ambient light interference according to claim 1, is characterized in that, described compensating module includes D/A converting circuit, signal conditioning circuit, electric current injection circuit;
Described D/A converting circuit is connected with described signal processing module, described signal conditioning circuit respectively;
Described signal conditioning circuit comprises: the first operational amplifier, the first electric capacity, the second electric capacity, the 3rd electric capacity, the 4th electric capacity, the first resistance, the second resistance, the 3rd resistance, ground terminal, output voltage terminal;
Described first resistance one end is connected to described D/A converting circuit, and the other end is connected serially to the first operational amplifier reverse input end; Described the first operational amplifier output terminal is connected with described the 3rd resistance, described output voltage terminal, described the 3rd electric capacity, described ground terminal order; Described the 4th Capacitance parallel connection is in described the 3rd electric capacity two ends; Described the second Capacitance parallel connection is in reverse input end and the outfan of described the first operational amplifier; Described the second resistance is parallel to described the first operational amplifier reverse input end and described output voltage terminal; Described the first Capacitance parallel connection is in described the second resistance two ends; Described the first operational amplifier non-inverting input is connected with described ground wire terminal;
Described electric current injection circuit is provided with the 8th resistance, and described the 8th resistance one end is connected to described output voltage terminal, and the other end accesses the node between described Optical Receivers and described current/voltage modular converter.
3. a kind of blood oxygen measuring device of anti-ambient light interference according to claim 2, is characterized in that, described current/voltage modular converter also comprises auxiliary current voltage conversion unit; Described auxiliary current voltage conversion unit is connected with described Optical Receivers, described signal processing module respectively;
Described electric current injection circuit is also provided with the 9th resistance.
4. a kind of blood oxygen measuring device of anti-ambient light interference according to claim 3, is characterized in that, described compensating module also comprises signal inversion circuit;
Described signals reverse circuit comprises the 4th resistance, the 5th resistance, the second operational amplifier, the common-mode voltage terminal of described current/voltage modular converter;
Described the 4th resistance one end is connected to described output voltage terminal, and the other end is connected to the second operational amplifier reverse input end; Described the 5th resistance is parallel between described the second operational amplifier reverse input end and the second operational amplifier output terminal; Described common-mode voltage connecting terminals is connected to described the second operational amplifier non-inverting input; Described the 9th resistance one end is connected to the second operational amplifier output terminal, the node between other end access Optical Receivers and auxiliary current voltage conversion unit.
5. a kind of blood oxygen measuring device of anti-ambient light interference according to claim 4, is characterized in that, described the 8th resistance and described the 9th resistance are set to trimmable resistance.
6. a kind of blood oxygen measuring device of anti-ambient light interference according to claim 5, it is characterized in that, between described current/voltage modular converter and described analog-to-digital conversion module, be also provided with signal condition module, described signal condition module is connected with described current/voltage modular converter, described analog-to-digital conversion module respectively.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106066397A (en) * | 2016-07-05 | 2016-11-02 | 深圳普门科技有限公司 | A kind of compensation system, method and immunity analysis instrument being applicable to current-output type photomultiplier tube |
| CN106264555A (en) * | 2016-10-17 | 2017-01-04 | 南方科技大学 | blood glucose monitor |
| CN106551681A (en) * | 2015-09-30 | 2017-04-05 | 株式会社东芝 | Organism measuring device and organism measurement system |
| CN111947689A (en) * | 2019-05-17 | 2020-11-17 | 敦宏科技股份有限公司 | Method for canceling ambient light and optical crosstalk of optical proximity sensing devices |
-
2014
- 2014-01-09 CN CN201420012141.0U patent/CN203693603U/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106551681A (en) * | 2015-09-30 | 2017-04-05 | 株式会社东芝 | Organism measuring device and organism measurement system |
| CN106066397A (en) * | 2016-07-05 | 2016-11-02 | 深圳普门科技有限公司 | A kind of compensation system, method and immunity analysis instrument being applicable to current-output type photomultiplier tube |
| CN106066397B (en) * | 2016-07-05 | 2019-10-18 | 深圳普门科技股份有限公司 | A kind of compensation system, method and immunity analysis instrument suitable for current-output type photomultiplier tube |
| CN106264555A (en) * | 2016-10-17 | 2017-01-04 | 南方科技大学 | blood glucose monitor |
| CN111947689A (en) * | 2019-05-17 | 2020-11-17 | 敦宏科技股份有限公司 | Method for canceling ambient light and optical crosstalk of optical proximity sensing devices |
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