WO2013097599A1

WO2013097599A1 - Blood oxygen measuring device

Info

Publication number: WO2013097599A1
Application number: PCT/CN2012/086345
Authority: WO
Inventors: 岑建; 周赛新
Original assignee: 深圳迈瑞生物医疗电子股份有限公司
Priority date: 2011-12-26
Filing date: 2012-12-11
Publication date: 2013-07-04
Also published as: CN103169478A

Abstract

Disclosed is a blood oxygen measuring device comprising: a light-emitting component arranged on one side of an object-for-measurement and used at least for emitting a first wavelength light and a second wavelength light; a light-detecting component arranged on the other side of the object-for-measurement and opposite the light-emitting component, where the light-detecting component comprises a first narrowband light detector and a second narrowband light detector, where the first narrowband light detector is used for receiving transmitting light of the first wavelength light transmitted through the object-for-measurement and for converting into an electric signal corresponding to the first wavelength light, and where the second narrowband light detector is used for receiving transmitting light of the second wavelength light transmitted through the object-for-measurement and for converting into an electric signal corresponding to the second wavelength light; and a signal processing circuit respectively coupled to output ends of the first narrowband light detector and of the second narrowband light detector for calculating blood oxygen saturation level. The present invention effectively suppresses interferences from ambient lights, while at the same time provides a possibility in improving the capability of the blood oxygen measuring device in terms of suppressing interferences from movements of the object-for-measurement.

Description

Blood oxygen measuring device

[Technical Field]

The invention relates to a blood oxygen measuring device.

【Background technique】

By studying the principle of pulse oximetry, it has been found that hemorrhage oxygen saturation can be measured by measuring the change in light intensity of transmitted light of two wavelengths in a complete pulse wave. At present, the basic principle of pulse oximetry is to determine blood oxygen saturation by projecting red and infrared light into the capillaries and measuring periodic changes in cardiac light absorption. The light source in the blood oxygen probe emits red light and infrared light. Light, and the corresponding photodetector enables detection of red and infrared light.

The blood oxygen measurement method assumes that all the pulsating components in the light absorption signal are caused by the filling of arterial blood, and are absorbed by light of red light (wavelength near 500-700 nm) and infrared wavelength (wavelength near 800-1000 nm). The ratio of the pulsating component (AC) to the upper DC component (DC) is calculated as:

Red=Red(AC)/Red(DC)

Ir=Ir(AC)/Ir(DC)

Further calculate the optical absorption ratio of the two light waves

R=Red/Ir

It is possible to find the corresponding oxygen saturation in the established R-Spo2 table by this R value, and this R-Spo2 table is a blood gas analysis based on the blood gas analyzer for the study of induced hypoxia in healthy adult volunteers. The result is determined.

As shown in FIG. 1, the blood oxygen measuring device mainly comprises a light source 11, a detector 12 and a signal processing circuit 13. The light source 11 uses two kinds of light sources, red light and infrared light, on one side of the detected object, and the detector 12 is located at the detected end. The other side of the object. When performing blood oxygen measurement, two sources of red light and infrared light alternately emit light and transmit the detected object, and the detector 12 detects the transmitted light intensity of the red and infrared light transmitted through the detected object, and the red light and the infrared light are The transmitted light is converted into an electrical signal and output to the signal processing circuit 13. The signal processing circuit 13 is used to process and calculate the detected signal to obtain blood oxygen saturation, and to drive the light source according to the designed light source illumination timing. The illumination timing is that the two sources of red light and infrared light alternately emit light, as shown in FIG. 2 .

[Summary of the Invention]

The invention provides a novel blood oxygen measuring device, which can improve the accuracy of the measurement result of the blood oxygen measuring device.

According to an aspect of the present invention, an apparatus for measuring blood oxygenation includes: a light emitting device disposed on a side of an object to be detected for emitting at least first wavelength light and second wavelength light; and photodetecting device disposed at On the other side of the detected object opposite to the light emitting device, the light detecting device includes a first narrowband photodetector and a second narrowband photodetector, and the first narrowband photodetector is configured to receive the first wavelength light transmission to be detected The transmitted light of the object is converted into an electrical signal corresponding to the first wavelength light, and the second narrowband photodetector is configured to receive the transmitted light of the second wavelength light transmitted through the detected object and convert it into electricity corresponding to the second wavelength light. a signal processing circuit coupled to the output ends of the first narrowband photodetector and the second narrowband photodetector, respectively, receiving an electrical signal corresponding to the first wavelength light and an electrical signal corresponding to the second wavelength light, according to The electrical signal corresponding to the first wavelength light and the electrical signal corresponding to the second wavelength light calculate blood oxygen saturation; the signal processing circuit is further coupled to the light emitting device.

According to another aspect of the present invention, there is provided an oximetry apparatus comprising: a light-emitting device disposed on a side of an object to be detected for emitting at least red light and infrared light; and a light detecting device disposed on the object to be detected On the other side opposite to the light-emitting device, the light detecting device includes a red light detector and an infrared light detector for receiving red light transmitted through the object to be detected and converted into red light. Corresponding electrical signals, the infrared light detector is configured to receive the transmitted light of the infrared light transmitted through the detected object, and is converted into an electrical signal corresponding to the infrared light; the signal processing circuit is respectively coupled to the red light detector and the infrared light detector The output end receives an electrical signal corresponding to the red light and an electrical signal corresponding to the infrared light, and calculates the blood oxygen saturation according to the electrical signal corresponding to the red light and the electrical signal corresponding to the infrared light.

According to another aspect of the present invention, there is provided an oximetry apparatus comprising: a light-emitting device disposed on a side of an object to be detected, the light-emitting device including a first light-emitting device for emitting light of a first wavelength and a second light emitting device for emitting light of a second wavelength, the first light emitting device and the second light emitting device being configured such that a light emitting time of both has a set delay difference; and the light detecting device is disposed on the object to be detected On the other side opposite to the light emitting device, the light detecting device includes a first photodetector and a second photodetector, the first photodetector for detecting the transmitted light of the first wavelength light transmitted through the detected object, and converting For the electrical signal corresponding to the first wavelength light, the second photodetector is configured to detect the transmitted light of the second wavelength light transmitted through the detected object, and convert it into an electrical signal corresponding to the second wavelength light, the first photodetector and At least one of the second photodetectors is a narrowband photodetector; a signal processing circuit coupled to the output of the first photodetector and the second photodetector, respectively, for receiving the first photodetector and the second photodetector output Signal and calculate blood oxygen saturation.

[Description of the Drawings]

1 is a schematic structural view of a conventional blood oxygen measuring device;

2 is a timing diagram of a conventional oximetry device;

3 is a schematic structural view of a blood oxygen measuring device in the first embodiment;

Figure 4 is a timing chart of the blood oxygen measuring device in the first embodiment;

Figure 5 is a schematic structural view of two blood oxygen measuring devices of the embodiment;

Figure 6 is a timing chart of the blood oxygen measuring device in the second embodiment;

Figure 7 is a schematic structural view of a blood oxygen measuring device in the third embodiment;

Figure 8 is a schematic structural view of a blood oxygen measuring device in the fourth embodiment;

Figure 9 is a timing chart of the blood oxygen measuring device in the fourth embodiment;

Figure 10 is a schematic structural view of a blood oxygen measuring device in the fifth embodiment;

Figure 11 is a timing chart of the blood oxygen measuring device of the fifth embodiment.

【detailed description】

The present invention will be further described in detail below with reference to the accompanying drawings.

In an embodiment of the present application, the oximetry device employs at least one narrowband photodetector to detect the transmitted light intensity of the two wavelengths transmitted through the object to be measured, and calculate the transmitted light intensity based on the two wavelengths. Blood oxygen saturation. The narrow-band photodetector detects only a certain wavelength range of light, and significantly attenuates the light outside the passband wavelength range. Therefore, by selecting the filter parameters of the two narrow-band photodetectors, the narrow-band photodetector can only pass the need. Calculate the transmitted light of two wavelengths, and filter out the ambient light and other wavelengths of transmitted light, thereby reducing the influence of ambient light and other wavelengths of light, and improving the accuracy of the measurement results of the oximeter.

In practical applications, the light emitted by the light source includes at least two wavelengths of the first wavelength light and the second wavelength light, and the light source may respectively emit the first wavelength light and the second wavelength light, or may emit the first wavelength light and the second wavelength. Wide-spectrum light of wavelength light. In the blood oxygen calculation, only the transmitted light intensities of the predetermined two wavelengths are selected to participate in the calculation, for example, the first wavelength light and the second wavelength light. In theory, the first wavelength light and the second wavelength light may be any two types of light suitable for different wavelengths that are detectable by the detected object and detectable on the light receiving side. In the following embodiments, the detected object is a human body tissue (for example, a finger), and the first wavelength light and the second wavelength light are respectively red light and infrared light.

In another embodiment of the present application, the blood oxygen measuring device adopts a driving scheme of modulating a light source, so that the light source emits high-frequency pulse light having a set width according to a set time interval, and the frequency of the high-frequency pulse light is much higher than that of an ordinary one. Ambient light, ambient light interference is reflected as out-of-band noise, which can be easily filtered, thereby reducing the impact of ambient light.

Embodiment 1:

Referring to FIG. 3, the blood oxygen measuring device includes a light emitting device 21, a light detecting device 22, and a signal processing circuit 23. The light emitting device 21 is disposed on one side of the human body tissue, and the light emitting device 21 includes a light source driving circuit 211, a first light emitting device 212, and a second light emitting device 213. In this embodiment, the first light emitting device 212 is red emitting red light. The light-emitting device, the second light-emitting device 213 is an infrared light-emitting device that emits infrared light, and the first light-emitting device 212 and the second light-emitting device 213 may specifically be a red light-emitting diode and an infrared light-emitting diode, a red light-emitting diode and an infrared light, respectively. The light emitting diodes are connected in parallel in the same direction at both ends of the light source driving circuit 211, and are driven by the light source driving circuit 211 to simultaneously emit light. The light detecting device 22 is disposed on the other side of the human body tissue opposite to the light emitting device 21, and the light detecting device 22 includes a first narrow band photodetector 221 and a second narrow band photodetector 222, when the first light emitting device 212 and the second When the light emitting device 213 emits red light and infrared light respectively, the first narrow band light detector 221 and the second narrow band light detector 222 correspond to a red light detector and an infrared light detector, and the red light detector is used to receive red light. The transmitted light of the human tissue is converted into an electrical signal corresponding to the red light, and the infrared light detector is configured to receive the transmitted light of the infrared light transmitted through the human tissue and convert it into an electrical signal corresponding to the infrared light. When the first narrowband photodetector 221 and the second narrowband photodetector 222 can adopt an existing narrowband photodetector, or a narrowband photodetector manufactured according to the prior art to meet the filtering parameter requirements, for example, with filtering a photodiode of the sheet to detect a transmitted light intensity of a specific light wavelength transmitted through the human body, and when the first narrow band photodetector 221 and the second narrow band photodetector 222 are a red light detector and an infrared light detector, respectively, The wavelength can be set to 660 nm and 940 nm. Of course, according to the content disclosed in the present application and the prior art, it should be understood in the art that the wavelengths of light detected by the first narrowband photodetector 221 and the second narrowband photodetector 222 may also be other set wavelengths. The signal processing circuit 23 is coupled to the output ends of the first narrowband photodetector 221 and the second narrowband photodetector 222, respectively, and receives an electrical signal corresponding to the red light and an electrical signal corresponding to the infrared light, according to the electrical power corresponding to the red light. The signal and the electrical signal corresponding to the infrared light calculate blood oxygen saturation. In one embodiment, signal processing circuit 23 includes signal amplification/conditioning circuitry 231, analog to digital conversion circuitry 232, and processor 233 that are sequentially coupled. The signal amplification/conditioning circuit 231 is connected to the output ends of the first narrowband photodetector 221 and the second narrowband photodetector 222, respectively, and receives the output of the first narrowband photodetector 221 and the second narrowband photodetector 222 corresponding to the red light. The electrical signal and the electrical signal corresponding to the infrared light, the electrical signal is amplified and other processing (other processing such as filtering), the analog-to-digital conversion circuit 232 performs analog-to-digital conversion on the amplified signal, and then outputs the signal to the processor 233 for processing. The 233 calculates the blood oxygen saturation based on the analog-to-digital converted signal. The blood oxygen saturation calculation method can use an existing algorithm or an algorithm that may occur in the future.

In practical applications, ambient light may exist in the detection environment in which the blood oxygen measuring device is located, and the ambient light has a direct current component and an alternating current component. If it is superimposed on the light emitted by the light emitting device, it is easy to cause interference on the transmitted light. Interference with the measurement. In this embodiment, the first narrowband photodetector detects only red light transmitted through the human tissue, and the second narrowband photodetector detects only infrared light transmitted through the human tissue, thereby filtering out ambient light and the light source. Other wavelengths of light reduce the interference of ambient light and other wavelengths of light.

In addition, in this embodiment, two kinds of narrow-band photodetectors are respectively used to detect the transmitted light intensity of the two optical signals, which provides the possibility of simultaneous transmission and reception of the two kinds of light. For example, the light source driving signals for the first light emitting device 212 and the second light emitting device 213 may be a pulse signal having a set period, as shown in FIG. 4, the light source driving signal driving the first light emitting device 212 and the second light emitting device. 213 simultaneously emits red light and infrared light, and the first narrow-band photodetector 221 and the second narrow-band photodetector 222 respectively detect red light transmitted light and infrared light transmitted through the human body tissue, and the detected red light transmitted light And the infrared light transmitted light signal is a synchronization signal. Therefore, this scheme improves the synchronism of the detection signal and facilitates the processing of the subsequent blood oxygen algorithm. When the blood flow of the pulse changes due to the movement of the detected object, there is also a time difference between the transmitted light of the red light and the transmitted light of the infrared light. The subsequent blood oxygenation algorithm is difficult to recognize that the time difference between the two signals is caused by the asynchronousness of the signal itself. It is still caused by the motion of the detected object. When the synchronization of the detection signals of the red light and the infrared light itself is improved, it is also possible for the subsequent blood oxygen algorithm to more accurately recognize the interference caused by the motion of the measured object and effectively suppress it. .

The light source driving signal may be generated by the light source driving circuit 211 according to the set timing, or may be generated by the processor 233 in the signal processing circuit 23 according to the set timing, and the processor 233 outputs the light source driving signal to the light source driving circuit of the light emitting device 21. 211. The first light emitting device 212 and the second light emitting device 213 are driven to emit light by the light source driving circuit 211 according to the light source driving signal.

In the above embodiment, the first light-emitting device 212 and the second light-emitting device 213 are connected in parallel at both ends of the light source driving circuit 211. In another specific example, each of the light-emitting devices may also have independent light source driving circuits, that is, each The light emitting devices are connected to both ends of the respective light source driving circuits, and the light source driving circuit drives the light. In this case, the first light-emitting device 212 and the second light-emitting device 213 may also emit light at different times, but have a set delay difference. For example, the light source driving circuit of the first light-emitting device passes the light source through the switch circuit or the delay circuit. The driving signal is delayed for a certain time, and the light source driving circuit of the second light emitting device does not delay the light source driving signal, so that the light emitted by the first light emitting device is delayed by a certain time than the light emitted by the second light emitting device, and There is also a certain time difference between the two transmitted lights detected by a narrowband photodetector and a second narrowband photodetector.

Embodiment 2:

Referring to FIG. 5, the blood oxygen measuring device includes a light emitting device 31, a light detecting device 32, and a signal processing circuit 33. The light emitting device 31 is disposed on one side of the human body tissue, and the light detecting device 32 is disposed on the other side of the body tissue opposite to the light emitting device 31. The light detecting device 32 includes a first narrow band photodetector 321 and a second narrow band photodetector. The first narrowband photodetector 321 is configured to detect the transmitted light intensity of the red light transmitted through the human body tissue, and the second narrowband light detector 322 is configured to detect the transmitted light intensity of the infrared light transmitted through the human tissue. The signal processing circuit 33 is coupled to the output ends of the first narrowband photodetector 321 and the second narrowband photodetector 322, respectively, and receives an electrical signal corresponding to the first wavelength light and an electrical signal corresponding to the second wavelength light, according to The oxygen saturation corresponding to the electrical signal corresponding to one wavelength of light and the electrical signal corresponding to the second wavelength of light are calculated. In this embodiment, the light-emitting device 31 is a wide-spectrum light source, and the emitted spectrum includes at least a red light spectrum and an infrared spectrum. Of course, those skilled in the art should understand that if the blood oxygen calculation uses two other wavelengths of light, the spectrum emitted by the broad spectrum light source should include at least two wavelengths of light used in the blood oxygen calculation, and the first narrowband light detection. The 321 and the second narrowband photodetector 322 also detect the transmitted light intensities of the two wavelengths. In the present embodiment, the light-emitting device 31 includes a light source driving circuit 311 and a wide-spectrum light source 312. The wide-spectrum light source 312 is connected to both ends of the light source driving circuit 311, and the light source driving circuit 311 drives the light-emitting according to the light source driving signal. The broad spectrum source 312 can employ an existing wide spectrum source or a new broad spectrum source in the future, such as a white LED or an incandescent source. The structures of the first narrowband photodetector 321, the second narrowband photodetector 322, and the signal processing circuit 33 may be the same as or different from those in the first embodiment. The first narrowband photodetector 321 and the second narrowband photodetector 322 are only sensitive to the infrared band or the red band, and are respectively used for detecting infrared and red transmitted light. The timing of the illuminating and receiving light of this embodiment is as shown in FIG. 6. When the wide-spectrum light source emits light, the two detectors can simultaneously detect the transmitted light signals of the red light and the infrared light, thereby ensuring extremely high synchronism and also Reduces the limitation of the light source and reduces the cost of the light source.

Embodiment 3:

Referring to FIG. 7, the blood oxygen measuring device includes a light emitting device 41, a light detecting device 42, and a signal processing circuit 43. The light emitting device 41 is disposed on one side of the human body tissue, and the light detecting device 42 is disposed on the other side of the body tissue opposite to the light emitting device 41. The light detecting device 42 includes a first narrowband photodetector and a second narrowband photodetector. The first narrowband photodetector is used to detect the transmitted light intensity of the red light passing through the human tissue, and the second narrowband photodetector is used to detect the transmitted light intensity of the infrared light passing through the human tissue. The first narrowband photodetector comprises a plurality of red light detectors, and the second narrowband photodetector comprises a plurality of infrared light detectors, and the red light detector and the infrared light detector can be arranged in the light detecting device in various ways according to design requirements. 42 is distributed on the photodetecting device 42 in a spaced manner or in a column spacing as shown in FIG.

In this embodiment, a plurality of detectors are evenly distributed in space, so that the optical paths of the two light sources are more consistent. Further, these detectors can be arranged in an array by a semiconductor process, and are fabricated on one chip, so that the single area of these detectors is smaller, the number is larger, and the distribution is more uniform.

In this embodiment, the structures of the light-emitting device 41 and the signal processing circuit 43 may be the same as or different from those of the first embodiment. The light-emitting device 41 may be two independent light sources, respectively emitting red light and infrared light, or may be a wide-spectrum light source.

Embodiment 4:

Ambient light sources, such as incandescent lamps and fluorescent lamps, usually contain a direct current component (that is, the light intensity is substantially constant, which does not change with time), and an alternating component, which is generally a power frequency (50 Hz or 60 Hz) frequency doubling component. They are superimposed on the light emitted by the light source and easily interfere with the detection of transmitted light, thereby affecting the blood oxygen measurement. Therefore, the background light interference can be suppressed in the following manner: the light source outputs a certain width of high-frequency pulse light at a certain time interval, and the frequency requirement of the high-frequency pulse light is significantly higher than the light-emitting interval of the light source, and is convenient for detecting by the blood oxygen measuring device. Just handle it.

During the higher frequency illumination of the light source, this can be achieved by switching control of the light source drive circuit or a change in drive current. This high-frequency pulse light waveform may be a square wave or a high-frequency wave such as a sine wave. After the high-frequency pulse-transmitted light is detected by the measuring device, the high-frequency pulse-transmitted light intensity is processed and used for blood oxygen value calculation. Due to the use of high-frequency pulsed light driving, ambient light interference is reflected as out-of-band noise, which can be easily filtered out and the corresponding transmitted light intensity is obtained.

In the present embodiment, referring to FIG. 8, the blood oxygen measuring device includes a light emitting device 51, a light detecting device 52, and a signal processing circuit 53. The light-emitting device 51 is disposed on one side of the human body tissue, and the light detecting device 52 is disposed on the other side of the body tissue opposite to the light-emitting device 51 for receiving transmitted light of a specific two wavelengths transmitted through the detected object. The light emitting device emits high frequency pulse light having a set width according to a set time interval. As shown in FIG. 9, the light source driving signal is a high frequency modulated signal, and the modulated signal source is a low frequency pulse signal, as shown in FIG. As shown in (a), the low-frequency modulation signal source may be a general light source driving signal of the light-emitting device, and the low-frequency modulation signal source is used to modulate a high-frequency signal having a frequency much higher than the frequency of the modulation signal source, and generated. The modulated light source driving signal, as shown in (b) of FIG. 9, drives the light emitting device 51 to emit light as the light source driving signal. Taking the light-emitting device 51 including the light source driving circuit 511 and the broad-spectrum light source 512 as an example, the timing of the light emitted by the light-emitting device 51 under the driving of the modulated light source driving signal is as shown in (b) of FIG. 9, which includes Red and infrared light. The light detecting device 52 includes a first narrowband photodetector 521 for detecting the transmitted light intensity of the red light transmitted through the human body, and a second narrowband photodetector 522 for the second narrowband photodetector 522. For detecting the transmitted light intensity of infrared light transmitted through human tissue. The timings of the transmitted light of the red light and the infrared light detected by the first narrowband photodetector 521 and the second narrowband photodetector 522 are respectively shown in (c) and (d) of FIG. 9, and are the same as the light source driving signal. High frequency modulated signal. The signal processing circuit 53 includes a signal amplifying/conditioning circuit 531, a detecting circuit 532, an analog-to-digital converting circuit 533 and a processor 534 which are sequentially connected, and an input end of the signal amplifying/conditioning circuit 531 is connected to the photo detecting device 52, and receives light detection. The high frequency modulated electrical signal outputted by the device 52 amplifies and filters the high frequency modulated electrical signal, and outputs the high frequency modulated electrical signal to the detection circuit 532, which detects and demodulates the high frequency modulated electrical signal. The analog to digital conversion circuit 533 performs analog-to-digital conversion on the detected electrical signal, and the processor 534 calculates blood oxygen saturation based on the analog-to-digital converted signal.

In another specific example, the light-emitting device 51 may also include two light sources that independently emit red light and infrared light. The light source driving circuit 511 drives the two light sources to emit light simultaneously according to the modulated light source driving signal, and the first narrow-band light detector 521 And the second narrowband photodetector 522 detects the transmitted light of the red light and the infrared light, and the detected light transmission timings of the red light and the infrared light are as shown in (c) and (d) of FIG.

Embodiment 5:

In this embodiment, the light-emitting device still emits light at a certain frequency, and emits light at a higher frequency during the light-emitting of the light-emitting device. After detecting the transmitted light, the detector detects the frequency and detects the transmitted light intensity. . Still using the modulated light source driving signal, referring to FIG. 10, the blood oxygen measuring device includes a light emitting device 61, a light detecting device 62, and a signal processing circuit 63. The light-emitting device 61 is disposed on one side of the human body tissue, and the light detecting device 62 is disposed on the other side of the human body tissue opposite to the light-emitting device 61 for receiving transmitted light of a specific two wavelengths transmitted through the detected object. The light emitting device 61 includes a light source driving circuit 611, a first light emitting device 612, and a second light emitting device 613. The first light emitting device 612 is a red light emitting device that emits red light, and the second light emitting device 613 is an infrared light emitting device that emits infrared light. The first light emitting device 612 and the second light emitting device 613 are oppositely connected in parallel at both ends of the light source driving circuit 611, and the light source driving circuit 611 drives the first light emitting device 612 and the second light emitting device 613 to alternately emit light according to the modulated light source driving signal. The timing of the light emitted by the first light-emitting device 612 and the second light-emitting device 613 is as shown in (a) and (b) of FIG. 11, and the light detecting device 62 is a wide-spectrum detector that detects red light and infrared light. The timing of the transmitted light is as shown in (c) of FIG. The signal processing circuit 53 includes a signal amplifying/conditioning circuit 531, a detecting circuit 532, an analog-to-digital converting circuit 533 and a processor 534 which are sequentially connected, and an input end of the signal amplifying/conditioning circuit 531 is connected to the photo detecting device 52, and receives light detection. The high frequency modulated electrical signal outputted by the device 52 amplifies and filters the high frequency modulated electrical signal, and outputs the high frequency modulated electrical signal to the detection circuit 532, which detects and demodulates the high frequency modulated electrical signal. The analog to digital conversion circuit 533 performs analog-to-digital conversion on the detected electrical signal, and the processor 534 calculates blood oxygen saturation based on the analog-to-digital converted signal.

In the above embodiments 4 and 5, the modulated light source driving signal may be generated by the light source driving circuit according to the set timing, or may be generated by the processor in the signal processing circuit according to the set timing, and the processor outputs the light source driving signal to the light emission. The light source driving circuit of the device is driven by the light source driving circuit to drive the light source according to the modulated light source driving signal. The modulated light source driving signal may be a voltage driving type or a current driving type, and the light source driving circuit may perform different circuit designs according to different driving types of the modulated light source driving signals.

In a further embodiment, when the light emitting device includes a first light emitting device for emitting light of a first wavelength and a second light emitting device for emitting light of a second wavelength, respectively, adjusting a light source driving signal to cause the first light emitting device And the illuminating time of the second illuminating device has a set delay difference, for example, the light emitting device comprises a red illuminating device that emits red light and an infrared illuminating device that emits infrared light, and the light source driving signal is as shown in FIG. There is a delay between the optical drive signal and the infrared drive signal. In this case, the photodetecting device also includes a first photodetector for detecting the transmitted light of the first wavelength light transmitted through the detected object, and a second photodetector corresponding to the first wavelength light. An electrical signal, the second photodetector is configured to detect the transmitted light of the second wavelength light transmitted through the detected object, and convert it into an electrical signal corresponding to the second wavelength light, and the first photodetector and the second photodetector At least one is a narrowband photodetector. Taking the first wavelength light as red light and the second wavelength light as infrared light, for example, in a specific example, the first photodetector is a narrow band photodetector with a passband wavelength of red wavelength, which can detect red light transmission. Through the transmitted light of the detected object, the second photodetector is a wide-spectrum detector, which can detect the transmitted light of the red and infrared light passing through the detected object, since the red light and the infrared light have the light-emitting timing. A certain time difference, according to the illumination timing, can detect the transmitted light intensity signal of the infrared light passing through the detected object. Of course, according to the disclosure of the present application, those skilled in the art should understand that the first photodetector can also be a narrow-band photodetector with a passband wavelength of infrared light wavelength, and the second photodetector is a wide-spectrum detector, according to illumination. Timing, the transmitted light intensity signal of the red light passing through the detected object can be detected. In addition, the first photodetector and the second photodetector may also be narrow-band photodetectors, one of which is a narrow-band photodetector having a passband wavelength of red wavelength, and the other is a narrowband of a passband wavelength of infrared wavelength. Photodetector.

Signal processing circuits are coupled to the outputs of the first photodetector and the second photodetector, respectively, receiving signals output by the first photodetector and the second photodetector and calculating blood oxygen saturation.

The above is a further detailed description of the present invention in connection with the specific embodiments, and the specific embodiments of the present invention are not limited to the description. It will be apparent to those skilled in the art that the present invention may be made without departing from the spirit and scope of the invention.

Claims

An apparatus for measuring blood oxygenation, comprising:

a light emitting device disposed on a side of the object to be detected for emitting at least first wavelength light and second wavelength light;

a photodetecting device disposed on the other side of the object to be detected opposite to the light emitting device, the photo detecting device comprising a first narrowband photodetector and a second narrowband photodetector, the first narrowband photodetector for receiving the first The wavelength light passes through the transmitted light of the detected object and is converted into an electrical signal corresponding to the first wavelength light, and the second narrowband photodetector is configured to receive the transmitted light of the second wavelength light transmitted through the detected object, and convert the same to An electrical signal corresponding to two wavelengths of light;

a signal processing circuit coupled to the output ends of the first narrowband photodetector and the second narrowband photodetector, respectively, receiving an electrical signal corresponding to the first wavelength light and an electrical signal corresponding to the second wavelength light, according to the first The electrical signal corresponding to the wavelength light and the electrical signal corresponding to the second wavelength light calculate blood oxygen saturation; the signal processing circuit is further coupled to the light emitting device.
The oximetry device according to claim 1, wherein said light-emitting device comprises a first light-emitting device for emitting light of a first wavelength and a second light-emitting device for emitting light of a second wavelength, The first light emitting device and the second light emitting device are configured to have a set delay difference based on the light source driving signal to synchronize the light emission or the light emitting time.
An apparatus for measuring blood oxygenation, comprising:

a light emitting device disposed on a side of the object to be detected for emitting at least red light and infrared light;

a light detecting device disposed on the other side of the object to be detected opposite to the light emitting device, the light detecting device includes a red light detector and an infrared light detector, and the red light detector is configured to detect red light passing through the detected object Transmitted light, an infrared light detector for detecting transmitted light of infrared light transmitted through the object to be detected;

a signal processing circuit coupled to the output ends of the red light detector and the infrared light detector, respectively, receiving an electrical signal corresponding to the red light and an electrical signal corresponding to the infrared light, according to the electrical signal corresponding to the red light and the infrared light The corresponding electrical signal calculates the blood oxygen saturation.
The blood oxygen measuring apparatus according to claim 3, wherein said signal processing circuit is further coupled to the light emitting device, and outputs a light source driving signal to the light emitting device to drive the light emitting device to emit light.
The oximetry device according to claim 3, wherein the red light detector has a plurality of red light detectors.
The oximetry device according to claim 5, wherein the plurality of red light detectors and the infrared light detectors are integrated on one chip.
The blood oxygen measuring device according to any one of claims 3 to 6, wherein the light emitting device comprises a red light emitting device and an infrared light emitting device, and the red light emitting device and the infrared light emitting device are Configured to synchronize illumination or illumination time with a set delay difference.
The oximetry device according to any one of claims 1 to 3, wherein the light-emitting device is a broad-spectrum light source.
An apparatus for measuring blood oxygenation, comprising:

a light emitting device disposed on a side of the object to be detected, the light emitting device comprising a first light emitting device for emitting light of a first wavelength and a second light emitting device for emitting light of a second wavelength, the first light emitting The device and the second light emitting device are configured such that the illumination time of both has a set delay difference;

a photodetecting device disposed on the other side of the object to be detected opposite to the light emitting device, the photo detecting device comprising a first photodetector and a second photodetector, the first photodetector for detecting the first wavelength of light transmissive Passing the transmitted light of the detected object and converting it into an electrical signal corresponding to the first wavelength light, and the second photodetector is configured to detect the transmitted light of the second wavelength light transmitted through the detected object, and convert to correspond to the second wavelength light Electrical signal, at least one of the first photodetector and the second photodetector is a narrowband photodetector;

A signal processing circuit is coupled to the outputs of the first photodetector and the second photodetector, respectively, receiving signals output by the first photodetector and the second photodetector and calculating blood oxygen saturation.
The blood oxygen measuring apparatus according to any one of claims 1 to 9, wherein the light emitting device emits high frequency pulse light having a set width at set time intervals.
The oximetry apparatus according to claim 10, wherein said signal processing circuit comprises a signal amplifying/conditioning circuit, a detecting circuit, an analog-to-digital converting circuit and a processor, which are sequentially connected, said signal amplifying/conditioning circuit The input end is connected to the photodetecting device, receives the high frequency modulated electrical signal output by the photodetecting device, amplifies and filters the high frequency modulated electrical signal, and outputs the high frequency modulated electrical signal to the detecting circuit, the detecting circuit is high The frequency modulated electrical signal is subjected to detection and demodulation, the analog to digital conversion circuit performs analog to digital conversion on the detected electrical signal, the processor calculates blood oxygen saturation according to the analog to digital converted signal, and the processor is further coupled to the light emission The device outputs a high frequency modulated modulated light source driving signal to the light emitting device.