CN1299646C - Optical-circuit-variable time-domain light-dividing differential wave length spectrometer for detecting tissue content and detection method thereof - Google Patents

Abstract

The invention discloses a variable optical path time-domain spectroscopic difference spectrometer with accurate measurement, convenient operation, and simultaneous measurement of tissue components of various tissue components, including broadband light source, spectroscopic device and its optical path, photosensitive sensor, analog detection channel, A/D conversion module, extrusion device, CPU and its peripheral circuits; the bandwidth of the broadband light source is 600-1300nm; the light splitting device and its optical path include a light splitting device and matching optical path devices; the light splitting device AOTF, filter or Fourier spectrometer is used; the signal after the above A/D conversion is processed by the CPU to obtain the first group of spectra; the electromagnetic extrusion device applies pressure to the measured human tissue to change the optical path length to obtain the A group of spectra; obtaining the content of the main components in the tissue components from the difference spectra of the first and second group of spectra. The invention also discloses a detection method of the spectrometer.

Description

Variable optical path time-domain spectroscopic difference spectrometer and detection method for tissue component detection

technical field

The invention relates to a clinical medical testing instrument and method, in particular to a tissue component measuring instrument and method.

Background technique

There is no doubt about the importance and great value of the non-invasive detection of tissue components for the diagnosis and treatment of diseases. Not only that, the realization of non-invasive detection of tissue components also has great academic significance and value in signal sensing, detection and processing.

In 1977, the American scientist Jobsis first reported the experimental results of using near-infrared light to observe the changes in the content of oxyhemoglobin, reduced hemoglobin and cytochrome c in the brain of adult cats, revealing that near-infrared light (700-1300nm) has a lower concentration in biological tissues. decay rate and the feasibility of noninvasive monitoring of tissue blood oxygen concentration by near-infrared spectroscopy. In view of the extremely attractive application prospects of this new non-invasive measurement method, researchers have done a large number of animal and human experiments to verify the clinical significance of monitoring tissue blood oxygen concentration with near-infrared spectroscopy. Subsequently, Delpy from the University of London in the UK, Jobsis from Duke University in the United States, Tamura and Yamamoto from Hokkaido University in Japan, and Shiga from Omron Corporation in Japan, etc., started from the Lambert-Beer law, and through models, animal and human experiments, proposed several kinds of absorbance. The calculation formula for calculating the change in the blood oxygen concentration of the tissue. In the development of measuring devices, a portable tissue oximeter that replaces the laser light source with an ordinary luminescent tube LED has appeared. However, because the current methods can only give the change amount or change trend of the blood oxygen concentration, and lack of versatility, they have not been put into clinical application.

In the 1980s, Dhne first proposed the method of non-invasive measurement of human blood glucose concentration by using near-infrared spectroscopy. In the past 15 years, companies such as Futrex, Bio-control, New-mexico University, University of Iowa, Medscience in West Germany, Mitsui Metals, Hitachi and Panasonic in Japan have all made unremitting efforts in this regard. Research. The research methods can be roughly divided into two categories, one is the research using the sugar aqueous solution model, such as the research group of Gray W. Small at the University of Iowa in the United States; the other is the direct measurement of the human body and the correlation with the blood measurement results Yes, such as the IMI company in the United States. Although the research on the aqueous model of sugar has made important progress in accurately testing the molecular absorption coefficient of glucose, the model is too simple and too different from the human body to be used as a reference. Although human experiments can directly verify the effectiveness of the method, the Lambert-Beer law, which is the basis of the inductive quantitative method, is actually not applicable to human tissues with strong scattering properties, so the measurement results are difficult to interpret, and they are not universal and comparable. repeatability. From the perspective of detecting biohistochemical components, tissue blood oxygen concentration faces similar problems to blood glucose detection. However, since the absorbance change signal caused by the absorption of blood sugar is much weaker than the absorbance change signal caused by water, at present, the research on the non-invasive optical detection technology of blood sugar is more focused on how to improve the measurement accuracy to pick out the blood sugar caused by the change of blood sugar content. The change of the optical signal comes. Therefore, although some world-renowned large companies have invested a lot of money in development in the past 20 years due to the potential huge economic benefits, the non-invasive detection of blood sugar is still a long way from practical application. Relatively speaking, the economic value of non-invasive detection of other blood components is a little lower, but it is more difficult (due to the low relative content and overlapping absorption spectra), and there are few related studies abroad, mainly focusing on blood lactic acid, hormones and other components. Measurement. And there is almost no research in China). Due to individual differences, overlapping spectra, and measurement conditions (measurement location, ambient temperature, and pressure), even the measurement of tissue blood oxygen and blood glucose, which has invested huge manpower and financial resources internationally, has not yet entered clinical practice (only pulse blood Oxygen, that is, arterial blood oxygen has generally entered clinical use and plays an extremely important role), not to mention the non-invasive detection of other blood components.

Chinese Patent Publication No. 1271562, published on November 1, 2000, the Chinese invention patent application document titled "Non-invasive self-test blood glucose meter" discloses a non-invasive self-test blood glucose meter, which is mainly composed of infrared light emitting tubes The infrared light source is composed of an optical path part, a photoelectric detection converter, an electric path part and a display part. Obviously, it is impossible to realize in vivo non-invasive arterial blood glucose measurement with a single wavelength light source.

Chinese Patent Publication No. 1222063, published on July 07, 1999, a Chinese invention patent application titled "Optical Method and Device for Determining Blood Glucose Concentration" discloses a method and device for measuring blood glucose concentration of subjects , the method comprising: a) providing a light pattern that has a greater amount of stimulation to the first retinal system than to the second retinal system, resulting in a first:second stimulation ratio greater than 1, wherein said light pattern stimulates Subjective visual characteristics as a function of first:second stimulus ratio, and wherein sensitivity of said first retinal system and second retinal system to said light pattern varies as a function of blood glucose concentration of said subject; b) causing said subject to observe said subjective visual characteristic of said light pattern; and c) correlating said subject's blood glucose concentration with said subjective visual characteristic. Obviously, this method is difficult to objectively and quantitatively measure the blood sugar content. The patent application document also discloses a non-invasive blood glucose measuring instrument. There are two structures to realize non-invasive blood glucose measurement: (1) Connect a probe to the existing blood glucose meter, the probe has an oxygen electrode, glucoamylase, and the probe is connected to the air pump, and the probe is close to the finger of the tester, and the oozing out of the finger The interstitial fluid interacts with glucoamylase, and the blood glucose meter measures the blood glucose concentration; (2) There is a controlled laser, and the infrared beam is divided into two beams through a grating and a beam splitter. Reaching the chopper, the chopper sends the two beams of light to the infrared receiver respectively, and the infrared receiver sends the signal to the microprocessor, the microprocessor combines the database to perform calculations, and the display shows the measurement results. The invention patent application uses the method of skin exudate with complex operation, low measurement accuracy, few types of measurement components, and high measurement cost.

Apparently, the operation of the detection device in the above-mentioned prior art is complicated, the measurement accuracy is low, the types of measurement components are few, and the measurement cost is high.

Contents of the invention

In order to overcome the deficiencies in the above-mentioned prior art, the present invention provides a method and an instrument that are accurate in measurement, easy to operate, and can measure multiple tissue components at the same time. In the differential spectroscopy involved in the following description of the present invention, its concept is to make a difference between two groups of spectral amplitudes measured under different optical paths, and the obtained spectrum has eliminated individual difference information to a large extent . In addition, the concept of the time-domain spectroscopic method involved in the description of the present invention refers to the generation of monochromatic light of different wavelengths at different times by performing light splitting in the time domain through a spectroscopic device.

In order to solve the above-mentioned technical problems, the technical solution adopted by the time-domain spectroscopic difference spectrometer with variable optical path for tissue composition detection in the present invention is to include a broadband light source, a spectroscopic device and its optical path, a photosensitive sensor, an analog detection channel, an A/D conversion module, a squeeze pressure device, CPU and its peripheral circuits; the broadband light source uses visible light or even near-infrared light with a bandwidth of 600-1300nm; The optical path device adopts one of the following devices: a condenser, a slit, a small hole; the optical splitter adopts an AOTF, an optical filter or a Fourier spectrometer; if the optical splitter adopts an AOTF, the optical path includes a broadband light source, a first condenser , AOTF spectroscopic device, measured human tissue, a second condenser lens and a photosensitive sensor; the function of the AOTF is to focus and split the outgoing light of the broadband light source into the measured human tissue, collect the outgoing light, and focus it Output light beam; that is, the outgoing light of the broadband light source becomes parallel light through the first condenser lens and enters the AOTF crystal. Under the control of the CPU, the AOTF crystal time-divisionally modulates the parallel light into monochromatic light of different wavelengths and enters the tissue under test. Afterwards, the outgoing light of the human tissue to be measured is focused by the second condenser lens, and the photoelectric conversion is performed by the photosensitive sensor at the focal point; film, measured human tissue, second condenser lens and photosensitive sensor; the function of the filter is to focus and split the outgoing light of the broadband light source to enter the measured human tissue, collect the outgoing light, and output it after focusing light beam; that is, the outgoing light of the broadband light source becomes parallel light incident on the optical filter through the first condenser lens, and under the control of the CPU, the optical filter time-divisionally modulates the parallel light into monochromatic light of different wavelengths incident on the measured After the human tissue is focused by the second concentrator, the outgoing light of the human tissue to be measured is converted by the photosensitive sensor at the focal point; Measuring human tissue, a second condenser, a Fourier spectrometer and a photosensitive sensor; the function of the Fourier spectrometer is to focus the outgoing light of the broadband light source into the measured human tissue, collect the outgoing light, focus and split the light, and output multiple Monochromatic light beam; that is, the outgoing light of the broadband light source becomes parallel light incident on the human tissue to be measured through the first condenser, and the outgoing light is sent to the Fourier spectrometer through the second condenser, and the output monochromatic light is detected by the photosensitive sensor. Photoelectric conversion; the signal after the above-mentioned A/D conversion is processed by the CPU to obtain the first group of spectra; the electromagnetic extrusion device applies pressure to the measured human tissue to change the optical path length to obtain the second group of spectra; from the first The content of the main components in the tissue components is obtained from the difference spectrum of the second group of spectra.

The function of the photosensitive sensor is to perform photoelectric conversion, and the photosensitive sensor adopts one of the following devices: a photosensitive tube and a gallium indium arsenic photosensitive device. The function of the analog detection channel is to convert the output signal of the photosensitive sensor into a voltage signal matched with the A/D conversion module. According to different detection methods adopted, the analog detection channel includes a photosensitive sensor, an I/V conversion circuit, an isolation Direct circuit, analog switch, filter, phase-sensitive detection circuit, anti-aliasing filter and A/D conversion circuit, the center frequency of the filter is set according to the wavelength switching frequency, and each wavelength is determined by the output frequency of the AOTF light wave . After the photosensitive sensor in the analog detection channel performs photoelectric conversion on the signal, the voltage output of a certain amplitude can be achieved through the I/V conversion circuit, and the number of channels of the analog switch and the number of analog detection channels are different from those of the adopted light splitting device. The number of characteristic light wavelengths after splitting is the same; the switching of the analog switch is synchronized with the wavelength switching of the splitting device, so that the photoelectric signals generated by incident light of different wavelengths are respectively transmitted to the corresponding analog detection channels; each analog detection channel has the same The conversion module includes a filtering circuit module and an amplifying circuit module, the output of which is a high-frequency voltage signal corresponding to a certain wavelength of incident light modulated by an analog switch; the phase-sensitive detection circuit detects the signal corresponding to the light intensity, Switch to the A/D conversion circuit through the analog switch, and convert it into a digital signal for post-processing by the CPU. The function of the A/D conversion module is to convert the analog voltage signal into a digital signal and transmit it to the CPU; the A/D conversion module includes an A/D conversion device and an interface circuit thereof; or the A/D The D conversion module is integrated in the CPU circuit. The CPU and its peripheral circuits include a CPU chip and its minimum expansion system, interface circuit, output circuit and device, man-machine dialogue module, and control circuit; the function of the CPU and its peripheral circuits is to accept the A/D conversion module The transmitted digital signal will be post-processed and necessary output, and at the same time, the overall control of the system and the man-machine dialogue process will be carried out.

In the present invention, the method for measuring the variable optical path time domain spectroscopic difference for tissue component detection includes the following steps: the first step is to connect the broadband light source, spectroscopic device and its optical path, photosensitive sensor, analog detection channel, and A/D conversion. A variable optical path time-domain spectroscopic difference spectrometer for tissue component detection composed of a module, a CPU and its peripheral circuits; the broadband light source uses visible light or even near-infrared light with a bandwidth of 600-1300nm; the second step is to test human tissue Place it in the optical path in a free state; the third step, according to the optical splitting device adopted in the optical path is AOTF, or optical filter, or Fourier spectrometer is different, the processing process of incident light is one of the following situations: when When the light splitting device in the optical path adopts AOTF, the outgoing light of the broadband light source is focused and split by the first condenser lens, and becomes parallel light and enters the AOTF crystal. Under the control of the CPU, the AOTF crystal time-shares the parallel light into different wavelengths Monochromatic light is incident on the tissue to be measured, and the emitted light is collected and output after being focused by the second condenser lens; or when the spectroscopic device in the optical path uses a filter, firstly, the outgoing light of the broadband light source is processed by the first condenser lens. After focusing and splitting, the monochromatic light is time-divided and incident on the measured human tissue, and the second condenser lens collects the outgoing light passing through the measured human tissue and focuses it to output the light beam; or when the light splitting device in the optical path adopts a Fourier spectrometer, First, the outgoing light of the broadband light source is focused by the first condenser lens and then incident on the human tissue to be measured, and the outgoing light is sent to the Fourier spectrometer through the second condenser lens, and the Fourier spectrometer collects, focuses and splits the outgoing light, and output a plurality of monochromatic light beams; the photosensitive sensor performs photoelectric conversion on the above-mentioned output beams; the fourth step, the above-mentioned converted signal enters the analog detection channel, and reaches a voltage output of a certain amplitude through the I/V conversion circuit; The number of channels of the analog switch and the number of analog detection channels are consistent with the number of characteristic light wavelengths adopted after being split by the optical splitter; The generated photoelectric signals are respectively transmitted to the corresponding analog detection channels; each analog detection channel has the same conversion module including a filter circuit module and a phase-sensitive detection circuit module, and its output corresponds to a certain wavelength of incident light, which is modulated by an analog switch The high-frequency voltage signal; the phase-sensitive detection circuit detects the spectral signal, thereby completing the time-sharing acquisition of the output signals of different analog detection channels, and switching to the A/D conversion circuit through the analog switch, and converting them into digital signals; the fifth The first step is to send the above-mentioned A/D converted digital signal into the CPU for processing. First, separate the data representing the differential spectrum of different wavelengths, that is, combine the signals originating from the outgoing light of the same wavelength of the optical splitting device to form a Corresponding photoelectric signal tracing sequence. Secondly, the amplitude of each group of signals is extracted to obtain a group of spectra; the sixth step is to apply pressure to the measured human tissue with an electromagnetic extrusion device to change the optical path length, and then repeat the third, fourth and fifth above In the process of steps, another group of absorption spectra of the measured human tissue can be detected; the seventh step is to subtract the above two groups of spectra to obtain the difference spectrum; The content of major components in arterial blood.

Compared with the prior art, the beneficial effect of the variable optical path time-domain spectroscopic difference spectrometer and detection method of the present invention is: since the differential spectrometer of the present invention adopts the differential detection method, the influence of individual differences can be greatly reduced. Therefore, it is accurate in measurement, easy to operate, and can measure multiple tissue components at the same time.

Description of drawings

Fig. 1 is the structural block diagram of differential spectrum measuring instrument of the present invention;

Fig. 2 is the optical path schematic diagram when AOTF is adopted in the differential spectrum measuring instrument of the present invention;

Fig. 3 is a schematic diagram of the optical path when using a filter in the differential spectrum measuring instrument of the present invention;

Fig. 4 is the optical path schematic diagram when adopting Fourier transform spectrometer in differential spectrum measuring instrument of the present invention;

Fig. 5 is the electrical block diagram of differential spectrum measuring instrument of the present invention;

Fig. 6 is a flow chart of the process of measuring with the differential spectrum measuring instrument of the present invention.

The following is an explanation of the main reference signs in the drawings of the specification of the present invention.

1——Broadband light source 2——Spectroscopic device and its optical path

3——Photosensitive sensor 4——Analog detection channel

5——A/D conversion module 6——CPU

7——First Condenser 8——AOTF Spectroscopic Device

9——Tested human tissue 10——Second condenser lens

11——Fourier transform spectrometer 13——DC blocking circuit

15——Optical filter 16——I/V conversion circuit

17——analog switch 19——filter

21——A/D converter 22——Extrusion device

25——phase sensitive detection circuit 31——anti-aliasing filter

Detailed ways

The variable optical path time-domain spectroscopic difference spectrometer and detection method for tissue component detection of the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figures 1 to 5, the variable optical path time-domain spectroscopic difference spectrometer for tissue component detection of the present invention includes a broadband light source 1, a spectroscopic device and its optical path 2, a photosensitive sensor 3, an analog detection channel 4, and an A/D conversion Module 5, extrusion device 22, CPU6 and its peripheral circuits; the broadband light source 1 uses visible light or even near-infrared light with a bandwidth of 600-1300nm; the light splitting device and its optical path 2 include a light splitting device and an optical path matching it device; the matching optical path device can adopt condenser lens, can also adopt slit or aperture; described spectroscopic device adopts AOTF8, can also optical filter 15 or Fourier transform spectrometer 11; If described spectroscope adopts AOTF8, then Include broadband light source 1, the first condenser lens 7, AOTF spectroscopic device 8, measured human tissue 9, the second condenser lens 10 and photosensitive sensor 3 in the light path; The effect of described AOTF8 is to focus and After splitting the light, it enters the measured human tissue 9, collects the outgoing light, and outputs the light beam after focusing; that is, the outgoing light of the broadband light source 1 becomes parallel light through the first condenser lens 7 and enters the AOTF crystal. Under the control of the CPU6, the AOTF The crystal time-divisionally modulates the parallel light into monochromatic light of different wavelengths incident on the tissue under test 9, and then focuses the outgoing light of the tissue under test 9 through the second condenser lens 10, and performs photoelectric conversion by the photosensitive sensor 3 at the focal point; or If when described beam splitter adopts optical filter 15, then optical path comprises broadband light source 1, the first converging lens 7, optical filter 15, measured human body tissue 9, the second converging lens 10 and photosensitive sensor 3; Described optical filter 15 The function is to focus and split the outgoing light of the broadband light source 1 into the measured human tissue 9, collect the outgoing light, and output the beam after focusing; that is, the outgoing light of the broadband light source 1 passes through the first condenser lens 7 It becomes parallel light and enters the filter 15. Under the control of CPU6, the filter 15 time-divisionally modulates the parallel light into monochromatic light of different wavelengths and enters the human body tissue 9 to be measured. The outgoing light of the tissue 9 is focused, and photoelectric conversion is performed by the photosensitive sensor 3 at the focal point; or if the beam splitter adopts a Fourier spectrometer 11, the optical path includes a broadband light source 1, a first condenser lens 7, a human tissue to be measured 9, a second Two condenser mirrors 10, a Fourier spectrometer 11 and a photosensitive device 3; the effect of the Fourier spectrometer 11 is to focus the outgoing light of the broadband light source 1 and then incident on the measured human tissue 9, and collect the outgoing light, and output more after focusing and light splitting A monochromatic light beam; that is, the outgoing light of the broadband light source 1 becomes parallel light incident to the human tissue 9 to be measured through the first condenser lens 7, and the outgoing light is sent to the Fourier spectrometer 11 through the second condenser lens 10, and the monochromatic light output by it is sent to the Fourier spectrometer 11 through the second condenser lens 10. The color light is photoelectrically converted by the photosensitive sensor 3;

The signal after the above-mentioned A/D conversion is processed by the CPU6 to obtain the first group of spectra; the electromagnetic extrusion device 22 applies pressure to the measured human tissue 9 to change the optical path length to obtain the second group of spectra; from the first and The content of the main components in the tissue components is obtained from the differential spectrum of the second group of spectra.

The function of the photosensitive sensor 3 is to perform photoelectric conversion, and the photosensitive sensor 3 can be a photosensitive tube or a gallium indium arsenic photosensitive device.

The effect of the analog detection channel 4 is to convert the output signal of the photosensitive sensor 3 into a voltage signal matched with the A/D conversion module 5. According to different detection methods adopted, the analog detection channel 4 includes the photosensitive sensor 3, I/O V conversion circuit 16, DC blocking circuit 13, analog switch 17, filter 19, phase-sensitive detection circuit 25, anti-aliasing filter 31 and A/D converter 21, the center frequency of the filter 19 is switched according to the wavelength frequency To set, take the output frequency of the AOTF light wave for each wavelength.

After the photosensitive sensor 3 in the analog detection channel 4 performs photoelectric conversion on the signal, the voltage output of a certain amplitude can be achieved by the I/V conversion circuit 16, and the number of channels of the analog switch 17 and the number of the analog detection channels 4 are the same as the number of the analog detection channels 4. The number of characteristic light wavelengths after splitting by the splitting device is the same; the switching of the analog switch 17 is synchronized with the wavelength switching of the splitting device, so that the photoelectric signals generated by incident light of different wavelengths are respectively transmitted to the corresponding analog detection channels 4; Each analog detection channel 4 has the same conversion module, including a filter circuit module and an amplifier circuit module, and its output is a high-frequency voltage signal corresponding to a certain wavelength of incident light modulated by an analog switch 17; the phase-sensitive detection circuit 25 The signal corresponding to the light intensity is detected, switched to the A/D conversion circuit 21 through the analog switch 17, and converted into a digital signal for post-processing by the CPU 6 .

The effect of described A/D conversion module 5 is to convert analog voltage signal into digital signal, and deliver to described CPU6; Described A/D conversion module 5 comprises A/D conversion device and interface circuit thereof; Or described The A/D conversion module 5 is integrated in the CPU circuit.

Described CPU6 and its peripheral circuit comprise CPU chip and minimum expansion system thereof, interface circuit, output circuit and device, man-machine dialogue module, control circuit; The effect of described CPU6 and its peripheral circuit is to accept described A/D conversion module 5. Transmit the digital signal, and perform post-processing and necessary output, and at the same time perform overall control and man-machine dialogue process on the system.

The working process of the variable optical path time-domain spectroscopic difference spectrometer used for tissue component detection of the present invention is shown in Figure 1 and Figure 6, the light of the required wavelength is emitted by the broadband light source 1, and is focused 102 by the first condenser lens 7, and then is carried out by the spectroscopic device. After time-domain spectroscopic analysis, it enters the measured human tissue 103, and the outgoing light is received by the photosensitive sensor 3 and converted into an electrical signal 104, and then converted by the circuit part in the analog detection channel 4, that is, sent to the corresponding signal through the analog switch. The analog detection channel 105 of each analog detection channel realizes signal conversion 106 with the corresponding analog detection channel; the A/D conversion module 5 performs A/D conversion on the photoelectric pulse wave of each analog detection channel, and converts it into a digital signal 107. The result of A/D conversion will be post-processed by the data processing system with CPU as the core. That is, at first, the data representing different differential pulse waves are separated to generate a pulse wave tracing sequence 108. If n characteristic wavelengths are used, then the mn+ith (i=1, 2, ..., n; m=0, 1 , 2,...) data together characterize the spectral information corresponding to the i-th characteristic wavelength; secondly, extract the characteristic wave amplitude of each waveform as the spectral amplitude corresponding to each incident light wavelength, and the first group can be obtained Spectrum, when extracting the spectral amplitude, the peak-to-peak value of the pulse signal or the amplitude of the fundamental component of the AC component can be extracted according to the obtained data as the characteristic amplitude of the spectrum, and the average amplitude of the absorption spectrum can also be extracted as the characteristic of the spectrum Amplitude 109. Using the electromagnetic extrusion device 22 to apply pressure to the measured human tissue 9 to change the optical path length, and then repeat the above process to obtain the second group of spectra 110; subtract the above two groups of spectra to obtain the difference spectrum 111; obtain the difference spectrum Finally, the content of the main components in the tissue is calculated from the differential spectrum by using the stoichiometric method 112 .

The detection method of the variable optical path time-domain spectroscopic difference spectrometer used for tissue component detection of the present invention comprises the following steps:

The first step is to connect the variable for tissue component detection composed of broadband light source 1, spectroscopic device and its optical path 2, photosensitive sensor 3, analog detection channel 4, A/D conversion module 5, CPU and its peripheral circuit 6. An optical path time-domain spectroscopic difference spectrometer; the broadband light source 1 uses visible light or even near-infrared light with a bandwidth of 600-1300nm;

In the second step, placing the measured human tissue 9 in the light path in a free state;

In the third step, depending on whether the spectroscopic device used in the optical path is an AOTF, or a filter, or a Fourier spectrometer, the processing of the incident light is one of the following situations:

When the light splitting device in the optical path adopts AOTF8, the outgoing light of the broadband light source 1 is focused and split by the first condenser lens 7, and then becomes parallel light and enters the AOTF crystal. Monochromatic light of different wavelengths is incident on the tissue under test 9, and the emitted light is collected and focused by the second condenser lens 10 to output a light beam; or

When the spectroscopic device in the optical path adopts the optical filter 15, firstly, after focusing and splitting the outgoing light of the broadband light source 1 through the first condenser lens 7, the monochromatic light is time-divisionally incident on the human tissue 9 to be measured, the first Two converging mirrors 10 collect and focus the outgoing light passing through the measured human tissue 9 to output the light beam; or

When the light-splitting device in the optical path adopts the Fourier spectrometer 11, at first, the outgoing light of the broadband light source 1 is incident on the human tissue 9 to be measured after being focused by the first condenser lens 7, and the outgoing light is sent into the Fourier spectrometer through the second condenser lens 10 11. The Fourier spectrometer 11 collects, focuses and splits the outgoing light, and outputs a plurality of monochromatic light beams;

The photosensitive sensor 3 performs photoelectric conversion on the output light beam;

In the fourth step, the above-mentioned converted signal enters the analog detection channel 4, and reaches a certain amplitude voltage output through the I/V conversion circuit 16; the number of channels of the analog switch 17 and the number of analog detection channels 4 are the same as those used The number of characteristic light wavelengths after the light splitting by the light splitting device is consistent; the switching of the analog switch 17 is synchronized with the wavelength switching of the light splitting device, and the photoelectric signals generated by incident light of different wavelengths are respectively transmitted to the corresponding analog detection channels 4; An analog detection channel 4 has the same conversion module including a filter circuit module and a phase-sensitive detection circuit module, and its output is a high-frequency voltage signal corresponding to a certain wavelength of incident light modulated by an analog switch 17; the phase-sensitive detection circuit 25 converts the spectrum Signal detection, thus, complete the time-sharing acquisition of the output signals of different analog detection channels 4, and switch to the A/D conversion circuit 21 through the analog switch 17, and convert them into digital signals;

In the fifth step, the above-mentioned A/D converted digital signal is sent to the CPU6 for processing. First, the data representing the differential spectrum of different wavelengths is separated, that is, the signals originating from the outgoing light of the same wavelength of the optical splitting device are combined together to form a The photoelectric signal corresponding to this wavelength traces the sequence. Second, extract the amplitude of each set of signals to obtain a set of spectra;

In the sixth step, the electromagnetic extrusion device 22 is used to apply pressure to the measured human tissue 9 to change the optical path length, and then repeat the above-mentioned third, fourth and fifth steps to detect another part of the measured human tissue 9 A set of absorption spectra;

In the seventh step, the above two groups of spectra are subtracted to obtain a differential spectrum; then, the content of the main components in the measured human arterial blood is calculated from the differential spectrum by a stoichiometric method.

Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative, rather than restrictive. Under the enlightenment of the present invention, many modifications can be made without departing from the purpose of the present invention and the scope of protection of the claims, and these all belong to the protection of the present invention.

Claims (7)

1. one kind is used for the change light path time domain beam split difference spectrograph that morphological element is detected, and it is characterized in that: comprise wideband light source (1), light-dividing device and light path (2) thereof, light sensor (3), analog detection passage (4), A/D modular converter (5), pressurizing unit (22), CPU (6) and peripheral circuit thereof; Described wideband light source (1) adopts visible light and even the near infrared light of bandwidth at 600～1300nm; Described light-dividing device and light path thereof (2) comprise light-splitting device and the light path devices that matches with it; The described light path devices that matches adopts one of following apparatus: condenser lens, slit, aperture;

Described light-splitting device adopts AOTF (8), optical filter (15) or Fourier sub-ray spectrometer (11);

If described beam splitter adopts AOTF (8), then comprise wideband light source (1), first condenser lens (7), AOTF light-splitting device (8), tested person soma (9), second condenser lens (10) and light sensor (3) in the light path; The effect of described AOTF (8) be the emergent light with described wideband light source (1) focus on beam split after incide tested person soma (9), and gather emergent light, focus on the back output beam; Promptly, the emergent light of described wideband light source (1) becomes directional light through first condenser lens (7) and incides the AOTF crystal, under the control of CPU (6), the AOTF crystal incides tested tissue (9) after second condenser lens (10) with the emergent light focusing of tested person soma (9), carries out light-to-current inversion by the light sensor that is in the focus place (3) with the monochromatic light that the directional light timesharing is modulated into different wave length; Or

If when described beam splitter adopted optical filter (15), then light path comprised wideband light source (1), first condenser lens (7), optical filter (15), tested person soma (9), second condenser lens (10) and light sensor (3); The effect of described optical filter (15) be the emergent light with described wideband light source (1) focus on beam split after incide tested person soma (9), and gather emergent light, focus on the back output beam; Promptly, the emergent light of described wideband light source (1) becomes directional light through first condenser lens (7) and incides optical filter (15), under the control of CPU (6), optical filter (15) incides tested person soma (9) after second condenser lens (10) with the emergent light focusing of tested person soma (9), carries out light-to-current inversion by the light sensor that is in the focus place (3) with the monochromatic light that the directional light timesharing is modulated into different wave length; Or

If described beam splitter adopts Fourier sub-ray spectrometer (11), then light path comprises wideband light source (1), first condenser lens (7), tested person soma (9), second condenser lens (10), Fourier sub-ray spectrometer (11) and light-sensitive device (3); The effect of described Fourier sub-ray spectrometer (11) is to incide tested person soma (9) after the emergent light of wideband light source (1) is focused on, and gathers emergent light, focus on and beam split after export a plurality of monochromatic light light beams; Promptly, the emergent light of described wideband light source (1) becomes directional light through first condenser lens (7) and incides tested person soma (9), emergent light is sent into Fourier sub-ray spectrometer (11) through second condenser lens (10), and the monochromatic light of its output carries out light-to-current inversion by light sensor (3);

Handle first group of spectrum of acquisition by the signal after the above-mentioned A/D conversion through CPU (6); Described electromagnetism squeezing device (22) is exerted pressure to tested person soma (9) and is changed optical path length to obtain second group of spectrum; From described first and second groups of spectrographic difference spectrums, obtain the content of the main component in the component of organization.

2. a kind of change light path time domain beam split difference spectrograph that morphological element is detected that is used for according to claim 1, it is characterized in that, the effect of described light sensor (3) is to carry out opto-electronic conversion, and described light sensor (3) adopts one of following apparatus: photosensitive tube and arsenic gallium indium light-sensitive device.

3. a kind of change light path time domain beam split difference spectrograph that morphological element is detected that is used for according to claim 1, it is characterized in that, the effect of described analog detection passage (4) is that the output signal with light sensor (3) converts the voltage signal with A/D modular converter (5) coupling to, according to the detection method difference that adopts, described analog detection passage (4) comprises light sensor (3), I/V translation circuit (16), block isolating circuit (13), analog switch (17), wave filter (19), phase-sensitive detection circuit (25), frequency overlapped-resistable filter (31) and A/D change-over circuit (21), the mid frequency of described wave filter (19) is set according to the wavelength switching frequency, gets the outgoing frequency of each wavelength by the AOTF light wave.

4. a kind of change light path time domain beam split difference spectrograph that morphological element is detected that is used for according to claim 3, it is characterized in that, after light sensor (3) carries out opto-electronic conversion to signal in the described analog detection passage (4), can reach the voltage output of certain amplitude by I/V translation circuit (16), and the number of the port number of analog switch (17) and analog detection passage (4), consistent with the characteristic light wavelength number that is adopted through after the light-splitting device beam split; The switching of analog switch (17) and the wavelength of light-splitting device switch synchronization action, and the photosignal that the different wave length incident illumination is produced is transferred to respectively in the corresponding analog detection passage (4) thus; Each analog detection passage (4) has identical modular converter, comprises filter circuit module, amplifying circuit module, and its output is corresponding to this wavelength incident illumination, through the synthetic high-frequency voltage signal of analog switch (17); Described phase-sensitive detection circuit (25) will detect corresponding to the signal of light intensity, switches to A/D change-over circuit (21) by analog switch (17), converts digital signal to, carries out post-processed for CPU (6).

5. a kind of change light path time domain beam split difference spectrograph that morphological element is detected that is used for according to claim 1 is characterized in that the effect of described A/D modular converter (5) is to convert analog voltage signal to digital signal, and passes to described CPU (6); Described A/D modular converter (5) comprises A/D converter spare and interface circuit thereof; Or described A/D modular converter (5) is integrated in the cpu circuit.

6. a kind of change light path time domain beam split difference spectrograph that morphological element is detected that is used for according to claim 1, it is characterized in that described CPU (6) and peripheral circuit thereof comprise cpu chip and minimal expansion system, interface circuit, output circuit and device, human computer conversation's module, control circuit; The effect of described CPU (6) and peripheral circuit thereof is to accept the digital signal that described A/D modular converter (5) transmission is come, and carries out post-processed and necessary output, simultaneously system is totally controlled the process with the human computer conversation.

7. one kind is used for the change light path time domain beam split difference detecting method that morphological element is detected, and it is characterized in that described detection method may further comprise the steps:

First step connects the change light path time domain beam split difference spectrograph that is used for morphological element's detection that comprises that wideband light source (1), light-dividing device and light path (2) thereof, light sensor (3), analog detection passage (4), A/D modular converter (5), CPU and peripheral circuit (6) thereof are formed; Described wideband light source (1) adopts visible light and even the near infrared light of bandwidth at 600～1300nm;

Second step places described light path with tested person soma (9) with free state;

Third step is AOTF according to the light-splitting device that is adopted in the light path, or filter lens, or Fourier sub-ray spectrometer difference, is one of following situation to the processing procedure of incident illumination:

When the light-splitting device in the light path adopts AOTF (8), the emergent light of wideband light source (1) through first condenser lens (7) focus on beam split after, become directional light and incide the AOTF crystal, under the control of CPU (6), the AOTF crystal incides the monochromatic light that the directional light timesharing is modulated into different wave length on the tested tissue (9), gathers described emergent light output beam after second condenser lens (10) focuses on; Or

When the light-splitting device in the light path adopts optical filter (15), at first, with the emergent light of wideband light source (1) through first condenser lens (7) focus on beam split after, tested person soma (9) is incided in the monochromatic light timesharing, and the emergent light that described second condenser lens (10) is gathered by tested person soma (9) focuses on the back output beam; Or

When the light-splitting device in the light path adopts Fourier sub-ray spectrometer (11), at first, the emergent light of wideband light source (1) after focusing on, first condenser lens (7) is incided tested person soma (9), its emergent light is sent into Fourier sub-ray spectrometer (11) through second condenser lens (10), described Fourier sub-ray spectrometer (11) to emergent light gather, focusing and beam split, and export a plurality of monochromatic light light beams;

Described light sensor (3) carries out light-to-current inversion to the light beam of above-mentioned output;

The 4th step, the signal after the above-mentioned conversion enter analog detection passage (4), reach the voltage output of certain amplitude by I/V translation circuit (16); The number of the port number of described analog switch (17) and analog detection passage (4), consistent with the characteristic light wavelength number that is adopted through after the light-splitting device beam split; The switching of described analog switch (17) and the wavelength of light-splitting device switch synchronization action, and the photosignal that is produced by the different wave length incident illumination is transferred to respectively in the corresponding analog detection passage (4); Each analog detection passage (4) has identical modular converter and comprises filter circuit module and phase-sensitive detection circuit module, and its output is corresponding to a certain wavelength incident illumination, through the synthetic high-frequency voltage signal of analog switch (17); Phase-sensitive detection circuit (25) detects spectral signal, thus, finishes the output signal of the different analog detection passages of acquisition time (4), and switches to A/D change-over circuit (21) by analog switch (17), converts digital signal to;

The 5th step is sent the digital signal of above-mentioned A/D conversion into CPU (6) and is handled, at first, the data separating of different wave length difference spectrum will be characterized, be about to stem from the signal of the same wavelength emergent light of light-splitting device, combine, form with the corresponding photosignal of this wavelength and trace sequence.Secondly, extract the amplitude of every group of signal, thereby obtain one group of spectrum;

The 6th step is used electromagnetism squeezing device (22) and is exerted pressure to tested person soma (9), to change optical path length, then, repeats above-mentioned the 3rd, the 4th and the 5th step process, can detect another group absorption spectrum of tested person soma (9);

The 7th step is subtracted each other the acquisition difference spectrum with above-mentioned two groups of spectrum; Then, by stoechiometric process, from difference spectrum, calculate the content of the main component in the tested human body arterial blood.

Images