JP2003235849A - Biological photometric apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biological photometric apparatus in which real time display is enabled and the continuation of a measurement or a condition change can be arbitrarily performed. <P>SOLUTION: In the biological photometric apparatus provided with a measuring probe for locating a plurality of optical fibers for radiation and optical fibers for detecting on the body surface of a biopsy, a photometric means for detecting the quantity of light received by the optical fibers for detection for each measuring position and a signal processing means for producing and displaying a biological information image by calculating the biological information of the biopsy on the basis of a signal corresponding to the detected quantity of light, the signal processing means stores measuring data for every prescribed time unit and displays the measuring data of the time units in real time during the measurement. Besides, after the unwanted data of the time units are deleted as needed, a signal for each time unit is added and the added result is displayed in real time. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to biological information such as blood circulation, hemodynamics and hemoglobin changes, which are obtained by irradiating a living body with light, detecting the light reflected on the surface of the living body, or detecting the light passing near the surface. The present invention relates to a biological optical measurement device for obtaining an image, and particularly to a biological optical measurement device suitable for measuring a relatively wide area.

[0002]

2. Description of the Related Art A biological light measuring device irradiates a living body with wavelengths in the visible to infrared region, detects light reflected from the living body or light passing through the living body (hereinafter collectively referred to as transmitted light), and It is a device for measuring the inside, and it is possible to obtain biological information such as hemodynamics inside the living body in a simple and non-invasive manner with low constraint on the subject. An apparatus capable of measuring a wide area by using a probe in which the tips of a plurality of optical fibers are arranged as a light emitting section and a light receiving section is being clinically applied (Japanese Patent Application Laid-Open No. 57-115232, Japanese Patent Application Laid-Open No. 57-115232). Sho 63-2753
No. 23).

As a measuring method using such a biological optical measuring device, an event mode measurement for detecting a sudden change such as an epileptic seizure by following a change in a signal over time and a predetermined method for a subject. A measurement method that repeatedly gives a load (task) and observes the activity state of the brain during task load (hereinafter referred to as load mode or stimulation mode measurement)
There is. Regarding the measurement of the load mode, for example, JP-A-9-
It is described in No. 98972, and in this measurement, while performing a predetermined load (task) such as light stimulation and exercise to the subject repeatedly at a fixed interval, biological light measurement is performed, and from the obtained results, the task load The relative change in hemoglobin concentration (change with respect to no load) is obtained. At this time, a method of adding load data obtained by repetition to enhance statistical reliability is also adopted (called measurement in addition mode).

[0004]

However, the measurement of the amount of change in hemoglobin concentration by the conventional addition mode is as follows.
It was done after the measurement, so until the measurement is completed,
I did not know whether the measurement site was appropriate, how the load was applied, or the number of repetitions was appropriate. Therefore, after the data analysis, for example, when it is found that the number of repetitions is not appropriate, the number of repetitions considered to be appropriate has to be set again and measured again. Further, noise may be mixed in due to the subject moving during the measurement, but since the noise also is reflected in the addition result, the measurement accuracy may be reduced.

Therefore, according to the present invention, the measurement result can be displayed in real time for each measurement in a unit of task in the biological light measurement in the addition mode, whereby the measurement under appropriate conditions can be performed by one measurement. An object of the present invention is to provide a biological optical measurement device. Another object of the present invention is to provide a living body optical measurement device capable of preventing noise from being mixed in the addition result and performing highly accurate measurement.

[0006]

A living body optical measuring apparatus of the present invention which achieves the above object comprises a measuring probe having a plurality of irradiation optical fibers and a plurality of detecting optical fibers arranged on the body surface of a living body, and the detecting light. Optical measuring means for detecting the amount of light received by the fiber for each measurement position, and signal processing means for calculating biological information of the subject based on a signal corresponding to the detected amount of light and forming and displaying a biological information image. In the living body optical measurement device including, the signal processing means stores the measurement data for each predetermined time unit (for example, relative change of hemoglobin concentration), and the measurement data in the time unit in real time during measurement. And means for displaying.

According to such a living body light measuring device, the living body light measurement at the time of task load can observe the measurement result in real time. Therefore, it is instantly judged whether or not the measurement is appropriate, and the measurement is continued. It is possible to set new conditions. Further, according to the present invention, since it is possible to grasp the presence or absence of noise and the characteristics of noise in real time, it is possible to remove measurement data in which noise is mixed according to it.
Accurate measurement results can be obtained.

In the living body optical measurement system of the present invention, the signal processing means includes means for adding measurement data in units of time,
The displaying means displays the measured data after addition in real time. In order to realize real-time display, the biological optical measurement device of the present invention includes, for example, a timepiece that controls the time unit of measurement, and the signal processing means measures the time for each time unit based on the operation signal from the timepiece. Data acquisition, addition processing, and display are time-divisionally processed or in parallel.

Further, in the biological light measuring apparatus of the present invention, the signal processing means includes means for selecting time unit measurement data to be removed from the addition target among time unit measurement data.
The addition means is to add using the measurement data in units of time not selected by the selection means.

According to this living body light measuring apparatus, it is possible to display the measurement result of which statistical significance is enhanced by the addition processing in real time. Further, by eliminating the data in the section in which noise is mixed in the addition processing, it is possible to obtain a highly accurate measurement result.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a living body optical measurement system of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an overall outline of a biological optical measurement device of the present invention. This biological optical measurement device is mainly
A light source unit 10 for irradiating a living body with near-infrared light, and light from the light source unit 10 transmitted through the living body or reflected or scattered from the living body
(Hereinafter, collectively referred to as transmitted light) is measured, and an optical measurement unit 20 that converts it into an electrical signal and biological information based on the signal from the optical measurement unit 20, specifically, a hemoglobin concentration change in blood is calculated. And a signal processing unit 30 for displaying the result. Further, this biological optical measurement device, the tip of the optical fiber that guides the light from the light source unit 10 is brought into contact with the measurement position of the subject, and the tip of the optical fiber that guides the transmitted light from the subject to the optical measurement unit 20. To contact the measurement position of the subject,
A mounting tool (together with the optical fiber tip is referred to as a measurement probe) 40 to which the tip of the optical fiber is fixed is provided.

The light source unit 10 emits light having a plurality of wavelengths within the wavelength range from visible light to infrared light, for example, light having wavelengths of 780 nm and 830 nm, and a semiconductor laser 11 that modulates these two wavelengths of light at a plurality of different frequencies. It is composed of a plurality of optical modules 12 equipped with modulators for the purpose of the above, and an optical fiber 13 for irradiating light. The two wavelengths of light emitted from the semiconductor laser 11 are mixed, then modulated to a different frequency for each optical module, passed through the optical fiber 13, and irradiated onto the examination site of the subject.

The optical measuring section 20 is connected to the detection optical fiber 21, and a photoelectric conversion element such as a photodiode 22 for converting the light guided by the detection optical fiber 21 into an electric signal corresponding to the amount of light, and the photodiode 22. Input the electrical signal from
It comprises a lock-in amplifier 23 for selectively detecting a modulation signal corresponding to the irradiation position and wavelength, and an A / D converter 24 for A / D converting the signal from the lock-in amplifier 23. The lock-in amplifier 23 includes at least the same number of lock-in amplifiers as the number of signals to be measured.

The probe 40 has sockets for connecting optical fibers so that the irradiation optical fiber tips and the detection optical fiber tips are alternately arranged in a matrix of an appropriate size such as 3 × 3, 4 × 4. It is arranged. The light detected by the detection optical fiber is a mixture of the lights emitted from the four irradiation optical fibers adjacent thereto and transmitted through the living body, and the lock-in amplifier 23 produces different modulation signals depending on the irradiation optical fibers. By selectively detecting, the information of the point (measurement point) between the detection optical fiber tip and the adjacent irradiation optical fiber tip can be obtained. These measurement points correspond to the channels detected by the lock-in amplifier 23. For example, in the case of a 4 × 4 matrix probe, the measurement point between the light irradiation position and the detection position is 24, and the light measurement of 24 channels is performed. be able to.

The signal processing section 30 includes a control section 31 for controlling the entire apparatus, storage means 31 for storing a voltage signal (digital signal) sent from the optical measuring section 20 and for storing data after signal processing. Processing means 32 for processing the voltage signal stored in the storage means 31, a signal indicating biological information, specifically, conversion into a hemoglobin signal indicating the hemoglobin concentration of the measurement site, and a processing means 32 for creating a topography image, and the processing result. And an input / output unit 33 for inputting an instruction necessary for measurement and signal processing to the control unit 31. Furthermore, the signal processing unit 30 is provided with a clock for controlling the time unit of measurement in the load mode measurement described later, and based on the operation signal from this clock, the measurement and the data acquisition of the time unit, the calculation of the image using the data And display.

In the living body light measuring apparatus having such a structure, the living body light measurement is performed by irradiating the light, which is modulated by the irradiation optical fiber 13 at different frequencies, from the probe attached to the living body and transmitting through the living body to detect the light. For optical fiber 21
The light guided by is converted into an electric signal by each photodiode 22, and it is detected at each measurement point which is an intermediate point between the irradiation position and the detection position to obtain a hemoglobin signal converted into the blood hemoglobin concentration at the measurement site. It is done by The information obtained by this measurement is generally oxygenated hemoglobin concentration (Oxy-Hb), deoxygenated hemoglobin concentration.
(Deoxy-Hb) and total amount of hemoglobin (Total-Hb), but substances other than hemoglobin, such as cytochrome, can also be measured as long as they are in-vivo substances that absorb in the near infrared.

Next, the operation in the case of measuring the hemoglobin concentration in the load mode (stimulation mode) using the above-mentioned biological light measuring device will be described. FIG. 2 is a diagram showing one embodiment of the biological optical measurement by the biological optical measurement device of the present invention. In this measurement, first, preliminary measurement is performed before performing a task load, and then a constant section including the task load. Is repeated to measure the relative change in hemoglobin concentration in the section. One section is the time pre before loading the task, the task load time t
It consists of ask, relaxation time after task load, and post time after that. Relaxation is the time required for the body reaction due to the load to return to its original state. Where pre, r
Elaxation and post are called rests, and one task and the rests associated with it are measured in units of one task, and this is repeated multiple times. The start of each section and each time in each section are controlled to be constant in each repetition in accordance with a clock (not shown) provided in the device.

FIG. 3 shows the measurement procedure. As shown in the figure, first, preliminary measurement is performed before task loading (step 301), and the state of measurement in a state where no task is loaded is checked (step 302). Next, the measurement is performed for each task, and the relative change of the hemoglobin Hb in the section, that is, the change with respect to the reference data is measured (step 303). The task-based measurement is repeated a preset number of times (N).

Raw data for each measurement is displayed on the display unit of the input / output unit 33 in a time course (step 304). Further, the measured data is stored in the memory of the storage means 31 for each measurement of one task unit (step 305). As shown in FIG. 4, the measurement data of one task unit consists of four data of pre, task, relaxation, and post for each channel (measurement point).

FIG. 5 shows an example of a display displayed on the display unit. In the figure, (c) is a time-course display of raw data (voltage), and here two types of measurement wavelengths (780n
Measurement data of 24 channels for m and 830 nm) are displayed on the time course. This is, for example, 0.1
Display every measurement of S. The data between the two vertical lines is the data when the task load. Further, (a) is an ID column for displaying the ID, name, and measurement date / time of the subject,
(B) shows the number and position of the measurement channel.

On the other hand, the processing means 32 obtains an approximate straight line or an approximate curve connecting pre and post of the task unit for the data of one task unit, and calculates the difference between the approximate straight line or the approximate curve and the data when the task is loaded. Figure 2
As shown in (a), the relative concentration of hemoglobin is calculated (step 306). Then, the calculated relative concentration is shown in FIG.
As shown in (d) on the display (step 30
9).

Similarly for the second task-based measurement, the raw data of the measurement is displayed on the display unit, and the difference between the raw data of the task and the approximate straight line or the approximate curve connecting pre and post of the task is taken to determine the relative hemoglobin. The density is calculated (step 306). The processing means 32 further processes this second data and the data measured before that (first data).
And the average value is calculated and displayed on the display (step
308, 309). Hereafter, up to the set number N, step 30
The process from 3 to step 309 is repeated to finally obtain the graph of the relative density which is the average value of the measurement in task units of N times. Although FIG. 5 shows an example in which the relative densities are displayed as a graph, the relative densities of the respective measurement points are displayed as a topography in which a contour line image is displayed on the measurement area instead of or together with the graph display. It is also possible.

The series of processes from step 303 to step 309 is performed by the processing means 3 as shown in FIG. 6 by the operation signal from the clock for controlling the measurement of the task unit.
It is performed in real time using the foreground of 2 and the background, which is the free time. That is, measurement and data acquisition (steps 303 to 305) are performed in the foreground, for example, every 0.1 second, and when the measurement in one task unit is completed, the background is activated and the image is calculated in each task unit. After that, the processing is performed in the background until the calculation of the image of the task unit and the display of the result are completed. At this time, the measurement display is processed as a job with a high priority following the measurement. Thus, the image can be displayed in real time in parallel with the measurement. Note that these processes may be processed in parallel by a plurality of processing means instead of being time-divisionally processed by a single processing means 32.

As described above, according to the present embodiment, when the biometric measurement is performed while the task load is repeatedly performed, it is possible to sequentially display the average value of the measurement results for each task in real time simultaneously with the measurement. It is possible to judge whether the measurement conditions (how to apply load or the number of repetitions of the measurement) are appropriate during the measurement by looking at the graphs etc., and change the conditions as necessary to continue the measurement. It is possible to finish. In this case,
Flow B of the input / output unit 33, as shown below, for example, after the preset number of repetitions N is completed (after step 310), it is determined whether or not to continue (step 311).
Via, the continuation or end of measurement is selected, and the condition for continuation is set (step 312). Then, when a new condition is set, preliminary measurement (from step 301) or task-based measurement (from step 303) is restarted depending on the condition.

In the above-mentioned biological optical measurement, the generation of noise can be known in real time by observing the raw data displayed in the time course. Therefore, the measurement data containing noise is deleted from the subsequent processing. It is also possible to do so. For such a determination, the deletion can be set manually by seeing the measurement result displayed in real time, but the processing means 33 can also make the determination automatically. Such automatic determination is shown as step 307 in FIG. In that case, a threshold value of the relative density (or signal value) at the time of task load is set in advance, and when the measurement data exceeds the threshold value, it is considered that a large noise has occurred, and the data is excluded from the calculation. At the same time, the measurement is not counted in the number of repetitions.

The biological optical measurement in the load mode in which the measurement is performed while repeatedly applying one type of load has been described above. However, the biological optical measurement device of the present invention is not limited to such a load mode, and, for example, how to apply the load. It can also be applied to the case where measurement is performed while making different or giving different tasks. Such an embodiment is shown in FIG. In this embodiment, for example, three types of tasks T1, T2,
T3 is cyclically repeated to observe the biological reaction.

Also in this biological light measurement, hemoglobin for each task unit is obtained from the difference between the measured raw data and the point where raw data is displayed as a time course for each measurement and the approximate straight line or approximate curve connecting pre and post for each task unit. The calculation of the relative change in concentration is the same as in the above embodiment. However, in this embodiment, the addition of the measurement data in task units is performed between tasks having the same task type. That is, the measurement data when the first task T1 is loaded and the measurement data when the second task T1 is loaded are added in the second and subsequent measurements following the measurement when the tasks T1, T2, and T3 are loaded three times. , Display in real time.

As another embodiment, it is also possible to measure the load by changing the load one after another without adding the data for each task unit, find an optimum load, or perform another test.

[0030]

As described above, according to the present invention, the measurement result can be observed in real time when measuring the biological light under the task load. Therefore, it is possible to instantly judge whether the measurement is appropriate,
Measurement can be continued and new conditions can be set. Further, according to the present invention, since the presence or absence of noise generation and the characteristics of noise can be grasped in real time, it is possible to eliminate measurement data in which noise is mixed according to it, and obtain an accurate measurement result.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall outline of a biological optical measurement device of the present invention.

FIG. 2 is a diagram for explaining load mode measurement using the biological optical measurement device of the present invention.

FIG. 3 is a flowchart showing an embodiment of measurement using the biological optical measurement device of the present invention.

FIG. 4 is a diagram showing an example of measurement data stored in a storage unit.

FIG. 5 is a diagram showing an example of a display of the biological optical measurement device of the present invention.

FIG. 6 is a diagram showing a processing state in a processing means.

FIG. 7 is a diagram showing another embodiment of measurement using the biological optical measurement device of the present invention.

[Explanation of symbols]

10 ... Light source 13 ... Irradiation optical fiber 20 ... Optical measurement unit 21 ... Detection optical fiber 30 ... Signal processing unit 31 ... Memory means 32 ... Processing means 40 ... probe

Claims (4)

[Claims] 1. A measurement probe having a plurality of irradiation optical fibers and a plurality of detection optical fibers arranged on the body surface of a living body, an optical measuring means for detecting the amount of light received by the detection optical fiber at each measurement position, and a detection. In the living body optical measurement device including a signal processing unit that calculates biological information of the subject based on a signal corresponding to the light amount, and forms and displays a biological information image, the signal processing unit is a predetermined A living body optical measurement device comprising: a unit that stores measurement data for each time unit; and a unit that displays the measurement data in units of time in real time during measurement. 2. The signal processing means comprises means for adding the measurement data in units of time, and the means for displaying is
The biological optical measurement device according to claim 1, wherein the measured data after the addition is displayed in real time. 3. The biological optical measurement device according to claim 1 or 2, wherein the signal processing means performs measurement every time unit.
A biological optical measurement device characterized by performing time division processing or parallel processing of measurement, data acquisition, addition processing, and display. 4. The signal processing means comprises means for selecting measurement data to be removed from the addition target among the measurement data in units of time, and the addition means is for the time not selected by the selection means. The living body optical measurement system according to claim 2 or 3, wherein addition is performed using measurement data in units.