JP5168247B2 - Optical measurement system - Google Patents

Description

The present invention relates to an optical measurement system that measures in-vivo internal information (measurement data) non-invasively using light. More specifically, the present invention relates to a light transmission point for irradiating light to a living body, and receiving light emitted from the living body. Multi-channel optical measurement system for measuring in-vivo information about a plurality of channels (sensitivity regions) each having a plurality of light-receiving points for performing light transmission and a light-receiving point. About.
The present invention is applied to, for example, a medical device that performs brain function measurement and cardiovascular system diagnosis by measuring changes in blood flow with time in each part of the brain and changes in oxygen supply in the living body.

In recent years, in order to observe the activity state of the brain, an optical brain functional imaging apparatus (optical measurement system) that performs noninvasive measurement using light simply has been developed. In such an optical brain functional imaging apparatus, three different types of wavelengths λ ₁ , λ ₂ , and λ ₃ (for example, 780 nm, 805 nm, and 830 nm) are close by a light transmission probe disposed on the head surface of the subject. Infrared light is irradiated onto the brain, and the intensity (received light amount information) A of the near-infrared light of each wavelength λ ₁ , λ ₂ , λ ₃ emitted from the brain by a light receiving probe arranged on the head surface. λ ₁ ), A (λ ₂ ), and A (λ ₃ ) are detected.
From the received light amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) thus obtained, the concentration / optical path length product [oxyHb] of oxyhemoglobin in the cerebral blood flow, and deoxy In order to obtain the hemoglobin concentration and the optical path length product [deoxyHb], for example, the simultaneous equations shown in relational expressions (1), (2), and (3) are created using the Modified Beer Lambert rule, and the simultaneous equations are solved. (For example, refer nonpatent literature 1). Furthermore, the concentration / optical path length product of total hemoglobin ([oxyHb] + [deoxyHb]) is calculated from the concentration / optical path length product [oxyHb] of oxyhemoglobin and the deoxyhemoglobin concentration / optical path length product [deoxyHb]. Yes.
A (λ ₁ ) = E _O (λ ₁ ) × [oxyHb] + E _d (λ ₁ ) × [deoxyHb] (1)
A (λ ₂ ) = E _O (λ ₂ ) × [oxyHb] + E _d (λ ₂ ) × [deoxyHb] (2)
A (λ ₃ ) = E _O (λ ₃ ) × [oxyHb] + E _d (λ ₃ ) × [deoxyHb] (3)
E _O (λm) is an absorbance coefficient of oxyhemoglobin in light having a wavelength λm, and E _d (λm) is an absorbance coefficient of deoxyhemoglobin in light having a wavelength λm.

Here, the relationship between the distance (channel) between the light transmitting probe and the light receiving probe and the measurement site will be described. FIG. 10A is a cross-sectional view showing a relationship between a pair of light transmitting probe and light receiving probe and a measurement site, and FIG. 10B is a plan view of FIG.
The light transmitting probe 12 is pressed against the light transmitting point T on the subject's head surface, and the light receiving probe 13 is pressed against the light receiving point R on the subject's head surface. Then, light is emitted from the light transmitting probe 12 and light emitted from the head surface is incident on the light receiving probe 13. At this time, among the light irradiated from the light transmission point T on the head surface, the light that has passed through the banana shape (measurement region) reaches the light receiving point R on the head surface. As a result, the light transmitting point T and the light receiving point R from the middle point M of the line L connecting the light transmitting point T and the light receiving point R at the shortest distance along the head surface of the subject in the measurement region. Received light quantity information A (λ ₁ ), A (λ for the measurement site S of the subject having a depth L / 2 that is half the distance of the line connecting the head and the head along the subject's head surface. ₂ ), A (λ ₃ ) is obtained.

In the optical brain functional imaging system, oxyhemoglobin concentration / optical path length product [oxyHb], deoxyhemoglobin concentration / optical path length product [deoxyHb] and total hemoglobin concentration / optical path length product (multiple measurement sites in the brain) In order to measure [oxyHb] + [deoxyHb]), for example, a near-infrared spectrometer is used (see, for example, Patent Document 1).
FIG. 11 is a block diagram showing an example of a schematic configuration of a conventional near-infrared spectrometer. FIG. 12 is a perspective view showing an example of the appearance of the near-infrared spectrometer shown in FIG. For ease of viewing, several light transmitting optical fibers and several light receiving optical fibers are omitted.
The near-infrared spectrometer 101 has a rectangular parallelepiped main housing 121.
Inside the housing 121 are a light source driver (light emitting unit) 2 that emits light, a light detector 3 that detects light, a detector power supply 4, an A / D 5, a light transmission / reception control unit 122, An operator control unit 124 and a memory 25 are provided, and on the outside of the housing 121, eight light transmitting probes 12, eight light receiving probes 13, eight light transmitting optical fibers 14, Eight receiving optical fibers 15, a display device 26 having a monitor screen 26 a and the like, and a keyboard (input device) 27 are provided.

The light source driver 2 is a light source that transmits light to each light transmission probe 12 by a drive signal input from the light transmission / reception control unit 122. For example, the light source driver 2 has three different wavelengths λ ₁ , λ ₂ , and λ ₃ . Semiconductor lasers LD1, LD2, and LD3 that can emit near-infrared light.
The photodetector 3 detects the near-infrared light received by each of the light receiving probes 13 to thereby detect eight light reception signals (light reception amount information) A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) To the light transmission / reception control unit 122 via the A / D 5, for example, a photomultiplier tube.

The optical fiber for light transmission 14 and the optical fiber for light reception 15 are tubular having a diameter of 2 mm and a length of 2 m to 10 m, can transmit near infrared light in the axial direction, and is incident from one end. Light passes through the inside and exits from the other end, or near-infrared light incident from the other end passes through the inside and exits from one end.
One light transmission optical fiber 14 is connected to both ends so that one light transmission probe 12 and one semiconductor laser of the light source driver 2 are separated by a set length (2 m to 10 m). Yes.
One light receiving optical fiber 15 connects one light receiving probe 13 and one photomultiplier tube of the photodetector 3 to both ends so as to be separated by a set length (2 m to 10 m). ing.

In such a near-infrared spectrometer 101, the holder 11 is used for bringing the eight light-transmitting probes 12 and the eight light-receiving probes 13 into contact with the subject's head surface in a predetermined arrangement. Is done. The holder 11 is provided with a plurality of through holes. By inserting the light transmitting probe 12 and the light receiving probe 13 into the through holes, the probe interval between the light transmitting probe 12 and the light receiving probe 13 becomes constant, and the head The received light amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) at a specific depth is obtained from the surface of the part. The probe interval is referred to as a channel, and generally a channel with a channel of 30 mm is used. When the channel is 30 mm, the received light amount information A (λ) at a depth of 15 mm to 20 mm from the midpoint of the channel. ₁ ), A (λ ₂ ), and A (λ ₃ ). That is, the position of 15 mm to 20 mm in depth from the head surface substantially corresponds to the brain surface region, and the received light quantity information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) related to the brain activity is obtained. .

FIG. 5 is a plan view showing an example of a holder into which eight light transmitting probes and eight light receiving probes are inserted. The light transmitting probes 12 _{T1 to} 12 _T8 and the light receiving probes 13 _{R1 to} 13 _R8 are arranged alternately in four in the vertical direction and four in the horizontal direction. Each through-hole has a different number (T1, T2,...) So that it can be recognized which light-transmitting probes 12 _{T1 to} 12 _T8 or light-receiving probes 13 _{R1 to} 13 _R8 are inserted into which through-holes of the holder 11. .., R1, R2,... Are assigned, and different numbers (T1, T2,...) Are assigned to the light transmitting probes 12 _{T1 to} 12 _T8 , respectively. Different numbers (R1, R2,...) Are assigned to the light receiving probes 13 _{R1 to} 13 _R8 , respectively. As a result, the light transmitting probes 12 _{T1 to} 12 _T8 and the light receiving probes 13 _{R1 to} 13 _R8 are inserted into the corresponding through holes.

In such a positional relationship between the eight light-transmitting probes 12 _{T1 to} 12 _T8 and the eight light-receiving probes 13 _{R1 to} 13 _R8 , one light-receiving probe 13 irradiates from a plurality of light-transmitting probes 12. The timing of irradiating light from the light transmitting probe 12 and the timing of receiving light by the light receiving probe 13 are adjusted so that only light irradiated from one light transmitting probe 12 is received without receiving light simultaneously. There is a need to. For this reason, the memory 25 stores a main table indicating the timing of emitting light by the light source driver 2 and the timing of detecting light by the photodetector 3.
FIG. 13 is a diagram for explaining an example of the main table.
The light transmission / reception control unit 122 having such a main table stored in the memory 25 outputs a drive signal for transmitting light to one light transmission probe 12 _T1 to the light source driver 2 at time t1, and 2 Two light reception signals (light reception amount information) received by the light reception probes 13 _R1 and 13 _R3 are detected by the photodetector 3. Then, feeding the light receiving control section 122, the time t2, and outputs a drive signal for sending a single light to the light-sending probe _{12 T2} to the light source driver 2, three light receiving probes ₁₃ R1, _{13 R2} , 13 The three light receiving signals received by _R4 are detected by the photodetector 3. In this manner, the light transmission / reception control unit 122 transmits light to the light transmission probe 12 one by one in order based on the main table and detects the light reception signal. At time t9, eight light receiving signals A ₀ received by the eight light receiving probes 13 _{R1 to} 13 _R8 without transmitting light to all the light transmitting probes 12 to adjust the baseline. Is detected by the photodetector 3.

The semiconductor lasers LD1, LD2, and LD3 of the light source driver 2 irradiate near-infrared light of three different wavelengths λ ₁ , λ ₂ , and λ ₃ , and the photomultiplier tube of the photodetector 3 has a wavelength of It is also necessary to adjust the timing of irradiating light from the light-transmitting probe 12 and the timing of receiving light by the light-receiving probe 13 so that near-infrared light of λ ₁ , λ ₂ , and λ ₃ is detected. For this reason, the memory 25 also stores a sub-table indicating the timing of emitting light by the light source driver 2 and the timing of detecting light by the photodetector 3.
FIG. 14 is a diagram for explaining an example of the sub-table.
The transmission / reception control unit 122 having such a sub-table stored in the memory 25 is based on a clock signal (Base Clock) indicating time and a start signal (Start) indicating measurement start time at time t1-1. A drive signal for transmitting light of wavelength λ _{1 to one} light transmission probe 12 _T1 is output to LD ₁ of the light source driver 2 and two light receptions received by the two light reception probes 13 _R1 and 13 _R3. A signal (received light amount information) A (λ ₁ ) is detected by the photomultiplier tube of the photodetector 3. Thereafter, the light transmission / reception controller 122 receives the received light amount information A (λ ₁ ) from the photomultiplier tube of the photodetector 3 via the A / D 5 and resets it to the photomultiplier tube of the photodetector 3. Outputs a signal (Reset).
Then, feeding the light receiving control section 122, the time t1-2, and outputs one drive signal for sending the light of the wavelength lambda ₂ to the light-sending probe _{12 T1} of the LD2 of the light source driver 2, two The two light receiving signals A (λ ₂ ) received by the light receiving probes 13 _R1 and 13 _R3 are detected by the photomultiplier tube of the photodetector 3. Thereafter, the transmission / reception controller 122 receives the received light amount information A (λ ₂ ) from the photomultiplier tube of the photodetector 3 via the A / D 5 and resets it to the photomultiplier tube of the photodetector 3. Output a signal.
As described above, the light transmission / reception control unit 122 transmits light of three types of wavelengths λ ₁ , λ ₂ , and λ ₃ to one light transmission probe 12 based on the clock signal, the start signal, and the sub-table. In addition, the light reception signals A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) are received.

As a result, when viewed in plan as shown in FIG. 5, a total of 24 (S1 to S24) received light quantity information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) is collected.
Then, the operator control unit 124 uses relational expressions (1), (2), and (3) based on a total of 24 received light amount information A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ). From the intensity of transmitted light at each wavelength (oxyhemoglobin absorption wavelength and deoxyhemoglobin absorption wavelength), oxyhemoglobin concentration / optical path length product [oxyHb], deoxyhemoglobin concentration / optical path length product [deoxyHb], and total hemoglobin The concentration / optical path length product ([oxyHb] + [deoxyHb]) will be obtained.

JP 2001-337033 A

Factors affecting the accuracy of near-infrared spectroscopy concentration calculations for focal changes in oxygenation parameters, NeuroImage 18, 865-879, 2003

By the way, when measuring a brain activation state or an oxygenation state, there are times when it is desired to measure the entire brain or a part of the brain. For example, it may be desired to change the positional relationship shown in FIG. 9 instead of the positional relationship shown in FIG. FIG. 9 is a plan view showing an example of a holder 11 ′ into which 16 light transmitting probes 12 _{T1 to} 12 _T16 and 16 light receiving probes 13 _{R1 to} 13 _R16 are inserted. The light transmitting probes 12 _{T1 to} 12 _T16 and the light receiving probes 13 _{R1 to} 13 _R16 are arranged alternately in four in the vertical direction and eight in the horizontal direction.
However, in order to perform the measurement with the positional relationship shown in FIG. 9, instead of the near-infrared spectrometer 101 that performs the measurement with the positional relationship shown in FIG. 5, another new near-infrared spectrometer is prepared. As a result, it was necessary to own two near-infrared spectrometers, which was very expensive.

Therefore, it is possible to increase the number of light transmitting probes 12 and the number of light receiving probes 13 in one near infrared spectrometer so that two near infrared spectrometers are not owned. Can be considered. In order to increase the number of the light transmitting probes 12 and the number of the light receiving probes 13 in this way, the light transmitting probe 12 and the light source driver 2 are connected to the near-infrared spectrometer 101. Mounting positions, mounting positions for connecting the light receiving probe 13 and the photodetector 3, and semiconductor lasers LD1, LD2, LD3 for transmitting light from the light source driver 2 to the new light transmitting probe 12 It is necessary to provide a photomultiplier tube or the like for detecting light from the new light receiving probe 13 with the photodetector 3 in advance.
However, if the number of channels that can be added is increased, there is a problem that the casing 121 of the near-infrared spectrometer 101 is increased in size. On the other hand, if the number of channels that can be added is reduced in order to reduce the size of the casing 121 of the near-infrared spectrometer 101, there is a problem that the number of channels cannot be increased.
Accordingly, an object of the present invention is to provide an optical measurement system in which the size and the number of channels can be freely set.

  An optical measurement system of the present invention made to solve the above problems includes a plurality of light transmitting probes for irradiating a subject with light, and a plurality of light receiving probes for receiving light emitted from the subject. And a light-transmitting probe and a light-receiving probe are attached to the holder to be attached to the subject, and the light-transmitting probe emits light and the light-receiving probe emits light. An optical measurement system including a control unit that obtains measurement data related to brain activity, having a sub-housing, and a light-emitting unit that emits light inside the sub-housing and detecting the light And a sub-control unit that controls the light-emitting unit and the light detection unit, and at least one light-transmitting probe, at least one light-receiving probe, Connect the light transmission probe and the light emitting section At least two transmission / reception units each including at least one light transmission optical fiber and at least one light reception optical fiber connecting the light receiving probe and the light detection unit; and a main housing, A main control unit is provided inside the body, and a main unit including an input device and a display device is provided outside the main housing so that the transmission / reception unit can communicate with the main unit. The main control unit can obtain the measurement data by controlling the sub-control unit of the attached transmission / reception unit.

According to the optical measurement system of the present invention, the main unit and at least two transmission / reception units are provided. The main unit includes a main control unit, but does not include a light emitting unit or a light detection unit. Therefore, the size of the main housing of the main unit can be reduced.
On the other hand, each transmitting / receiving unit includes a light emitting unit, a light detecting unit, a sub control unit, at least one light transmitting probe, at least one light receiving probe, at least one light transmitting optical fiber, and at least one light receiving light. Fiber. The transmission / reception unit can be attached and detached so as to communicate with the main unit. Thus, when the number of channels is increased, the number of transmission / reception units is increased, while when the number of channels is decreased, the number of transmission / reception units is decreased. That is, the size of the transmission / reception unit can correspond to the number of channels.
The main control unit controls the sub-control unit of the attached transmission / reception unit. That is, the timing of light transmission control and light reception control in a plurality of transmission / reception units is adjusted. Thereby, even if each transmission / reception unit is mutually independent, the measurement data obtained between one transmission / reception unit and another transmission / reception unit can also be obtained.

  As described above, according to the optical measurement system of the present invention, the size and the number of channels can be freely set.

(Means and effects for solving other problems)
In the optical measurement system of the present invention, the main control unit of the main unit emits light from the light emitting unit in the attached transmission / reception unit based on the input signal from the input device before performing the measurement. The sub-control unit of each transmission / reception unit receives a clock signal indicating time and the table from the main control unit of the main unit. The main control unit of the main unit creates a start signal indicating a measurement start time based on the input signal from the input device when performing measurement, and the sub-control unit of each transmission / reception unit A start signal is received from the main control unit of the main unit, and based on the start signal, clock signal, and table, the light emitting unit emits light and the light detection unit detects light. It may be.
According to the optical measurement system of the present invention, the clock signal and the start signal are received from the main unit even if each transmission / reception unit is independent from each other, so that the timing between the light transmission control and the light reception control can be accurately adjusted. Can do.

Furthermore, in the optical measurement system of the present invention, the holder includes a plurality of holder parts having a single letter shape, and the holder part includes a socket part for holding a light transmitting probe or a light receiving probe at both ends, and the socket part. And the holder part can be rotated with other holder parts around the socket part as a rotation axis within the contact surface of the head surface of the subject. Moreover, you may make it have flexibility by a connection part in the normal line direction of the said head surface.
According to the optical measurement system of the present invention, a holder capable of fixing an arbitrary number of light transmitting probes or light receiving probes can be manufactured.

FIG. 1 is a block diagram illustrating an example of a schematic configuration of an optical measurement system according to an embodiment of the present invention. It is a detailed block diagram which shows schematic structure of the transmission / reception unit shown in FIG. It is a detailed block diagram which shows schematic structure of the main unit shown in FIG. It is a perspective view which shows an example of the external appearance of an optical measurement system. It is a top view which shows an example of the holder in which eight light transmission probes and eight light reception probes are inserted. It is a disassembled perspective view which shows a light transmission probe, a nut component, two connection components, and a socket component. It is a figure which shows the light transmission probe, nut component, two connection components, and socket component after an assembly. It is a perspective view which shows another example of the external appearance of an optical measurement system. It is a top view which shows an example of the holder in which 16 light transmission probes and 16 light reception probes are inserted. It is a figure for demonstrating an example of a main table. It is a figure for demonstrating an example of a subtable. It is a figure which shows the relationship between a pair of light transmission probe and light reception probe, and a measurement site | part. It is a block diagram which shows an example of schematic structure of the conventional near-infrared spectrometer. It is a perspective view which shows an example of the external appearance of the near-infrared spectrometer shown in FIG. It is a figure for demonstrating another example of a main table. It is a figure for demonstrating another example of a subtable.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and it goes without saying that various aspects are included without departing from the spirit of the present invention.

FIG. 1 is a block diagram showing a schematic configuration of an optical measurement system according to an embodiment of the present invention. 2 is a detailed block diagram showing a schematic configuration of the transmission / reception unit shown in FIG. 1, and FIG. 3 is a detailed block diagram showing a schematic configuration of the main unit shown in FIG.
FIG. 4 is a perspective view showing an example of the external appearance of the optical measurement system, and FIG. 5 is a plan view showing an example of a holder into which eight light transmitting probes and eight light receiving probes are inserted. .
On the other hand, FIG. 8 is a perspective view showing another example of the appearance of the optical measurement system, and FIG. 9 is a plan view showing an example of a holder into which 16 light transmitting probes and 16 light receiving probes are inserted. It is.
The optical measurement system 1 includes one main unit 20, a plurality of transmission / reception units 40 a to 40 p, and one holder 11.

The main unit 20 includes a rectangular parallelepiped main casing 21, a main control unit 24 provided inside the main casing 21, and a display device including a monitor screen 26 a and the like outside the main casing 21. 26 and a keyboard (input device) 27.
The transmission / reception unit 40 has a rectangular parallelepiped sub-housing 41, and inside the sub-housing 41, a light source driver (light emitting unit) 2 that emits light, a light detector 3 that detects light, and a detector The power supply 4, the A / D 5, the sub control unit 45, and the memory 46 are provided, and one light transmitting probe 12, one light receiving probe 13, and one are provided outside the sub housing 41. Optical transmission fiber 14, one light receiving optical fiber 15, and one Ethernet (registered trademark) cable 43.
The holder 11 is for bringing the light transmitting probe 12 and the light receiving probe 13 into contact with the head surface of the subject in a predetermined arrangement.

First, components constituting the holder 11 will be described. FIG. 6 is an exploded perspective view showing the light transmission probe 12, the nut part 32, the two connection parts 31, and the socket part 33. FIG. 7 is a view showing the light transmitting probe 12, the nut part 32, the two connecting parts 31, and the socket part 33 after being assembled.
The holder 11 includes a plurality of socket parts 33 for fixing the light transmitting probe 12 and the light receiving probe 13, a plurality of connection parts 31, and a plurality of nut parts 32.

  The connection part 31 is a plate-shaped body having a single letter shape. And the connection component 31 has the annular-shaped insertion part 31a at both ends, and the connection part 31b which connects the insertion part 31a of both ends with the channel length X. FIG. In the center of each insertion portion 31a, a circular through-hole for inserting the socket component 33 is opened. The connecting portion 31b has a width of 10 mm and a thickness of 0.1 mm, and is formed such that the distance between the center of the through hole and the center of the through hole is a channel length of 30 mm. Only flexible in the direction. That is, the insertion portions 31a at both ends are always held at the channel length X.

The socket part 33 has a cylindrical main body part 33a, an annular jaw part 33b, and an annular bottom part 33c, and allows the light transmitting probe 12 and the light receiving probe 13 to be inserted therein. The nut part 32 is screwed onto the outer peripheral surface of the main body 33a.
The nut part 32 has an annular shape having a circular through hole, and a female screw that is screwed into the main body part 33 a of the socket part 33 is formed on the inner peripheral surface thereof. Note that the size of the through hole is larger than the size of the main body portion 33 a of the socket component 33 and smaller than the jaw portion 33 b of the socket component 33 when viewed from above.
Thus, the insertion portion 31a of the connection component 31 is inserted between the jaw portion 33b of the socket component 33 and the nut component 32 by inserting the main body portion 33a of the socket component 33 into the nut component 32 using a screw mechanism. It can be pinched and fixed. At this time, when fixing one connection component 31, the insertion portion 31 a of one connection component 31 is sandwiched between the jaw portion 33 b of the socket component 33 and the nut component 32. On the other hand, when the four connection parts 31 are fixed, the insertion parts 31 a of the four connection parts 31 are sandwiched between the jaw part 33 b of the socket part 33 and the nut part 32. In other words, an arbitrary number of connection parts 31 can be fixed.

Then, for example, the holder 11 shown in FIG. 5 is manufactured using 16 socket parts 33, 24 connection parts 31, and 16 nut parts 32. According to such a holder 11, as shown in FIG. 7 (a), one connecting component 31 and the other connecting component 31 are sockets as viewed from above in order to be mounted in close contact with the head surface. As shown in FIG. 7 (b), the connecting portion 31b of the connecting component 31 is flexible so as to form a desired angle with the component 33 as an axis, and therefore has a curvature that matches the head surface. It can deform | transform so that it may have a surface. At this time, if the angle formed by the angle between one connection component 31 and the other connection component 31 is fixed in a deformed state, the curvature is maintained.
Thereafter, each of the light transmitting probes 12 _{T1 to} 12 _T8 and each of the light receiving probes 13 _{R1 to} 13 _R8 is inserted inside the socket component 33 having a corresponding number.
When it is desired to measure a part of the brain, for example, as shown in FIG. 5, the holder 11 is produced using 16 socket parts 33, 24 connection parts 31 and 16 nut parts 32. On the other hand, when it is desired to measure the entire brain, for example, as shown in FIG. 9, the holder 11 ′ is produced using 32 socket parts 33, 48 connection parts 31 and 32 nut parts 32. Will do. That is, according to such a holder 11, holders 11 and 11 ′ capable of fixing an arbitrary number of light transmitting probes 12 or light receiving probes 13 can be manufactured.

Next, the transmission / reception unit 40a will be described.
The transmission / reception unit 40 a has a rectangular parallelepiped sub-housing 41.
The sub-housing 41 includes the light source driver 2, the light detector 3, the detector power supply 4, the A / D 5, the sub-control unit 45, and the memory 46, and the outside of the sub-housing 41. Includes one light transmitting probe 12, one light receiving probe 13, one light transmitting optical fiber 14, one light receiving optical fiber 15, and one Ethernet (registered trademark) cable. 43a.

One light transmission optical fiber 14 connects one light transmission probe 12 and the semiconductor lasers LD1, LD2, and LD3 of the light source driver 2 to both ends so as to be separated by a set length (2 m to 10 m). ing.
One light receiving optical fiber 15 connects one light receiving probe 13 and the photomultiplier tube of the photodetector 3 to both ends so as to be separated by a set length (2 m to 10 m).
The light transmission probe 12 has an elongated cylindrical shape whose upper end portion is slightly larger to be fixed to the socket component 33. And the upper end part of the light transmission probe 12 is connected with the light source driver 2 via the optical fiber 14 for light transmission, and irradiates light from a lower end part.
The light receiving probe 13 is also in the shape of an elongated cylinder having a slightly larger upper end similar to the light transmitting probe 12. The upper end portion of the light receiving probe 13 is connected to the photodetector 3 via the light receiving optical fiber 15 and receives light at the lower end portion thereof.

The Ethernet (registered trademark) cable 43a has a tubular shape with a diameter of 2 mm and a length of 2 m to 10 m. A transmission / reception unit side connector portion 42 is provided so as to be connected to the main control portion 24. Thereby, by connecting the transmission / reception unit side connector part 42 with the main unit side connector part 23 of the main unit 20, between the sub control part 42 of the sub housing 41 and the main control part 24 of the main unit 20, A light reception signal, a clock signal, and the like can be transmitted.
Note that a plurality of such main unit side connector portions 23 are formed, and in each main unit side connector portion 23, the transmission / reception unit side connector portion 42 of which Ethernet (registered trademark) cable 43 of which transmission / reception unit 40 is inserted. Different numbers (module 1, module 2,..., Module 4) are assigned to each main unit connector 23 so that it can be recognized.

Further, the function processed by the sub-control unit 45 will be described as a block. The light emission control unit 45a that outputs a drive signal to the light source driver 2 and the light reception signal (light reception amount information) by receiving the light reception signal from the photodetector 3 are described. ) A light detection control unit 45b that stores A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) in the memory 46, and a communication control unit 45c that communicates with the main control unit 24 of the main unit 20. .
The communication control unit 45c performs control to communicate with the control unit 24 of the main unit 20 via the Ethernet (registered trademark) cable 43a.
For example, the communication control unit 45c receives a clock signal (Base Clock), a main table, and a sub table from the main control unit 24 by communicating with the main control unit 24 of the main unit 20 before performing measurement.
Further, the communication control unit 45c receives a start signal (Start) from the main control unit 24 by communicating with the main control unit 24 of the main unit 20 during measurement or during measurement. Thereafter, the received light amount information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) is transmitted to the main control unit 24.
As described above, since the clock signal and the start signal are received from the main control unit 24, various processes can be executed at an accurate timing even when independent of other transmission / reception units 40.

When the light emission control unit 45a receives the start signal from the main control unit 24, the light emission control unit 45a generates a drive signal for transmitting light to the light transmission probe 12 based on the clock signal stored in the memory 46, the main table, and the sub table. Control to output to the driver 2 is performed.
For example, in the main table shown in FIG. 10, the light emission control unit 45a of the transmitting and receiving unit 40a of the module 1, the time t1, and outputs a drive signal for sending light to the light source driver 2 to the light-sending probe 12 _T1. Further, the light emission control unit 45a of the transmitting and receiving units 40b of the module 2, the time t1, does not output the driving signal for sending light to the light source driver 2 to the light-sending probe _{12 T2.}
Further, the light emission control unit 45a of the transmitting and receiving unit 40a of the module 1, the time t2, does not output the driving signal for sending light to the light source driver 2 to one of the light transmitting probe 12 _T1. Further, the light emission control unit 45a of the transmitting and receiving units 40b of the module 2, the time t2, and outputs a drive signal for sending light to the light source driver 2 to one of the light transmitting probe _{12 T1.}
As described above, the light emission control units 35a of the transmission / reception units 40a to 40h are independent of each other, but output a drive signal to the light source driver 2 based on the start signal, the clock signal, the main table, and the sub table. It will follow.

When the light detection control unit 45b receives the start signal from the main control unit 24, one light reception amount information A from the light detector 3 based on the clock signal, the main table, and the sub table stored in the memory 46. Control is performed to store (λ ₁ ), A (λ ₂ ), and A (λ ₃ ) in the memory 46.
For example, FIG. In the main table shown in 10, the photodetection control unit 45b of the module 1 of handset unit 40a is the time t1, one of one photodetection signal A received by the light receiving probe _{13 R1} (lambda _1), A (λ ₂ ) and A (λ ₃ ) are detected by the photodetector 3 and stored in the memory 46. Further, the light emission control unit 45a of the transmission / reception unit 40b of the module 2 does not detect one light reception signal received by one light reception probe _13R2 by the light detection unit 3 at time t1.
Further, the light detection control unit 45b of the module 1 of handset unit 40a is the time t2, 1 is received by one receiving probe _{13 R2} amino photodetection signal _{A (λ 1), A (} λ 2), A ( λ ₃ ) is detected by the photodetector 3 and stored in the memory 46. Further, the light detection control unit 45b of the transmitting and receiving units 40b of the module 2, the time t2, 1 is received by one receiving probe _{13 R2} amino photodetection signal _{A (λ 1), A (} λ 2), A ( λ ₃ ) is detected by the photodetector 3 and stored in the memory 46.
As described above, the light detection control units 45b of the transmission / reception units 40a to 40h are independent of each other, but based on the start signal, the clock signal, the main table, and the sub table, the light reception signal A (λ ₁ ), A (λ ₂ ) and A (λ ₃ ) are stored in the memory 46.

  When it is desired to measure a part of the brain, for example, eight such transmission / reception units 40 are prepared as shown in FIG. 3, while when it is desired to measure the entire brain, for example, as shown in FIG. 16 will be prepared. That is, an arbitrary number of light-transmitting probes 12 or light-receiving probes 13 can be prepared and can be set to an arbitrary size.

Next, the main unit 20 will be described.
The main unit 20 has a rectangular parallelepiped main housing 21.
A main control unit 24 is provided inside the main housing 21, and a display device 26 having a monitor screen 26 a and the like and a keyboard 27 are provided outside the main housing 21. A main unit connector 23 to which an Ethernet (registered trademark) cable 43 of the transmission / reception unit 40 is attached is provided on the outer surface of the main housing 21.
By attaching the transmission / reception unit side connector 42 of the Ethernet (registered trademark) cable 43 to the main unit side connector 23, the main control unit 24 of the main unit 20 and the sub control unit 45 of the transmission / reception unit 40 communicate. On the other hand, by removing the transmission / reception unit side connector part 42 of the Ethernet (registered trademark) cable 43 from the main unit side connector part 23, the main control part 24 of the main unit 20 and the sub unit of the transmission / reception unit 40 are connected. The control unit 45 cannot communicate with the control unit 45.

Further, the functions processed by the main control unit 24 will be described as a block. A communication control unit 24a that communicates with the sub control unit 45 of the transmission / reception unit 40, a table creation unit 24b that creates a main table and a sub table, It has the calculating part 24c and the brain activity image display control part 24d.
The table creation unit 24 b performs control to create a main table and a sub table based on an input signal from the keyboard 27.
Here, a table creation method for creating the main table and the sub-table will be described. FIG. 10 is a diagram for explaining an example of the main table, and FIG. 11 is a diagram for explaining an example of the sub table.
For example, when the user measures a part of the brain, the user creates the holder 11 that can fix the eight light transmitting probes 12 and the eight light receiving probes 13 shown in FIG. At this time, different numbers (T1, T2,..., R1, R2,...) Are assigned to the respective through holes.
Next, the user prepares eight transmission / reception units 40 a to 40 h in order to fix the eight light transmission probes 12 and the eight light reception probes 13. At this time, different numbers (module 1, module 2,..., Module 8) are assigned to the transmission / reception units 40a to 40h, respectively.

Next, the user inserts the light transmission probe 12 _T1 of the transmission / reception unit 40 a of the module 1 into the through hole of number 11 of the holder 11 and inserts the light receiving probe 13 _R1 into the through hole of number 11 of the holder 11. Further, the transmission / reception unit side connector part 42 of the Ethernet (registered trademark) cable 43 a of the transmission / reception unit 40 a of the module 1 is inserted into the main unit side connector part 23 of the number module 1 of the main unit 20.
Next, the user inserts the light-receiving probe 13 _R2 into the through-hole of the number R2 of the holder 11 while inserting the light-receiving probe 13 _R2 into the through-hole of the number 11 of the light-transmitting probe 12 _T2 holder 11 of the module 2. Further, the transmission / reception unit side connector portion 42 of the Ethernet (registered trademark) cable 43 b of the transmission / reception unit 40 b of the module 2 is inserted into the main unit side connector portion 23 of the number module 2 of the main unit 20.
Similarly, the light transmitting probes 12 of the other transmitting / receiving units 40 c to 40 h are inserted into the through holes of the holder 11, and the light receiving probes 13 are inserted into the through holes of the holder 11. Further, the transmission / reception unit side connector part 42 of the Ethernet (registered trademark) cables 43 cb to 43 h of the other transmission / reception units 40 c to 40 h is inserted into the main unit side connector part 23.

Next, the user uses the keyboard 27 to create a main table indicating the timing of emitting light by each light source driver 2 and the timing of detecting light by each photodetector 3 (see FIG. 10). For example, the time t1, as well as sending the light into one light transmitting probe _{12 T1,} detects the two light receiving signal received by the two light receiving probes ₁₃ R1, _{13 R3.} The time t2, as well as sending the light into one light transmitting probe _{12 T2,} detects three light reception signal received by three light receiving probes _{13 R1, 13 R2, 13 R4} . In this way, a main table is prepared so that light is transmitted to the light transmitting probe 12 one by one in order and the received light signal is detected.

Next, the user uses the keyboard 27 to create a sub-table indicating the timing of emitting light by the light source driver 2 and the timing of detecting light by the photodetector 3 (see FIG. 11). For example, time t1-1, and outputs a drive signal for sending the one optical wavelength lambda ₁ to the light-sending probe _{12 T1} in LD1 of the light source driver 2, at two light receiving probes ₁₃ R1, _{13 R3} Two received light reception signals (light reception amount information) A (λ ₁ ) are detected by the photomultiplier tube of the photodetector 3. Thereafter, the received light amount information A (λ ₁ ) is received from the photomultiplier tube of the photodetector 3 via the A / D 5, and a reset signal (Reset) is output to the photomultiplier tube of the photodetector 3.
The time t1-2, and outputs a drive signal for sending the light of the wavelength lambda ₂ to the LD2 of the light source driver 2 to one of the light transmitting probe _{12 T1,} it is received by two light receiving probes ₁₃ R1, _{13 R3} The two received light signals A (λ ₂ ) are detected by the photomultiplier tube of the photodetector 3. Thereafter, the received light amount information A (λ ₂ ) is received from the photomultiplier tube of the photodetector 3 via the A / D 5, and a reset signal is output to the photomultiplier tube of the photodetector 3.
In this way, the light transmission / reception control unit 122 transmits light of three types of wavelengths λ ₁ , λ ₂ , λ ₃ to one light transmission probe 12 and also receives the light reception signals A (λ ₁ ), A ( A sub-table for receiving λ ₂ ) and A (λ ₃ ) is created.

  When the user wants to measure the entire brain, for example, a holder 11 ′ that can fix the 16 light transmitting probes 12 and the 16 light receiving probes 13 shown in FIG. A main table and a sub table corresponding to the holder 11 'are created. At this time, the light transmitting probes 12 that transmit light at the same time select the ones that are separated from each other, so that one light receiving probe 13 simultaneously receives the light emitted from the plurality of light transmitting probes 12. Instead, only the light emitted from one light transmission probe 12 may be received.

The communication control unit 24a performs control to communicate with the sub-control unit 45 of the transmission / reception units 40a to 40h via the Ethernet (registered trademark) cables 43a to 43h.
For example, the communication control unit 22a transmits a clock signal, a main table, and a sub table to each sub control unit 45 by communicating with the sub control unit 45 of the transmission / reception units 40a to 40h before performing the measurement. Further, the communication control unit 24a transmits a start signal to each sub-control unit 45 by communicating with the sub-control unit 45 of the transmission / reception units 40a to 40h during measurement or measurement. Thereafter, light reception signals (light reception amount information) A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) are received from each sub-control unit 45 and stored in the memory 25.
Based on the received light amount information A (λ ₁ ), A (λ ₂ ), A (λ ₃ ) stored in the memory 25, the calculation unit 24c uses the relational expressions (1), (2), and (3), From the transmitted light intensity of each wavelength (oxyhemoglobin absorption wavelength and deoxyhemoglobin absorption wavelength), oxyhemoglobin concentration / optical path length product [oxyHb], deoxyhemoglobin concentration / optical path length product [deoxyHb] and total hemoglobin concentration Control to obtain the optical path length product ([oxyHb] + [deoxyHb]) is performed.
The brain activity image display control unit 24d performs control to display information on the monitor screen 26a. For example, oxyhemoglobin concentration / optical path length product [oxyHb], deoxyhemoglobin concentration / optical path length product [deoxyHb] and total hemoglobin concentration / optical path length product ([oxyHb] + [deoxyHb]) Is displayed.

  As described above, according to the optical measurement system of the present invention, the size and the number of channels can be freely set.

(Other embodiments)
(1) In the optical measurement system described above, the transmission / reception unit 40 is configured to include one light transmission probe 12 and one light reception probe 13, but for example, two light transmission probes 12 and Two light receiving probes 13 may be provided, or three light transmitting probes 12 and one light receiving probe 13 may be provided.

(2) In the optical measurement system described above, the main table shown in FIG. 10 and the sub-table shown in FIG. 11 are created. For example, the main table shown in FIG. 15 and the sub-table shown in FIG. It is good also as a structure which produces.
The optical measurement system in which the main table shown in FIG. 15 is stored in the memory outputs a drive signal for transmitting light to one light transmission probe 12 _T1 to the light source driver at time t1, and eight light reception probes. The eight light receiving signals received by 13 _{R1 to} 13 _R8 are detected by the photodetector. The time t2, and outputs a drive signal for sending light to the light source driver to one of the light transmitting probe 12 _T2, photodetector eight light receiving signal received by the eight light receiving probes 13 _R1 to 13 _R8 Detect with instrument. In this way, based on the main table, light is transmitted to the light transmitting probe 12 one by one in order and eight light receiving signals are detected.

In addition, the optical measurement system in which the sub-table shown in FIG. 16 is stored in the memory transmits a drive signal for transmitting light of wavelength λ _{1 to one} light transmission probe 12 _T1 at time t1-1 as a light source driver LD1. And eight received light signals (received light amount information) A (λ ₁ ) received by the eight light receiving probes 13 _{R1 to} 13 _R8 are detected by the photomultiplier tube of the photodetector.
The time t1-2, and outputs a drive signal for sending the light of the wavelength lambda ₂ to the LD2 of the light source driver to one of the light transmitting probe _{12 T1,} it received at eight light receiving probes ₁₃ R1 _{to 13 R8} Eight received light signals A (λ ₂ ) are detected by the photomultiplier tube of the photodetector.
Then, the time T1-4, in order to adjust the baseline, the whole of the light transmitting probe ₁₂ T1 _{to 12 T8} without outputting a driving signal for sending light, eight light receiving probes ₁₃ R1 _{to 13 R8} eight light receiving signal a ₀ that is received is detected by the photomultiplier photodetector.
As described above, the light of the three types of wavelengths λ ₁ , λ ₂ , and λ ₃ is transmitted to one light transmitting probe 12, and the received light signals A (λ ₁ ), A (λ ₂ ), and A (λ ₃ ), _A0 is received.

(3) In the optical measurement system described above, the main control unit 24 and the transmission / reception unit 40 of the main unit 20 are provided by attaching the transmission / reception unit side connector 42 of the Ethernet (registered trademark) cable 43 to the main unit side connector 23. The sub-control unit 45 can communicate with each other. For example, the main control unit of the main unit and the sub-control unit of the transmission / reception unit communicate with each other by, for example, an optical fiber, a dedicated wired cable, or wireless communication. It is good also as a structure which performs.

  INDUSTRIAL APPLICABILITY The present invention can be used for an optical measurement system that irradiates light inside a living body and acquires information inside the living body.

1: Optical measurement system 2: Light source driver (light emitting unit)
3: Photodetector 11: Holder 12: Light transmitting probe 13: Light receiving probe 14: Light transmitting optical fiber 15: Light receiving optical fiber 20: Main unit 21: Main housing 24: Main control unit 27: Keyboard (input device) )
40: Transmission / reception unit 41: Sub housing 45: Sub control unit

Claims (3)

A plurality of light transmission probes for irradiating the subject with light;
A plurality of light receiving probes for receiving light emitted from the subject;
A light-transmitting probe and a light-receiving probe are attached, and a holder to be attached to the subject;
A light measurement system comprising: a control unit that obtains measurement data related to brain activity by controlling the light-transmitting probe to emit light and the light-receiving probe to receive emitted light;
The sub-casing includes a light emitting unit that emits light, a light detecting unit that detects light, and a sub-control unit that controls the light emitting unit and the light detecting unit. And at least one light transmitting probe, at least one light receiving probe, at least one light transmitting optical fiber connecting the light transmitting probe and the light emitting unit, and a light receiving probe. And at least two light receiving / receiving units comprising at least one light receiving optical fiber connecting the light detecting unit and the light detecting unit;
The main housing includes a main control unit inside the main housing, and a main unit including an input device and a display device outside the main housing,
The transmission / reception unit can be attached and detached so as to communicate with the main unit,
The said main control part acquires the said measurement data by controlling the sub-control part of the attached transmission / reception unit, The optical measurement system characterized by the above-mentioned. Before the measurement, the main control unit of the main unit, based on the input signal from the input device, the timing of emitting light by the light emitting unit and the timing of detecting light by the light detecting unit in the attached transmission / reception unit, Create a table showing
The sub-control unit of each transmission / reception unit receives a clock signal indicating time and the table from the main control unit of the main unit,
When performing measurement, the main control unit of the main unit creates a start signal indicating the measurement start time based on the input signal from the input device,
The sub-control unit of each transmission / reception unit receives a start signal from the main control unit of the main unit, emits light at the light-emitting unit and outputs light at the light detection unit based on the start signal, the clock signal, and the table. The optical measurement system according to claim 1, wherein: The holder is composed of a plurality of holder parts having a single letter shape,
The holder part has a socket part for holding a light transmitting probe or a light receiving probe at both ends, and a connecting part for connecting the socket part at a constant interval,
The holder component can be rotated with another holder component around the socket portion as a rotation axis within the contact surface of the subject's head surface, and by a connecting portion in the normal direction of the head surface. The optical measurement system according to claim 1, wherein the optical measurement system has flexibility.

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