Optical probe and optical probe unit

Abstract

This optical probe comprises: a light reflection part having a reflection surface that reflects, along a second optical axis, light that is incident along a first optical axis; a housing that accommodates the light reflection part so as to enable sliding in a first direction parallel to the first optical axis, the housing holding an end part of an optical fiber so as to be positioned on the first optical axis and so as to face the light reflection part in the first direction; a first urging member for urging the light reflection part to the first side in the first direction within the housing; and an adjustment part that adjusts the position of the light reflection part in the first direction by pressing the light reflection part toward the second side in the first direction within the housing.

Description

Optical probe and optical probe unit

[0001] The present disclosure relates to an optical probe and an optical probe unit.

[0002] Patent Document 1 describes a probe device used in a biological optical measurement device for measuring changes in local hemodynamics within a living organism. The probe device described in Patent Document 1 includes multiple probes including a light-emitting probe and a light-detecting probe, and a shell portion that holds the multiple probes. With each probe, the contact state of the fiber bundle end with the living organism can be adjusted while the shell portion is attached to the living organism. This prevents, for example, hair or the like from becoming caught between the living organism and the fiber bundle end, and ensures an optical path between the living organism and the probe.

[0003] Japanese Patent Application Laid-Open No. 2007-236963

[0004] However, in the probe device described in Patent Document 1, the contact state of the fiber bundle end with the living body is adjusted by adjusting the position of the fiber bundle end with respect to the living body, which may result in a greater load than expected being applied to the living body.

[0005] Therefore, an object of the present disclosure is to provide an optical probe and an optical probe unit that can reliably ensure an optical path between the subject and the optical probe while suppressing the load acting on the subject.

[0006] An optical probe according to one aspect of the present disclosure is [1] "an optical probe comprising: a light reflecting unit having a reflective surface that reflects light incident along one of a first optical axis and a second optical axis that intersect with each other, along the other of the first optical axis and the second optical axis; a housing that accommodates the light reflecting unit so that it is slidable in a first direction parallel to the first optical axis, and that holds an end of an optical fiber so that it is positioned on the first optical axis and faces the light reflecting unit in the first direction; a first biasing member that biases the light reflecting unit toward a first side in the first direction in the housing; and an adjustment unit that adjusts the position of the light reflecting unit in the first direction by pressing the light reflecting unit toward a second side in the housing opposite the first side in the first direction."

[0007] In the optical probe described in [1] above, an end of the optical fiber faces the light reflecting portion on a first optical axis, and the subject faces the light reflecting portion on a second optical axis. In this state, a first biasing member biases the light reflecting portion, which is slidable in a first direction, toward a first side in the first direction. The adjustment unit presses the light reflecting portion, which is slidable in the first direction, toward a second side in the first direction, thereby adjusting the position of the light reflecting portion in the first direction. This prevents, for example, hair from becoming trapped between the subject and the light reflecting portion, and ensures an optical path between the subject and the light reflecting portion. Here, the sliding direction of the light reflecting portion, the biasing direction by the first biasing member, and the pressing direction by the adjustment unit are all in a first direction parallel to the first optical axis and intersect with a direction parallel to a second optical axis in which the subject faces the light reflecting portion. Therefore, the load acting on the subject can be reduced when adjusting the position of the light reflecting portion in the first direction. As described above, the optical probe described in [1] above can reliably ensure an optical path between the subject and the subject while suppressing the load acting on the subject.

[0008] An optical probe according to one aspect of the present disclosure may be [2] "the optical probe according to the above [1], wherein the light reflecting portion has an inclined surface corresponding to the reflecting surface, the adjustment portion includes a pressing member having a pressing surface in contact with the inclined surface, and the housing accommodates the pressing member so as to be slidable in a second direction parallel to the second optical axis." According to the optical probe described in [2], by utilizing the inclined surface of the light reflecting portion corresponding to the reflecting surface to adjust the position of the light reflecting portion in the first direction, it is possible to easily and reliably operate the adjustment portion from the side opposite to the subject in the second direction.

[0009] An optical probe according to one aspect of the present disclosure may be [3] "the optical probe according to the above [2], wherein the adjustment unit further includes a screw member attached to the housing so as to be able to advance and retreat along the second direction, one end of the screw member in the second direction being in contact with the pressing member, and the other end of the screw member in the second direction being exposed to the outside of the housing." According to the optical probe described in [3], by accessing the other end of the screw member in the second direction, it is possible to more easily and reliably operate the adjustment unit from the side opposite to the subject in the second direction.

[0010] An optical probe according to one aspect of the present disclosure may be [4] "the optical probe according to the above [3], wherein the pressing member has a recess in which the one end of the screw member is disposed." The optical probe according to [4] can suppress positional deviation of the one end of the screw member relative to the pressing member, and can accurately adjust the position of the light reflecting portion in the first direction.

[0011] An optical probe according to one aspect of the present disclosure may be [5] "the optical probe according to any one of [2] to [4] above, wherein the light reflecting section includes a light transmitting member and a metal layer disposed on a surface of the light transmitting member, and the reflecting surface is a surface of the metal layer facing the light transmitting member." According to the optical probe described in [5], light incident along one of the first optical axis and the second optical axis can be reliably reflected along the other of the first optical axis and the second optical axis.

[0012] An optical probe according to one aspect of the present disclosure may be [6] "the optical probe according to the above [5], wherein the light reflecting portion further includes a protective layer disposed on a surface of the metal layer opposite to the light transmitting member, and the inclined surface is a surface of the protective layer opposite to the metal layer." According to the optical probe described in [6], it is possible to suppress wear of the metal layer while maintaining a desired contact state between the inclined surface of the light reflecting portion and the pressing surface of the pressing member.

[0013] An optical probe according to one aspect of the present disclosure may be [7] "the optical probe according to any one of [2] to [4] above, wherein the light reflecting section includes a light transmitting member, and the light transmitting member has the reflecting surface and the inclined surface as the same surface." The optical probe according to [7] can be simply configured to reflect light incident along one of the first optical axis and the second optical axis along the other of the first optical axis and the second optical axis.

[0014] An optical probe according to one aspect of the present disclosure may be [8] "the optical probe according to the above [7], in which the pressing surface is a rough surface." According to the optical probe according to [8], a sufficient refractive index difference can be ensured on the reflective surface of the light-transmitting member, so that light incident along one of the first optical axis and the second optical axis can be reliably reflected along the other of the first optical axis and the second optical axis.

[0015] An optical probe according to one aspect of the present disclosure may be [9] "the optical probe according to any one of [1] to [8] above, further including a second biasing member that biases the light reflecting portion toward the second side in the first direction in the housing." According to the optical probe described in [9], the adjustment unit can smoothly and stably slide the light reflecting portion to a position determined by pressing the light reflecting portion toward the second side in the first direction.

[0016] An optical probe according to one aspect of the present disclosure may be

[10] "the optical probe according to the above [9], in which the biasing force of the first biasing member is greater than the biasing force of the second biasing member." According to the optical probe according to

[10] , the adjustment unit can more smoothly and stably slide the light reflecting portion to a position determined by pressing the light reflecting portion toward the second side in the first direction.

[0017] An optical probe according to one aspect of the present disclosure may be

[11] "the optical probe according to the above [1], wherein the adjustment unit further includes a screw member attached to the housing so as to be able to advance and retreat along the first direction, one end of the screw member in the first direction being in contact with the light reflecting unit, and the other end of the screw member in the first direction being exposed to the outside of the housing." The optical probe according to

[11] can achieve adjustment of the position of the light reflecting unit in the first direction with a simple configuration.

[0018] An optical probe unit according to one aspect of the present disclosure is

[12] "an optical probe unit comprising: a plurality of optical probes, each of which is the optical probe described in [1] to

[11] above; and a holder that holds the plurality of optical probes."

[0019] According to the optical probe unit described in

[12] above, by using a plurality of optical probes as an optical probe for guiding light to be irradiated onto a subject and an optical probe for guiding light emitted from the subject, it is possible to reliably ensure an optical path between the plurality of optical probes and the subject while suppressing the load acting on the subject, and as a result, it is possible to perform optical inspection of the subject with high accuracy.

[0020] According to the present disclosure, it is possible to provide an optical probe and an optical probe unit that can reliably ensure an optical path between the subject and the optical probe while suppressing the load acting on the subject.

[0021] Fig. 1 is a configuration diagram of an optical measurement device including an optical probe unit of one embodiment. Fig. 2 is a plan view of an optical probe included in the optical probe unit shown in Fig. 1. Fig. 3 is a cross-sectional view of the optical probe taken along line III-III shown in Fig. 2. Fig. 4 is a cross-sectional view of the optical probe taken along line IV-IV shown in Fig. 2. Fig. 5 is a cross-sectional view of the optical probe taken along line III-III shown in Fig. 2.

[0022] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or equivalent elements will be designated by the same reference numerals, and redundant description will be omitted. [Configuration of the optical measurement device]

[0023] As shown in FIG. 1 , the optical measurement device 100 includes an optical probe unit 10 and a device main body 110. The optical measurement device 100 irradiates a predetermined region of the subject S with light via the optical probe unit 10 attached to the subject S and detects the light emitted from the predetermined region of the subject S, thereby measuring the optical characteristics of the predetermined region of the subject S. As an example, the optical measurement device 100 irradiates a deep brain region of a human subject S with near-infrared light via the optical probe unit 10 attached to the head of the human subject S and detects the light emitted from the deep brain, thereby measuring the amount of light attenuation or temporal diffusion in the deep brain and measuring hemoglobin dynamics (e.g., oxygenated hemoglobin concentration, decarboxylated hemoglobin concentration, tissue oxygen saturation) in the deep brain based on the measured values. Note that the subject S to which the optical probe unit 10 is attached may be a region other than the human head, or even a region of a living body other than a human.

[0024] The optical probe unit 10 includes a pair of optical probes 1A and 1B and a holder 11. The optical probe 1A is a probe that emits light toward the subject S, and the optical probe 1B is a probe into which light is incident from the subject S. The holder 11 holds the pair of optical probes 1A and 1B. Specifically, the holder 11 holds the pair of optical probes 1A and 1B so that a predetermined distance is maintained between the pair of optical probes 1A and 1B and so that the light emission surface of the optical probe 1A and the light incidence surface of the optical probe 1B are in contact with the subject S. The holder 11 is, for example, a pad-like member that is elastic and flexible.

[0025] The device main body 110 includes a light source unit 111, a light detection unit 112, an optical characteristic determination unit 113, a calculation unit 114, and a control unit 115. The light source unit 111 is optically connected to the optical probe 1A via an optical fiber 121. The light detection unit 112 is optically connected to the optical probe 1B via an optical fiber 122.

[0026] The light source unit 111 emits light to be irradiated onto a predetermined portion of the subject S. The light source unit 111 is configured with a light-emitting element (e.g., a light-emitting diode, a laser diode, etc.). The light emitted from the light source unit 111 is guided from the light source unit 111 to the optical probe 1A by an optical fiber 121, and is irradiated onto a predetermined portion of the subject S from the optical probe 1A.

[0027] The photodetector 112 detects light emitted from a predetermined region of the subject S. The photodetector 112 is composed of a photodetector element (for example, a photomultiplier tube, a photodiode, an avalanche photodiode, a PIN photodiode, an MPPC (Multi-Pixel Photon Counter), etc.). The light emitted from the predetermined region of the subject S is guided from the optical probe 1A to the photodetector 112 by an optical fiber 122 and detected by the photodetector 112.

[0028] The optical characteristic determination unit 113 determines the optical characteristics at a predetermined site of the subject S based on the detection signal output from the light detection unit 112. The calculation unit 114 derives a measurement value at a predetermined site of the subject S based on the optical characteristic data output from the optical characteristic determination unit 113. The control unit 115 controls the light source unit 111, the light detection unit 112, the optical characteristic determination unit 113, and the calculation unit 114. As an example, in the optical measurement device 100, the optical characteristic determination unit 113 and the calculation unit 114 derive hemoglobin dynamics in the deep brain of the subject S. [Configuration of the Optical Probe]

[0029] As shown in FIGS. 2, 3, and 4, each of the optical probes 1A and 1B includes a light reflecting unit 2, a housing 3, a first biasing member 4, a second biasing member 5, and an adjustment unit 6. The optical probe 1A emits light incident from an end 121a of an optical fiber 121 along a first optical axis A1 toward a subject S along a second optical axis A2. The optical probe 1B emits light incident from the subject S along the second optical axis A2 toward an end 122a of an optical fiber 122 along the first optical axis A1. Since the optical probe 1B has the same configuration as the optical probe 1A, the following description will focus on the configuration of the optical probe 1A, and a description of the configuration of the optical probe 1B will be omitted. In the following description, a first direction parallel to the first optical axis A1 will be referred to as the X-axis direction, a second direction parallel to the second optical axis A2 will be referred to as the Z-axis direction, and a direction perpendicular to the first optical axis A1 and the second optical axis A2 will be referred to as the Y-axis direction. In this embodiment, the second optical axis A2 is perpendicular to the first optical axis A1, but it is sufficient that the second optical axis A2 intersects with the first optical axis A1.

[0030] The light reflecting section 2 includes a light transmitting member 21, a metal layer 22, and a protective layer 23. The light transmitting member 21 includes a support section 24, a reflecting section 25, and a pair of protrusions 26 and 27. The reflecting section 25 is disposed on one side of the support section 24 in the Z-axis direction. The pair of protrusions 26 and 27 are disposed on both sides of the support section 24 in the Y-axis direction. As an example, the support section 24, the reflecting section 25, and the pair of protrusions 26 and 27 are integrally formed from a transparent resin.

[0031] The support portion 24 has a plurality of surfaces 24a, 24b, 24c, 24d, and 24e. Surface 24a is a surface perpendicular to the X-axis direction and faces one side in the X-axis direction. Surface 24b is a surface perpendicular to the X-axis direction and faces the other side in the X-axis direction. Surface 24c is a surface perpendicular to the Y-axis direction and faces one side in the Y-axis direction. Surface 24d is a surface perpendicular to the Y-axis direction and faces the other side in the Y-axis direction. Surface 24e is a surface perpendicular to the Z-axis direction and is a surface perpendicular to the second optical axis A2.

[0032] The reflecting portion 25 has a plurality of surfaces 25a, 25b, 25c, and 25d. The surface 25a is a surface perpendicular to the X-axis direction and perpendicular to the first optical axis A1. The surface 25b is a surface parallel to the Y-axis direction and is a surface where the first optical axis A1 and the second optical axis A2 intersect in terms of the relationship between the angle of incidence and the angle of reflection. The surface 25c is a surface perpendicular to the Y-axis direction and faces one side in the Y-axis direction. The surface 25d is a surface perpendicular to the Y-axis direction and faces the other side in the Y-axis direction.

[0033] The protrusion 26 protrudes from the surface 24c of the support portion 24 with its height direction aligned in the Y-axis direction, and extends in the X-axis direction. The protrusion 27 protrudes from the surface 24d of the support portion 24 with its height direction aligned in the Y-axis direction, and extends in the X-axis direction.

[0034] The surface 24a of the support portion 24 and the surface 25a of the reflector 25 are located on the same plane. The surface 24c of the support portion 24 and the surface 25c of the reflector 25 are located on the same plane. The surface 24d of the support portion 24 and the surface 25d of the reflector 25 are located on the same plane.

[0035] The metal layer 22 is disposed on a surface 25b of the reflecting portion 25, which is the surface of the light transmitting member 21. In the light reflecting portion 2, the surface of the metal layer 22 facing the light transmitting member 21 is a reflecting surface 2a that reflects light incident along the first optical axis A1 along the second optical axis A2. The material of the metal layer 22 is, for example, aluminum, silver, vanadium, or gold. The thickness of the metal layer 22 is, for example, 0.7 μm or more and 0.8 μm or less. Note that in the optical probe 1B, the reflecting surface 2a reflects light incident along the second optical axis A2 along the first optical axis A1.

[0036] The protective layer 23 is disposed on the surface of the metal layer 22 opposite to the light transmitting member 21. In the light reflecting section 2, the surface of the protective layer 23 opposite to the metal layer 22 is the inclined surface 2b corresponding to the reflecting surface 2a. The material of the protective layer 23 is, for example, silicon monoxide (SiO). The thickness of the protective layer 23 is, for example, 1 nm or more and 0.1 μm or less. Note that the inclined surface 2b corresponding to the reflecting surface 2a means that the inclined surface 2b faces the reflecting surface 2a via at least one layer, or that the inclined surface 2b is the same surface as the reflecting surface 2a.

[0037] The housing 3 includes a plurality of walls 31, 32, 33, 34, and 35 and a pair of claws 36 and 37. The wall 31 is disposed on one side in the X-axis direction with respect to the space within the housing 3. The wall 31 has an inner surface 31a perpendicular to the X-axis direction. The wall 32 is disposed on the other side in the X-axis direction with respect to the space within the housing 3. The wall 32 has an inner surface 32a perpendicular to the X-axis direction. The wall 33 is disposed on one side in the Y-axis direction with respect to the space within the housing 3. The wall 33 has an inner surface 33a perpendicular to the Y-axis direction. The wall 34 is disposed on the other side in the Y-axis direction with respect to the space within the housing 3. The wall 34 has an inner surface 34a perpendicular to the Y-axis direction. The wall 35 is disposed on one side in the Z-axis direction with respect to the space within the housing 3. The wall 35 has an inner surface 35a perpendicular to the Z-axis direction. The pair of claws 36 and 37 face each other in the Y-axis direction. Each of the claws 36, 37 extends from the wall 31 to the side opposite the space within the housing 3. As an example, the multiple wall portions 31, 33, 34, 35 and the pair of claws 36, 37 are integrally formed from black resin, and the wall 32 is formed separately from them from black resin.

[0038] A groove 33b is formed in the wall 33. The groove 33b opens to the inner surface 33a with its depth direction aligned in the Y-axis direction and extends in the X-axis direction. A groove 34b is formed in the wall 34. The groove 34b opens to the inner surface 34a with its depth direction aligned in the Y-axis direction and extends in the X-axis direction. The light reflecting unit 2 is disposed within the housing 3, with the protrusion 26 disposed in the groove 33b and the protrusion 27 disposed in the groove 34b. The distance between the surface 24a of the support unit 24 and the surface 24b of the support unit 24 in the X-axis direction (i.e., the distance between the surface 25a of the reflecting unit 25 and the surface 24b of the support unit 24 in the X-axis direction) is smaller than the distance between the inner surface 31a of the wall 31 and the inner surface 32a of the wall 32 in the X-axis direction. The surface 24c of the support unit 24 and the surface 25c of the reflecting unit 25 are in contact with the inner surface 33a of the wall 33. The surface 24d of the support portion 24 and the surface 25d of the reflecting portion 25 are in contact with the inner surface 34a of the wall portion 34. This allows the light reflecting portion 2 to slide in the X-axis direction within the housing 3. In other words, the housing 3 accommodates the light reflecting portion 2 so that it can slide in the X-axis direction. The end faces of the walls 31, 32, 33, and 34 opposite the wall portion 35 and the surface 24e of the support portion 24 are located on the same plane.

[0039] A through hole 31b is formed in the wall portion 31. The through hole 31b penetrates the wall portion 31 with the first optical axis A1 as its center line. The through hole 31b faces the surface 25a of the reflecting portion 25 in the X-axis direction. The through hole 31b is located between the pair of claws 36, 37 when viewed from the X-axis direction. A portion of the end 121a of the optical fiber 121 is disposed within the through hole 31b. As a result, the end 121a of the optical fiber 121 faces the light reflecting portion 2 on the first optical axis A1. In this state, the end 121a of the optical fiber 121 is gripped by the pair of claws 36, 37. In other words, the housing 3 holds the end 121a of the optical fiber 121 so that it is located on the first optical axis A1 and faces the light reflecting portion 2 in the X-axis direction.

[0040] A bottomed hole 31c is formed in the wall portion 31. The bottomed hole 31c opens to the inner surface 31a of the wall portion 31, with its depth direction aligned in the X-axis direction. The bottomed hole 31c faces the surface 24a of the support portion 24 in the X-axis direction. A first biasing member 4 is disposed between the bottom surface of the bottomed hole 31c and the surface 24a of the support portion 24. The first biasing member 4 is a coil spring disposed in a compressed state between the bottom surface of the bottomed hole 31c and the surface 24a of the support portion 24.

[0041] A bottomed hole 32b is formed in the wall portion 32. The bottomed hole 32b opens to the inner surface 32a of the wall portion 32, with its depth direction aligned in the X-axis direction. The bottomed hole 32b faces the surface 24b of the support portion 24 in the X-axis direction. A second biasing member 5 is disposed between the bottom surface of the bottomed hole 32b and the surface 24b of the support portion 24. The second biasing member 5 is a coil spring disposed in a compressed state between the bottom surface of the bottomed hole 32b and the surface 24b of the support portion 24.

[0042] The first biasing member 4 biases the light reflecting portion 2 toward the X1 side (first side) in the X-axis direction of the housing 3. The second biasing member 5 biases the light reflecting portion 2 toward the X2 side (second side opposite to the first side) in the X-axis direction of the housing 3. The biasing force of the first biasing member 4 is greater than the biasing force of the second biasing member 5.

[0043] The adjustment unit 6 adjusts the position of the light reflection unit 2 in the X-axis direction by pressing the light reflection unit 2 toward the X2 side in the X-axis direction in the housing 3. In this embodiment, the adjustment unit 6 includes a pressing member 61 and a screw member 62.

[0044] The pressing member 61 has a pressing surface 61a. The pressing surface 61a is in contact with the inclined surface 2b of the light reflecting portion 2. More specifically, the pressing surface 61a is a surface parallel to the inclined surface 2b of the light reflecting portion 2 and is in surface contact with the inclined surface 2b of the light reflecting portion 2. The pressing member 61 further has multiple surfaces 61b, 61c, 61d, and 61e. The surface 61b is a surface perpendicular to the X-axis direction and is in contact with the inner surface 32a of the wall portion 32. The surface 61c is a surface perpendicular to the Y-axis direction and is in contact with the inner surface 33a of the wall portion 33. The surface 61d is a surface perpendicular to the Y-axis direction and is in contact with the inner surface 34a of the wall portion 34. The surface 61e is a surface perpendicular to the Z-axis direction and faces the inner surface 35a of the wall portion 35. As a result, the pressing member 61 is slidable in the Z-axis direction within the housing 3. That is, the housing 3 accommodates the pressing member 61 so as to be slidable in the Z-axis direction. As an example, the pressing member 61 is made of black resin.

[0045] A recess 61f is formed in the pressing member 61. The recess 61f opens to a surface 61e of the pressing member 61 with its depth in the Z-axis direction. A screw hole 35b is formed in the wall portion 35. The screw hole 35b penetrates the wall portion 35 along the Z-axis direction. The screw hole 35b faces the recess 61f in the Z-axis direction. A screw member 62 is threaded into the screw hole 35b and penetrates the wall portion 35 along the Z-axis direction. In other words, the screw member 62 is attached to the housing 3 so as to be able to advance and retreat along the Z-axis direction. One end 62a of the screw member 62 in the Z-axis direction is disposed within the recess 61f and contacts the pressing member 61. The other end 62b of the screw member 62 in the Z-axis direction is exposed to the outside of the housing 3. The other end 62b of the screw member 62 is configured as a rotation knob.

[0046] In the optical probe 1A configured as described above, when the other end 62b of the screw member 62 is rotated forward and the screw member 62 is advanced from the state shown in Fig. 3 to the state shown in Fig. 5, the pressing force of the screw member 62 causes the pressing member 61 to slide toward the side opposite the wall 35, and the inclined surface 2b of the light reflecting portion 2 is pressed by the pressing surface 61a of the pressing member 61, causing the light reflecting portion 2 to slide toward the X2 side. On the other hand, when the other end 62b of the screw member 62 is rotated backward and the screw member 62 is retreated from the state shown in Fig. 5 to the state shown in Fig. 3, the light reflecting portion 2 slides toward the X1 side due to the biasing force obtained by subtracting the biasing force of the second biasing member 5 from the biasing force of the first biasing member 4, and the pressing surface 61a of the pressing member 61 is pressed by the inclined surface 2b of the light reflecting portion 2, causing the pressing member 61 to slide toward the wall 35. In this way, in the optical probe 1A, the position of the light reflecting unit 2 in the X-axis direction (i.e., the position of the second optical axis A2) is adjusted by rotating the other end 62b of the screw member 62.

[0047] In the optical probe 1A (1B), the end 121a (122a) of the optical fiber 121 (122) faces the light reflecting unit 2 on the first optical axis A1, and the subject S faces the light reflecting unit 2 on the second optical axis A2. In this state, the first biasing member 4 biases the light reflecting unit 2, which is slidable in the X-axis direction, toward the X1 side in the X-axis direction. Conversely, the adjustment unit 6 presses the light reflecting unit 2, which is slidable in the X-axis direction, toward the X2 side in the X-axis direction, thereby making it possible to adjust the position of the light reflecting unit 2 in the X-axis direction. Therefore, it is possible to prevent, for example, hair or the like from becoming caught between the subject S and the light reflecting unit 2, and to ensure an optical path between the subject S and the light reflecting unit 2. Here, the sliding direction of the light reflecting unit 2, the biasing direction by the first biasing member 4, and the pressing direction by the adjustment unit 6 are all in the X-axis direction parallel to the first optical axis A1 and intersect with the direction parallel to the second optical axis A2 along which the subject S faces the light reflecting unit 2, so that it is possible to suppress the load acting on the subject S when adjusting the position of the light reflecting unit 2 in the X-axis direction. As described above, with the optical probe 1A (1B), it is possible to reliably secure an optical path between the subject S and the light reflecting unit 2 while suppressing the load acting on the subject S.

[0048] In particular, when the head of an infant is used as the subject S, the head is functionally and structurally immature. Furthermore, in order to minimize fluctuations in respiratory and circulatory dynamics, it is necessary to minimize the time that the optical probe unit 10 is attached to the subject S. In response to this, the optical probe 1A (1B) can reliably ensure an optical path between the subject S and the optical probe 1A (1B) while suppressing the load acting on the subject S, as described above.

[0049] In the optical probe 1A (1B), the light reflecting unit 2 has an inclined surface 2b corresponding to the reflecting surface 2a, the adjustment unit 6 includes a pressing member 61 having a pressing surface 61a in contact with the inclined surface 2b, and the housing 3 accommodates the pressing member 61 so as to be slidable in the Z-axis direction parallel to the second optical axis A2. By utilizing the inclined surface 2b of the light reflecting unit 2 corresponding to the reflecting surface 2a to adjust the position of the light reflecting unit 2 in the X-axis direction, the adjustment unit 6 can be easily and reliably operated from the side opposite the subject S in the Z-axis direction. Furthermore, since the adjustment unit 6 can be operated at a position away from the subject S, it is possible to prevent the tool or hand used to operate the adjustment unit 6 from coming into contact with the subject S.

[0050] In the optical probe 1A (1B), the adjustment unit 6 includes a screw member 62 attached to the housing 3 so as to be movable forward and backward along the Z-axis direction, with one end 62a of the screw member 62 in the Z-axis direction being in contact with the pressing member 61, and the other end 62b of the screw member 62 in the Z-axis direction being exposed to the outside of the housing 3. This makes it possible to more easily and reliably operate the adjustment unit 6 from the opposite side of the subject S in the Z-axis direction by accessing the other end 62b of the screw member 62 in the Z-axis direction.

[0051] In the optical probe 1A (1B), a recess 61f is formed in the pressing member 61, in which one end 62a of the screw member 62 is disposed. This makes it possible to suppress positional deviation of the one end 62a of the screw member 62 relative to the pressing member 61, and to accurately adjust the position of the light reflecting portion 2 in the X-axis direction.

[0052] In the optical probe 1A (1B), the light reflecting section 2 includes a metal layer 22 disposed on the surface of a light transmitting member 21, and the surface of the metal layer 22 facing the light transmitting member 21 serves as a reflecting surface 2a. This allows light incident along one of the first optical axis A1 and the second optical axis A2 to be reliably reflected along the other of the first optical axis A1 and the second optical axis A2.

[0053] In the optical probe 1A (1B), the light reflecting section 2 includes a protective layer 23 disposed on the surface of the metal layer 22 opposite to the light transmitting member 21, and the surface of the protective layer 23 opposite to the metal layer 22 is an inclined surface 2b. This makes it possible to suppress wear of the metal layer 22 and to achieve a desired contact state between the inclined surface 2b of the light reflecting section 2 and the pressing surface 61a of the pressing member 61.

[0054] In the optical probe 1A (1B), the second biasing member 5 biases the light reflecting portion 2 toward the X2 side in the X-axis direction in the housing 3. This allows the light reflecting portion 2 to slide smoothly and stably to a position determined by the adjustment portion 6 pressing the light reflecting portion 2 toward the X2 side in the X-axis direction.

[0055] In the optical probe 1A (1B), the biasing force of the first biasing member 4 is greater than the biasing force of the second biasing member 5. This allows the light reflecting portion 2 to slide more smoothly and stably to the position determined by the adjustment portion 6 pressing the light reflecting portion 2 toward the X2 side in the X-axis direction.

[0056] In the optical probe 1A (1B), the light reflecting unit 2 has a support portion 24 and a reflecting unit 25 aligned in the Z-axis direction, and the support portion 24 is biased toward the X1 side in the X-axis direction by the first biasing member 4. The inclined surface 2b provided on the surface 25a of the reflecting unit 25 is pressed toward the X2 side in the X-axis direction by the adjustment unit 6. The reflecting surface 2a provided on the surface 25a of the reflecting unit 25 guides light from one of the first optical axis A1 and the second optical axis A2 to the other of the first optical axis A1 and the second optical axis A2. Therefore, it is possible to simultaneously bias the light transmitting member 21 toward the X1 side and press it toward the X2 side, and guide light from one of the first optical axis A1 and the second optical axis A2 to the other of the first optical axis A1 and the second optical axis A2.

[0057] According to the optical probe unit 10, the optical probe 1A guides the light to be irradiated onto the subject S, and the optical probe 1B guides the light emitted from the subject S, thereby making it possible to reliably secure an optical path between the pair of optical probes 1A and 1B and the subject S while suppressing the load acting on the subject S. As a result, optical inspection of the subject S can be performed with high accuracy. [Modification]

[0058] The present disclosure is not limited to the above-described embodiment. In the above embodiment, the pressing member 61 is slidable in the Z-axis direction parallel to the second optical axis A2, but is not limited to this. For example, the pressing member 61 may be slidable in a direction inclined at an angle of 45 degrees or less with respect to the second optical axis A2. Even in such a case, the light reflecting unit 2 can slide in the X-axis direction by sliding the pressing member 61.

[0059] In the above embodiment, the inclined surface 2b faces the reflecting surface 2a via at least one layer, but this is not limited thereto. In the optical probe 1A (1B) of the first modified example, the light transmitting member 21 may have the reflecting surface 2a and the inclined surface 2b as the same surface. That is, it is sufficient that the inclined surface 2b of the light transmitting member 21 corresponds to the reflecting surface 2a. For example, the light transmitting member 21 may be a prism, and light incident along one of the first optical axis A1 and the second optical axis A2 may be refracted at the surface 25b of the reflecting unit 25 and reflected along the other of the first optical axis A1 and the second optical axis A2. Furthermore, the light reflecting unit 2 may not have the metal layer 22 and the protective layer 23, and the pressing surface 61a of the pressing member 61 may be in surface contact with the surface 25b of the reflecting unit 25 and press the light reflecting unit 2 toward the X2 side. According to the optical probe 1A (1B) of this first modified example, it is possible to realize, with a simple configuration, the reflection of light incident along one of the first optical axis A1 and the second optical axis A2 along the other of the first optical axis A1 and the second optical axis A2.

[0060] In the optical probe 1A (1B) of the first modified example, the pressing surface 61a of the adjustment unit 6 may be a rough surface. "The pressing surface 61a is a rough surface" means that the pressing surface 61a has a surface roughness of 20 μm or more. For example, the pressing surface 61a may have an arithmetic mean roughness Ra of 25 μm or more, or may be a so-called roughly finished surface. When the pressing surface 61a is a rough surface, for example, when the pressing surface 61a contacts the surface 25b of the reflecting unit 25, the surface 25b includes an interface with air. According to the optical probe 1A (1B) of the first modified example, a sufficient refractive index difference can be ensured on the surface 25b of the reflecting unit 25, so that light incident along one of the first optical axis A1 and the second optical axis A2 can be reliably reflected along the other of the first optical axis A1 and the second optical axis A2.

[0061] In the above embodiment, it is sufficient that the adjustment unit 6 presses the light reflecting unit 2 toward the X2 side in the X-axis direction to adjust the position of the light reflecting unit 2 in the X-axis direction. For example, in the optical probe 1A (1B) of the second modified example, the screw member 62 may be movable forward and backward in the X-axis direction, and one end 62a of the screw member 62 may be in contact with the surface 61b of the pressing member 61. In the optical probe 1A (1B) of the second modified example, when the other end 62b of the screw member 62 is rotated forward to advance the screw member 62, the pressing force of the screw member 62 causes the pressing member 61 to slide toward the X2 side, and the light reflecting unit 2 slides toward the X2 side, as in the above embodiment. On the other hand, when the other end 62b of the screw member 62 is rotated backward to retreat the screw member 62, the pressing member 61 slides toward the X1 side in the X-axis direction, as in the above embodiment.

[0062] Furthermore, for example, in the optical probe 1A (1B) of the third modified example, the adjustment unit 6 may include only a screw member attached to the housing 3 so as to be movable forward and backward along the X-axis direction. In this case, the optical probe 1A (1B) does not need to have the second biasing member 5, and, for example, the screw member may be attached to the wall portion 32. One end of the screw member in the X-axis direction may be in contact with the surface 24b of the support portion 24 of the light reflecting unit 2, and the other end of the screw member in the X-axis direction may be exposed to the outside of the housing 3. According to this optical probe 1A (1B) of the third modified example, it is possible to adjust the position of the light reflecting unit 2 in the X-axis direction with a simple configuration.

[0063] In the optical probe 1A (1B) of the third modified example, when the other end of the screw member is rotated forward and the screw member is advanced toward the X2 side in the X-axis direction, the pressing force of the screw member causes the one end of the screw member to press the surface 24b of the support portion 24, causing the light reflecting portion 2 to slide toward the X2 side. On the other hand, when the other end of the screw member is rotated backward and the screw member is retreated toward the X1 side in the X-axis direction, the biasing force of the first biasing member 4 causes the light reflecting portion 2 to slide toward the X1 side.

[0064] In the above embodiment and each modified example, it is only necessary that the position of the light reflecting unit 2 in the X-axis direction is adjustable, and therefore it is only necessary that the light reflecting unit 2 is pressed toward the X2 side in the X-axis direction by the adjustment unit 6 and is biased toward the X1 side in the X-axis direction by the first biasing member 4. Therefore, the optical probe 1A does not need to have the second biasing member 5.

[0065] In the above embodiment and each modified example, it is sufficient that one end 62a of the screw member 62 in the Z-axis direction is in contact with the pressing member 61. Therefore, the pressing member 61 does not need to be formed with the recess 61f.

[0066] In the above embodiment and each modified example, the screw member 62 may be any screw member that is attached to the housing 3 and that can advance and retreat in a predetermined direction. For example, the screw member 62 may be a set screw.

[0067] In the above embodiment and each modified example, the optical probe unit 10 has one optical probe 1A and one optical probe 1B, but it is sufficient if it has at least one optical probe 1A and at least one optical probe 1B.

[0068] In the optical probe unit 10, one of the pair of optical probes 1A, 1B may be arranged on a straight line including the first optical axis A1 of the other of the pair of optical probes 1A, 1B. In this case, by adjusting the position of the light reflecting part 2 in a direction parallel to the first optical axis A1 of the other optical probe, it is possible to adjust the distance between the second optical axis A2 of optical probe 1A and the second optical axis A2 of optical probe 1B according to the depth of the site whose optical characteristics are to be measured.

[0069] 1A, 1B...optical probe, 2...light reflecting portion, 2a...reflecting surface, 2b...inclined surface, 3...housing, 4...first biasing member, 5...second biasing member, 6...adjustment portion, 10...optical probe unit, 11...holder, 21...light transmitting member, 22...metal layer, 23...protective layer, 61...pressing member, 61a...pressing surface, 61f...recess, 62...screw member, 62a...one end portion, 62b...other end portion, 121, 122...optical fiber, 121a, 122a...end portion, A1...first optical axis, A2...second optical axis.

Claims

1. An optical probe comprising: a light reflecting portion having a reflective surface that reflects light incident along one of a first optical axis and a second optical axis that intersect with each other, along the other of the first optical axis and the second optical axis; a housing that contains the light reflecting portion so that it can slide in a first direction parallel to the first optical axis, and that holds an end of an optical fiber so that it is located on the first optical axis and faces the light reflecting portion in the first direction; a first biasing member that biases the light reflecting portion toward a first side in the first direction in the housing; and an adjustment portion that adjusts the position of the light reflecting portion in the first direction by pressing the light reflecting portion toward a second side in the housing opposite the first side in the first direction.

2. An optical probe as described in claim 1, wherein the light reflecting portion has an inclined surface corresponding to the reflecting surface, the adjustment portion includes a pressing member having a pressing surface in contact with the inclined surface, and the housing accommodates the pressing member so as to be slidable in a second direction parallel to the second optical axis.

3. The optical probe described in claim 2, wherein the adjustment section further includes a screw member attached to the housing so as to be movable back and forth along the second direction, one end of the screw member in the second direction is in contact with the pressing member, and the other end of the screw member in the second direction is exposed outside the housing.

4. The optical probe according to claim 3, wherein said pressing member is formed with a recess in which said one end of said screw member is disposed.

5. An optical probe according to any one of claims 2 to 4, wherein the light reflecting portion includes a light-transmitting member and a metal layer arranged on a surface of the light-transmitting member, and the reflecting surface is a surface of the metal layer facing the light-transmitting member.

6. The optical probe according to claim 5, wherein the light reflecting portion further includes a protective layer disposed on a surface of the metal layer opposite the light transmitting member, and the inclined surface is the surface of the protective layer opposite the metal layer.

7. An optical probe according to any one of claims 2 to 4, wherein the light reflecting portion includes a light transmitting member, and the light transmitting member has the reflecting surface and the inclined surface as the same surface.

8. The optical probe of claim 7, wherein the pressing surface is a rough surface.

9. An optical probe according to any one of claims 1 to 8, further comprising a second biasing member biasing the light reflecting portion toward the second side in the first direction in the housing.

10. The optical probe of claim 9, wherein the biasing force of the first biasing member is greater than the biasing force of the second biasing member.

11. The optical probe described in claim 1, wherein the adjustment portion further includes a screw member attached to the housing so as to be movable back and forth along the first direction, one end of the screw member in the first direction is in contact with the light reflecting portion, and the other end of the screw member in the first direction is exposed outside the housing.

12. An optical probe unit comprising: a plurality of optical probes, each of which is an optical probe according to any one of claims 1 to 11; and a holder for holding the plurality of optical probes.

Images