JP2017018483A - Medical probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical probe which can measure a dynamic component of a blood flow or the like inside a biological tissue without hiding a surface of the biological tissue.SOLUTION: A medical probe 2 includes: a first transmission channel 8 which transmits laser beams P, Q emitted to a biological tissue A and emits from an emission end 8a; a second transmission channel 9 which receives scattering light from the biological tissue A including information on a dynamic component in the biological tissue A at an incident end 9a and transmits the light; an optical element 10 which refracts the laser beams P, Q emitted from the emission end 8a to emit the refracted laser beams to the biological tissue A, condenses the scattering light R from the biological tissue A to allow the incident end 9a to receive condensed light, and has positive power as a whole; and a separation element 11 which separates the scattering light R returning from the biological tissue A along an optical path of the laser beams P, Q refracted by the optical element 10 from the optical path of the laser beams P, Q to make the separated scattering light be incident on the incident end 9a.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a medical probe.

  Conventionally, a laser that irradiates a living body with laser light through an emitted light propagation fiber, detects scattered light from the living body with a photodiode through the scattered light propagation fiber, and measures blood flow by frequency analysis of interference components of scattered light by Doppler shift A blood flow meter is known (for example, refer to Patent Document 1).

JP 2008-278983 A

  However, the laser blood flow meter of Patent Document 1 is a method in which the sensor head is in close contact with the surface of the living body, and during the measurement of blood flow, the living body is hidden by the sensor head, and a blood vessel with a large blood flow is formed. Even if it is discovered, there is an inconvenience that the operator cannot visually recognize the position of the blood vessel.

  The present invention has been made in view of the above-described circumstances, and provides a medical probe capable of measuring dynamic components such as blood flow in a living tissue without hiding the surface of the living tissue. It is aimed.

In order to achieve the above object, the present invention provides the following means.
According to one embodiment of the present invention, a first transmission path that transmits laser light to be irradiated onto a living tissue and emits the laser light from an emission end, and scattered light from the living tissue that includes information on dynamic components in the living tissue. A second transmission path that receives and transmits light at the incident end, irradiates the living tissue by refracting the laser light emitted from the emitting end, and collects scattered light from the living tissue to collect the scattered light. An optical element having positive power as a whole that is received at the incident end, and a separating element that separates scattered light returning from the living tissue along the optical path of the laser light from the optical path of the laser light and enters the incident end A medical probe comprising:

  According to this aspect, the laser beam emitted from the exit end of the first transmission path is refracted by the optical element having positive power, so that the light flux having a smaller diffusion angle than the state emitted from the exit end It is irradiated to the living tissue. The laser light incident on the living tissue is scattered on the surface and inside of the living tissue, becomes scattered light, is collected by an optical element having a positive power, and is received by the incident end of the second transmission path. Since the received scattered light includes information on the dynamic component in the living tissue, it is possible to measure fluctuations in the living body by frequency analysis of the interference component of the scattered light due to Doppler shift.

In this case, since the diffusion angle of the laser beam is reduced by the optical element having a positive power, it is possible to irradiate the living tissue with the laser light having a high light density even if the optical element is separated from the living tissue. The intensity of the scattered light received by the incident end can be improved to improve the SN ratio, and the dynamic component in the living tissue can be accurately measured.
Moreover, since the scattered light returning along the optical path of the laser beam is separated from the optical path of the laser beam by the separating element and is incident on the incident end, the laser beam is irradiated regardless of the distance from the medical probe to the living tissue. Scattered light with high intensity from the region of the living tissue can be detected, and detection sensitivity can be improved.

In the above aspect, the separation element may be a prism including a partial reflection unit that reflects at least part of the scattered light in a region through which the laser light emitted from the emission end is transmitted.
In this way, when the laser light is incident on the partial reflection portion of the prism, the laser light is transmitted through the partial reflection portion and irradiated onto the living tissue. On the other hand, when the scattered light returning from the vicinity of the irradiation position of the laser light in the living tissue along the optical path of the laser light enters the partial reflection portion of the prism, at least a part of the scattered light is reflected and separated from the optical path of the laser light. Thereby, the dynamic component in a biological tissue can be accurately measured with a simple configuration.

  In the above aspect, the prism includes a first incident surface on which the laser light is incident and a second incident surface on which the scattered light is incident, and these incident surfaces are the laser. A parallel flat plate made of a transparent material, which is disposed with an inclination with respect to the principal ray of light and the luminous flux of the scattered light, and the partial reflection portion is provided in the laser light incident area of the first incident surface. The scattered light that is provided and is transmitted through the second incident surface and reflected by the partial reflecting portion is incident on the second incident surface again from the inside to reflect the scattered light that has entered the first incident surface. A reflective region that exits from the incident surface may be provided.

  By doing in this way, the laser beam that has entered and transmitted through the first incident surface of the prism also passes through the second incident surface and is irradiated onto the living tissue. Scattered light returning from the laser light irradiation position in the living tissue along the optical path of the laser light is incident on and transmitted through the second incident surface of the prism, and then provided in the laser light incident region of the first incident surface. A part of the reflected light is reflected from the optical path of the laser beam.

  Since the first incident surface is arranged so as to be inclined with respect to the principal ray of the scattered light flux, when the first incident surface is reflected by the partial reflection portion of the first incident surface, the first incident surface is deflected in a direction according to the inclination angle. Re-enters a different region of the incident surface. Since this region is provided with a reflection region, the scattered light is reflected and emitted from the first incident surface to the outside of the prism and is incident on the incident end of the second transmission path. Thereby, the exit end of the first transmission path and the incident end of the second transmission path can be arranged to face the first incident surface side of the prism, and the configuration can be simplified.

In the above aspect, the separation element may be a prism including a partial reflection portion that transmits at least part of the scattered light in a region that reflects the laser light emitted from the emission end.
In this way, when the laser light is incident on the partial reflection portion of the prism, the laser light is reflected by the partial reflection portion and irradiated onto the living tissue. On the other hand, when the scattered light returning from the vicinity of the irradiation position of the laser light in the living tissue along the optical path of the laser light is incident on the partial reflection portion of the prism, at least a part of the scattered light is transmitted and separated from the optical path of the laser light. Thereby, the dynamic component in a biological tissue can be accurately measured with a simple configuration.

  In the above aspect, the prism includes a first incident surface on which the laser light is incident and a second incident surface on which the scattered light is incident, and these incident surfaces are the laser. A parallel flat plate made of a transparent material and inclined with respect to the principal ray of the light beam and the scattered light beam, and the laser light transmitted through the first incident surface is incident on the second incident surface A reflection region for reflecting the laser light is provided in a region incident from the inside, and the partial reflection portion is provided in a region where the laser light reflected in the reflection region is incident on the first incident surface again from the inside. The partial reflection portion may be partially disposed in a part of the region that transmits the scattered light.

  By doing in this way, the laser beam which has entered and transmitted through the first incident surface of the prism is reflected in the reflection region provided on the second incident surface. Since the second incident surface is inclined with respect to the principal ray of the laser light beam, when reflected by the reflection region of the second incident surface, the second incident surface is deflected in a direction according to the inclination angle, and the first incident surface is reflected. Re-enter the different areas of the surface. Since the partial reflection portion is provided in this region, the laser light is reflected by the partial reflection portion, is emitted from the second incident surface to the outside of the prism, and is irradiated onto the living tissue.

  On the other hand, the scattered light returning from the irradiation position of the laser beam in the living tissue along the optical path of the laser beam is incident on the second incident surface of the prism and transmitted therethrough, and then enters the incident region of the laser beam on the first incident surface. The light incident on a wide range including the provided partial reflection portion and transmitted through the region excluding the partial reflection portion is separated from the optical path of the laser light. Thereby, the exit end of the first transmission path and the incident end of the second transmission path can be arranged to face the first incident surface side of the prism, and the configuration can be simplified.

Moreover, in the said aspect, it is preferable that the numerical aperture of a said 2nd transmission line is larger than the numerical aperture of a said 1st transmission line.
By doing so, the scattered light beam that can be received is larger than the laser light beam, and a sufficient amount of scattered light can be captured.

Moreover, in the said aspect, the said output end may be arrange | positioned in the focal distance vicinity of the said optical element, and the said incident end may be arrange | positioned in the position away from this optical element rather than the focal distance of the said optical element.
By doing so, the scattered light incident on the incident end becomes a light beam that converges larger than the light beam of the laser light from the optical element toward the living tissue on the side of the living tissue. As a result, while ensuring a large amount of scattered light that passes around the partially reflecting part that reflects the laser light, the overlapping of the laser light beam and the scattered light beam in the living tissue is increased to efficiently detect the scattered light. can do.

Moreover, in the said aspect, a half mirror may be sufficient as the said partial reflection part.
By doing so, the laser light and scattered light incident on the partial reflection portion are partially transmitted and partially reflected according to the reflectance of the half mirror, so that the scattered light can be easily separated from the optical path of the laser light. can do.

Further, in the above aspect, the partial reflection unit may be a polarization beam splitter that transmits the laser light having a predetermined polarization.
In this way, by setting the polarization direction of the polarization beam splitter constituting the partial reflection unit according to the polarization direction of the laser light transmitted through the first transmission path, the laser in the partial polarization unit is set. Light loss can be reduced and the SN ratio can be improved.

In the above aspect, the surface of the optical element disposed at a position where the light beam of the laser light and the light beam of the scattered light overlap with each other is inclined with respect to the principal ray of the laser light beam. Also good.
By doing in this way, it can prevent that the laser beam reflected in the surface of the optical element mixes with the light beam of scattered light, and injects into an incident end, and can improve S / N ratio.

In the above aspect, the surface of the separation element disposed at a position where the light beam of the laser light and the light beam of the scattered light overlap with each other is inclined with respect to the principal ray of the laser light beam. Also good.
By doing in this way, it can prevent that the laser beam reflected in the surface of the isolation | separation element mixes with the light beam of scattered light, and injects into an incident end, and can improve S / N ratio.

  According to the present invention, it is possible to measure a dynamic component such as a blood flow in a living tissue without hiding the surface of the living tissue.

It is a typical whole block diagram which shows a measurement system provided with the medical probe which concerns on one Embodiment of this invention. It is a figure which shows the positional relationship of the front-end | tip part of the medical probe of FIG. 1, and the light beam of a 1st laser beam and scattered light. It is a figure which shows the modification at the time of using it instead of the condensing lens of the medical probe of FIG. FIG. 4 is an enlarged view showing a modification of the medical probe of FIG. 2 and showing the medical probe in which each surface of the prism and the condenser lens is inclined. FIG. 4 is an enlarged view showing a modification of the medical probe of FIG. 3 and showing the medical probe in which each surface of the prism and the green lens is inclined. It is a modification of the medical probe of FIG. 2, Comprising: It is an enlarged view which shows a medical probe provided with the prism which has a parallelogram longitudinal cross-section. It is a top view of (a) 1st surface and (b) 2nd surface of the prism of the medical probe of FIG. It is a modification of the medical probe of FIG. 6, Comprising: It is an enlarged view which shows the medical probe which replaced the prism and the condensing lens. It is a top view of (a) 1st surface and (b) 2nd surface of the prism of the medical probe of FIG. FIG. 7 is a modified example of the medical probe of FIG. 6, and is an enlarged view showing a medical probe in which an illumination optical fiber and a detection optical fiber are interchanged. It is a top view of (a) 1st surface and (b) 2nd surface of the prism of the medical probe of FIG. FIG. 11 is a diagram showing a modification of the medical probe of FIG. 10 and showing the medical probe in which the incident end of the detection optical fiber is larger than the focal length of the condensing lens and separated from the condensing lens. It is a figure which shows the light beam of the 1st laser beam in the medical probe of FIG. 12 by hatching. In the medical probe of FIG. 12, it is a figure which shows the light beam of the scattered light which injects into the incident end of a detection optical fiber by hatching.

A medical probe 2 according to an embodiment of the present invention will be described below with reference to the drawings.
The medical probe 2 according to this embodiment is provided in the measurement system 1 shown in FIG.
The measurement system 1 includes a medical probe 2 according to the present embodiment, a measurement light source 3 that generates a first laser beam P supplied to the medical probe 2, and a display that generates a second laser beam Q. The light source 4, the light detector 5 that detects the scattered light R received by the medical probe 2, and the intensity information of the scattered light R detected by the light detector 5 are processed to determine the presence or absence of the blood vessel B. And a processor 6.

The first laser beam P is a laser beam having a near-infrared or infrared wavelength with a high degree of advancement to the living tissue A.
The second laser light Q is a laser light having a visible wavelength band. Since the biological tissue A is red, in order to improve visibility, the second laser light Q is preferably a laser light having a green or blue wavelength band.

The photodetector 5 is, for example, a photodiode, and outputs a signal having an intensity corresponding to the amount of scattered light R.
The processor 6 obtains a frequency characteristic by performing a fast Fourier transform process on the signal output from the photodetector 5, analyzes the frequency characteristic, determines the presence or absence of the thick blood vessel B, and determines that the thick blood vessel B exists. In such a case, the display light source 4 is activated to supply the second laser light Q to the medical probe 2. In the figure, reference numeral 7 denotes an optical coupler that causes the second laser light Q from the display light source 4 to enter the illumination optical fiber 8 that propagates the first laser light P.

  As shown in FIG. 2, the medical probe 2 according to this embodiment includes an illumination optical fiber (first transmission path) 8 that is connected to the measurement light source 3 and propagates the first laser light P, and light. A detection optical fiber (second transmission path) 9 that is connected to the detector 5 and propagates the scattered light R from the living tissue A, an emission end 8a of the illumination optical fiber 8, and an incidence end 9a of the detection optical fiber 9 Are provided with a condensing lens (optical element) 10 having a positive power and a prism (separating element) 11 arranged at a distance from each other.

  The illumination optical fiber 8 includes an exit end 8a orthogonal to the longitudinal axis. The first laser beam P or the second laser beam Q transmitted from the measurement light source 3 or the display light source 4 is emitted from the emission end 8a with a diffusion angle of a predetermined numerical aperture. Yes.

  Further, the detection optical fiber 9 includes an incident end 9a orthogonal to the longitudinal axis. Of the scattered light R from the living tissue A, the scattered light R collected by the condenser lens 10 is incident on the incident end 9a at a convergence angle of a predetermined numerical aperture, and is transmitted through the detection optical fiber 9. It is propagated to the detector 5.

  The prism 11 is configured in a substantially L shape by joining a first prism 12 having a parallelogram-shaped vertical section and a second prism 13 having a trapezoidal vertical section. The joining surface 14 is provided with a half mirror (partial reflection portion) 14a. The first prism 12 and the second prism 13 are made of an optically transparent material having the same refractive index, for example, glass.

The incident surface 13a of the second prism 13 is arranged in close proximity to the exit end 8a of the illumination optical fiber 8, and is emitted from the exit end 8a and incident in a direction perpendicular to the entrance surface 13a. Q is incident with less refraction.
In addition, the exit surface 12a of the first prism 12 is disposed in close proximity to the incident end 9a of the detection optical fiber 9, and is scattered light R emitted from the exit surface 12a in a direction orthogonal to the exit surface 12a. Is emitted with less refraction. The first prism 12 includes an inclined surface 12b that is parallel to the bonding surface 14 and that forms an angle of 45 ° with respect to the exit surface 12a. The inclined surface 12b reflects the scattered light R.

In the present embodiment, the condenser lens 10 is disposed at a position separated from the exit end 8a of the illumination optical fiber 8 and the entrance end 9a of the detection optical fiber 9 by the focal length of the condenser lens 10 in terms of air. ing. As a result, the laser beams P and Q emitted from the exit end 8a of the illumination optical fiber 8 pass through the prism 11 and are refracted by the condenser lens 10 to become a substantially parallel light beam and irradiate the living tissue A. It has come to be.
On the other hand, only the scattered light R from the living tissue A that forms a substantially parallel light beam along the same optical path as the laser beams P and Q and enters the condenser lens 10 is detected light via the prism 11. The light enters the incident end 9 a of the fiber 9.

The operation of the medical probe 2 according to this embodiment configured as described above will be described below.
In order to measure the blood vessel B existing in the living tissue A using the medical probe 2 according to the present embodiment, the medical probe 2 is inserted into the patient's body as shown in FIG. The part is arranged to face the surface of the biological tissue A to be measured with a space therebetween.
At this time, the surface of the living tissue A in the vicinity of the region facing the medical probe 2 is photographed by an endoscope (not shown) separately inserted into the body and displayed on a monitor (not shown).

  In this state, the measurement light source 3 is operated to generate the first laser beam P. The first laser light P generated in the measurement light source 3 is propagated through the illumination optical fiber 8 connected to the measurement light source 3 to the vicinity of the distal end portion of the medical probe 2. The first laser light P propagated by the illumination optical fiber 8 is emitted from the exit end 8a of the illumination optical fiber 8, and the portion that has passed through the prism 11 is refracted by the condenser lens 10 having positive power. The living tissue A is irradiated in a state of being substantially parallel light.

  The first laser light P irradiated on the living tissue A is scattered on the surface and inside of the living tissue A, and the scattered light R collected by the condenser lens 10 passes through the prism 11 and is a detection optical fiber. 9 is incident on the incident end 9 a, propagated by the detection optical fiber 9, and detected by the photodetector 5. From the photodetector 5, a signal corresponding to the intensity of the detected scattered light R is output. The output signal is subjected to fast Fourier transform in the processor 6 to obtain frequency characteristics.

  When a large blood vessel B is present in the living tissue A, the scattered light R includes dynamic information of blood flow, so that the average frequency included in the scattered light R increases due to Doppler shift. The frequency characteristics change. The processor 6 determines that a large blood vessel B exists when the average frequency is higher than a predetermined threshold value, and causes the display light source 4 to emit the second laser light Q.

  The second laser light Q emitted from the display light source 4 is incident on the illumination optical fiber 8 by the optical coupler 7 and is irradiated toward the living tissue A from the emission end 8a. Since the second laser light Q is visible laser light that can be visually recognized by the operator, the operator can recognize the presence of the internal blood vessel B by a color change on the surface of the biological tissue A displayed on the monitor. it can.

  In this case, according to the medical probe 2 according to the present embodiment, the condensing lens 10 having a positive power for the first laser light P diffusing from the emission end 8a of the illumination optical fiber 8 with a predetermined numerical aperture. Therefore, even when the interval from the medical probe 2 to the living tissue A is wide, the living tissue A can be irradiated without reducing the light density of the first laser beam P, and the intensity of the first laser beam P is increased. Scattered light R can be generated.

  By irradiating the biological tissue A with the first laser light P, the scattered light R scattered in the biological tissue A, in particular, the scattered light R that travels to the inside of the biological tissue A and scatters the first laser light P. The intensity is highest in the vicinity of the irradiation region. In the present embodiment, the scattered light R collected by the condenser lens 10 and incident on the front end surface 12c of the first prism 12 via the same optical path as the light beam of the first laser beam P is joined to the bonding surface 14. Is partially reflected and deflected by 90 °, reflected by the inclined surface 12b, further deflected by 90 °, emitted from the exit surface 12a of the first prism 12, and incident on the incident end 9a of the detection optical fiber 9.

As a result, of the scattered light R from the living tissue A, the scattered light R that returns along a path substantially equivalent to the light beam of the first laser light P can be incident on the incident end 9a.
That is, according to the medical probe 2 according to the present embodiment, the scattered light R that returns along the same path as the first laser beam P by the half mirror 14 a provided on the joint surface 14 of the two prisms 12 and 13. Is separated from the optical path of the first laser beam P, so that the principal ray of the light beam of the first laser beam P emitted from the emission end 8a and the incident end 9a are incident on the living tissue A side from the condenser lens 10. The principal ray of the scattered light beam R can be made substantially coincident.

Thereby, the irradiation region in the living tissue A of the first laser beam P and the generation region of the scattered light R having high intensity that can be incident on the incident end 9a are overlapped over a wide range at each position in the optical axis direction. Can be made.
As a result, even if the interval between the living tissue A and the medical probe 2 is changed, it is possible to continue to detect the scattered light R having a relatively large intensity, and to improve the SN ratio and perform highly accurate measurement. There is an advantage. Since it is not necessary to set the distance of the medical probe 2 with respect to the living tissue A strictly, usability can be improved.

  In the present embodiment, the half mirror 14a is formed as the partial reflection portion. Instead, a polarization maintaining fiber is used as the illumination optical fiber 8, and a polarization beam splitter is formed as the partial reflection portion. It may be. In this case, the polarization beam splitter transmits the first laser light P and the second laser light Q having the predetermined polarization transmitted through the illumination optical fiber 8 and reflects the light having other polarization directions. It has properties. Thereby, compared with the case of the half mirror 14a, a part of the scattered light R is lost through the polarization beam splitter, but the intensity of the first laser light P irradiated to the living tissue A can be increased. There is an advantage that the SN ratio can be improved.

  In the present embodiment, instead of the condenser lens 10, as shown in FIG. 3, a green lens (optical element) 15 having a positive power may be employed. Thereby, it is not necessary to provide a space between the prism 11 and the green lens 15, and a compact configuration can be achieved.

  Further, in the present embodiment, as shown in FIGS. 2 and 3, the main light beams of the laser beams P and Q are applied to the front end surface 12 c of the prism 11 and the front end surfaces 10 a and 15 a of the condenser lens 10 or the grin lens 15. Although an example having a plane orthogonal to the light beam is illustrated, instead of this, as shown in FIGS. 4 and 5, the front end surface 12 c of the prism 11 and the front end surfaces 10 a and 15 a of the condenser lens 10 or the green lens 15 are used. May be tilted with respect to the principal rays of the light beams of the laser beams P and Q. Moreover, about the condensing lens 10, you may decenter the incident position of the laser beams P and Q. FIG.

  The laser beams P and Q incident on the front end surface 12c of the prism 11, the curved surface 10b of the condensing lens 10 and the front end surface 10a of the condensing lens 10 are partially reflected and returned, but these surfaces are inclined, Alternatively, by decentering the condenser lens 10, the laser beams P and Q can be reflected in a direction different from the optical path of the scattered light R. That is, a part of the laser beams P and Q incident on the curved surface 10b of the condensing lens 10 and the front end surface 10a of the condensing lens 10 is reflected on these surfaces and returns to the same optical path as the scattered light R. There is an advantage that it is possible to prevent the light from being detected by being mixed with the scattered light R.

Moreover, in the medical probe 2 according to the present embodiment, the substantially L-shaped prism 11 in which the two prisms 12 and 13 are combined is provided, but instead, as shown in FIG. You may decide to employ | adopt the prism (separation element) 16 which consists of a single parallel flat plate which has a parallelogram longitudinal cross section.
In this case, the two parallel planes 16a and 16b of the prism 16 are inclined and arranged with respect to the longitudinal axes of the illumination optical fiber 8 and the detection optical fiber 9 arranged substantially in parallel.

  As shown in FIG. 7A, the first laser beam P is incident on the first surface (first incident surface) 16a of the prism 16 on which the first laser beam P emitted from the emission end 8a is incident. Is applied to the range including the region where the scattered light R is incident from the outside (the hatched range in the figure), and a half mirror (partial reflection portion) 16c is formed. Further, the range includes a region in which the scattered light R incident on the second surface 16b of the prism 16 is reflected by the half mirror 16c on the first surface 16a and reenters the second surface (second incident surface) 16b from the inside. As shown in FIG. 7B, a reflective surface 16d that reflects the scattered light R is formed in (the hatched range in the figure). The half mirror 16c is provided in a region that does not overlap with a region where the scattered light R is emitted. The reflection surface 16d is also formed at a position that does not overlap with the region through which the first laser light P and scattered light R are transmitted.

  In this case, the exit end 8a of the illumination optical fiber 8 and the entrance end 9a of the detection optical fiber 9 are arranged at positions away from the condenser lens 10 by the focal length of the condenser lens 10 in terms of air. ing. As a result, the first laser beam P emitted from the exit end 8a of the illumination optical fiber 8 passes through the prism 16 and is refracted by the condenser lens 10 to become substantially parallel light and irradiate the living tissue A. It has come to be. On the other hand, the scattered light R generated in the living tissue A returns as a light beam equivalent to the light beam of the first laser light P, and is collected by the condenser lens 10 and transmitted through the prism 16 to detect light. The light enters the incident end 9 a of the fiber 9.

  With this configuration, the same effect can be obtained using a simple parallel plate prism 16. Since the second surface 16b is inclined, it is possible to suppress the first laser light P from being mixed with the scattered light R and returning.

  Further, in the present embodiment, the case where the prism 16 is disposed between the illumination optical fiber 8 and the detection optical fiber 9 and the condenser lens 10 has been described. However, as shown in FIG. 10 and prism 16 may be interchanged. The first laser beam P that has become substantially parallel light by the condenser lens 10 and the scattered light R that is substantially parallel light that is refracted by the condenser lens 10 and incident on the incident end 9a is converted into a prism in the state of substantially parallel light. The same effect can be obtained by transmitting or reflecting the light in the 16. The half mirror 16c and the reflecting surface 16d in this case are as shown in FIGS. 9 (a) and 9 (b).

  Further, as shown in FIGS. 10 and 11A and 11B, the positions of the illumination optical fiber 8 and the detection optical fiber 9 with respect to the prism 16 may be switched. In this case, it is preferable that the numerical aperture of the detection optical fiber 9 be smaller than the numerical aperture of the illumination optical fiber 8.

  That is, in the example shown in FIG. 10, when the first laser light P emitted from the emission end 8a of the illumination optical fiber 8 passes through the first surface 16a and enters the second surface 16b from the inside, The light is reflected on the surface 16b and is incident on the first surface 16a again. As shown in FIGS. 11A and 11B, a reflecting surface (hatched range in the figure) 16e coated in the shape of the incident light beam is formed in the incident area of the first surface 16a. As a result, all of the first laser light P can be reflected and transmitted through the second surface 16b, and the living tissue A can be irradiated by the condenser lens 10.

  On the other hand, the scattered light R that has entered the second surface 16b cannot pass through the reflecting surface 16e of the first surface 16a, but the light that has passed through the surrounding area enters the incident end 9a of the optical fiber 9 for detection. The area of the doughnut-shaped region surrounding the reflecting surface 16e can be easily made larger than the region of the reflecting surface 16e, and a sufficient amount of scattered light R can be detected.

  Further, instead of or in addition to making the numerical aperture of the detection optical fiber 9 larger than the numerical aperture of the illumination optical fiber 8, as shown in FIGS. The position of the incident end 9a may be shifted from the condenser lens 10 in a direction away from the focal distance of the condenser lens 10 in terms of air. In this case, the position of the exit end 8 a of the illumination optical fiber 8 is arranged at a position away from the condenser lens 10 by the focal length of the condenser lens 10. By doing in this way, the form of the light beam of the scattered light R which injects into the incident end 9a can be made into the form which constricts toward the biological tissue A from the condensing lens 10. FIG.

  In other words, the first laser light P emitted from the emission end 8a of the illumination optical fiber 8 is made substantially parallel light by the condenser lens 10 and irradiated onto the living tissue A as shown by hatching in FIG. Therefore, even if the position of the living tissue A with respect to the condensing lens 10 changes, the range in which the first laser beam P is irradiated does not vary greatly, and the first laser beam P with a high light density is applied to the living tissue A. Can be irradiated.

  On the other hand, the light flux of the scattered light R returning from the biological tissue A is provided on the first surface 16a because it is constricted from the condenser lens 10 toward the biological tissue A as shown by hatching in FIG. The central portion of the light beam of the scattered light R is blocked by the reflected surface 16e, but the overlap between the light beam of the laser light P and the light beam of the scattered light R in the living tissue A is increased to detect the scattered light R efficiently. can do. That is, there is an advantage that it is possible to detect the scattered light R with high intensity returning from the region of the living tissue A irradiated with the first laser light P, and to improve the measurement sensitivity.

Moreover, in this embodiment, although the example which employ | adopted the single condensing lens 10 as an optical element which has a positive power was shown, it replaces with this and is equipped with a some lens and the positive power as a whole is shown. You may employ | adopt the lens group which will have.
In the present embodiment, the first laser light P is refracted into substantially parallel light by the condenser lens 10, but instead, the first laser light P emitted from the emission end 8a is changed. You may decide to condense into the light which diffuses with the diffusion angle smaller than a diffusion angle, or the convergent light near parallel light.

2 Medical probe 8 Optical fiber for illumination (first transmission line)
9 Optical fiber for detection (second transmission line)
10 Condensing lens (optical element)
11 Prism (separation element)
15 Green lens (optical element)
16 Prism (separation element, parallel plate)
16a 1st incident surface 16b 2nd incident surface 16c Half mirror (partial reflection part)
A biological tissue P laser light R scattered light

Claims (11)

A first transmission path for transmitting a laser beam for irradiating a living tissue and emitting it from the exit end;
A second transmission path for receiving and transmitting scattered light from the living tissue containing dynamic component information in the living tissue at an incident end;
An optical element having a positive power as a whole, which refracts the laser light emitted from the exit end to irradiate the living tissue and collects scattered light from the living tissue and causes the incident end to receive the light. When,
A medical probe comprising: a separation element that separates scattered light returning from the biological tissue along the optical path of the laser light from the optical path of the laser light and enters the incident end.   The medical probe according to claim 1, wherein the separation element is a prism including a partial reflection portion that reflects at least a part of the scattered light in a region that transmits the laser light emitted from the emission end. The prism includes a first incident surface on which the laser light is incident and a second incident surface on which the scattered light is incident, and the incident surfaces are light fluxes of the laser light and the scattered light. Is a parallel plate made of a transparent material, inclined with respect to the principal ray of
The partial reflection portion is provided in an incident region of the laser light on the first incident surface,
The scattered light that has been transmitted through the second incident surface and reflected by the partial reflection portion is incident on the second incident surface again from the inside to reflect the scattered light that has entered the first incident surface. The medical probe according to claim 2, wherein a reflection region to be emitted from is provided.   The medical probe according to claim 1, wherein the separation element is a prism including a partial reflection portion that transmits at least part of the scattered light in a region that reflects the laser light emitted from the emission end. The prism includes a first incident surface on which the laser light is incident and a second incident surface on which the scattered light is incident, and the incident surfaces are light fluxes of the laser light and the scattered light. Is a parallel plate made of a transparent material, inclined with respect to the principal ray of
A reflection region for reflecting the laser beam is provided in a region where the laser beam transmitted through the first incident surface is incident on the second incident surface from the inside;
The partial reflection portion is provided in a region where the laser light reflected in the reflection region is incident on the first incident surface again from the inside;
The medical probe according to claim 4, wherein the partial reflection portion is partially arranged in a part of a region through which the scattered light is transmitted.   The medical probe according to claim 5, wherein a numerical aperture of the second transmission path is larger than a numerical aperture of the first transmission path. The exit end is disposed near the focal length of the optical element;
The medical probe according to claim 5 or 6, wherein the incident end is disposed at a position farther from the optical element than a focal length of the optical element.   The medical probe according to any one of claims 1 to 7, wherein the partial reflection portion is a half mirror.   The medical probe according to any one of claims 1 to 7, wherein the partial reflection unit is a polarization beam splitter that transmits the laser light having a predetermined polarization.   10. The surface of the optical element disposed at a position where the light beam of the laser light and the light beam of the scattered light overlap with each other is disposed so as to be inclined with respect to the principal ray of the light beam of the laser light. The medical probe according to any one of the above.   10. The surface of the separation element disposed at a position where the light beam of the laser light and the light beam of the scattered light overlap with each other is disposed so as to be inclined with respect to the principal ray of the light beam of the laser light. The medical probe according to any one of the above.

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