JP2008264578A - Optically excited fluorescein detector suitable for measuring physical property of cartilage tissue - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detector capable of measuring physical properties of a biological tissue, especially a cartilage tissue, in a living body without destroying the tissue. <P>SOLUTION: The optically excited acoustic wave detector is obtained by combining a laser beam generation source, a laser beam emitter one end of which is attached closely to the laser beam generation source and the other end of which contains an optical fiber for laser beam transmission having a laser beam emission surface, an acoustic wave detection with conversion means which has a detecting surface of an acoustic wave generated by exciting laser beams and converting the acoustic wave detected by the detecting surface to an electric signal, and an acoustic wave detector electrically connected with the conversion means. The laser beam emission surface of the optical fiber and the acoustic wave detection surface of the acoustic wave detection and conversion means are fixed to a tip end surface of a separately prepared supporting tool in a positional relation decided in advance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photoexcitation acoustic wave detection device and a photoexcitation fluorescence detection device suitable for measuring physical properties of cartilage tissue.

  In joints such as knees, there is cartilage that relieves friction between bones in the joints and absorbs shocks applied to the joints. The cartilage is formed so as to cover each of the opposing surfaces of the joint bone. There is a synovial membrane that constantly secretes a small amount of synovial fluid around the joint between the bones of the joint. The cartilage tissue absorbs the synovial fluid secreted by the synovium, smoothes the surface, and relieves friction between the bones. Since the cartilage tissue absorbs synovial fluid and is flexible, for example, the impact applied to the knee joint or the like during walking is absorbed by the cartilage flexibly changing its shape.

  If the cartilage matrix (collagen, proteoglycan, etc.) that forms the cartilage tissue is denatured or the molecular chain is broken due to unbalanced diet, aging, or overuse of the joint, the cartilage tissue becomes difficult to absorb synovial fluid, and the bones and bones of the joint Osteoarthritis with pain in the joints develops due to friction with or impact on the joints.

  In the early stage of osteoarthritis, a treatment is performed in which the function of the cartilage tissue is restored by a well-balanced diet or appropriate exercise, or the cartilage tissue is regenerated by administration of a drug. If such treatment does not improve symptoms such as pain, diagnosis and treatment using an endoscope is performed. For example, in the case of a knee joint that has developed osteoarthritis, several holes are opened from the outside of the knee to the inside of the joint, and an endoscope and a diagnostic or therapeutic instrument are inserted into the joint from the hole. Then, diagnosis and treatment are performed while observing the cartilage tissue with an endoscope.

  Whether the cartilage tissue has a normal function (relaxation of friction between joint bones or absorption of shock applied to the joint) is determined by measuring physical properties such as viscosity, elastic modulus, thickness or composition of the cartilage tissue. It is preferable to evaluate quantitatively. However, in diagnosis using a conventional endoscope, the function of the cartilage tissue is qualitatively evaluated by observing the appearance of the cartilage tissue with an endoscope or touching the cartilage tissue with a diagnostic instrument. Yes. The function of the cartilage tissue may be qualitatively evaluated by extracting a part of the cartilage tissue and judging the extracted cartilage tissue pathologically.

  The quantitative evaluation of the function of the cartilage tissue may be performed by extracting a part of the cartilage tissue and measuring the physical properties in vitro using a viscoelasticity measuring device (eg, rheometer). It is not preferable to remove (destroy) a part of a patient's cartilage tissue, and physical properties (especially mechanical properties such as viscosity and elastic modulus) are mostly measured to evaluate the original function of the cartilage tissue. The current situation is not.

  On the other hand, for the treatment of osteoarthritis, it is obtained by extracting cartilage tissue of the patient's own healthy part (cartilage tissue that has not developed arthropathy) and growing it in vitro (proliferated by culture) Cartilage tissue may be transplanted into the affected area. It is necessary to measure physical properties of such a cartilage tissue for transplantation in order to evaluate its function. Similarly to the above, in the case of a cartilage tissue for transplantation, a part of the grown cartilage tissue is cut out (destroyed) and evaluated by histopathological evaluation or physical property measurement.

Patent Document 1 discloses an apparatus that applies ultrasonic waves to cartilage tissue and measures the mechanical characteristics of cartilage tissue from ultrasonic waves (ultrasound echoes) reflected on the surface of the cartilage tissue.
JP 2002-345821 A

The objective of this invention is providing the apparatus which can measure the physical property of a biological tissue, especially a cartilage tissue, without destroying a structure | tissue in the living body.
Another object of the present invention is to provide a method for measuring the physical properties of cartilage tissue grown in vitro without destroying the cartilage tissue.

  The present inventor is a measuring device capable of reducing the size of the detection unit in order to facilitate insertion of the detection unit for measuring physical properties into the living body, and does not destroy biological tissue by measuring physical properties. As a requirement, we examined the possibility of applying various physical property measuring devices in vivo. As a result, it has been found that by devising the configuration of the photoexcitation acoustic wave detection device, a photoexcitation acoustic wave detection device suitable for measuring physical properties of a living tissue (particularly, cartilage tissue) in a living body can be provided. In addition, by using a photoexcited acoustic wave detection device, the physical properties necessary for evaluating the function of the cartilage tissue such as viscosity, elastic modulus, thickness or composition of the cartilage tissue grown in vitro can be measured without destroying the tissue. I found out that I can do it.

  The present invention relates to a laser beam generation apparatus, a laser beam irradiation apparatus including a laser beam transmission optical fiber having one end attached close to the laser beam generation source and having a laser beam irradiation surface at the other end, and a laser beam An acoustic wave detection conversion means for converting an acoustic wave detected on the detection surface into an electrical signal, and an acoustic wave detection electrically connected to the acoustic wave detection conversion means A photo-excited acoustic wave detection device formed by combining the devices, wherein the laser light irradiation surface of the optical fiber and the acoustic wave detection surface of the acoustic wave detection / conversion means are determined in advance on the tip surface of a separately prepared support tool. The photoexcited acoustic wave detection device is fixed in a predetermined positional relationship.

The preferable aspect of the photoexcitation acoustic wave detection apparatus of this invention is as follows.
(1) The support is cylindrical, the laser light irradiation surface of the optical fiber and the acoustic wave detection surface of the acoustic wave detection conversion means are fixed to the tip surface of the cylindrical support, and the laser light irradiation of the optical fiber The portion connected to the surface and the acoustic wave detection / conversion means are accommodated in the cylindrical support.
(2) The acoustic wave detection surface is in an annular shape surrounding the light irradiation surface fixed to the support tool front end surface.
(3) The acoustic wave detection / conversion means is a piezoelectric transducer.

(4) The optical fiber is provided with a separation means for separating the laser light and the fluorescence, and a fluorescence detection means attached to the separation means.
(5) A light detection optical fiber having a light detection surface disposed near one side of the laser light irradiation surface of the optical fiber at one end, and a fluorescence detection means attached to the light detection optical fiber are provided.
(6) For measuring physical properties of cartilage tissue.

  The present invention also provides a laser light emitting device, a laser light emitting device including a laser light transmitting optical fiber having one end attached close to the laser light generating source and having a laser light emitting surface at the other end. Separation means for separating the laser light and fluorescence attached to the transmission optical fiber, and a photoexcitation fluorescence detection device having fluorescence detection means attached to the separation means, wherein the laser light irradiation surface of the optical fiber is There is also a photoexcitation fluorescence detection device characterized in that it is fixed to a tip surface of a support prepared separately.

  The present invention also provides a laser light irradiation apparatus including a laser light generation source, and a laser light transmission optical fiber having one end attached to the laser light generation source and having a laser light irradiation surface at the other end, A light detection optical fiber having a light detection surface disposed at one end of the optical fiber adjacent to the laser light irradiation surface of the optical fiber, and a fluorescence detection means attached to the light detection optical fiber. In addition, there is also a photoexcited fluorescence detection device in which the laser light irradiation surface and the light detection surface of the optical fiber are fixed to a tip surface of a separately prepared support.

  The two photoexcited fluorescence detection devices of the present invention are preferably used for measuring physical properties of cartilage tissue.

  The present invention also provides a laser beam generation apparatus, a laser beam irradiation apparatus including a laser beam transmission optical fiber having one end adjacent to the laser beam generation source and having a laser beam irradiation surface at the other end. An acoustic wave detection / conversion means for converting an acoustic wave detected on the detection surface into an electric signal, and an acoustic wave electrically connected to the acoustic wave detection / conversion means. Measure physical properties of cartilage tissue by irradiating cartilage tissue grown in vitro with laser light and detecting acoustic waves generated in cartilage tissue using a photoexcited acoustic wave detection device combined with a detection device There is also a way.

Preferred embodiments of the method for measuring physical properties of cartilage tissue of the present invention are as follows.
(1) The laser light irradiation surface of the optical fiber and the detection surface of the acoustic wave detection / conversion means are arranged to face each other with the cartilage tissue interposed therebetween.
(2) Using the above-described optical fiber, a photoexcitation acoustic wave detection device provided with a separation means for separating laser light and fluorescence, and a fluorescence detection means attached to the separation means, and cartilage tissue by laser light irradiation. The physical properties of the cartilage tissue are measured by detecting the acoustic wave and fluorescence generated in the above.
(3) A light detection optical fiber having a light detection surface disposed near one side of the laser light irradiation surface of the optical fiber at one end, and a fluorescence detection means attached to the light detection optical fiber are provided. The physical property of the cartilage tissue is measured by detecting the acoustic wave and fluorescence generated in the cartilage tissue by the laser light irradiation using the photoexcited acoustic wave detection device.

  The present invention also provides a laser light irradiation apparatus including a laser light generation source, and a laser light transmission optical fiber having one end attached to the laser light generation source and having a laser light irradiation surface at the other end, Using a light excitation fluorescence detection apparatus having a separation means for separating laser light and fluorescence attached to the optical fiber and a fluorescence detection means attached to the separation means, the cartilage tissue grown outside the body is irradiated with laser light. There is also a method for measuring physical properties of cartilage tissue by detecting fluorescence generated in cartilage tissue.

  The present invention also provides a laser light irradiation apparatus including a laser light generation source, and a laser light transmission optical fiber having one end attached to the laser light generation source and having a laser light irradiation surface at the other end, A light detection optical fiber having a light detection surface disposed at one end of the optical fiber adjacent to the laser light irradiation surface, and a light excitation fluorescence detection device having a fluorescence detection means attached to the light detection optical fiber There is also a method for measuring physical properties of cartilage tissue by irradiating a cartilage tissue grown in vitro with laser light and detecting fluorescence generated in the cartilage tissue.

  The present invention also includes a laser light irradiation device including a laser light generation source, an acoustic wave detection conversion device that has an acoustic wave detection surface generated by excitation of the laser light and converts the acoustic wave detected on the detection surface into an electrical signal. And a photoexcited acoustic wave detection device combined with an acoustic wave detection device electrically connected to the acoustic wave detection / conversion means, irradiating the cartilage tissue grown in vitro with laser light, There is also a method for measuring the physical properties of cartilage tissue by detecting the generated acoustic waves.

  In the above-described method for measuring physical properties of cartilage tissue of the present invention (without using an optical fiber for optical transmission), excitation of laser light and laser light disposed between the laser light source and the cartilage tissue to be measured Using a photoexcited acoustic wave detection device equipped with a separation means for separating the fluorescence generated by the above and a fluorescence detection means attached to the separation means, and the acoustic wave and fluorescence generated in the cartilage tissue by laser light irradiation It is preferable to measure the physical properties of the cartilage tissue by detecting.

  The present invention also provides a laser beam irradiation apparatus including a laser beam generation source, a separation unit that separates the laser beam and fluorescence generated by excitation of the laser beam, and a photoexcitation fluorescence detection unit that includes a fluorescence detection unit attached to the separation unit. There is also a method for measuring physical properties of cartilage tissue by irradiating a cartilage tissue grown in vitro with laser light and detecting fluorescence generated in the cartilage tissue.

  In the present specification, “cartilage tissue” includes cartilage-like tissue grown ex vivo (proliferated by culture).

  With the photoexcitation acoustic wave detection device of the present invention, the physical properties of a living tissue, particularly cartilage tissue can be measured in vivo without destroying the tissue. Further, the physical property measurement method of cartilage tissue of the present invention can measure the physical property of cartilage tissue grown in vitro without destroying the tissue. In the present invention, the function of the cartilage tissue can be consistently evaluated by measuring the physical properties of the cultured cartilage tissue and the physical properties of the cartilage tissue after in vivo transplantation. Useful in the field.

  A photoexcited acoustic wave detection device of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration of an example of a photoexcitation acoustic wave detection device according to the present invention. FIG. 2 is a partially cutaway perspective view showing the support of the photoexcited acoustic wave detection device of FIG. 1 and the internal structure thereof.

  The photoexcitation acoustic wave detection apparatus shown in FIGS. 1 and 2 is a laser beam having a laser beam source 11 and one end portion close to the laser beam source 11 and a laser beam irradiation surface 12 at the other end portion. A laser beam irradiation device including the transmission optical fiber 13, an acoustic wave detection conversion unit 15 that has an acoustic wave detection surface 14 generated by excitation of the laser beam and converts the acoustic wave detected on the detection surface 14 into an electrical signal. The acoustic wave detection device 16 is a photoexcited acoustic wave detection device that is combined with the acoustic wave detection device 16 electrically connected to the acoustic wave detection conversion means 15. The acoustic wave detection device 16 is electrically connected to the acoustic wave detection conversion means 15 by an electrical wiring 17. The acoustic wave detection device 16 may be provided with an amplification output means 18 for an electrical signal corresponding to the acoustic wave converted by the acoustic wave detection conversion means 15. Regarding the photoexcited acoustic wave detector having such a configuration and measurement of physical properties of skin tissue in vitro using this device, a research report by Shunichi Sato et al. (Optics, Vol. 30, No. 10, 2001, 658 to 662). Page) for more details.

  In the photoexcited acoustic wave detection device according to the present invention, the laser light irradiation surface 12 of the optical fiber 13 and the acoustic wave detection surface 14 of the acoustic wave detection conversion means 15 are further provided on the distal end surface of a separately prepared support 19. It is characterized in that it is fixed in a predetermined positional relationship. As shown in FIG. 1, the support 19 is preferably cylindrical so that it can be easily inserted into a living body. When the support 19 is cylindrical, a portion (a part of the optical fiber) connected to the laser light irradiation surface 12 of the optical fiber 13 and the acoustic wave detection conversion means 15 are accommodated in the cylindrical support. Preferably it is. In consideration of insertion of the support into the living body, particularly measurement of physical properties of the living tissue under endoscopic observation, the outer diameter of the support is preferably 15 mm or less, and more preferably 10 mm or less. The length of the support is preferably in the range of 100 to 800 mm, and more preferably in the range of 150 to 500 mm.

  If a support tool supports optical fiber 13 and acoustic wave detection conversion means 15, and can insert these in a living body, there will be no restriction in the shape in particular. For example, the support may be in the shape of an elongated bar. The support 19 may be formed of any material as long as it is harmless to living tissue. Examples of the material forming the support 19 include metals such as iron, copper, titanium, and aluminum, alloy compositions such as stainless steel, resins such as polyethylene and polypropylene, glass, and ceramics.

  FIG. 9 is a diagram showing another configuration example of the support of the photoexcited acoustic wave detection device of FIG. 1 and the internal structure thereof. The laser beam irradiation surface 12 of the optical fiber 13 and the acoustic wave detection surface 94 of the acoustic wave detection conversion means 95 are fixed to the distal end surface of the support 99 shown in FIG. As shown in FIG. 9, the acoustic wave detection surface 94 is preferably in an annular shape surrounding the light irradiation surface 12 fixed to the tip surface of the support 99. By making the acoustic wave detection surface 94 into an annular shape, the detection sensitivity of acoustic waves generated in the cartilage tissue can be increased.

  The main reason for using the photoexcited acoustic wave detection device for the measurement of physical properties of living tissue in vivo is described below.

  (1) A photo-excited acoustic wave detector is a device that measures physical properties of a material to be measured by irradiating the material to be measured with laser light and detecting an acoustic wave generated in the material by excitation of the laser light. It is. Laser light used for physical property measurement by the photoexcited acoustic wave detection device can be easily introduced into a living body by using an optical fiber. A piezoelectric transducer or the like that can be miniaturized can be used as acoustic wave detection / conversion means for detecting an acoustic wave generated by excitation of laser light and converting it into an electrical signal. Accordingly, a detection unit (a part of an optical fiber including a laser beam irradiation surface to be inserted into a living body and an acoustic wave detection / conversion unit) that needs to be arranged close to a living tissue to be measured in measuring physical properties. Can be reduced in size and integrated, and the insertion of the detection unit into the living body can be facilitated by using a support.

  (2) The photoexcited acoustic wave detection device can measure the physical properties of the living tissue without destroying the living tissue by adjusting the intensity of the laser light applied to the living tissue.

  (3) The photoexcited acoustic wave detector can be multi-functional so that physical properties can be measured based on various principles using light. For example, when a living tissue is irradiated with laser light, the composition or composition change of the living tissue can be measured by detecting fluorescence generated in the living tissue. Such fluorescence detection can be introduced into a photoexcited acoustic wave detection device. In addition, the photoexcitation acoustic wave detection device detects the second harmonic of infrared light, scattered light, reflected light, scattered light, or scattered light generated in the biological tissue when the biological tissue is irradiated with light. It is also possible to make it multifunctional so as to measure physical properties of living tissue.

  (4) The photoexcited acoustic wave detector can measure the viscosity, elastic modulus, and thickness of the cartilage tissue necessary for evaluating the function of the cartilage tissue.

  The acoustic wave generated on the surface (or near the surface) of the cartilage tissue by laser light irradiation (excitation by the laser light) propagates through the cartilage tissue while gradually decreasing its intensity. From the acoustic wave waveform (specifically, the change of the intensity of the acoustic wave with respect to time), a relaxation time correlated with the ratio of the viscosity and the elastic modulus of the propagation medium of the acoustic wave can be obtained. The relaxation time of the acoustic wave having a correlation with the ratio between the viscosity and the elastic modulus is described in many documents (for example, Ultrasound Handbook (Maruzen Co., Ltd., 1999, p. 244). The “storage modulus” and the viscosity are sometimes referred to as “loss modulus”.

  Further, a method for measuring the absolute value of the elastic modulus of an object from an acoustic wave incident on the object and reflected from the object is already known. Based on the same principle, in the present invention, the absolute value of the elastic modulus of the cartilage tissue (corresponding to the object) can be measured. Specifically, an acoustic wave is generated by absorbing laser light in a part away from the surface of the cartilage tissue (eg, joint fluid present around the cartilage tissue), and is reflected on the surface of the cartilage tissue. Similarly, the absolute value of the elastic modulus of the cartilage tissue can be measured from the acoustic wave.

  Then, the absolute value of the viscosity of the cartilage tissue can be obtained from the absolute value of the measured elastic modulus and the relaxation time correlated with the ratio of the viscosity and the elastic modulus.

  In addition, the acoustic wave generated on the surface (or near the surface) of the cartilage tissue by the laser light propagation propagates into the cartilage tissue. The acoustic wave is reflected on the surface of the subchondral bone under the cartilage (the interface between the cartilage and the subchondral bone) and reaches the surface of the cartilage tissue. Therefore, in the waveform of the electrical signal corresponding to the acoustic wave obtained by the acoustic wave detection device, the acoustic wave is reflected on the surface of the subchondral bone from the generation of the acoustic wave on the surface (or near the surface) of the cartilage tissue, and the cartilage By detecting the time to reach the surface of the tissue and using this time and the speed of sound of the acoustic wave, the thickness of the cartilage tissue can be obtained. The principle of measuring the thickness of the cartilage tissue is the same as that of an ultrasonic thickness gauge. The acoustic wave may be called a pressure wave or a stress wave.

  As mentioned above, the viscosity, elastic modulus, or thickness of the cartilage tissue can be obtained as a specific value, but it corresponds to each of normal cartilage tissue and cartilage tissue after onset of osteoarthritis The waveform of the electrical signal based on the acoustic wave is prepared in advance as a reference waveform, and the reference waveform is compared with the waveform obtained by measuring the physical properties of the patient's cartilage tissue. The same function can be evaluated. Similarly, a standard fluorescence detection result for the composition of the cartilage tissue is prepared in advance, and this is compared with the fluorescence detection result obtained by measuring the physical property of the patient's cartilage tissue to evaluate the function of the cartilage tissue. You can also

  The physical property values (viscosity, elastic modulus, etc.) of the cartilage tissue obtained as described above can be easily determined visually to what extent the values are relative to normal cartilage tissue. It is preferable to display by a method that can be used.

  For example, if the measured physical property value is approximately equal to the normal cartilage tissue property value, the measured value is displayed in blue, and the measured value increases as the difference from the normal cartilage tissue physical property value increases. Is preferably displayed in a color close to red. In addition, when the physical property value of the cartilage tissue is measured in a two-dimensional direction along the surface of the cartilage tissue, it is also preferable to display the measured physical property value as a pseudo color image corresponding to the two-dimensional direction.

  The laser light source 11 preferably generates a pulse laser. Examples of the laser light source 11 include an excimer laser, a Nd: YAG (Yttrium Aluminum Garnet) laser, a Ho: YAG laser, an Er: YAG laser, and an optical parametric oscillator. A laser light source has a configuration in which a laser light source that continuously generates laser light and a device such as a chopper or an optical shuttering device that converts the generated laser light into pulsed laser light are combined. You may do it. The laser light source 11 shown in FIG. 1 is provided with a lens 21 for making the laser light 20 generated from the laser light source incident on the optical fiber 13.

  When measuring the physical properties of the cartilage tissue, it is preferable to irradiate the cartilage tissue with a laser beam having a wavelength that is easily absorbed by the cartilage tissue, for example, collagen of the cartilage tissue or moisture.

  In order to efficiently absorb laser light into the collagen of the cartilage tissue, it is preferable to irradiate the cartilage tissue with laser light having a wavelength of 100 nm or more and less than 700 nm, and to irradiate laser light with a wavelength of 100 nm or more and less than 500 nm. More preferably. As such short-wavelength laser light, laser light generated by an excimer laser, or third harmonic, fourth harmonic, or fifth harmonic of laser light generated by a YAG laser can be used.

  In order to efficiently absorb laser light into the water of the cartilage tissue, it is preferable to irradiate the cartilage tissue with laser light having a wavelength of 2 to 3 μm. As such a long wavelength laser beam, a laser beam (wavelength: 2.1 μm) generated by a Ho: YAG laser or a laser beam (wavelength: 2.9 μm) generated by an Er: YAG laser is used. it can.

  It is preferable to set the wavelength and intensity (energy) of the laser light applied to the cartilage tissue under conditions that do not affect the proliferation activity of the cartilage cells of the cartilage tissue.

  As the acoustic wave detection conversion means 15, a known transducer that detects an acoustic wave and converts it into an electrical signal can be used. Examples of acoustic wave detection / conversion means include a microphone and a piezoelectric transducer. A piezoelectric transducer is preferably used because it is easy to downsize and has high acoustic wave detection sensitivity. Examples of piezoelectric transducers include piezoelectric ceramic transducers and piezoelectric polymer transducers. A piezoelectric polymer transducer is preferably used as the piezoelectric transducer. Examples of the piezoelectric polymer material used for the piezoelectric polymer transducer include PVDF (polyvinylidene fluoride) and P (VdF / TrFE) (vinylidene fluoride / ethylene trifluoride copolymer). As the acoustic wave detection conversion means 15 shown in FIG. 2, a piezoelectric polymer transducer using PVDF (polyvinylidene fluoride) film is used.

  As the acoustic wave detection device 16 electrically connected to the acoustic wave detection / conversion means 15, a device conventionally used in a photoexcitation acoustic wave detection device can be used. As described above, the physical properties (viscosity, elasticity, or thickness) of the cartilage tissue can be obtained from the waveform of the electrical signal corresponding to the acoustic wave converted by the acoustic wave detection conversion means 15. As the acoustic wave detection device 16, a device that displays a waveform of an electric signal or processes information of the electric signal to display information on the physical property can be used. A commercially available oscilloscope is used as the acoustic wave detection device 16 shown in FIG.

  The acoustic wave detection device 16 can be provided with electrical signal amplification output means 18 for amplifying the electrical signal converted by the acoustic wave detection conversion means 15. As the electric signal amplification output means 18 shown in FIG. 1, an FET (Field Effect Transistor) amplifier is used. In addition, the acoustic wave detection device (oscilloscope) 16 is provided with a biplanar photoelectric tube 22 in order to synchronize the waveform of the detected electric signal with the waveform of the pulse laser generated by the laser light source 11. Instead of the biplanar phototube, a known photodetector (for example, a photodiode) can be used. The response time of the photodetector is preferably shorter than the pulse width of the pulse laser generated by the laser light source.

  FIG. 3 is a diagram showing a configuration of another example of the photoexcited acoustic wave detection device according to the present invention. The configuration of the photoacoustic wave detection apparatus of FIG. 3 is the same as that of FIG. 3 except that the optical fiber 13 is provided with a separation means 31 for separating laser light and fluorescence, and a fluorescence detection means 32 connected to the separation means. This is the same as the photoexcited acoustic wave detection apparatus 1.

  When the laser light irradiation apparatus irradiates the material to be measured (in the present invention, biological tissue) with laser light, fluorescence may be generated in the material to be measured by excitation of the laser light. A method for detecting such fluorescence and measuring the composition of the material to be measured or a change in the composition is generally known as a laser induced fluorescence (LIF) method. In the present invention, in order to use a photoexcited acoustic wave detection device for measuring physical properties of a living tissue in vivo, the optical fiber 13 provided in the device is used to emit fluorescence generated from the living tissue by excitation of laser light outside the living body. It can be taken out. By detecting the obtained fluorescence 33 by the fluorescence detection means 32, the composition of the living tissue or the change in the composition can also be measured.

  Examples of the fluorescence detection means 32 include a spectroscope such as a polychromator, and an optical multi-channel analyzer provided with a charge coupled device (CCD). In order to guide the fluorescence to the fluorescence detection means 32, the optical fiber 13 is provided with a separation means 31 for separating the laser light and the fluorescence 33. Examples of the separating unit 31 include a half mirror and a dielectric multilayer mirror that selectively reflects a specific wavelength. The separating means 31 can also be disposed between the laser light source 11 and the lens 21.

  FIG. 4 is a diagram showing an example of a light excitation fluorescence detection device according to the present invention. The configuration of the photoexcited fluorescence detection device of FIG. 4 is the same as that of the photoexcitation acoustic wave detection device of FIG. 3 except that the configuration does not detect acoustic waves (a configuration that does not use the acoustic wave detection conversion means and the acoustic wave detection device). is there. When it is not necessary to know the mechanical properties (viscosity, elastic modulus, or thickness) of a living tissue, the composition of the living tissue can be measured with such a simple configuration.

  FIG. 5 is a diagram showing a configuration of another example of the photoexcitation fluorescence detection device according to the present invention. The configuration of the photoexcited fluorescence detection apparatus in FIG. 5 includes a light detection optical fiber 53 having a light detection surface 52 disposed at one end thereof in the vicinity of the laser light irradiation surface 12 of the laser light transmission optical fiber 13. Except for the fact that the fluorescence detection means 32 is attached to the optical fiber 53 for light detection, it is the same as the photoexcitation fluorescence detection apparatus of FIG. 5, the laser light irradiation surface 12 of the laser light transmission optical fiber 13 and the light detection surface 52 of the light detection optical fiber 53 are fixed to the distal end surface of the support 19.

  The light detection optical fiber 53 guides the fluorescence generated from the living tissue by the excitation of the laser light to the fluorescence detection means 32, so that the separation means included in the light excitation fluorescence detection apparatus of FIG. 4 can be dispensed with. Similarly, in the case of the photoexcited acoustic wave detection device of FIG. 3, the separation means can be made unnecessary by attaching the optical fiber for light detection.

  The photoexcited acoustic wave detection device and photoexcitation fluorescence detection device of the present invention can be preferably used for physical property measurement of cartilage tissue in vivo (particularly for diagnosis of cartilage tissue under endoscopy). It can also be used to measure physical properties of living tissues. In this case, it is possible to appropriately set the wavelength of the laser light that is easily absorbed by the measurement target living tissue and is likely to generate acoustic waves and fluorescence.

  Further, when measuring the physical properties of transplanted cartilage tissue used in the treatment of osteoarthritis or the like, the photoexcitation acoustic wave detection device or the photoexcitation fluorescence detection device does not necessarily have a support. It does not need to be provided. By irradiating cartilage tissue grown in vitro with laser light and detecting acoustic waves or fluorescence generated in the cartilage tissue in the same manner as described above, the physical properties (viscosity, elastic modulus) of the cartilage tissue for transplantation , Thickness or composition) can be measured non-destructively and the function of the cartilage tissue for transplantation can be evaluated (quality control). When measuring the physical properties of the cartilage tissue in vitro, the acoustic wave detecting means can be arranged on the surface opposite to the surface of the cartilage tissue irradiated with the laser light.

  FIG. 6 is a diagram for explaining an example of a method for measuring physical properties of cartilage tissue by directly irradiating the cartilage tissue with laser light and detecting acoustic waves and fluorescence generated in the cartilage tissue. The photoexcited acoustic wave detection device of FIG. 6 has a laser light irradiation device including a laser light generation source 11 and a detection surface 14 of an acoustic wave generated by excitation of the laser light, and the acoustic wave detected by the detection surface 14 is electrically converted. This is an optically-excited acoustic wave detecting device formed by combining an acoustic wave detecting / converting means 15 for converting into a signal and an acoustic wave detecting device 16 electrically connected to the converting means 15.

  As shown in FIG. 6, when measuring the physical properties of cartilage tissue grown in vitro, the laser beam 20 of the laser beam generation source is directly irradiated to the cartilage tissue 61 (without using a laser beam transmission fiber). You can also It is known in a conventional photoexcitation acoustic wave detection apparatus (for example, a photoacoustic microscope) to directly irradiate a measurement target material with laser light from a laser light irradiation apparatus without using an optical fiber.

  Further, in the photoexcited acoustic wave detection apparatus of FIG. 6, a separating means 31 for separating a laser beam disposed between the laser beam generation source 11 and the cartilage tissue 61 to be measured and a fluorescence generated by the excitation of the laser beam. And the fluorescence detection means 32 attached to the separation means 31 is provided. The separating means 31 can also be disposed between the laser light source 11 and the lens 21. The physical property of the cartilage tissue is measured by irradiating the cartilage tissue 61 with the laser beam 20 and detecting the acoustic wave and the fluorescence generated in the cartilage tissue by the excitation of the laser beam by the photoexcited acoustic wave detection device of FIG. Can do.

  When only the acoustic wave generated in the cartilage tissue 61 by the excitation of the laser beam 20 is detected (when measuring the viscosity, elasticity or thickness of the cartilage tissue), it is necessary to provide the separation means 31 and the fluorescence detection means 32. Absent. When only the fluorescence 33 generated in the cartilage tissue 61 by the excitation of the laser beam 20 is detected (when measuring the composition or composition change of the cartilage tissue), the acoustic wave detection conversion means 15 and the electric signal amplification output means 18 and the acoustic wave detection device 16 need not be additionally provided.

  When measuring the physical properties of cartilage tissue grown in vitro, the physical properties of a plurality of cartilage tissues can be measured simultaneously (or sequentially). In this case, a plurality of optical transmission optical fibers for irradiating each cartilage tissue with laser light from a laser light generation source, acoustic wave detection conversion means for detecting acoustic waves generated from each cartilage tissue, and acoustic wave detection What is necessary is just to attach an apparatus. In addition, when directly irradiating each cartilage tissue with laser light from a laser light source, a plurality of microlenses for converging the laser light to each cartilage tissue and acoustic waves generated from each cartilage tissue are detected. The acoustic wave detection conversion means and the acoustic wave detection device may be attached. In addition, when detecting acoustic waves and fluorescence generated in cartilage tissue by laser light excitation, the physical properties of a plurality of cartilage tissues can be measured simultaneously (or in order) in the same way when detecting only fluorescence. Can do.

  FIG. 10 is a diagram for explaining a method for measuring the physical properties of the cartilage tissue by irradiating the cartilage tissue grown in vitro with laser light and detecting acoustic waves generated in the cartilage tissue. FIG. 10 shows a configuration example of a photoexcited acoustic wave detection device that can be preferably used for carrying out the method of the present invention. The configuration of the photoexcited acoustic wave detection device of FIG. 10 is generated in the cartilage tissue by irradiating the cartilage tissue 61 with the laser light 20 generated by the laser light source 11 using the optical fiber 13. 6 is the same as the apparatus of FIG. 6 except that the fluorescence to be detected is not detected (separation means and fluorescence detection means are not provided).

  In the photoexcited acoustic wave detection apparatus of FIG. 10, the acoustic wave generated in the cartilage tissue 61 is detected by the acoustic wave detection / conversion means 15 disposed on the surface of the cartilage tissue opposite to the laser light irradiation surface. As shown in FIG. 10, the laser light irradiation surface 12 of the optical fiber 13 and the acoustic wave detection surface 14 of the acoustic wave detection conversion means 15 are disposed to face each other with the cartilage tissue 61 interposed therebetween.

  The laser light generated by the laser light source 11 of the photoexcited acoustic wave detection device of FIG. 10 is irradiated to the cartilage tissue 61 grown outside the living body, and the acoustic wave generated in the cartilage tissue is converted into acoustic wave detection / conversion means. By detecting at 15, the physical properties of the cartilage tissue can be measured.

  As described above, when detecting an acoustic wave generated in a cartilage tissue by laser light irradiation, the acoustic wave can be detected on the laser light irradiation surface of the cartilage tissue, or the laser light irradiation surface of the cartilage tissue. It is also possible to detect on the opposite surface. Hereinafter, a method of detecting an acoustic wave on the laser light irradiation surface of the cartilage tissue is referred to as a reflection method, and a method of detecting an acoustic wave on the surface opposite to the laser light irradiation surface of the cartilage tissue is referred to as a transmission method. .

  FIG. 11 is a diagram illustrating a waveform of an electric signal corresponding to an acoustic wave detected by the transmission method. In the waveform diagram of FIG. 11, the horizontal axis indicates the time after the pulsed laser light is irradiated to the cartilage tissue. That is, it means that the laser beam was irradiated to the cartilage tissue at a time of 0 μsec on the horizontal axis. The vertical axis indicates the voltage value of the electrical signal corresponding to the acoustic wave detected by the acoustic wave detection / conversion means.

The acoustic wave generated in the cartilage tissue by the irradiation of the pulsed laser beam is transmitted while attenuating the inside of the cartilage tissue from the laser beam irradiation surface of the cartilage tissue, and reaches the surface where the acoustic wave detection conversion means of the cartilage tissue is arranged. To do. This acoustic wave is detected by the acoustic wave detection and conversion means, and the peak P ₁ in the waveform of the electric signal in FIG. Next, the acoustic wave propagates through the cartilage tissue while being repeatedly reflected on the surface on which the acoustic wave detection / conversion means of the cartilage tissue is arranged and the laser light irradiation surface, and peaks P ₂ and P ₃ in the waveform of the electric signal in FIG. And yields P ₄ . As described above, the thickness of the cartilage tissue can be obtained from the peak interval (time) of these electric signals and the sound velocity of the acoustic wave.

  In the case of the transmission method, the relaxation time τ can be determined from the value of τ when the exponential function curve 111 (exp (−t / τ)) is fitted to the peak of the waveform of the electrical signal, for example. .

FIG. 12 is a diagram illustrating a waveform of an electrical signal corresponding to an acoustic wave detected by the reflection method. In the waveform of the electric signal in FIG. 12, the peak P ₀ indicates that the acoustic wave generated on the surface (or near the surface) of the cartilage tissue by the irradiation of the pulsed laser light is transmitted along the laser light irradiation surface of the cartilage tissue. This is a peak that occurs when the acoustic wave detection conversion means is reached.

In the case of the reflection method, the relaxation time τ is determined by fitting the exponential function curve 121 to the peaks other than the above-described peak P ₀ (the peak generated by the acoustic wave transmitted along the laser light irradiation surface) in the same manner as described above. can do.

[Comparative Example 1]
Cartilage tissue was extracted from rabbits, chondrocytes were isolated, cultured and expanded to grow cartilage tissue (to be exact, it is called cartilage-like tissue because it did not form complete cartilage tissue) . A part of the growing cartilage tissue was cut out (destroying the cartilage tissue) and viscoelasticity was measured using a rheometer. FIG. 7 shows the measurement results. In the graph of FIG. 7, the horizontal axis represents the culture period (weeks) of the cartilage tissue, and the vertical axis represents the reciprocal of the phase angle (1 / tan δ) measured by the rheometer. The value of (1 / tan δ) is proportional to the ratio of elastic modulus to viscosity (elastic modulus / viscosity). The measurement value (1 / tan δ) was normalized based on the measurement value in chondrocytes having a culture period of 3 weeks.

  Then, the normal cartilage tissue extracted from the rabbit was similarly measured for viscoelasticity using a rheometer. As a result, the measured value (1 / tan δ) was normalized in the same manner as described above, and the value was about 0.58. That is, it can be seen that the viscoelasticity of the cultured cartilage tissue approaches that of normal cartilage as the culture period becomes longer. The amount of collagen contained in the cultured cartilage tissue was measured by a collagen assay method. As a result, it was confirmed that the cultured cartilage tissue was close to normal cartilage tissue with an increase in collagen content as the culture period became longer.

  In this way, it was confirmed that the function of the cultured cartilage tissue can be evaluated from the results of viscoelasticity measurement using a rheometer.

[Example 1]
Piezoelectric polymer using optical parametric oscillator as laser light source, quartz fiber as optical fiber for laser transmission (core diameter 600 μm, length 1 m), and P (VdF / TrFE) film 4 mm in diameter as acoustic wave detection conversion means A photoexcited acoustic wave detection device was configured using a transducer (manufactured by Kureha Co., Ltd.), an FET amplifier as an electrical amplification output means, and a digital oscilloscope as the acoustic wave detection device.

  Using a photoexcited acoustic wave detector, the cartilage tissue grown in Comparative Example 1 was irradiated with a pulsed laser beam having a wavelength of 250 nm, and an acoustic wave generated from the cartilage tissue was detected by excitation of the laser beam. The pulse energy of the laser beam was set to 50 μJ. The acoustic wave is detected by a piezoelectric polymer transducer and converted into an electrical signal. The acoustic wave relaxation time τ was obtained by fitting an exponential function curve (exp (−t / τ)) to the waveform of the electrical signal corresponding to the acoustic wave observed with the oscilloscope in the same manner as described above. The relaxation time is proportional to the ratio of elastic modulus to viscosity (elastic modulus / viscosity). FIG. 7 shows the relaxation time of the acoustic wave obtained from the waveform of the electric signal. The measured relaxation times were normalized based on the measured values in chondrocytes having a culture period of 3 weeks.

  As shown in FIG. 7, it can be seen that the measurement result by the rheometer and the measurement result by the photoexcited acoustic wave detection device show almost the same tendency. Therefore, it can be seen that the physical property (viscoelasticity) of the cartilage tissue grown in vitro can be measured non-destructively by detecting the acoustic wave generated in the cartilage tissue using the photoexcited acoustic wave detection device.

  In the oscilloscope, since the acoustic wave is repeatedly reflected on the surface and bottom surface of the cartilage tissue, the peak of the electric signal is periodically observed. It was also confirmed that the period of the electrical signal (the peak between the electrical signals) changed in accordance with the thickness of the grown cartilage tissue. Therefore, the thickness of the cartilage tissue grown in vitro can be measured using the waveform of the electrical signal corresponding to the acoustic wave generated in the cartilage tissue detected by the photoexcited acoustic wave detection device and the sound velocity of the acoustic wave. Recognize.

[Example 2]
A stainless steel cylindrical support having an outer diameter of 8 mm and a length of 150 mm was prepared. The laser light irradiation surface (one end of the optical fiber) of the optical fiber and the acoustic wave detection surface of the piezoelectric polymer transducer of the photoexcited acoustic wave detection device used in Example 1 are placed on the tip surface of the cylindrical support. A part of the optical fiber fixed and connected to the laser light irradiation surface and the photoacoustic wave detection / conversion means were accommodated inside the cylindrical support. In this way, the photoexcited acoustic wave detection device of FIG. 1 was produced. By using the support tool, it is possible to measure the physical properties of the living tissue in a living body in a non-destructive manner. For example, when measuring the physical properties of the cartilage of the knee joint in vivo, one or more holes from the outside of the knee to the inside of the joint are opened, and the endoscope and the cylindrical support are connected to the holes. From inside the joint. Then, by measuring the physical properties of the cartilage tissue in the same manner as in Example 1, the physical properties (viscoelasticity) of the cartilage tissue can be measured in vivo without removing (destroying) the cartilage tissue.

[Example 3]
An optically excited fluorescence detection device is constructed using an optical parametric oscillator as the laser light source, a quartz fiber as the optical fiber for laser transmission (core diameter 600 μm, length 1 m), a half mirror as the separation means, and a polychromator as the fluorescence detection means. did. Next, by fixing the laser light irradiation surface (one end portion of the optical fiber) of the optical fiber to the tip surface of the cylindrical support used in Example 2, the photoexcited fluorescence detection device shown in FIG. 4 is manufactured. did.

  Next, the cartilage tissue was removed from the knee joint of the pig, and the cartilage tissue was denatured by enzyme treatment (6 hours, 24 hours). Trypsin was used as the enzyme. Using the photoexcited fluorescence detection device, the cartilage tissue immediately after excision and the cartilage tissue before the enzyme treatment and the cartilage tissue after the enzyme treatment are irradiated with laser light and generated from the cartilage tissue by excitation of the laser light. Fluorescence was detected with a polychromator. The fluorescence spectrum obtained with the polychromator is shown in FIG.

  In FIG. 8, the fluorescence spectrum 81 shows the spectrum of the cartilage tissue before the enzyme treatment, the fluorescence spectrum 82 shows the cartilage tissue treated with the enzyme for 6 hours, and the fluorescence spectrum 83 shows the spectrum of the cartilage tissue treated with the enzyme for 24 hours. There are two peaks in each measured fluorescence spectrum. In FIG. 8, the fluorescence spectra before and after the enzyme treatment are overlapped and standardized with a peak existing around 390 nm as a reference. It has been found that the peak appearing near the wavelength of 390 nm is a peak derived from collagen forming cartilage tissue.

  From the fluorescence spectrum of FIG. 8, it can be seen that when the cartilage tissue is softened by the enzyme treatment, the intensity and the position where the peak appears of the peak existing in the vicinity of the wavelength of 320 to 330 nm change. The peak appearing in the vicinity of the wavelength of 320 to 330 nm has so far been unknown from which component that forms cartilage, but it can be determined that the component that forms cartilage is degraded or denatured.

  Therefore, it can be seen that the physical property (composition or change in composition) of the cartilage tissue grown in vitro can be measured nondestructively by detecting the fluorescence generated in the cartilage tissue using the photoexcited fluorescence detection device. As described above, when measuring the physical properties of the cartilage tissue in vitro, it is not necessary to use a support. And the physical property of the biological tissue in the living body can be measured nondestructively by the photoexcited fluorescence detecting device provided with the support.

It is a figure which shows the structure of an example of the optical excitation acoustic wave detection apparatus according to this invention. It is a partially cutaway perspective view which shows the support of the photoexcitation acoustic wave detection apparatus of FIG. 1, and its internal structure. It is a figure which shows the structure of another example of the optical excitation acoustic wave detection apparatus according to this invention. It is a figure which shows the structure of an example of the optical excitation fluorescence detection apparatus according to this invention. It is a figure which shows the structure of another example of the optical excitation fluorescence detection apparatus according to this invention. It is a figure explaining an example of the method of measuring the physical property of the cartilage tissue of this invention which irradiates a cartilage tissue with a laser beam directly, and detects the acoustic wave and fluorescence which generate | occur | produce in a cartilage tissue. It is a figure which shows the viscoelasticity measurement result of the cartilage tissue grown in vitro. It is a figure which shows the measurement result of the fluorescence spectrum of the fluorescence which generate | occur | produces in a cartilage tissue. It is a partially cutaway perspective view which shows another structural example of the support tool of the optical excitation acoustic wave detection apparatus of FIG. 1, and the structure of the inside. It is a figure explaining the measuring method of the physical property of the cartilage tissue according to this invention by detecting the acoustic wave which generate | occur | produces in a cartilage tissue. It is a figure which shows the waveform of the electric signal corresponding to the acoustic wave detected by the transmission method. It is a figure which shows the waveform of the electric signal corresponding to the acoustic wave detected by the reflection method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Laser light generation source 12 Laser light irradiation surface 13 Optical fiber for laser light transmission 14 Acoustic wave detection surface 15 Acoustic wave detection conversion means 16 Acoustic wave detection apparatus 17 Electrical wiring 18 Electrical signal amplification output means 19 Support tool 20 Laser light 21 Lens DESCRIPTION OF SYMBOLS 22 Viplanar photoelectric tube 23 Light irradiation surface fixing tool 31 Separation means 32 Fluorescence detection means 33 Fluorescence 52 Photodetection surface 53 Optical fiber for light detection 61 Cartilage tissue grown ex vivo 81, 82, 83 Fluorescence spectrum 94 Annular acoustic wave detection surface 95 Acoustic wave detection conversion means 99 Support 111, 121 Exponential function curve P0-P4 Peak of waveform of electric signal corresponding to acoustic wave

Claims (19)

  A laser light source including a laser light transmission optical fiber having a laser light transmission optical fiber having one end attached close to the laser light source and having a laser light irradiation surface on the other end, by excitation of the laser light An acoustic wave detection / conversion unit that has a detection surface for the generated acoustic wave, converts the acoustic wave detected on the detection surface into an electric signal, and an acoustic wave detection device electrically connected to the conversion unit are combined. The optically excited acoustic wave detection device, wherein the laser light irradiation surface of the optical fiber and the acoustic wave detection surface of the acoustic wave detection / conversion means have a predetermined positional relationship with the tip surface of a separately prepared support tool. An optically-excited acoustic wave detection device fixed by   The support is cylindrical, the laser light irradiation surface of the optical fiber and the acoustic wave detection surface of the acoustic wave detection conversion means are fixed to the tip surface of the cylindrical support, and the laser light irradiation surface of the optical fiber The detection device according to claim 1, wherein a portion connected to the acoustic wave detection means and the acoustic wave detection / conversion means are accommodated in the cylindrical support.   The detection device according to claim 1, wherein the acoustic wave detection surface has an annular shape surrounding a light irradiation surface fixed to the front end surface of the support.   The detection apparatus according to claim 1, wherein the acoustic wave detection conversion means is a piezoelectric transducer.   The detection apparatus according to any one of claims 1 to 4, wherein the optical fiber includes a separation unit that separates laser light and fluorescence, and a fluorescence detection unit attached to the separation unit. .   A light detection optical fiber having a light detection surface disposed at one end thereof in proximity to the laser light irradiation surface of the optical fiber, and fluorescence detection means attached to the light detection optical fiber. Item 5. The detection device according to any one of Items 1 to 4.   The detection device according to any one of claims 1 to 6, which is used for measuring physical properties of cartilage tissue.   Laser light generation source, and laser light irradiation apparatus including a laser light transmission optical fiber having one end adjacent to the laser light generation source and having a laser light irradiation surface at the other end, attached to the optical fiber Separating means for separating the emitted laser light and fluorescence, and a photo-excited fluorescence detecting apparatus having fluorescence detecting means attached to the separating means, wherein the laser light irradiation surface of the optical fiber is provided separately. A photo-excited fluorescence detection device characterized by being fixed to the tip surface of the tool.   LASER LIGHT GENERATION SOURCE, LASER LIGHT IRRADIATION DEVICE INCLUDING LASER LIGHT TRANSMISSION OPTICAL FIBER HAVING ONE END TERMINAL ASSOCIATED WITH THE LASER LIGHT GENERATION SOURCE AND LASER LIGHT EMITTING SURFACE ON THE OTHER A photo-excited fluorescence detection device comprising a light detection optical fiber having a light detection surface disposed near one side of a light irradiation surface at one end, and a fluorescence detection means attached to the light detection optical fiber, A photo-excited fluorescence detection device, wherein a laser beam irradiation surface and a light detection surface of an optical fiber are fixed to a tip surface of a separately prepared support.   The detection device according to claim 8 or 9, which is used for measuring physical properties of cartilage tissue.   A laser light source including a laser light transmission optical fiber having a laser light transmission optical fiber having one end attached close to the laser light source and having a laser light irradiation surface on the other end, by excitation of the laser light An acoustic wave detection / conversion unit that has a detection surface for the generated acoustic wave, converts the acoustic wave detected on the detection surface into an electric signal, and an acoustic wave detection device electrically connected to the conversion unit are combined. A method for measuring physical properties of a cartilage tissue by irradiating a cartilage tissue grown outside a living body with a laser beam and detecting an acoustic wave generated in the cartilage tissue using a photoexcited acoustic wave detection device.   The method according to claim 11, wherein the laser light irradiation surface of the optical fiber and the detection surface of the acoustic wave detection / conversion means are arranged to face each other with the cartilage tissue interposed therebetween.   In the optical fiber, using a photoexcitation acoustic wave detection device provided with a separation means for separating laser light and fluorescence, and a fluorescence detection means attached to the separation means, the cartilage tissue is irradiated with laser light. The method according to claim 11 or 12, wherein the physical properties of the cartilage tissue are measured by detecting the generated acoustic waves and fluorescence.   Photoexcitation provided with a light detection optical fiber having a light detection surface disposed at one end thereof in proximity to the laser light irradiation surface of the optical fiber, and a fluorescence detection means attached to the light detection optical fiber The method according to claim 11 or 12, wherein the physical property of the cartilage tissue is measured by detecting an acoustic wave and fluorescence generated in the cartilage tissue by irradiation with laser light using an acoustic wave detection device.   Laser light generation source, and laser light irradiation apparatus including a laser light transmission optical fiber having one end adjacent to the laser light generation source and having a laser light irradiation surface at the other end, attached to the optical fiber Using a light-excited fluorescence detection device having a separation means for separating the laser light and fluorescence, and a fluorescence detection means attached to the separation means, the cartilage tissue grown outside the body is irradiated with laser light, and the cartilage tissue A method for measuring physical properties of the cartilage tissue by detecting fluorescence generated in the above.   LASER LIGHT GENERATION SOURCE, LASER LIGHT IRRADIATION DEVICE INCLUDING LASER LIGHT TRANSMISSION OPTICAL FIBER HAVING ONE END TERMINAL ASSOCIATED WITH THE LASER LIGHT GENERATION SOURCE AND LASER LIGHT EMITTING SURFACE ON THE OTHER A photo-excited fluorescence detection apparatus having a photo-detection optical fiber having a photo-detection surface disposed close to the light-irradiation surface at one end, and a fluorescence detection means attached to the photo-detection optical fiber is used in vitro. A method of measuring physical properties of a cartilage tissue by irradiating the grown cartilage tissue with laser light and detecting fluorescence generated in the cartilage tissue.   A laser light irradiation device including a laser light generation source, an acoustic wave detection conversion means for converting an acoustic wave detected on the detection surface into an electric signal, and a detection surface for an acoustic wave generated by excitation of the laser light; Using a photo-excited acoustic wave detection device combined with an acoustic wave detection device electrically connected to the conversion means, the cartilage tissue grown ex vivo is irradiated with laser light, and the acoustic wave generated in the cartilage tissue is emitted. A method for measuring the physical properties of the cartilage tissue by detection.   Separating means for separating laser light and fluorescence generated by excitation of the laser light, which are arranged between the laser light generation source and the cartilage tissue to be measured, and fluorescence detecting means attached to the separating means The method according to claim 17, wherein the physical property of the cartilage tissue is measured by detecting an acoustic wave and fluorescence generated in the cartilage tissue by laser light irradiation using a photoexcited acoustic wave detection device.   A laser light irradiation apparatus including a laser light generation source, a separation means for separating laser light and fluorescence generated by excitation of the laser light, and a light excitation fluorescence detection apparatus having a fluorescence detection means attached to the separation means, A method of measuring physical properties of a cartilage tissue by irradiating a cartilage tissue grown outside with a laser beam and detecting fluorescence generated in the cartilage tissue.

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