JP5672104B2 - Ultrasonic modulated light measuring device and ultrasonic modulated light measuring method - Google Patents

Description

  The present invention relates to an ultrasonic modulated light measuring device and an ultrasonic modulated light measuring method.

  In recent years, development of a biological light measurement device has been promoted as a technique capable of measuring a living tissue with minimal invasiveness. In such a biological light measurement device, it is possible to detect the morphological information and physiological information of the biological tissue from the measured results, and to measure the oxygen concentration and the like in the blood. However, since the biological tissue is a light scattering medium, even if the biological tissue is irradiated with the measuring light, the measuring light can go straight up to a few millimeters at most, and the range that can be measured is limited to the vicinity of the surface of the biological body. There was a problem that.

  Therefore, in recent years, development of an ultrasonic modulation light measurement technique that combines the above-described optical measurement technique and an ultrasonic wave that can penetrate to a deeper position in a living body has been advanced (for example, Patent Document 1, Non-patent document 1 etc.).

  When the living tissue is irradiated in a state where the ultrasonic waves are converged, it is known that the ultrasonic waves are not scattered so much in the living tissue and propagate in a straight line state unlike the case where the measurement light is irradiated. Therefore, in the method of ultrasonic modulation light measurement, a portion (hereinafter referred to as a test portion) in a living tissue is specified by ultrasonic waves using the characteristics of the ultrasonic waves.

  A coarse / dense state is formed in the test portion of the living tissue irradiated with ultrasonic waves. When the measurement light is irradiated there, the measurement light spreads in the living tissue including the test portion while being scattered in the living tissue. At that time, the density of the test portion formed by ultrasonic waves as described above interacts with the measurement light, and the measurement light is modulated. Hereinafter, the measurement light modulated in this way is referred to as ultrasonic modulation light.

  Then, the ultrasonic modulated light is measured by, for example, a photodetector arranged on the surface of the living body, the signal of the measured ultrasonic modulated light is analyzed, and only the modulated component is extracted from the signal to be detected. It is possible to obtain information on the living tissue at the part. In this way, in the ultrasonic modulation light measurement method, the morphological information, physiological information, and the like of the living tissue are detected using the ultrasonic waves and the measurement light.

  By the way, an ultrasonic modulation speckle light measurement method is known as a further developed method of such an ultrasonic modulation light measurement method (see Non-Patent Document 2). When highly coherent light such as laser light is applied to a surface that scatters and reflects light, a spotted pattern, that is, a speckle pattern is obtained.

  In the ultrasonic modulation speckle light measurement method, using this phenomenon, highly coherent light such as laser light (hereinafter simply referred to as laser light) is used as measurement light in the ultrasonic modulation light measurement method described above, and living tissue. The speckle pattern is photographed by irradiating the test portion with ultrasonic waves and laser light, detecting reflected light at a position at an arbitrary depth from the living body surface of the test portion.

  In this case, the speckle pattern is obtained when it is assumed that a minute surface (see, for example, FIGS. 6A and 6B described later) exists at a position at an arbitrary depth from the living body surface of the test portion. It is brought about by the reflected light at the minute surface. Further, the speckle pattern can be similarly photographed by detecting the transmitted light of the minute surface instead of the reflected light of the minute surface.

  In this specification, it is expressed as a speckle pattern by reflected light (or transmitted light) of laser light. However, actually, reflected light (or transmitted light) of laser light is further scattered in a living tissue. Then, the speckle pattern due to the scattered light is detected.

For example, in the speckle pattern analysis method described in Non-Patent Document 2, for example, An _{n, i, j} is _expressed as a depth z _n = 0.1 × n [mm from the living body surface of the test portion. ] (N is an integer of 0 or more), the pixel value at the pixel at the position of the coordinate (i, j) on the photographed speckle pattern image, and the depth from the living body surface of the test part for each n The following numerical value S _n is calculated for each z _n .

Note that, in Non-Patent Document 2, when t ₀ = 0 when the time point when the irradiated pulsed ultrasonic wave passes through the position (z = 0) on the living body surface is represented by time t _n = 0.1. Although the speckle patterns photographed after × n [μs], when the ultrasonic sound speed in the living body tissue and v, and the depth z _n and time t _n from the living body surface of the subject portion z _n = v × t _n is associated with one to one. Therefore, as described above, the same applies to the case where the depth z _n is used.

Then, a speckle pattern is imaged for each depth z _n while scanning while changing the depth z _n from the living body surface of the test portion (that is, changing the time t _n ). When the numerical values S _n at the depth z _n are calculated according to the above equation (1), the above numerical values are obtained at a position where there is no light-absorbing object such as blood, that is, a position of a living tissue other than a blood vessel or the like. _Sn is almost 1 (see FIG. 5B of the same document).

This is because the pixel value A _{n, i, j} of each pixel of the speckle pattern at the position of the depth z _n from the living body surface of the test part and each pixel value A _{0, i} at the position of the depth z _{0. , j} (see the numerator on the right side of equation (1) above) and each pixel value A _{1, i, j} at the position of depth z ₁ and each pixel value A at the position of depth z _{0 This} represents that the sum of differences from _{0, i, j} (see the denominator on the right side of the above equation (1)) is almost equal.

However, when the depth z _{n of the} test portion from the living body surface is a position where an object that absorbs light, such as blood, is present, that is, a position of a blood vessel or the like, the numerical value S _n is significantly larger than 1. . That is, at that position, the sum of differences between the pixel values A _{n, i, j} at the position of the depth z _n and the pixel values A _{0, i, j} at the position of the depth z ₀ ((1 ) (See the numerator on the right side of the equation) is the sum of the differences between the pixel values A _{1, i, j} at the position of the depth z ₁ and the pixel values A _{0, i, j} at the position of the depth z ₀ ( (See denominator on right side of equation (1) above).

In this way, the speckle pattern is photographed for each depth z _n while scanning while changing the depth z _n from the living body surface of the test portion, and the numerical value _Sn is calculated according to, for example, the above equation (1). Then, by analyzing the signal waveform of numbers S _n for each depth z _n, or a blood vessel such as the location of any depth z _n in the object part is present is known.

Then, the test unit of the biological tissue, by scanning two-dimensionally, for example, the depth z _n a direction perpendicular to the direction (i.e. a direction parallel to the surface of a living body), the three-dimensional position of the blood vessel or the like in the living tissue Can be detected automatically.

JP 2010-17375 A

Lihong V. Wang, Geng Ku, OPTICS LETTERS, Vol.23, No.12, p.975-977 (1998) Yu Sasakura, 1 other, “Research-Reflection-type ultrasonic modulation speckle light measurement method”, Biomedical engineering, Japan Society for Biomedical Engineering, 2007, Vol. 45, No. 4, p.235- 241

By the way, in the method described in Non-Patent Document 2 described above, for example, a pulsed ultrasonic wave having a frequency of 5.4 [MHz] is irradiated on a body tissue to be examined in a converged state. That is, 5.4 × 10 ⁶ vibrations (mainly longitudinal waves) are generated per second by the ultrasonic waves in the test portion. Then, a laser beam having a pulse width of 250 [ns] is irradiated there.

That is, in the above method, while the pulsed laser beam is irradiated, 5.4 × 10 ⁶ [Hz] × 2.5 × 10 ⁻⁷ [s] = 1. This means that 35 vibrations, that is, one or more vibrations (that is, the phase is 0 ° to 360 °) or more are generated.

Therefore, as described above, even if the speckle pattern at the position of the depth z _n from the living body surface of the test part is photographed, the speckle pattern to be photographed has a constant biological tissue at the depth z _n . A speckle pattern obtained by averaging the speckle patterns for each phase of 0 ° to 360 ° when vibrated with ultrasonic waves of amplitude is obtained. The pixel value _{An, i, j} of each pixel of the speckle pattern is also an average value of the pixel values for each phase.

Therefore, it is calculated numerically S _n according to the above (1), for example, a numerical value S _n in the numerical S _n and position of the biological tissue other than a blood vessel or the like in a position where a blood vessel or the like is present, no longer less appear large differences It is thought that.

  Thus, for example, Non-Patent Document 2 proposes using a femtosecond titanium sapphire laser that can irradiate a laser beam with a femtosecond pulse width as a laser beam irradiation means. It is expensive and may increase the cost of the ultrasonic modulation light measuring device.

  For this reason, an ultrasonic modulation light measurement device using the ultrasonic modulation speckle light measurement method is a relatively inexpensive ordinary semiconductor laser capable of continuous light irradiation or pulsed light irradiation on the order of several tens of nanoseconds to several nanoseconds. In addition, it is desirable that the position where an object that absorbs light such as blood is present in the living tissue can be accurately specified.

  The present invention has been made in view of the above problems, and it is possible to accurately specify a position where an object that absorbs light such as blood exists in a living tissue using a normal semiconductor laser or the like. It is an object of the present invention to provide a possible ultrasonic modulated light measuring device and ultrasonic modulated light measuring method.

In order to solve the above-mentioned problem, the ultrasonic modulation light measuring device of the present invention is
A plurality of ultrasonic irradiation means for irradiating ultrasonic waves so that each of the irradiated ultrasonic waves intersects at a position at a predetermined depth from the biological surface,
Laser light irradiation means for irradiating the test portion with laser light;
Detecting means for detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or transmitting the position of the test portion;
With
The ultrasonic waves irradiated from each of the ultrasonic irradiation means have different frequencies,
Said detection means, said at a plurality of timings at which the amplitude at the position of the object part of the interference pattern of the composite wave in which each ultrasonic wave is formed by being crossed is different amplitude, the specification of each of the laser beam It is characterized by detecting a blue pattern.

In addition, the ultrasonic modulation light measuring device of the present invention is
A plurality of ultrasonic irradiation means for irradiating ultrasonic waves so that each of the irradiated ultrasonic waves intersects at a position at a predetermined depth from the biological surface,
Laser light irradiation means for irradiating the test portion with laser light;
Detecting means for detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or transmitting the position of the test portion;
With
The detection means changes the phase of the ultrasonic waves emitted from the respective ultrasonic irradiation means, and the amplitude of the interference fringes of the synthetic wave formed by intersecting the ultrasonic waves at the position of the test portion characterized in that in each condition that different amplitudes to detect the speckle pattern of the laser beam.

Furthermore, the ultrasonic modulation light measuring device of the present invention is
A plurality of ultrasonic irradiation means for irradiating ultrasonic waves so that each of the irradiated ultrasonic waves intersects at a position at a predetermined depth from the biological surface,
Laser light irradiation means for irradiating the test portion with laser light;
Detecting means for detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or transmitting the position of the test portion;
With
The detection means changes the crossing angle of the ultrasonic waves emitted from the respective ultrasonic wave irradiation means, and the interference fringes of the synthetic wave formed by crossing the ultrasonic waves at the position of the test portion. The speckle pattern of the laser beam is detected in each state where the amplitudes are different from each other .

In addition, the ultrasonic modulation light measurement method of the present invention,
An ultrasonic irradiation step of irradiating ultrasonic waves so that a plurality of irradiated ultrasonic waves intersect each other at a position at a predetermined depth from the surface of the living body in a test portion of the biological tissue;
A laser beam irradiation step of irradiating the test portion with a laser beam;
A detection step of detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or passing through the position of the test portion;
Have
The ultrasonic waves applied to the position in the ultrasonic irradiation step have different frequencies,
Wherein in the detection step, the at a plurality of timings at which the amplitude becomes different amplitude at the position of the object part of the interference pattern of the composite wave in which each ultrasonic wave is formed by being crossed, the specification of each of the laser beam It is characterized by detecting a blue pattern.

Furthermore, the ultrasonic modulation light measuring method of the present invention is:
An ultrasonic irradiation step of irradiating ultrasonic waves so that a plurality of irradiated ultrasonic waves intersect each other at a position at a predetermined depth from the surface of the living body in a test portion of the biological tissue;
A laser beam irradiation step of irradiating the test portion with a laser beam;
A detection step of detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or passing through the position of the test portion;
Have
In the ultrasonic irradiation step, the phase of the ultrasonic wave irradiated to the position is changed, and the ultrasonic waves are irradiated so that the plurality of irradiated ultrasonic waves intersect,
Wherein in the detection step, it is amplitude different from the amplitude at the position of the object part of the ultrasonic interference fringes of the composite wave in which the respective ultrasonic changing the phase is formed by being cross-irradiated to the position in each state, characterized in that it detects the speckle pattern of the laser beam.

Furthermore, the ultrasonic modulation light measuring method of the present invention is:
An ultrasonic irradiation step of irradiating ultrasonic waves so that a plurality of irradiated ultrasonic waves intersect each other at a position at a predetermined depth from the surface of the living body in a test portion of the biological tissue;
A laser beam irradiation step of irradiating the test portion with a laser beam;
A detection step of detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or passing through the position of the test portion;
Have
In the ultrasonic irradiation step, by changing the intersecting angle of the ultrasonic waves irradiated to the position, each of the irradiated ultrasonic waves is irradiated so that the ultrasonic waves cross each other,
Wherein in the detection step, the amplitude of the amplitude at the position of the object part of the ultrasonic interference fringes of the composite wave in which the respective ultrasonic changing the crossing angle is formed by being crossed in the irradiated are different from the positions The speckle pattern of the laser beam is detected in each state .

  According to the ultrasonic modulation light measurement device and the ultrasonic modulation light measurement method of the present invention, when an object that absorbs light, such as blood, is present at a predetermined position of the test portion, blood or the like Since the laser beam is absorbed, the intensity of the reflected or transmitted light of the laser beam is weakened. Therefore, the change that appears in the information of the speckle pattern obtained is relatively small depending on whether the amplitude of the interference fringes of the synthesized wave of the ultrasonic waves irradiated so as to intersect at the position is large or small.

  In addition, when there is a living tissue that is difficult to absorb light other than blood vessels at the position, the speckle pattern information obtained depends on whether the amplitude of the interference fringes of the synthesized wave of each ultrasonic wave is large or small. A relatively large change will appear.

  Therefore, for example, by detecting the difference in change that appears in such speckle pattern information, the position where an object that absorbs light such as blood exists in the living tissue, that is, the position where the blood vessel or the like exists is accurately determined. It becomes possible to specify.

  Further, in the ultrasonic modulation light measuring apparatus of the system as in the present invention, it is not necessary to use an expensive and large light source such as a femtosecond titanium sapphire laser as the laser light irradiation means, continuous light irradiation or several tens of nanoseconds The above configuration can be realized by using a relatively inexpensive ordinary semiconductor laser or the like capable of irradiating pulsed light on the order of several nanoseconds. Therefore, it becomes possible to manufacture the ultrasonic modulation light measurement device at a low cost. In addition, since the semiconductor laser is usually small, it is possible to manufacture the ultrasonic modulation light measuring device in a smaller size.

It is a block diagram which shows the structure of the ultrasonic modulated light measuring device which concerns on each embodiment. It is a figure at the time of seeing the ultrasonic modulation light measuring device of Drawing 1 from the side. It is a graph showing the synthetic wave of each ultrasonic wave which has an interference fringe. It is a figure which shows the interference fringe formed in the synthetic wave of each ultrasonic wave formed in the predetermined position of a to-be-tested part in 1st Embodiment. (A) is an enlarged view of FIG. 4, (B) is a figure which shows the state after predetermined time passes from the state of (A). (A) It is a figure explaining the interference fringe of the synthetic wave formed in the circumference | surroundings of the said position on the virtual micro surface orthogonal to a depth direction including a predetermined position, (B) is the state of (A) It is a figure which shows the state after predetermined time passes since. 4 is a graph showing a composite wave of each ultrasonic wave formed at a predetermined position of a test part in the second and third embodiments, where (A) shows a case where the amplitude is large, and (B) shows a case where the amplitude is small. Represent.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an ultrasonic modulation light measurement apparatus and an ultrasonic modulation light measurement method according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of an ultrasonically modulated light measuring apparatus according to the first embodiment of the present invention. The ultrasonic modulation light measuring apparatus 1 is composed of a plurality of ultrasonic irradiation means 2a, 2b, laser light irradiation means 3, detection means 4, control means 5, analysis means 6, and the like.

  If necessary, an external device such as a memory or a printer is connected to the control means 5 or the analysis means 6, for example. For example, the control means 5 and the analysis means 6 can be configured on a single computer (not shown). Furthermore, the ultrasonic irradiation means 2a and 2b, the laser light irradiation means 3, the detection means 4 and the like shown in FIG. 1 and FIG. 2 to be described later can be integrated, or they can be integrated with the control means 5. It is also possible to construct it.

  Further, δ in FIG. 1 will be described in a third embodiment to be described later.

  In the ultrasonic modulation light measuring apparatus 1, a plurality of ultrasonic irradiation means 2 are provided. In the following, a case where two ultrasonic irradiation means 2 are provided will be described. However, three or more ultrasonic irradiation means 2 may be provided and will be described in the same manner.

  As shown in FIG. 1, the plurality of ultrasonic irradiation means 2 a and 2 b are applied to each ultrasonic wave irradiated at a position Pz at a predetermined depth z from the biological surface Bs in the test portion Ba of the biological tissue B. The ultrasonic waves Swa and Swb are irradiated so that Swa and Swb intersect each other.

In the present embodiment, the ultrasonic irradiation means 2a and 2b include ultrasonic transducers 21a and 21b that respectively emit ultrasonic waves Swa and Swb, and ultrasonic transducer drivers 22a that drive the ultrasonic transducers 21a and 21b, respectively. 22b and function generators 23a and 23b for setting the frequency f _SW [MHz] and the phase θ of the ultrasonic waves Swa and Swb irradiated from the ultrasonic transducers 21a and 21b, respectively.

  In the present embodiment, the ultrasonic wave irradiation means 2a and 2b converge the ultrasonic waves Swa and Swb irradiated from the ultrasonic transducers 21a and 21b at a predetermined position Pz in the test portion Ba. The converging devices 24a and 24b are provided respectively.

  As shown in FIG. 1, the laser beam irradiation means 3 irradiates the test portion Ba with a laser beam Lb that is measurement light. In FIG. 1 and FIG. 2 described later, the laser beam irradiation means 3 is directed toward the position Pz of the test portion Ba where the ultrasonic waves Swa and Swb irradiated from the ultrasonic wave irradiation means 2a and 2b intersect. The case where it is comprised so that the laser beam Lb which is measurement light may be irradiated is shown. However, if the laser beam Lb is irradiated so that the laser beam Lb reaches the test portion Ba from the laser beam irradiation means 3, the laser beam Lb is scattered in the living tissue B and reaches the position Pz. Therefore, it is not always necessary to irradiate the laser beam Lb toward the position Pz.

In the present embodiment, the laser light irradiation means 3 sets a light source 31 that emits the laser light Lb, a light source driver 32 that drives the light source 31, a frequency f _L [MHz] of the laser light Lb that is emitted from the light source 31, and the like. The function generator 33 is provided.

  In the present embodiment, the light source 31 is not an expensive and large light source such as a femtosecond titanium sapphire laser, but is a relatively inexpensive ordinary light that can be irradiated with continuous light or pulsed light on the order of several tens of nanoseconds to several nanoseconds. A semiconductor laser or the like is used. In the present embodiment, the laser beam irradiation means 3 is provided with a condensing lens 34 for condensing the laser beam Lb irradiated from the light source 31 at a predetermined position Pz in the test portion Ba. ing.

  In addition, since the laser beam Lb irradiated from the laser beam irradiation unit 3 is diffused in the living tissue B, the condensing lens 34 is not necessarily provided. However, when the condensing lens 34 is used, for example, the distribution of the light absorption region in the vicinity (for example, subcutaneous number [mm]) of the living body surface Bs (see FIG. 1) can be detected with high spatial resolution. Therefore, for example, the condensing lens 34 can be configured to be detachably attached to the laser light irradiation means 3.

  In FIG. 1, the laser beam irradiation unit 3 is expressed so as to be provided at a position between the two ultrasonic beam irradiation units 2 a and 2 b, but it is possible to irradiate the laser beam Lb to the test portion Ba. As long as the position is possible, the laser beam irradiation means 3 can be provided at an arbitrary position.

  In the present embodiment, each of the ultrasonic waves Swa and Swb irradiated from the two ultrasonic irradiation units 2a and 2b and the laser beam Lb irradiated from the laser light irradiation unit 3 are both continuous waves (CW: Although it is assumed that the wave is a continuous wave, any of the above can be a pulse wave (PW) as described in Non-Patent Document 2, for example. Also, one of the ultrasonic waves Swa, Swb and the laser beam Lb can be a continuous wave and the other can be a pulse wave.

  Further, when any one or both of the ultrasonic waves Swa and Swb and the laser beam Lb are converted into pulse waves, for example, ultrasonic wave irradiation units 2a and 2b and laser beam irradiation units that emit pulse waves from the control unit 5 described later. 3 can be configured to transmit a trigger signal to synchronize the irradiated pulse wave.

  The ultrasonic irradiation means 2 and the laser light irradiation means 3 that irradiate the ultrasonic wave Sw and the laser light Lb as a continuous wave are generally cheaper than the ultrasonic irradiation means 2 and the like that irradiate the ultrasonic wave Sw as a pulse wave. is there. Therefore, if the ultrasonic wave irradiation means 2 or the laser light irradiation means 3 that irradiates the ultrasonic wave Sw or the laser light Lb as a continuous wave is used, the ultrasonic modulation light measuring device 1 can be manufactured at a low cost. There is.

  As shown in FIG. 1, the detection means 4 detects a speckle pattern by the reflected light Lr reflected from the laser light Lb at the position Pz of the test portion Ba.

  In the speckle pattern, it is assumed that a minute surface (see, for example, the minute surface M in FIGS. 6A and 6B described later) exists at the position Pz of the test portion Ba where the ultrasonic waves Swa and Swb intersect. In this case, it is also caused by the reflected light Lr on the minute surface, but as described above, the speckle pattern can be similarly photographed even if the transmitted light (not shown) of the minute surface is detected. Therefore, in the following, the case where the speckle pattern is photographed by detecting the reflected light Lr will be described, but it is also possible to detect the transmitted light and photograph the speckle pattern by the transmitted light.

  In addition, the detection unit 4 includes, for example, ultrasonic waves Swa and Swb and laser beam irradiation units irradiated from the ultrasonic irradiation units 2a and 2b as shown in FIG. 3 is provided at a position where the laser beam Lb irradiated from 3 is not blocked.

  The detection means 4 may be configured to photograph a speckle pattern using a CCD (Charge Coupled Device) camera or the like as a multi-element photodetector as described in Non-Patent Document 2, for example. Is possible. Further, for example, a photomultiplier tube (also referred to as photomultiplier) can be used as the detection means 4.

In the present embodiment, the detection means 4 uses the detected speckle pattern information (that is, the pixel value A _{n, i, j of} each pixel described above when using a CCD camera as a multi-element photodetector, for example). It transmits to the analysis means 6 mentioned later.

  The control means 5 includes a computer (not shown), a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface connected to a bus, and a dedicated control circuit. The ultrasonic irradiation means 2a, 2b, the laser light irradiation means 3, the detection means 4 and the like are controlled to start, stop, and operate.

The control unit 5 includes an input unit (not shown), and the frequency f of the ultrasonic waves Swa and Swb irradiated from the ultrasonic transducers 21a and 21b to the function generators 23a and 23b of the ultrasonic wave irradiation units 2a and 2b. _SW , phase θ, and the like can be set, and the frequency f _L of the laser light Lb emitted from the light source 31 can be set for the function generator 33 of the laser light irradiation means 3.

  In addition, the control means 5 may emit a pulse wave when the ultrasonic waves Swa, Swb and the laser light Lb are emitted from the ultrasonic wave irradiation means 2a and 2b and the laser light irradiation means 3 as described above. For example, a trigger signal is transmitted to the irradiating ultrasonic wave irradiation means 2a, 2b and the laser light irradiation means 3, and appropriate control is performed on each means.

  The analysis means 6 is composed of a computer or the like, and analyzes the speckle pattern information detected and transmitted by the detection means 4 to identify the position where an object that absorbs light such as blood exists in the living tissue. The process of doing is performed. The processing in the analyzing means 6 will be described later.

[Configurations Characteristic of the Embodiment]
Hereinafter, a characteristic configuration and the like of the present embodiment will be described. The operation of the ultrasonic modulated light measurement device 1 and the ultrasonic modulated light measurement method according to this embodiment will also be described.

  In the ultrasonic modulated light measuring apparatus 1 according to the present embodiment, as shown in FIG. 1, the laser light irradiation means 3 irradiates the test portion Ba with the laser light Lb that is measurement light (laser light irradiation step). Then, as described above, the ultrasonic waves Swa and Swb are irradiated from the plural ultrasonic irradiation units 2a and 2b, respectively. Then, in the test portion Ba of the biological tissue B, the ultrasonic waves Swa and Swb are respectively applied so that the irradiated ultrasonic waves Swa and Swb intersect at a position Pz at a predetermined depth z from the biological surface Bs. Irradiation (ultrasonic irradiation process).

  At this time, in the present embodiment, the frequencies fa and fb of the ultrasonic waves Swa and Swb irradiated from the ultrasonic irradiation units 2a and 2b are set to be slightly different from each other. .

Now, assuming that the frequencies of the ultrasonic waves Swa and Swb are fa and fb, respectively, and the waveforms of the ultrasonic waves Swa and Swb are expressed by sin (2πfat) and sin (2πfbt), the position of the test portion Ba The combined wave of each ultrasonic wave Swa and Swb at Pz is
sin (2πfat) + sin (2πfbt)
= 2 cos {2π (fa−fb) t / 2} × sin {2π (fa + fb) t / 2} (2)
It is expressed.

  When the frequencies fa and fb of the ultrasonic waves Swa and Swb are slightly different from each other as described above, the beat period Tb is 1 / (fa -Fb) [s] (the beat frequency is the reciprocal of fa-fb [Hz]) interference fringes appear.

  As described above, in this embodiment, the ultrasonic waves Swa and Swb having slightly different frequencies fa and fb are irradiated from the ultrasonic irradiation units 2a and 2b so as to intersect at the predetermined position Pz of the test portion Ba. As shown in FIG. 4, the interference fringes are formed in the combined wave of the ultrasonic waves Swa and Swb formed at the predetermined position Pz of the test portion Ba of the biological tissue B. ing.

  Note that in FIG. 4 and FIGS. 5A, 5B, 6A, and 6B described later, the amplitude Am (see FIG. 3) of the interference fringes of the ultrasonic waves Swa and Swb is shaded. In the portion shown in black, the amplitude Am is small, and the whiter the amplitude Am is, the larger the amplitude Am is. 4 and 5A, 6B, 6A, and 6B show the cases where the ultrasonic waves Swa and Swb are continuous waves, but the ultrasonic waves Swa and Swb are the same. Even in the case of a pulse wave, interference fringes appear in the combined wave at the position Pz.

  Ultrasonic waves are only longitudinal waves in gas or liquid (that is, the same wave propagation direction and vibration direction), but in solids, longitudinal waves and transverse waves (that is, the wave propagation direction and vibration direction are at right angles). Direction) or even waves including torsional waves, surface waves, and the like. In the present embodiment, since the two ultrasonic waves Swa and Swb are irradiated so as to intersect, the propagation directions of the ultrasonic waves Swa and Swb are not the same.

  Therefore, in practice, the combined wave of each of the ultrasonic waves Swa and Swb cannot be simply expressed as in the above equation (2). However, in the following, based on the above equation (2) in order to simplify the explanation. I will explain.

  Further, as the frequencies fa and fb of the ultrasonic waves Swa and Swb become closer to each other, the beat frequency fa-fb [Hz] of the interference fringes of those combined waves becomes smaller and the beat cycle Tb (= 1 / (fa−fb) [s]) becomes longer. Then, among the interference fringes in which the beat period Tb becomes longer and slowly increases and decreases, the synthesized wave itself shown by the solid line in FIG. 3 is the frequency fa of the original ultrasonic wave Swa (or the frequency fb of the original ultrasonic wave Swb). As with, it vibrates violently on the order of MHz.

  In FIG. 3 and FIGS. 7A and 7B described later, the vertical axis represents the displacement in the propagation direction in the composite wave formed at the position Pz of the test portion Ba. Therefore, the amplitude Am represents the amplitude in the propagation direction of the composite wave.

  On the other hand, as shown in FIG. 3 and the above equation (2) (refer to the term 2cos {2π (fa−fb) t / 2} on the right side), the synthesis of the respective ultrasonic waves Swa and Swb at the position Pz of the test portion Ba. The amplitude Am of the wave interference fringes changes with time t.

  That is, as shown in the enlarged views of FIGS. 5A and 5B in which the magnitudes of the amplitudes Am of the interference fringes at different times t are expressed in shades, at the position Pz of the portion Ba to be examined, The amplitude Am of the interference fringes of the synthesized wave of the ultrasonic waves Swa and Swb changes. Note that FIG. 5B shows a state after a predetermined time has elapsed from the state of FIG.

  Further, when the above-described virtual minute surface that includes the position Pz of the test portion Ba and is orthogonal to the depth z direction is viewed, the interference fringes of the combined wave of the ultrasonic waves Swa and Swb are shown in FIG. As shown in FIG. 5, the portion is also formed around the position Pz on the minute surface M. Then, the interference fringes on the minute surface M also change according to the time t as shown in FIG.

  Note that FIG. 6B shows a state after a predetermined time has elapsed from the state of FIG. 6 (A) and 6 (B), the minute surface M is represented large so that the interference fringes on the minute surface M can be easily seen. It is virtually assumed as a very small surface having a focus size of each of the ultrasonic waves Swa and Swb converged at the position Pz of Ba.

  Therefore, in the present embodiment, as described above, the ultrasonic waves Swa and Swb having slightly different frequencies fa and fb from the ultrasonic irradiation units 2a and 2b intersect at the predetermined position Pz of the test portion Ba. The interference fringes are formed in the synthesized wave at the position Pz. Then, the speckle pattern is detected by the detection means 4 at a plurality of timings (that is, at a plurality of different times t) at which the interference Am amplitude Am (see FIG. 3) at the interference fringe position Pz becomes different amplitudes. Configured (detection step).

  That is, in this embodiment, the speckle pattern by the reflected light Lr from the predetermined position Pz of the part Ba to be detected is detected by the detection means 4 at different timings, so that the amplitude Am of the interference fringes at the position Pz is obtained. Information on the speckle pattern when it is large and information on the speckle pattern when the amplitude Am of the interference fringes is small are detected.

  In each speckle pattern, not only the difference between the case where the amplitude Am of the interference fringes at the position Pz is large and the case where it is small, but also the minute surface M as shown in FIGS. 6 (A) and 6 (B). The change of the interference fringes of the synthetic wave irradiated on is also reflected.

  If comprised in this way, the following effects will be acquired.

  In the method described in Non-Patent Document 2 described above, pulsed ultrasonic waves and pulsed laser light are applied to the test portion Ba of the living tissue B, but the pulsed laser light is applied to the test portion Ba. During the irradiation of the position Pz, vibrations of one cycle or more are generated at the position Pz by the ultrasonic waves. Therefore, the detected speckle pattern information is averaged data for one cycle or more of vibrations of biological tissue or blood generated by the ultrasonic waves at the position Pz.

Therefore, numerical values in their be calculated numerically S _n in accordance with the equation (1) based on the information, for example, a numerical S _n at a position such as a blood vessel is present which blood flows, the position of the biological tissue other than a blood vessel such as S _It was thought that no big difference appeared with _n .

  On the other hand, also in the present embodiment, the ultrasonic waves Swa and Swb and the laser beam Lb (see FIG. 1 and the like) to be irradiated are ultrasonic waves at the position Pz of the test portion Ba, whether they are continuous waves or pulse waves. The speckle pattern information detected by irradiation with the Swa, Swb and the laser beam Lb is averaged data for one period or more of vibrations of the living tissue or blood generated by the ultrasonic waves at the position Pz. .

  However, in the present embodiment, as described above, the speckle pattern information when the interference Am amplitude Am is large at the position Pz and the speckle pattern information when the interference Am amplitude Am is small are detected. can do. As described above, the information of each speckle pattern also reflects the change in the interference fringes of the composite wave irradiated on the minute surface M as shown in FIGS. 6 (A) and 6 (B). (The same applies to the following).

  Therefore, a speckle pattern when the biological tissue or blood is greatly shaken by the interference fringes of the synthesized waves of the ultrasonic waves Swa and Swb at the position Pz of the test portion Ba (that is, when the amplitude Am of the interference fringes is large). And the speckle pattern information when the way in which the biological tissue or blood is shaken by the interference fringes is small (that is, when the amplitude Am of the interference fringes is small) can be detected separately.

  In addition, as described above, information on a plurality of speckle patterns with different ways of shaking, such as living tissue or blood, can be obtained at the position Pz of the test portion Ba. Thus, the position where the blood vessel or the like is present in the living tissue B can be accurately specified.

  The analyzing means 6 analyzes the speckle pattern information detected a plurality of times by the detecting means 4 as described above, that is, the speckle pattern information when the amplitude Am of the interference fringes at the position Pz is large and small. Thus, processing such as specifying a position where an object that absorbs light, such as blood, is present in the living tissue is performed (analysis step).

In the analysis means 6, for example, using the speckle pattern analysis method described in Non-Patent Document 2 described above, the predetermined part from the biological surface Bs in the test portion Ba of the biological tissue B according to the above equation (1). The numerical value S _n at the position Pz of the depth z _n can be calculated.

In the present embodiment, as described above, as speckle pattern information, information on at least two types of speckle patterns when the amplitude Am of the interference fringes at the position Pz is large and small (that is, the aforementioned biological tissue, blood, etc.) Information on a plurality of speckle patterns with different ways of shaking. Therefore, as a numerical value S _n at position Pz of predetermined depth z _n, in response to each case, and numbers S _n based on the information of the speckle pattern when the amplitude Am of the interference fringes at the position Pz is large, interference and numerical S _n based on the information of the speckle pattern when fringe amplitude Am is small are calculated.

Then, scanning is performed by changing the depth z _n from the living body surface Bs where the ultrasonic waves Swa and Swb irradiated from the ultrasonic irradiation units 2a and 2b intersect with each other. A plurality of speckle pattern information is detected for each position Pz. Each ultrasonic Swa, scan Swb is performed also in the direction perpendicular to the depth z _n direction (i.e. a direction parallel to the surface of the living body).

Then, each time the information on a plurality of speckle patterns at the position Pz is transmitted from the detection means 4, the analysis means 6 is a numerical value based on the information on the speckle pattern when the amplitude Am of the interference fringes at the position Pz is large. and S _n, continue to calculate the numerical value S _n, respectively, based on the speckle pattern information when the amplitude Am of the interference fringes is small.

Therefore, in the present embodiment, the signal waveform of the depth z _n direction numbers S _n of the subject portion Ba (see FIG. 5 in Non-Patent Document 2 (b)) is large amplitudes Am of the interference fringes at the position Pz and numerical S _n based on the speckle pattern information in the case, in the numeric S _n based on the speckle pattern information when the amplitude Am of the interference fringes is small, will be obtained by two kinds.

Therefore, for example, by comparing the signal waveforms of numbers S _n obtained on the basis of the information in each case, it is accurately determined whether the blood vessel or the like is present in each position Pz of the test portion Ba It becomes possible. In addition, by detecting the existence position of a blood vessel or the like based on a plurality of detection results in this way, it is possible to further improve the accuracy of detection of the existence position of the blood vessel or the like.

  On the other hand, the analyzing means 6 analyzes the change in the speckle pattern information detected each time based on the speckle pattern information detected a plurality of times at different timings as described above. It is also possible to configure so as to specify a position where a blood vessel or the like is present.

  That is, for example, the speckle pattern information when the amplitude Am of the interference fringes at the position Pz is small and the information of the speckle pattern when the amplitude Am of the interference fringes is large are compared, and how they change. It is also possible to configure such that the position where the blood vessel or the like exists in the living tissue B is identified.

  Specifically, when there is a living tissue that hardly absorbs light other than blood vessels at the position Pz as compared to the case where an object that absorbs light such as blood exists at the position Pz of the test portion Ba, A relatively large change appears in the speckle pattern information obtained depending on whether the amplitude Am of the interference fringes of the synthesized wave of the ultrasonic waves Swa and Swb is large or small (that is, in each case where the shaking is different). .

  On the other hand, when there is an object that absorbs light such as blood at the position Pz of the test portion Ba, the blood or the like absorbs the laser light Lb, and thus the reflected light Lr (or transmitted light) of the laser light Lb. The intensity of light is weakened. Therefore, the speckle pattern obtained by the case where the amplitude Am of the interference fringes of the combined wave of the ultrasonic waves Swa and Swb is large and small as compared with the case where a living tissue that hardly absorbs light exists at the position Pz. Changes that appear in information are relatively small. Or almost the same data.

Therefore, for example, using an analysis method of the speckle pattern that is described in Non-Patent Document 2 described above to calculate the numerical value S _n for each of the foregoing cases, comparing the signal waveforms of numbers S _n. Then, identify ultrasound Swa, a portion numeric S _n changes greatly when a large amplitude Am than when the amplitude Am of the interference fringes of the composite wave of Swb is small as a portion there is biological tissue other than a blood vessel, a portion numeric S _n is not significantly changed can be configured to identify a portion of a blood vessel or the like is present.

  If comprised in this way, based on the difference in the characteristic of the blood tissue etc. which absorb light, and the biological tissue which hardly absorbs light, the position where the object which absorbs light, such as blood, exists in the biological tissue B, ie, blood vessel It becomes possible to specify the position where etc. exist exactly.

  In the case of such a configuration, as described above, it is not necessary to use the analysis method described in Non-Patent Document 2 or use a CCD camera or the like that is a multi-element photodetector as the detection means 4. Good. For example, it is possible to use a photomultiplier tube composed of one element as the detection means 4.

When a CCD camera or the like, which is a multi-element photodetector, is used as the detection means 4, as described above, the speckle pattern at the position Pz at the depth z _n from the biological surface Bs is received for each pixel, and for each pixel. The pixel value A _{n, i, j} is detected. On the other hand, when a photomultiplier tube made up of one element is used as the detection means 4, it is equivalent to the total value of the pixel values _{An, i, j} of the speckle pattern for each pixel of the multi-element photodetector. value (hereinafter, referred to as the total value a _n.) so that is detected.

However, also in this case, the total value A _n detected by the photomultiplier tubes and the like, when the object that absorbs light such as blood at a position Pz of the object part Ba is present, interference in the position Pz change of the total value a _n with the case and the case fringe amplitude Am is large or small decreases, when the living body tissue other than a blood vessel or the like is present in the position Pz, the amplitude Am of the interference fringes in the position Pz change of the total value a _n is increased in the case when large and small.

Therefore, in the same manner as described above, a living tissue other than a blood vessel has a portion where the total value _An greatly changes when the amplitude Am is larger than when the amplitude Am of the interference fringes of the combined waves of the ultrasonic waves Swa and Swb is small. identified as a partial present, a portion where the total value a _n is not significantly changed by specifying a portion where a blood vessel or the like is present, it is possible to identify to accurately position the blood vessel or the like is present in the living body tissue B .

  As described above, according to the ultrasonic modulated light measurement device 1 and the ultrasonic modulated light measurement method according to the present embodiment, the ultrasonic waves having slightly different frequencies fa and fb from the plurality of ultrasonic irradiation units 2a and 2b. Swa and Swb are irradiated so as to intersect at a position Pz at a predetermined depth z from the living body surface Bs of the test portion Ba of the living tissue B, and the laser beam Lb is applied from the laser light irradiation means 3 to the test portion Ba. The reflected light Lr of the laser beam Lb is irradiated at a plurality of timings when the amplitude Am at the position Pz of the interference fringes of the synthesized wave formed by irradiation and the intersecting ultrasonic waves Swa and Swb are different from each other. A speckle pattern by (or transmitted light) is detected.

  When an object that absorbs light, such as blood, is present at the position Pz of the test portion Ba, blood or the like absorbs the laser light Lb, and therefore the intensity of the reflected light Lr (or transmitted light) of the laser light Lb. Is weakened. Therefore, the changes appearing in the information of the speckle pattern obtained are compared between the case where the amplitude Am of the interference fringes of the combined wave of the ultrasonic waves Swa and Swb is large and the case where the amplitude Am is small (that is, in each case where the shaking is different). Become smaller.

  On the other hand, when there is a living tissue that hardly absorbs light other than blood vessels at the position Pz, speckles obtained depending on whether the amplitude Am of the interference fringes of the combined wave of the ultrasonic waves Swa and Swb is large or small are obtained. A relatively large change appears in the pattern information.

  In this case, as described above, the change in the speckle pattern information also reflects the change in the interference fringes of the composite wave irradiated on the minute surface M (see FIGS. 6A and 6B). However, the change in the speckle pattern due to this also appears to be greatly affected when there is an object that absorbs light such as blood at the position Pz of the test portion Ba. When there is a living tissue that hardly absorbs light, the influence of changes that appear is reduced.

  Therefore, for example, it is possible to detect a difference in change appearing in such speckle pattern information, and a position in the living tissue B where an object that absorbs light such as blood exists, that is, a position where a blood vessel or the like exists. Can be accurately identified.

  In this case, it is not necessary to use an expensive and large light source such as a femtosecond titanium sapphire laser as the laser light irradiation means 3, and continuous light irradiation or pulsed light irradiation on the order of several tens of nanoseconds to several nanoseconds is possible. The above configuration can be realized by using a relatively inexpensive ordinary semiconductor laser or the like. Therefore, it becomes possible to manufacture the ultrasonic modulation light measuring device 1 at a low cost. Moreover, since the semiconductor laser is usually small, the ultrasonic modulated light measuring device 1 can be manufactured in a smaller size.

  In the present embodiment and the following embodiments described later, for each position Pz of the test portion Ba of the biological tissue B, twice when the amplitude Am of the interference fringe of the synthesized wave at the position Pz is large and small. However, the detection of the speckle pattern at each position Pz is not limited to two times, but is configured to be performed three or more times. Is also possible.

[Second Embodiment]
In the first embodiment, the frequencies fa and fb of the ultrasonic waves Swa and Swb that intersect at the predetermined position Pz of the test portion Ba of the biological tissue B are slightly different from each other, and are formed at the position Pz. The case has been described in which interference fringes are generated in the combined wave of each of the ultrasonic waves Swa and Swb, and the speckle pattern is detected when the amplitude Am of the interference fringes is large and when the amplitude Am is small.

  In the present embodiment and a third embodiment to be described later, a case will be described in which ultrasonic waves Swa and Swb having the same frequency f are irradiated from the ultrasonic irradiation units 2a and 2b and intersected at the position Pz of the test portion Ba. .

  Although description by the equation such as the equation (2) is omitted, in this case as well, interference fringes are generated in the combined wave of the ultrasonic waves Swa and Swb at the predetermined position Pz of the test portion Ba where the ultrasonic waves Swa and Swb intersect. Formed. However, in this case, since the frequencies f of the ultrasonic waves Swa and Swb are the same, the amplitude Am of the interference fringes at the position Pz does not change with time as in the case of the first embodiment.

  That is, in the case of the present embodiment, the amplitude Am is the time as shown by 2 cos {2π (fa−fb) t / 2} corresponding to the amplitude Am in the above equation (2) shown in the first embodiment. There is no change. Therefore, the interference fringes do not change with time from the state shown in FIG. 5A to the state shown in FIG. 5B, for example, and are shown at the position Pz in FIG. 5A, for example. When the interference fringes in the state are formed, the interference fringes continue to be in the state shown in FIG.

  That is, in the present embodiment, the interference fringes that appear in the combined wave have the same amplitude Am as shown in FIG. 7A, for example, as shown in FIG. Is maintained. Therefore, as in the first embodiment, the speckle pattern may be detected when the amplitude Am of the interference fringe is large and when the amplitude Am of the interference fringe is small using the temporal change of the interference fringe of the synthesized wave. Can not.

  Therefore, in the present embodiment, the synthesized wave formed by intersecting the ultrasonic waves Swa and Swb by changing the phase θ of the ultrasonic waves Swa and Swb irradiated from the ultrasonic wave irradiation means 2a and 2b. The speckle pattern is detected a plurality of times such that the amplitude Am at the position Pz of the test portion Ba has different amplitudes.

Specifically, when the phase θ of each ultrasonic wave Swa and Swb is expressed as θa and θb (both frequencies are f), the waveform of each ultrasonic wave Swa and Swb is expressed as sin (2πft + θa) and sin (2πft + θb), respectively. Therefore, if the combined wave at the position Pz follows the above equation (2),
sin (2πft + θa) + sin (2πft + θb)
= 2 cos {(θa−θb) / 2} × sin {2πft + (θa + θb) / 2} (3)
It is expressed.

In this case, the term 2cos {(θa−θb) / 2} does not include time t. Then, 2cos {(θa−θb) / 2} represents the amplitude Am of the interference fringe of the composite wave at the position Pz of the test portion Ba. That is,
Am = 2 cos {(θa−θb) / 2} (4)

  In addition, the above equation (4) is obtained by changing the phase θa of the ultrasonic wave Swa, the phase θb of the ultrasonic wave Swb, or both, and changing θa−θb, thereby detecting the ultrasonic waves Swa and Swb. This also shows that the amplitude Am of the interference fringes of the combined wave at the position Pz of the part Ba can be changed as shown in FIGS. 7A and 7B, for example.

  Therefore, in the present embodiment, first, each ultrasonic irradiation means 2a is set so that the ultrasonic waves Swa and Swb having predetermined phases θa and θb (both frequencies are f) intersect each other at the position Pz of the test portion Ba. 2b, the respective ultrasonic waves Swa and Swb are irradiated (ultrasonic irradiation step). Then, the laser beam Lb is irradiated from the laser beam irradiation means 3 to the test portion Ba (laser beam irradiation step). And the speckle pattern is detected by the detection means 4 (detection process).

  Subsequently, while maintaining the state in which the ultrasonic waves Swa and Swb intersect at the position Pz of the test portion Ba, one or both of the phases θa and θb of the ultrasonic waves Swa and Swb are changed to make θa−θb. Then, again, the respective ultrasonic waves Swa and Swb are irradiated from the respective ultrasonic irradiation means 2a and 2b (ultrasonic irradiation step). Then, the laser beam Lb is irradiated from the laser beam irradiation means 3 (laser light irradiation process) to the test portion Ba, and the speckle pattern is detected by the detection means 4 (detection process).

  Also in this case, as described above, the speckle pattern is not limited to detecting the speckle pattern twice by changing the phases θa and θb of the ultrasonic waves Swa and Swb, and the speckle pattern is detected by changing it three times or more. It is also possible to configure so as to.

  When configured as described above, as in the case of the first embodiment, the amplitude Am of the interference fringes of the combined wave of the ultrasonic waves Swa and Swb at the position Pz of the test portion Ba is large (see FIG. 7 (A)) and small case (FIG. 7B), it is possible to detect a speckle pattern by reflected light Lr (or transmitted light) from the position Pz. .

  Also in this case, by changing either one or both of the phases θa and θb of the ultrasonic waves Swa and Swb, the virtual position that includes the position Pz of the test portion Ba and is orthogonal to the depth z direction described above. For example, the interference fringes on the minute surface M also change from the state shown in FIG. 6A to the state shown in FIG. The change is reflected in the information of each speckle pattern.

  Therefore, as in the case of the first embodiment, in the ultrasonic modulated light measurement device 1 and the ultrasonic modulated light measurement method according to the present embodiment, blood or the like in the living tissue B based on such information. It is possible to accurately specify a position where an object that absorbs light exists, that is, a position where a blood vessel or the like exists.

  Also in this embodiment, it is not necessary to use an expensive and large light source such as a femtosecond titanium sapphire laser as the laser light irradiation means 3, and continuous light irradiation or pulsed light on the order of several tens of nanoseconds to several nanoseconds. The above-described configuration can be realized using a relatively inexpensive ordinary semiconductor laser that can be irradiated. Therefore, it becomes possible to manufacture the ultrasonic modulation light measuring device 1 at a low cost. Moreover, since the semiconductor laser is usually small, the ultrasonic modulated light measuring device 1 can be manufactured in a smaller size.

[Third Embodiment]
In the second embodiment described above, the ultrasonic waves Swa and Swb having the same frequency f are irradiated from the ultrasonic irradiation units 2a and 2b and intersected at the position Pz of the test portion Ba, and the phases of the ultrasonic waves Swa and Swb are intersected. The case where the amplitude Am of the interference fringe of the composite wave at the position Pz is changed by changing θa and θb has been described.

  However, the frequencies f of the ultrasonic waves Swa and Swb are the same, and the relative ultrasonic waves Swa and Swb irradiated from the ultrasonic wave irradiation means 2a and 2b can be compared without changing the phases θa and θb. By changing the crossing angle δ (see FIG. 1), the amplitude Am at the position Pz of the interference fringes of the composite wave formed by crossing the ultrasonic waves Swa and Swb is shown in FIG. ) And (B).

  In this case, since it is not always easy to explain with mathematical formulas such as the above formula (2), explanation using mathematical formulas is omitted. Also in this case, as in the case of the second embodiment, an interference fringe appears in the combined wave of the ultrasonic waves Swa and Swb at the position Pz of the test portion Ba, but the interference fringe position Pz. In this state, the amplitude Am does not change with time.

  In this embodiment, for example, position changing means (not shown) is provided in either one or both of the ultrasonic irradiation means 2a and 2b shown in FIG. 1, and first, the position of each ultrasonic irradiation means 2a and 2b. Is fixed at a position such that the intersection angle δ of the irradiated ultrasonic waves Swa and Swb becomes a predetermined angle.

  In this state, the ultrasonic waves Swa and Swb are irradiated from the ultrasonic wave irradiation means 2a and 2b so that the ultrasonic waves Swa and Swb intersect at the position Pz of the test portion Ba (ultrasonic irradiation process). . Then, the laser beam Lb is irradiated from the laser beam irradiation means 3 to the test portion Ba (laser beam irradiation step). And the speckle pattern by the reflected light Lr (or transmitted light) is detected by the detection means 4 (detection process).

  Subsequently, by changing the position of one or both of the ultrasonic irradiation means 2a and 2b, the position of each of the ultrasonic irradiation means 2a and 2b is determined by the intersection angle δ of the irradiated ultrasonic waves Swa and Swb. Is fixed at a position such that is at another predetermined angle. And each ultrasonic wave Swa and Swb are again irradiated from each ultrasonic irradiation means 2a and 2b so that each ultrasonic wave Swa and Swb cross | intersect at the said position Pz of to-be-tested part Ba (ultrasonic irradiation process). Then, the laser beam Lb is irradiated from the laser beam irradiation means 3 (laser light irradiation process) to the test portion Ba, and the speckle pattern by the reflected light Lr (or transmitted light) is detected by the detection means 4 (detection process). .

  Also in this case, as described above, the present invention is not limited to the case where the position of each ultrasonic irradiation means 2a, 2b is changed only once, but the position of each ultrasonic irradiation means 2a, 2b is changed twice or more. It is also possible to configure to detect each speckle pattern.

  With this configuration, as in the case of the second embodiment, the amplitude Am of the interference fringes of the combined wave of the ultrasonic waves Swa and Swb at the position Pz of the test portion Ba is large (FIG. 7). In each case (in the case of (A)) and small case (in the case of FIG. 7B), it is possible to detect the speckle pattern from the position Pz.

  Also in this case, the relative crossing angle δ (see FIG. 1) of each of the irradiated ultrasonic waves Swa and Swb is changed to include the position Pz of the test portion Ba described above in the depth z direction. The interference fringes on the virtual micro surface M orthogonal to each other also change, for example, from the state shown in FIG. 6A to the state shown in FIG. The change is reflected in the information of each speckle pattern.

  Therefore, as in the case of the first embodiment and the second embodiment, in the ultrasonic modulated light measuring device 1 and the ultrasonic modulated light measuring method according to the present embodiment, the living tissue is based on the information. It is possible to accurately specify the position where an object that absorbs light such as blood exists in B, that is, the position where a blood vessel or the like exists.

  Also in this embodiment, it is not necessary to use an expensive and large light source such as a femtosecond titanium sapphire laser as the laser light irradiation means 3, and continuous light irradiation or pulsed light on the order of several tens of nanoseconds to several nanoseconds. The above-described configuration can be realized using a relatively inexpensive ordinary semiconductor laser that can be irradiated. Therefore, it becomes possible to manufacture the ultrasonic modulation light measuring device 1 at a low cost. Moreover, since the semiconductor laser is usually small, the ultrasonic modulated light measuring device 1 can be manufactured in a smaller size.

[Fourth Embodiment]
By the way, in said 1st-3rd embodiment, the laser beam irradiation means 3 demonstrated on the assumption that the laser beam of a single wavelength was irradiated to the position Pz of to-be-tested part Ba.

  However, for example, the laser beam irradiation unit 3 shown in FIGS. 1 and 2 irradiates the laser beam Lb having a different wavelength, or the laser beam irradiation that irradiates the laser beam Lb having a different wavelength although not shown. A plurality of means 3 are provided, and the laser beam Lb having a different wavelength is irradiated onto the test portion Ba. And it is also possible to comprise so that the speckle pattern by the reflected light Lr (or transmitted light) of each laser beam Lb may each be detected by the detection means 4.

  For example, hemoglobin in blood is bound to oxygen (hereinafter, this state is referred to as oxygenated hemoglobin) and is not bound (hereinafter referred to as reduced hemoglobin (deoxygenated hemoglobin)). It is also known as oxygenated hemoglobin.))) And the absorption spectrum in the near infrared region is known to change.

  That is, in the near-infrared region where the wavelength is about 800 [nm], in the region where the wavelength is about 800 [nm] or more, oxygenated hemoglobin has higher absorbance than reduced hemoglobin, and the wavelength is about 800 [nm]. In the following regions, conversely, reduced hemoglobin has a feature that the absorbance is higher than oxygenated hemoglobin.

  Therefore, in the ultrasonic modulation light measuring apparatus 1 described above, for example, the laser beam Lb having a wavelength of around 760 [nm] and the laser beam Lb having a wavelength of around 840 [nm] are respectively irradiated to the test portion Ba. Thus, a speckle pattern by the reflected light Lr (or transmitted light) is detected for each laser light Lb. Then, the speckle pattern information is analyzed by the analysis means 6 as described above for each wavelength of the laser beam Lb.

  If comprised in this way, similarly to the case of said 1st-3rd embodiment, also in the ultrasonic modulation light measuring device 1 and ultrasonic modulation light measurement method which concern on this embodiment, it is based on those information. Thus, it is possible to accurately specify the position where an object that absorbs light such as blood exists in the living tissue B, that is, the position where the blood vessel or the like exists. In addition, it is possible to obtain information such as a portion where a lot of oxygenated hemoglobin is present and a portion where a lot of reduced hemoglobin is present in the specified blood vessel.

  For example, when cancer has developed in the living tissue B, a blood vessel may be newly formed in the cancer portion. Further, since a large amount of oxygen is consumed in the cancer portion, it is known that more reduced hemoglobin is present than oxygenated hemoglobin in the blood vessels and new blood vessels in the cancer portion.

  Therefore, if the ultrasonic modulation light measurement device 1 and the ultrasonic modulation light measurement method are configured as in this embodiment, the ultrasonic modulation light measurement device 1 is used to diagnose whether or not cancer has occurred in the living tissue B. It is also possible to use for such as.

DESCRIPTION OF SYMBOLS 1 Ultrasonic modulation light measuring device 2a, 2b Ultrasonic irradiation means 3 Laser light irradiation means 31 Light source 34 Condensing lens 4 Detection means 6 Analysis means Am Amplitude B Biological tissue Ba Test part Bs Living body surface fa, fb Frequency Lb Laser light Pz Position Swa, Swb Ultrasound z, z _n Depth δ Crossing angle θa, θb Phase

Claims (13)

A plurality of ultrasonic irradiation means for irradiating ultrasonic waves so that each of the irradiated ultrasonic waves intersects at a position at a predetermined depth from the biological surface,
Laser light irradiation means for irradiating the test portion with laser light;
Detecting means for detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or transmitting the position of the test portion;
With
The ultrasonic waves irradiated from each of the ultrasonic irradiation means have different frequencies,
Said detection means, said at a plurality of timings at which the amplitude at the position of the object part of the interference pattern of the composite wave in which each ultrasonic wave is formed by being crossed is different amplitude, the specification of each of the laser beam An ultrasonically modulated light measuring device characterized by detecting a laser pattern. A plurality of ultrasonic irradiation means for irradiating ultrasonic waves so that each of the irradiated ultrasonic waves intersects at a position at a predetermined depth from the biological surface,
Laser light irradiation means for irradiating the test portion with laser light;
Detecting means for detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or transmitting the position of the test portion;
With
The detection means changes the phase of the ultrasonic waves emitted from the respective ultrasonic irradiation means, and the amplitude of the interference fringes of the synthetic wave formed by intersecting the ultrasonic waves at the position of the test portion It is different for each condition that the amplitude, the ultrasonic modulated light measuring device, characterized in that the detect the speckle pattern of the laser beam. A plurality of ultrasonic irradiation means for irradiating ultrasonic waves so that each of the irradiated ultrasonic waves intersects at a position at a predetermined depth from the biological surface,
Laser light irradiation means for irradiating the test portion with laser light;
Detecting means for detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or transmitting the position of the test portion;
With
The detection means changes the crossing angle of the ultrasonic waves emitted from the respective ultrasonic wave irradiation means, and the interference fringes of the synthetic wave formed by crossing the ultrasonic waves at the position of the test portion. An ultrasonic-modulated light measuring apparatus , wherein the speckle pattern of the laser light is detected in each state where the amplitudes are different from each other . The laser light irradiation means includes a condenser lens that condenses the laser light emitted from the light source,
The said laser beam irradiated from the said light source is irradiated to the said to-be-tested part in the state condensed with the said condensing lens, The Claim 1 characterized by the above-mentioned. Ultrasound modulated light measurement device.   5. The ultrasonic irradiation unit according to claim 1, wherein the ultrasonic irradiation unit irradiates each ultrasonic wave so as to converge at the predetermined position of the test portion. The ultrasonic modulation light measuring device according to item.   The ultrasonic-modulated light measurement apparatus according to claim 1, wherein the laser light is a continuous wave.   The ultrasonic-modulated light measurement apparatus according to claim 1, wherein each of the ultrasonic waves is a continuous wave.   Analyzing means for analyzing a change in the information detected each time based on the information of the speckle pattern detected a plurality of times so that the amplitude at the position of the test part is different. The ultrasonic-modulated light measuring device according to claim 1, wherein the ultrasonic-modulated light measuring device is characterized in that Irradiating each of the laser beams having different wavelengths from the laser beam irradiating means, or comprising a plurality of the laser beam irradiating means for irradiating the laser beams having different wavelengths,
The said detection means detects the said speckle pattern obtained by reflecting at the position of the said to-be-tested part, or permeate | transmitting the position of the to-be-tested part about the laser beam from which the said wavelength differs, It is characterized by the above-mentioned. The ultrasonic-modulated light measuring device according to any one of claims 1 to 8.   The ultrasonic modulation according to any one of claims 1 to 9, wherein at least the plurality of ultrasonic irradiation units, the laser beam irradiation unit, and the detection unit are integrally configured. Optical measuring device. An ultrasonic irradiation step of irradiating ultrasonic waves so that a plurality of irradiated ultrasonic waves intersect each other at a position at a predetermined depth from the surface of the living body in a test portion of the biological tissue;
A laser beam irradiation step of irradiating the test portion with a laser beam;
A detection step of detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or passing through the position of the test portion;
Have
The ultrasonic waves applied to the position in the ultrasonic irradiation step have different frequencies,
Wherein in the detection step, the at a plurality of timings at which the amplitude becomes different amplitude at the position of the object part of the interference pattern of the composite wave in which each ultrasonic wave is formed by being crossed, the specification of each of the laser beam An ultrasonically modulated light measuring method characterized by detecting a laser pattern. An ultrasonic irradiation step of irradiating ultrasonic waves so that a plurality of irradiated ultrasonic waves intersect each other at a position at a predetermined depth from the surface of the living body in a test portion of the biological tissue;
A laser beam irradiation step of irradiating the test portion with a laser beam;
A detection step of detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or passing through the position of the test portion;
Have
In the ultrasonic irradiation step, the phase of the ultrasonic wave irradiated to the position is changed, and the ultrasonic waves are irradiated so that the plurality of irradiated ultrasonic waves intersect,
Wherein in the detection step, it is amplitude different from the amplitude at the position of the object part of the ultrasonic interference fringes of the composite wave in which the respective ultrasonic changing the phase is formed by being cross-irradiated to the position in each state, the ultrasonic modulated optical measurement method characterized in that it detects the speckle pattern of the laser beam. An ultrasonic irradiation step of irradiating ultrasonic waves so that a plurality of irradiated ultrasonic waves intersect each other at a position at a predetermined depth from the surface of the living body in a test portion of the biological tissue;
A laser beam irradiation step of irradiating the test portion with a laser beam;
A detection step of detecting a speckle pattern obtained by reflecting the laser beam at the position of the test portion or passing through the position of the test portion;
Have
In the ultrasonic irradiation step, by changing the intersecting angle of the ultrasonic waves irradiated to the position, each of the irradiated ultrasonic waves is irradiated so that the ultrasonic waves cross each other,
Wherein in the detection step, the amplitude of the amplitude at the position of the object part of the ultrasonic interference fringes of the composite wave in which the respective ultrasonic changing the crossing angle is formed by being crossed in the irradiated are different from the positions An ultrasonically modulated light measuring method , wherein the speckle pattern of the laser light is detected in each state .