Instruments and systems for measuring photoacoustic signals.

Abstract

To provide a technology to check whether or not a device inserted into a subject, in which a photoacoustic generation source is installed at the tip, and a light generation device for irradiating the photoacoustic generation source with light through the device are connected to each other.SOLUTION: A beacon device 14 is housed in a concave part 44. A tip 14a of the beacon device 14 is housed in the tip part 44a. A photoacoustic wave generation source 14d is installed at the tip 14a. An ultrasonic propagation medium such as water is housed at the tip part 44a. In a state where the beacon device 14 is housed in the concave part 44, a light generation device 16 is connected to a rear end 14b, and a laser beam is radiated to the photoacoustic wave generation source 14d from the light generation device 16. A photoacoustic signal generated from the photoacoustic wave generation source 14d is received by an ultrasonic probe 18. On the basis of the received signal, it is determined whether or not the beacon device 14 and the light generation device 16 are connected to each other.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a technique for measuring a photoacoustic signal from a photoacoustic wave generation source installed at the tip of a device inserted into a subject.

Background Art

[0002] In order to improve the visibility of the tip of a device inserted into a subject, a technique for visualizing the tip of the device using the photoacoustic effect is known. The device is a tubular instrument inserted into a blood vessel, such as a guide wire or a catheter. Hereinafter, the visualization technique using the photoacoustic effect is referred to as "beacon technology", and a device equipped with the beacon technology is referred to as a "beacon device".

[0003] An optical fiber is installed along the beacon device. At the tip of the optical fiber (the end inserted into the subject), a photoacoustic wave generation source such as a light absorber is installed. At the rear end of the optical fiber (the end opposite to the end where the light absorber is installed), an optical generation device including a light source is installed. The light (for example, laser light) generated from the optical generation device passes through the optical fiber and is irradiated onto the light absorber installed at the tip of the optical fiber. Thereby, a photoacoustic signal (ultrasonic wave) is generated from the light absorber. The generated photoacoustic signal is received by an ultrasonic imaging device, and an image is generated based on the received photoacoustic signal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, conventionally, there is no technology to confirm whether the beacon device and the photogenerator are properly connected, and whether a photoacoustic signal is being properly generated from the photoacoustic source installed at the tip of the beacon device, until the beacon device is actually inserted into the subject and used. Since the photogenerator and the beacon device are not electrically connected, it is not possible to confirm whether or not they are connected using a Sync signal or the like.

[0006] Before actually using the beacon device, it is possible to confirm the presence or absence of the above connection by manually touching the tip of the beacon device to the surface of the ultrasonic probe and receiving the photoacoustic signal with the ultrasonic probe.

[0007] However, since the beacon device is inserted into the subject, it is necessary to keep the beacon device itself clean. If the tip of the beacon device is brought into contact with the surface of the ultrasound probe before actually using the beacon device, the cleanliness of the beacon device may not be maintained. In addition, due to the effects of multiple reflections and electrical noise generated at very shallow depths, it is difficult to determine from the image whether or not a photoacoustic signal has been detected.

[0008] The object of the present invention is to provide a technique for confirming whether a device inserted into a subject, having a photoacoustic source installed at its tip, is connected to a photogenerating device that irradiates the photoacoustic source with light via the device. [Means for solving the problem]

[0009] One aspect of the present invention is a photoacoustic signal measuring instrument used to measure a photoacoustic signal from a photoacoustic wave source installed at the tip of a device inserted into a subject, characterized in that it includes a holding part that houses the tip of the device and holds a material through which the photoacoustic signal passes, and a fixing part that fixes the relationship between the position where the ultrasonic probe is installed and the position of the tip of the device without the tip of the device coming into contact with the ultrasonic probe that receives the photoacoustic signal.

[0010] With the above configuration, the tip of the device is housed in the holding section, and the photoacoustic signal generated from the photoacoustic wave source is received by the ultrasonic probe. This allows the photoacoustic signal to be received by the ultrasonic probe without the tip of the device coming into contact with the tip of the ultrasonic probe (i.e., the transmitting / receiving surface). Therefore, the cleanliness of the device tip is maintained. Furthermore, since the holding section contains a material that allows photoacoustic signals to pass through, the photoacoustic signal is received by the ultrasonic probe through this material. Thus, the effects of multiple reflections and electrical noise can be suppressed.

[0011] The above-described photoacoustic signal measuring instrument may further include a housing for housing the device. The holding portion may be a recess formed on the surface of the housing. When the device is housed in the housing, the tip of the device may be housed in the recess. The housing may have a space formed outside the recess for positioning the ultrasonic probe toward the recess.

[0012] The bottom surface of the recess may include an inclined surface.

[0013] The holding portion may be a container for containing the substance. The fixing portion may be a through-hole formed in the surface of the container and leading to the inside of the container into which the tip of the device is inserted. The container may have an acoustic window on the outside of the container into which the ultrasonic probe is installed and which allows photoacoustic signals from the photoacoustic wave source to pass through.

[0014] One aspect of the present invention is a photoacoustic signal measuring system comprising a photoacoustic signal measuring instrument used to measure a photoacoustic signal from a photoacoustic wave source installed at the tip of a device inserted into a subject, and a determination unit, wherein the photoacoustic signal measuring instrument includes a holding part that accommodates the tip of the device and holds a material through which the photoacoustic signal passes, and a fixing part that fixes the relationship between the position on which the ultrasonic probe is installed and the position on the tip of the device without the tip of the device coming into contact with the ultrasonic probe that receives the photoacoustic signal, wherein a photoacoustic signal is generated from the photoacoustic wave source when light is irradiated from a photogenerator through the device, and the determination unit determines the state of connection between the photogenerator and the device based on the photoacoustic signal generated from the photoacoustic wave source and received by the ultrasonic probe.

[0015] The above-described photoacoustic signal measurement system may further include a control unit that controls the irradiation of light from the photogenerator to the photoacoustic wave source and the reception of photoacoustic signals from the photoacoustic wave source. The control unit may control the execution of a first process including the irradiation of light and the reception of a photoacoustic signal corresponding to that irradiation, and the execution of a second process including the reception of a photoacoustic signal when no light is being irradiated.

[0016] The above-described photoacoustic signal measurement system may further include a signal processing unit that processes the photoacoustic signal received by the ultrasonic probe. The signal processing unit may calculate the difference between the photoacoustic signal received by the execution of the first process and the photoacoustic signal received by the execution of the second process. The determination unit may determine the connection status between the photogenerator and the device based on the difference.

[0017] The determination unit may determine the connection status between the light generator and the device based on the photoacoustic signal from a region corresponding to the photoacoustic signal measuring instrument.

[0018] The region corresponding to the photoacoustic signal measurement device may be a region corresponding to the position of the tip of the device fixed by the fixing portion.

[0019] The determination unit may determine the connection state between the light generation device and the device based on the ratio between the photoacoustic signal from the region corresponding to the photoacoustic signal measurement device and the photoacoustic signal from other regions.

Advantages of the Invention

[0020] According to the present invention, it is possible to confirm whether a device having a photoacoustic generation source installed at its tip and inserted into a subject is connected to a light generation device that irradiates light to the photoacoustic generation source through the device.

Brief Description of the Drawings

[0021] [Figure 1] It is a block diagram showing the configuration of a photoacoustic signal measurement system according to an embodiment. [Figure 2] It is a flowchart showing the flow of a process for measuring a photoacoustic signal in a non-contact state. [Figure 3] It is a top view when viewing the photoacoustic signal measurement device from above (in the direction of the Z-axis). [Figure 4] It is a cross-sectional view taken along the line A-A in FIG. 3. [Figure 5] It is a top view when viewing the photoacoustic signal measurement device from above. [Figure 6] It is a side view when viewing the photoacoustic signal measurement device from the side (in the direction of the Y-axis). [Figure 7] It is a side view when viewing the photoacoustic signal measurement device from the side (in the direction of the X-axis). [Figure 8] It is a top view when viewing the tip of the holding portion from above. [Figure 9] It is a side view when viewing the photoacoustic signal measurement device from the side (in the direction of the Y-axis). [Figure 10] It is a side view when viewing the photoacoustic signal measurement device from the side (in the direction of the Y-axis). [Figure 11]This is a top view of the photoacoustic signal measuring instrument as seen from above (in the Z-axis direction). [Figure 12] This is a top view of the photoacoustic signal measuring instrument as seen from above (in the Z-axis direction). [Figure 13] This is a cross-sectional view of BB in Figure 12. [Figure 14] This is a side view of the photoacoustic signal measuring instrument as seen from the side (in the direction of the Y axis). [Figure 15] This is a side view of the photoacoustic signal measuring instrument as seen from the side (in the direction of the X axis). [Figure 16] This is diagram BB in Figure 12. [Figure 17] This figure shows the timing of laser light irradiation and the timing of photoacoustic signal reception. [Figure 18] This diagram shows the timing related to the conventional technology. [Figure 19] This figure shows the relationship between the cumulative number of frames, the signal-to-noise ratio, and the threshold value. [Figure 20] This is a diagram showing the screen. [Figure 21] This figure shows an example of how the judgment results are displayed. [Figure 22] This figure shows an example of how the judgment results are displayed. [Figure 23] This figure shows an example of how the judgment results are displayed. [Figure 24] This figure shows an example of how the judgment results are displayed. [Figure 25] This figure shows an example of how the judgment results are displayed. [Figure 26] This is a diagram showing the screen. [Modes for carrying out the invention]

[0022] Referring to Figure 1, the photoacoustic signal measurement system according to the embodiment will be described. Figure 1 shows the configuration of the photoacoustic signal measurement system according to the embodiment. The photoacoustic signal measurement system 10 according to the embodiment is, as an example, a system that supports treatment using a beacon device.

[0023] The photoacoustic signal measurement system 10 includes, as an example, an ultrasonic imaging device 12, a beacon device 14, and a light generator 16.

[0024] The ultrasound imaging device 12 includes an ultrasound probe 18 and a device body 20, and generates image data by transmitting and receiving ultrasound using the ultrasound probe 18. For example, the ultrasound imaging device 12 transmits ultrasound into a subject and receives the ultrasound reflected from inside the subject to generate image data representing the tissue inside the subject.

[0025] Furthermore, a photoacoustic wave source 14d, such as a light absorber, is installed at the tip of the beacon device 14, and the ultrasonic imaging device 12 generates image data by receiving the photoacoustic signal generated from the photoacoustic wave source 14d.

[0026] The beacon device 14 is a device inserted into a subject and is equipped with beacon technology. This device is a tubular instrument inserted into a blood vessel, such as a guidewire or catheter (e.g., balloon catheter, microcatheter, nutritional catheter). This is just one example, and the treatment supported by the photoacoustic signal measurement system 10 is not limited to treatments using guidewires or catheters, but can be any treatment using an instrument inserted into the subject.

[0027] The beacon device 14 includes an optical fiber (not shown). The optical fiber is installed along the beacon device 14. A photoacoustic wave source 14d is installed at the tip of the optical fiber (the end inserted into the subject). A light generator 16, such as a light source, is installed at the rear end of the optical fiber (the end opposite to the end where the photoacoustic wave source 14d is installed).

[0028] The photoacoustic wave source 14d generates a photoacoustic signal (ultrasound) by the photoacoustic effect, for example. However, ultrasound may be generated using principles other than the photoacoustic effect. For example, instead of the photoacoustic wave source 14d, an ultrasonic transducer such as a piezoelectric element may be installed at the tip of the beacon device 14, and ultrasound may be generated from the ultrasonic transducer. Multiple photoacoustic wave sources 14d may be installed. For example, the photoacoustic wave source 14d may be installed at a location other than the tip.

[0029] The light generator 16, as an example, includes a light source that generates laser light and a transmitting / receiving control unit 22, and generates a photoacoustic signal from the photoacoustic wave source 14d by irradiating the photoacoustic wave source 14d with laser light.

[0030] The transmit / receive control unit 22 controls the generation of laser light from the light source by controlling the light source. For example, the transmit / receive control unit 22 controls the timing of laser light irradiation. In addition, the transmit / receive control unit 22 controls the timing of receiving the photoacoustic signal generated from the photoacoustic wave source 14d by transmitting a trigger signal for receiving the photoacoustic signal to the main unit 20 of the device. In this way, the transmit / receive control unit 22 controls the irradiation of laser light and the reception of photoacoustic signals.

[0031] The optical fiber included in the beacon device 14 functions as a light guide, directing the laser light emitted from the light source to the photoacoustic wave source 14d located at the tip of the optical fiber. In other words, the laser light emitted from the light source passes through the optical fiber and is directed to the photoacoustic wave source 14d located at the tip of the optical fiber. This causes the photoacoustic wave source 14d to generate a photoacoustic signal (ultrasound). The generated photoacoustic signal is received by the ultrasonic imaging device 12, and image data is generated based on the received photoacoustic signal.

[0032] The photoacoustic wave source 14d generates photoacoustic waves by receiving laser light from a light source. For example, the photoacoustic wave source 14d may be composed of a known dye (e.g., a photosensitizer), metal nanoparticles, or a carbon-based compound. The tip of the optical fiber and the photoacoustic wave source 14d installed at that tip are covered with a resin sealing member or the like.

[0033] The photoacoustic waves generated from the photoacoustic wave source 14d are received by an ultrasound probe 18 placed on the surface of the subject's body. The device body 20 generates image data representing the photoacoustic wave source 14d based on the photoacoustic waves received by the ultrasound probe 18. The ultrasound probe 18 also transmits ultrasound into the subject and receives the ultrasound reflected within the subject. Based on the received ultrasound, the device body 20 generates image data (e.g., cross-sectional image data) representing the tissue within the subject (e.g., tissue including blood vessels). The image representing the photoacoustic wave source 14d is superimposed on the cross-sectional image representing the tissue within the subject, and these images are displayed on the screen. This allows the operator to determine the position of the tip of the beacon device 14 within the subject (e.g., within blood vessels).

[0034] The ultrasound probe 18 is a device that transmits and receives ultrasound waves. The ultrasound probe 18 includes, for example, a 1D array transducer. The 1D array transducer is composed of multiple ultrasound transducers arranged in one dimension. An ultrasound beam is formed by the 1D array transducer, and the ultrasound beam is repeatedly scanned electronically. As a result, a scanning surface is formed in the living body with each electronic scan. The scanning surface corresponds to a two-dimensional echo data acquisition space. The ultrasound probe 18 may also include a 2D array transducer, which is formed by multiple vibrating elements arranged in two dimensions, instead of a 1D array transducer. An ultrasound beam is formed by the 2D array transducer, and when the ultrasound beam is repeatedly scanned electronically, a scanning surface as a two-dimensional echo data acquisition space is formed with each electronic scan. When the ultrasound beam is scanned two-dimensionally, a three-dimensional space as a three-dimensional echo data acquisition space is formed. As a scanning method, sector scanning, linear scanning, or convex scanning can be used. The ultrasound probe is not limited to one placed on the body surface; ultrasound probes placed elsewhere on the body surface, such as ultrasound probes used in intravascular ultrasound (IVUS), may also be used.

[0035] The main unit 20 of the device includes a transmitting unit 24, a receiving unit 26, a signal processing unit 28, a control unit 30, an input unit 32, and a display unit 34.

[0036] The transmitting unit 24 functions as a transmitting beamformer. The receiving unit 26 functions as a receiving beamformer. During transmission, the transmitting unit 24 supplies multiple transmitting signals with a certain delay relationship to multiple ultrasonic transducers included in the ultrasonic probe 18. This forms an ultrasonic transmitting beam. During reception, reflected waves (RF signals) from within the body are received by the ultrasonic probe 18, and multiple receiving signals are output from the ultrasonic probe 18 to the receiving unit 26. The receiving unit 26 forms a receiving beam by applying phase-aligning summation processing to the multiple receiving signals. This beam data is output to the signal processing unit 28. That is, the receiving unit 26 applies delay processing to the received signals obtained from each ultrasonic transducer according to the delay processing conditions for each ultrasonic transducer, and forms a receiving beam by summing the multiple received signals obtained from multiple ultrasonic transducers. The delay processing conditions are defined by received delay data indicating the delay time. A received delay data set (i.e., a set of delay times) corresponding to multiple ultrasonic transducers is supplied from the control unit 30.

[0037] The ultrasonic beam (i.e., the transmitting beam and the receiving beam) is electronically scanned by the actions of the transmitting unit 24 and the receiving unit 26, thereby forming a scanning plane. The scanning plane corresponds to multiple beam data, which constitute received frame data (specifically, RF signal frame data). Each beam data consists of multiple echo data arranged in the depth direction. By repeatedly performing electronic scanning of the ultrasonic beam, multiple received frame data arranged on the time axis are output from the receiving unit 26. These constitute a sequence of received frames.

[0038] When the ultrasonic beam is electronically scanned two-dimensionally by the actions of the transmitting unit 24 and the receiving unit 26, a three-dimensional echo data acquisition space is formed, and volume data as an echo data set is acquired from this three-dimensional echo data acquisition space. By repeating the electronic scanning of the ultrasonic beam, multiple volume data sets arranged on the time axis are output from the receiving unit 26. These constitute a volume data sequence.

[0039] The signal processing unit 28 is a device that generates image data (for example, a B-mode image) by applying signal processing such as detection, logarithmic compression, and conversion functions (such as coordinate transformation and interpolation functions using a DSC (digital scan converter)) to the beam data output from the receiving unit 26.

[0040] The control unit 30 controls the transmission and reception of ultrasound by the ultrasound probe 18 and generates image data based on the ultrasound received by the ultrasound probe 18. The control unit 30 also controls the timing and number of times reflected ultrasound images and photoacoustic images are captured.

[0041] A reflected ultrasound image is image data generated based on ultrasound waves (i.e., reflected waves) transmitted from the ultrasound probe 18 and reflected within the subject. In other words, a reflected ultrasound image is image data generated based on the reflected ultrasound signal output from the receiving unit 26 that received the reflected ultrasound. Acquiring a reflected ultrasound image involves transmitting ultrasound waves from the ultrasound probe 18 and receiving the reflected waves of those transmitted ultrasound waves to generate a reflected ultrasound image. Hereinafter, the acquisition of a reflected ultrasound image will be referred to as "reflected ultrasound imaging".

[0042] The photoacoustic image is image data generated based on photoacoustic waves from the photoacoustic wave source 14d. In other words, the photoacoustic image is image data generated based on the photoacoustic signal output from the receiving unit 26 that receives the photoacoustic waves. The acquisition of a photoacoustic image is the process of generating a photoacoustic image based on photoacoustic waves from the photoacoustic wave source 14d. Hereafter, the acquisition of a photoacoustic image will be referred to as "photoacoustic imaging".

[0043] The control unit 30 controls the number of imaging cycles, imaging period, and timing for both reflected ultrasonic imaging and photoacoustic imaging. To perform reflected ultrasonic imaging, the control unit 30 controls the transmission of ultrasonic waves by the transmitter 24 and the reception of ultrasonic waves by the receiver 26. This generates a reflected ultrasonic signal, and a reflected ultrasonic image is generated based on this signal. The control unit 30 also receives a trigger signal for receiving the photoacoustic signal from the photogenerator 16 and controls the reception of photoacoustic waves by the receiver 26 according to this trigger signal. This generates a photoacoustic signal, and a photoacoustic image is generated based on this signal. The control unit 30 may also include a transmit / receive control unit 22, which controls the timing of laser light irradiation to the photoacoustic wave source 14d and the timing of photoacoustic wave reception by the receiver 26.

[0044] The signal processing unit 28 includes a photoacoustic signal processing unit 36 ​​and a signal determination unit 38.

[0045] The photoacoustic signal processing unit 36 ​​generates a photoacoustic image by applying signal processing to the photoacoustic signal output from the receiving unit 26 through photoacoustic imaging. In other words, the photoacoustic signal processing unit 36 ​​generates a photoacoustic image by imaging the photoacoustic signal.

[0046] For example, the control unit 30 generates a display image by superimposing a photoacoustic image onto a reflected ultrasonic image, and displays this display image on the display unit 34.

[0047] The signal determination unit 38 is an example of a determination unit, and it determines the connection status between the photo-generator 16 and the beacon device 14 based on the photo-acoustic signal generated from the photo-acoustic wave source 14d and received by the ultrasonic probe 18. The control unit 30 displays information indicating the determination result on the display unit 34.

[0048] For example, the transmit / receive control unit 22 controls the execution of a first process and a second process. The first process includes the transmission (i.e., irradiation) of laser light and the reception of a photoacoustic signal in response to that transmission. The second process includes the reception of a photoacoustic signal when no laser light is being transmitted.

[0049] The photoacoustic signal processing unit 36 ​​calculates the difference between the photoacoustic signal received by the execution of the first process and the photoacoustic signal received by the execution of the second process. The signal determination unit 38 determines the connection status between the light generator 16 and the beacon device 14 based on this difference.

[0050] The input unit 32 is a device for the user to input conditions, commands, etc., necessary for imaging into the main unit 20. For example, the input unit 32 may be an operation panel, switch, button, keyboard, mouse, or joystick.

[0051] The display unit 34 is a display such as a liquid crystal display or an EL display. The display unit 34 displays the reflected ultrasonic image and the photoacoustic image. Alternatively, the reflected ultrasonic image and the photoacoustic image may be displayed on the display unit 34 with the photoacoustic image superimposed on the reflected ultrasonic image. The display unit 34 may be a device that combines a display and an input unit 32. For example, a GUI (Graphical User Interface) may be implemented by the display unit 34. Alternatively, a user interface such as a touch panel may be implemented by the display unit 34.

[0052] The main body of the device 20 includes a storage device (not shown). The storage device is a device that constitutes one or more storage areas for storing data. The storage device is, for example, a hard disk drive (HDD), a solid state drive (SSD), various types of memory (e.g., RAM, DRAM, ROM, etc.), other storage devices (e.g., optical discs, etc.), or a combination thereof. For example, reflected ultrasonic images or photoacoustic images are stored in the storage device.

[0053] Each of the transmit / receive control unit 22, signal processing unit 28, and control unit 30 can be implemented using hardware resources such as a processor or electronic circuit, and devices such as memory may be used as needed in their implementation. Alternatively, each of the transmit / receive control unit 22, signal processing unit 28, and control unit 30 may be implemented by a computer. In other words, all or part of each of the transmit / receive control unit 22, signal processing unit 28, and control unit 30 may be implemented through the cooperation of hardware resources such as the CPU (Central Processing Unit) and memory of a computer, and software (programs) that define the operation of the CPU, etc. The program is stored in a storage device via a recording medium such as a CD or DVD, or via a communication path such as a network. As another example, each of the transmit / receive control unit 22, signal processing unit 28, and control unit 30 may be implemented by a DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), or FPGA (Field Programmable Gate Array), etc. Of course, a GPU (Graphics Processing Unit), etc., may also be used. The transmit / receive control unit 22, the signal processing unit 28, and the control unit 30 may each be implemented by a single device, or each function may be implemented by one or more devices.

[0054] The photoacoustic signal measurement system 10 also includes a photoacoustic signal measuring instrument 40. The photoacoustic signal measuring instrument 40 is an instrument that houses the beacon device 14. The photoacoustic signal measuring instrument 40 is used to measure the photoacoustic signal generated from the photoacoustic wave source 14d without bringing the ultrasonic probe 18 and the beacon device 14 into contact. For example, the photoacoustic signal is measured with the beacon device 14 housed in the photoacoustic signal measuring instrument 40 before the beacon device 14 is inserted into the subject and actually used. The signal determination unit 38 determines the connection status between the photogenerator 16 and the beacon device 14 based on the measured photoacoustic signal. The control unit 30 displays information indicating the determination result on the display unit 34. The specific configuration of the photoacoustic signal measuring instrument 40 will be described in detail later.

[0055] The following describes the process for measuring the photoacoustic signal without contact between the ultrasonic probe 18 and the beacon device 14, with reference to Figure 2. Figure 2 shows a flowchart illustrating the process for measuring the photoacoustic signal in a non-contact state.

[0056] First, the beacon device 14, housed within the photoacoustic signal measuring instrument 40, is connected to the photogenerator 16 (S01). In this state, the photoacoustic wave source 14d is housed within the photoacoustic signal measuring instrument 40. As a preset, the type of beacon device 14 may be selected by the ultrasonic imaging device 12 (S02).

[0057] Next, laser light is shone from the light generator 16 onto the photoacoustic wave source 14d (S03). The laser light is shone onto the photoacoustic wave source 14d via the optical fiber contained in the beacon device 14. As a result, a photoacoustic signal is generated from the photoacoustic wave source 14d.

[0058] The photoacoustic signal generated from the photoacoustic wave source 14d is received by the ultrasonic probe 18. For example, the ultrasonic probe 18 is placed on the surface of the photoacoustic signal measuring instrument 40. The ultrasonic probe 18 receives the photoacoustic signal generated from the photoacoustic wave source 14d of the beacon device 14 housed within the photoacoustic signal measuring instrument 40.

[0059] The photoacoustic signal received by the ultrasonic probe 18 is processed by the receiving unit 26 and the photoacoustic signal processing unit 36 ​​(S04).

[0060] The signal determination unit 38 determines whether the beacon device 14 and the photogenerator 16 are connected based on the photoacoustic signal (S05). Specifically, the signal determination unit 38 determines whether the photoacoustic signal has been received by the ultrasonic probe 18 and whether the photoacoustic signal has been detected.

[0061] If no photoacoustic signal is detected (S06, No), the control unit 30 outputs information indicating an instruction to reconnect the beacon device 14 (S07). For example, the control unit 30 displays a message on the display unit 34 prompting the user, such as the surgeon, to confirm the connection between the beacon device 14 and the light generator 16. Subsequently, each process from step S01 onwards is executed.

[0062] If an optical acoustic signal is detected (S06, Yes), the control unit 30 outputs information indicating that the initial operation of the beacon device 14 has been confirmed (S08). For example, the control unit 30 displays a message indicating that the initial operation has been confirmed on the display unit 34.

[0063] With the above configuration, the user, such as a surgeon, can confirm the connection status between the beacon device 14 and the photoacoustic signal measuring instrument 40 while the beacon device 14 is housed inside the photoacoustic signal measuring instrument 40.

[0064] <Instruments for measuring photoacoustic signals> The photoacoustic signal measuring instrument 40 will be described below. The photoacoustic signal measuring instrument 40 includes a holding part that accommodates the tip of the beacon device 14 and holds a material through which the photoacoustic signal passes. The photoacoustic signal measuring instrument 40 also includes a fixing part that fixes the relationship between the position where the ultrasonic probe 18 is installed and the position of the tip of the beacon device 14 without the tip of the beacon device 14 coming into contact with the ultrasonic probe 18.Specific embodiments of the photoacoustic signal measuring instrument 40 will be described below.

[0065] (Example 1) Referring to Figures 3 to 8, the photoacoustic signal measuring instrument 40 according to Example 1 will be described. Here, a three-dimensional Cartesian coordinate system is defined. The X, Y, and Z axes are mutually orthogonal axes.

[0066] Figure 3 is a top view of the photoacoustic signal measuring instrument 40 as seen from above (in the Z-axis direction). Figure 4 is a cross-sectional view of AA in Figure 3. Figures 3 and 4 show the photoacoustic signal measuring instrument 40 when the beacon device 14 is not housed within it. Figure 5 is a top view of the photoacoustic signal measuring instrument 40 as seen from above. Figure 6 is a side view of the photoacoustic signal measuring instrument 40 as seen from the side (in the Y-axis direction). Figure 7 is a side view of the photoacoustic signal measuring instrument 40 as seen from the side (in the X-axis direction). Figure 8 is a top view of the tip of the holding part as seen from above.

[0067] The photoacoustic signal measuring instrument 40 includes a packaging container 42, a recess 44, and adhesive tape 46. The packaging container 42 is, for example, a container such as a sterilized packaging pack. For example, the packaging container 42 is a thin container made of a resin such as polypropylene.

[0068] The recess 44 is an example of a retaining part and is formed on one surface 42a of the packaging container 42. The recess 44 is, for example, a groove. The beacon device 14 is housed and held within the recess 44. For example, the recess 44 is formed by a wall 48. That is, the wall 48 is installed on surface 42a so that the recess 44 is formed.

[0069] The recess 44 includes a front end 44a, a rear end 44b, and an intermediate portion 44c. The front end 44a is the recess located at the front of the recess 44. The rear end 44b is the recess located at the rear end of the recess 44. The intermediate portion 44c is located between the front end 44a and the rear end 44b and is a recess connecting the front end 44a and the rear end 44b.

[0070] The tip 14a of the beacon device 14 is housed in the tip 44a. The rear end 14b of the beacon device 14 is housed in the rear end 44b. The middle section 44c houses the middle portion of the beacon device 14 (the portion other than the tip 14a and the rear end 14b). For example, the middle section 44c has an annular shape when viewed from above (in the Z-axis direction).

[0071] As shown in Figures 5 to 7, the beacon device 14 is rolled up to fit the annular shape of the middle section 44c and housed in the recess 44. At this time, the tip 14a of the beacon device 14 is housed in the tip 44a of the recess 44, and the rear end 14b of the beacon device 14 is housed in the rear end 44b of the recess 44. Of course, this method of housing is just one example, and for example, the beacon device 14 may be folded into a shape other than an annular shape and housed in the recess 44.

[0072] The adhesive tape 46 is a component that secures the beacon device 14 housed in the recess 44. As shown in Figure 5, with the beacon device 14 housed in the recess 44, multiple adhesive tapes 46 are applied so as to span the recess 44. This secures the beacon device 14 to the packaging container 42 while it is housed in the recess 44.

[0073] Furthermore, as shown in Figure 5, the packaging container 42 has a space formed outside the recess 44 for installing the ultrasonic probe 18 facing the recess 44. Specifically, the space outside the tip portion 44a on the surface 42a is the space in which the ultrasonic probe 18 is installed. For example, the tip (i.e., the transmitting / receiving surface) of the ultrasonic probe 18 is in contact with the wall 48 that forms the tip portion 44a. The tip 14a of the beacon device 14 is housed within the tip portion 44a of the recess 44, and the inside and outside of the tip portion 44a are separated by the wall 48, so the transmitting / receiving surface of the ultrasonic probe 18 does not come into contact with the tip 14a of the beacon device 14. In this way, by housing the beacon device 14 within the recess 44, the relationship between the position in which the ultrasonic probe 18 is installed and the position of the tip 14a of the beacon device 14 is fixed without the tip 14a of the beacon device 14 coming into contact with the ultrasonic probe 18. In Embodiment 1, the recess 44 functions as an example of a fixed part. Since the beacon device 14 is firmly fixed by the adhesive tape 46, the recess 44 and the adhesive tape 46 may function as an example of a fixing part.

[0074] A photoacoustic wave source 14d is installed at the tip 14a of the beacon device 14. When measuring a photoacoustic signal from the photoacoustic wave source 14d, a permeable material 50 is contained in the recess 44, as shown in Figures 4 and 8. The permeable material 50 is a substance through which the photoacoustic signal passes, and examples include sterilized water, physiological saline solution, or ultrasonic gel.

[0075] With the beacon device 14 and the permeable material 50 housed within the recess 44, the ultrasonic probe 18 is positioned outside the tip portion 44a of the recess 44, as shown in Figures 5 and 8. At this time, the ultrasonic probe 18 is positioned so that its tip contacts the wall 48 that forms the tip portion 44a of the recess 44.

[0076] The rear end 14b of the beacon device 14 is connected to the photogenerator 16. For example, the rear end 14b is taken out of the recess 44 and connected to the photogenerator 16. Laser light generated from the photogenerator 16 passes through the optical fiber of the beacon device 14 and is irradiated onto the photoacoustic wave source 14d installed at the tip 14a. As a result, a photoacoustic signal is generated from the photoacoustic wave source 14d and received by the ultrasonic probe 18 installed on the outside of the tip 44a. The signal determination unit 38 determines whether the beacon device 14 and the photogenerator 16 are connected based on the photoacoustic signal received by the ultrasonic probe 18. In other words, it is determined whether the rear end 14b of the beacon device 14 and the photogenerator 16 are connected and whether a photoacoustic signal has been detected by the ultrasonic probe 18.

[0077] As described above, with the photoacoustic signal measuring instrument 40 according to Embodiment 1, it is possible to confirm whether or not the beacon device 14 is connected to the photogenerator 16 while the beacon device 14 is housed in the recess 44. Since the beacon device 14 is housed in the recess 44, it is possible to confirm whether or not the beacon device 14 is connected to the photogenerator 16 without bringing the tip surface (i.e., transmitting / receiving surface) of the ultrasonic probe 18 into contact with the tip 14a of the beacon device 14. As a result, it is possible to confirm whether or not the beacon device 14 is connected to the photogenerator 16 while maintaining the cleanliness of the beacon device 14.

[0078] Furthermore, a transparent material 50 is contained within the recess 44, and the photoacoustic signal is received by the ultrasonic probe 18 through this transparent material 50. This makes it possible to suppress the occurrence of multiple reflections and electrical noise that occurs in the very shallow depths.

[0079] Figure 9 shows a modification 1 of Example 1. Figure 9 is a side view of the photoacoustic signal measuring instrument 40 as seen from the side (in the direction of the Y axis).

[0080] As shown in Figure 9, the bottom surface 44d of the tip portion 44a may include an inclined surface. For example, the inclined surface is formed such that the depth of the tip portion 44a increases as it moves away from the boundary between the tip portion 44a and the intermediate portion 44c towards the tip portion 44a. As a result, the tip 14a of the beacon device 14 is positioned at an angle within the tip portion 44a. The transparent material 50 is contained in this inclined portion, and the photoacoustic signal generated from the photoacoustic wave source 14d is received by the ultrasonic probe 18.

[0081] Figure 10 shows a modified example 2 of Example 1. Figure 10 is a side view of the photoacoustic signal measuring instrument 40 as seen from the side (in the direction of the Y axis).

[0082] As shown in Figure 10, a sheet 44e is installed on the upper part of the tip portion 44a. The sheet 44e is a material that allows ultrasound to pass through. The sheet 44e is, for example, a film. The transmitting and receiving surface of the ultrasound probe 18 is brought into contact with the sheet 44e, and the photoacoustic signal generated from the photoacoustic wave source 14d is received by the ultrasound probe 18. Of course, the ultrasound probe 18 may also be installed as shown in Figure 8. The sheet 44e may be pre-installed on the tip portion 44a, or it may be installed by a user such as an operator when measuring the photoacoustic signal. The bottom surface 44d of the tip portion 44a may or may not include an inclined surface.

[0083] Figure 11 shows a third modification of Example 1. Figure 11 is a top view of the photoacoustic signal measuring instrument 40 as seen from above (in the Z-axis direction).

[0084] As shown in Figure 11, when measuring the photoacoustic signal, a notch 44f is formed by cutting a notch in the side of the tip 44a. A wall is formed in the notched portion, similar to the wall 48, so that even when the side is notched, an ultrasonic propagation medium such as water is contained in the tip 44a. Folds or perforations are formed on the side of the tip 44a so that the notch 44f can be formed. The transmitting and receiving surface of the ultrasonic probe 18 is brought into contact with the notch 44f, and the photoacoustic signal generated from the photoacoustic wave source 14d is received by the ultrasonic probe 18. Of course, the ultrasonic probe 18 may also be installed as shown in Figure 8. The bottom surface 44d of the tip 44a may or may not include an inclined surface.

[0085] (Example 2) The photoacoustic signal measuring instrument 60, used as a photoacoustic signal measuring instrument according to Example 2, will be described below with reference to Figures 12 to 16.

[0086] Figure 12 is a top view of the photoacoustic signal measuring instrument 60 as seen from above (in the Z-axis direction). Figure 13 is a cross-sectional view of BB in Figure 12. Figure 13 shows a cross-section of the photoacoustic signal measuring instrument 60 when the tip 14a of the beacon device 14 is not inserted into the photoacoustic signal measuring instrument 60. Figure 14 is a side view of the photoacoustic signal measuring instrument 60 as seen from the side (in the Y-axis direction). Figure 15 is a side view of the photoacoustic signal measuring instrument 60 as seen from the side (in the X-axis direction). Figure 16 is a BB diagram in Figure 12. Figure 16 shows a cross-section of the photoacoustic signal measuring instrument 60 when the tip 14a of the beacon device 14 is inserted into the photoacoustic signal measuring instrument 60.

[0087] The photoacoustic signal measuring instrument 60 includes a container 62, which is an example of a holding part. The container 62 is, for example, a sterilized box. As shown in Figures 13 and 15, a through hole 64 leading to the inside of the container 62 is formed on the side of the container 62. The through hole 64 corresponds to an example of a fixing part. As will be described later, the tip 14a of the beacon device 14 is inserted into the through hole 64. The size of the through hole 64 is such that the beacon device 14 can pass through it, and is also such that no gap is formed in the through hole 64 when the beacon device 14 is inserted. When the beacon device 14 is inserted into the through hole 64, the beacon device 14 is supported by the container 62, and the position of the beacon device 14 is fixed.

[0088] An acoustic window 66 is installed on the top surface of the container 62. The acoustic window 66 is made of a material that transmits ultrasonic waves. As will be described later, the ultrasonic probe 18 is installed on the acoustic window 66, so the ultrasonic probe 18 is installed on the outside of the container 62. The through hole 64 is formed on a surface different from the surface on which the acoustic window 66 is installed. As shown in Figure 13, the inside of the container 62 is filled with a permeable substance 68. The permeable substance 68 is a substance through which photoacoustic signals are transmitted, and examples include sterilized water, physiological saline solution, or ultrasonic gel. Before the photoacoustic signal measuring instrument 60 is used, a sealing member that closes the through hole 64 is attached to the surface on which the through hole 64 is formed. When using the photoacoustic signal measuring instrument 60, the sealing member is peeled off and the tip 14a of the beacon device 14 is inserted into the through hole 64.

[0089] As shown in Figure 16, the tip 14a of the beacon device 14 is inserted into the through-hole 64 and then into the container 62 through the through-hole 64. The container 62 is filled with a permeable material 68, and the tip 14a of the beacon device 14 is positioned within the permeable material 68. The ultrasonic probe 18 is also placed on the acoustic window 66 so that its transmitting and receiving surface contacts the acoustic window 66. As the beacon device 14 is inserted into the through-hole 64, it is supported by the container 62, and the relationship between the position where the ultrasonic probe 18 is placed (i.e., the position of the acoustic window 66) and the position of the tip 14a of the beacon device 14 is fixed.

[0090] Similar to Example 1, the rear end 14b of the beacon device 14 is connected to the photogenerator 16. Laser light generated from the photogenerator 16 passes through the optical fiber of the beacon device 14 and irradiates the photoacoustic wave source 14d installed at the tip 14a. As a result, a photoacoustic signal is generated from the photoacoustic wave source 14d, which is emitted to the outside of the container 62 through the acoustic window 66 and received by the ultrasonic probe 18 installed on the acoustic window 66.

[0091] The signal determination unit 38 determines whether the beacon device 14 and the photogenerator 16 are connected based on the photoacoustic signal received by the ultrasonic probe 18. In other words, it determines whether the rear end 14b of the beacon device 14 and the photogenerator 16 are connected and whether the photoacoustic signal is detected by the ultrasonic probe 18.

[0092] As described above, the photoacoustic signal measuring instrument 60 according to Example 2 allows confirmation of whether the beacon device 14 is connected to the photogenerator 16 while the beacon device 14 is supported by the container 62. Since the tip 14a of the beacon device 14 is housed inside the container 62, confirmation of whether the beacon device 14 is connected to the photogenerator 16 can be made without contacting the transmitting / receiving surface of the ultrasonic probe 18 with the tip 14a of the beacon device 14. As a result, confirmation of whether the beacon device 14 is connected to the photogenerator 16 can be made while maintaining the cleanliness of the beacon device 14.

[0093] Furthermore, the container 62 is filled with a permeable material 68, and the photoacoustic signal is received by the ultrasonic probe 18 through this permeable material 68. This makes it possible to suppress the occurrence of multiple reflections and electrical noise that occurs in the very shallow depths.

[0094] A support member for guiding the ultrasonic probe 18 may be installed on the upper surface of the container 62 (i.e., the surface where the acoustic window 66 is formed). For example, a support member (e.g., a frame) having a shape that covers the tip of the ultrasonic probe 18 may be installed on the upper surface, and the tip of the ultrasonic probe 18 may be fitted into the support member, thereby fixing the ultrasonic probe 18 to the upper surface. In this way, the relationship between the position of the ultrasonic probe 18 and the position of the tip 14a of the beacon device 14 may be fixed.

[0095] Sound-absorbing materials or the like to prevent sound reflection may be installed on the photoacoustic signal measuring devices 40 and 60.

[0096] <Method for controlling the irradiation of light to the photoacoustic wave source 14d and the reception of photoacoustic signals> The following describes a method for controlling the irradiation of light onto the photoacoustic wave source 14d and the reception of photoacoustic signals.

[0097] Referring to Figure 17, the timing of laser light irradiation onto the photoacoustic wave source 14d and the timing of reception of the photoacoustic signal will be explained.

[0098] Reference numeral 70 indicates the irradiation timing of the laser light emitted from the photogenerator 16. Reference numeral 72 indicates the generation timing of the trigger signal that instructs the reception of the photoacoustic signal. The trigger signal is output from the photogenerator 16 to the control unit 30 in response to the irradiation of the laser light from the photogenerator 16. Reference numeral 74 indicates the timing of the transmission of ultrasound from the ultrasonic probe 18. Reference numeral 76 indicates the timing of the reception of ultrasound by the ultrasonic probe 18.

[0099] Period Ta is the period during which ultrasound is transmitted from the ultrasound probe 18. Period Ra is the period during which ultrasound (i.e., reflected waves) is received by the ultrasound probe 18 in response to that transmission.

[0100] Timings T1, T2, T3, and T4 are the timings at which laser light is irradiated from the light generator 16 to the photoacoustic wave source 14d, respectively.

[0101] Trigger signal A1 is output from the light generator 16 to the control unit 30 at timings T1, T2, T3, and T4. In other words, trigger signal A1 is output from the light generator 16 to the control unit 30 in response to laser light irradiation. Trigger signal A2 is output from the light generator 16 to the control unit 30 during periods when laser light is not being irradiated. For example, trigger signal A2 is output from the light generator 16 to the control unit 30 at a later timing than trigger signal A1. Trigger signal A2 may be output at a timing earlier than trigger signal A1, as long as it is a signal output during periods when laser light is not being irradiated.

[0102] Periods R1 and R2 are the periods during which the photoacoustic signal is received by the ultrasonic probe 18. Periods R1 and R2 correspond to the irradiation of laser light from the photogenerator 16 to the photoacoustic wave source 14d, respectively. Period R1 corresponds to the period of trigger signal A1, and period R2 corresponds to the period of trigger signal A2. In other words, period R1 corresponds to the timing when the laser light was irradiated, and period R2 corresponds to the period when the laser light was not irradiated.

[0103] The control unit 30 controls the irradiation of laser light from the photogenerator 16 to the photoacoustic wave source 14d and the reception of photoacoustic signals from the photoacoustic wave source 14d. Specifically, the control unit 30 controls the timing of laser light irradiation and the timing of photoacoustic signal reception. Of course, the transmitting / receiving control unit 22 and the control unit 30 may cooperate to control the timing of laser light irradiation and photoacoustic signal reception.

[0104] For example, the control unit 30 controls the execution of a first process and a second process. The first process includes irradiating with laser light and receiving a photoacoustic signal corresponding to that irradiation. The second process includes receiving a photoacoustic signal when laser light is not being irradiated.

[0105] In the example shown in Figure 17, the first process is a combination of irradiating with laser light at timing T1 and receiving a photoacoustic signal during period R1 corresponding to trigger signal A1. The second process is receiving a photoacoustic signal during period R2 corresponding to trigger signal A2.

[0106] At timing T1, laser light is emitted, and in response to this emission, a photoacoustic signal is received (period R1 corresponding to trigger signal A1). Next, at a time when laser light is not emitted, trigger signal A2 is output from the photogenerator 16 to the control unit 30, and in response to trigger signal A2, a photoacoustic signal is received (period R2 corresponding to trigger signal A2). These operations will be explained in detail below.

[0107] The control unit 30 generates laser light in the photogenerator 16 at timing T1. As a result, the laser light irradiates the photoacoustic wave source 14d, and a photoacoustic signal is generated from the photoacoustic wave source 14d. When the laser light from the photogenerator 16 irradiates the photoacoustic wave source 14d, a trigger signal A1 corresponding to timing T1 is output from the photogenerator 16 to the control unit 30, and further, a trigger signal A2 corresponding to the period when the laser light is not irradiated is output from the photogenerator 16 to the control unit 30.

[0108] The control unit 30 controls the reception of ultrasound (i.e., photoacoustic signals) by the ultrasonic probe 18 and the receiving unit 26 during a period R1 corresponding to the trigger signal A1. The control unit 30 also controls the reception of ultrasound (i.e., photoacoustic signals) by the ultrasonic probe 18 and the receiving unit 26 during a period R2 corresponding to the trigger signal A2. As a result, photoacoustic signals are received by the ultrasonic probe 18 and the receiving unit 26 during period R1, and photoacoustic signals are received by the ultrasonic probe 18 and the receiving unit 26 during period R2.

[0109] Even after timing T2, laser light irradiation, reception during period R1, and reception during period R2 are performed.

[0110] Hereinafter, the photoacoustic signal received during period R1 will be referred to as "photoacoustic signal S1," and the photoacoustic signal received during period R2 will be referred to as "photoacoustic signal S2."

[0111] Period R2 corresponds to the period when laser light is not being emitted. Therefore, the photoacoustic signal S2 received during period R2 is a signal (e.g., noise) received by the ultrasonic probe 18 and the receiving unit 26 when laser light is not being emitted.

[0112] In the example shown in Figure 17, the second process, which receives a photoacoustic signal without irradiating with laser light, is performed immediately after the first process, which involves irradiating with laser light and receiving a photoacoustic signal. In other words, ultrasonic transmission and reception (transmission during period Ta and reception during period Ra) are not performed between the first and second processes, and the first and second processes are performed consecutively. In another example, ultrasonic transmission and reception may be performed between the first and second processes, and the first and second processes may not be performed consecutively. For example, the processes may be performed in the order of the first process, ultrasonic transmission and reception, and then the second process. In this case, the reception periods are determined in the order of period R1, period Ra, and period R2.

[0113] As yet another example, the control unit 30 may turn the irradiation of laser light from the light generator 16 on and off at regular intervals, or it may transmit a predetermined code.

[0114] Figure 18 shows the timing and other aspects of the conventional technology. In the conventional technology, period R2 is not set, and the photoacoustic signal is received during period R1, which corresponds to the irradiation of laser light.

[0115] The photoacoustic signal processing unit 36 ​​calculates the difference between the photoacoustic signal received by the execution of the first process and the photoacoustic signal received by the execution of the second process. The signal determination unit 38 determines the connection status between the light generator 16 and the beacon device 14 based on this difference.

[0116] The photoacoustic signal received by the execution of the first process is photoacoustic signal S1. The photoacoustic signal received by the execution of the second process is photoacoustic signal S2.

[0117] The photoacoustic signal processing unit 36 ​​calculates the difference ΔS between the photoacoustic signal S1 received during period R1 and the photoacoustic signal S2 received during period R2. The photoacoustic signal S2 is the photoacoustic signal received during period R2, which corresponds to the period when the laser light is not irradiated. Therefore, by calculating the difference between the photoacoustic signal S1 and the photoacoustic signal S2, signals such as noise are removed, and a difference ΔS corresponding to an intensity-enhanced photoacoustic signal is obtained.

[0118] The method for obtaining the difference ΔS is not limited; the difference ΔS may be obtained using an envelope signal, RF signal, or image data, etc. The photoacoustic signal processing unit 36 ​​may perform multiple peak hold operations or frame integration. Since the effects of body movement and camera shake do not need to be considered, there is no limit to the number of images used for peak hold or frame integration.

[0119] The signal determination unit 38 determines whether the beacon device 14 and the light generator 16 are connected based on the difference ΔS.

[0120] For example, the signal determination unit 38 determines that the beacon device 14 and the light generator 16 are connected if the difference ΔS is greater than or equal to a threshold, and determines that the beacon device 14 and the light generator 16 are not connected if the difference ΔS is less than the threshold. The threshold is, for example, a predetermined value and may be changed by a user such as a surgeon.

[0121] The signal determination unit 38 outputs information indicating the determination result to the control unit 30. The control unit 30 displays the information indicating the determination result on the display unit 34.

[0122] The signal determination unit 38 may set thresholds for the intensity and S / N ratio of the photoacoustic signal to determine whether the beacon device 14 and the photogenerator 16 are connected. Alternatively, the signal determination unit 38 may determine whether the beacon device 14 and the photogenerator 16 are connected based on the time-dependent change in the intensity of the photoacoustic signal.

[0123] Figure 19 shows the relationship between the cumulative number of frames, the signal-to-noise ratio (S / N ratio), and the threshold. If the S / N ratio relative to the cumulative number of frames is greater than or equal to the threshold, the signal determination unit 38 determines that the beacon device 14 and the light generator 16 are connected.

[0124] The following explains an example of how the judgment results will be displayed.

[0125] Figure 20 shows the screen 80 displayed on the display unit 34. The screen 80 includes display areas 82, 84, and 86. Display area 82 displays an ultrasound image (e.g., a tomographic image or an image based on photoacoustic signals). Display area 84 or display area 86 displays information indicating the judgment result.

[0126] Figures 21 to 24 show examples of how the judgment results are displayed.

[0127] Figure 21 shows image 88, Figure 22 shows image 90, Figure 23 shows image 92, and Figure 24 shows image 94. Images 88, 90, 92, and 94 represent the judgment results, respectively.

[0128] Images 88, 90, 92, and 94 display the results of the "light source connection" determination, the "light source power supply" determination, and the "photoacoustic signal" determination.

[0129] The "light source connection" determination result indicates whether or not a light source is connected in the light generator 16. The "light source power supply" determination result indicates whether or not the power supply to the light source is turned on in the light generator 16. The "light source connection" determination and the "light source power supply" determination may be performed by the light generator 16 or by the control unit 30.

[0130] The determination result for the "photoacoustic signal" is the result of the determination by the signal determination unit 38, that is, the result of the determination of whether or not the beacon device 14 and the light generator 16 are connected.

[0131] The control unit 30 displays one of the images 88, 90, 92, or 94 in the display area 84 or display area 86, depending on the determination result.

[0132] If the signal determination unit 38 determines that the beacon device 14 and the light generator 16 are connected, the control unit 30 displays the image 88 shown in Figure 21 in the display area 84 or display area 86. Here, as an example, the light source is connected to the light generator 16 and the power to the light source is turned on. Image 88 displays an image 96 (e.g., a mark or icon) indicating that the beacon device 14 and the light generator 16 are connected. Additionally, image 98 (e.g., a mark or icon) indicating that the light source is connected to the light generator 16 and image 100 (e.g., a mark or icon) indicating that the power to the light source is turned on are displayed in image 88. The control unit 30 may also display a message such as "Please proceed with the procedure" on image 88. Alternatively, the control unit 30 may display a string of characters indicating that the beacon device 14 and the light generator 16 are connected on image 88 instead of image 96.

[0133] If the signal determination unit 38 determines that the beacon device 14 and the light generator 16 are not connected, the control unit 30 displays the image 90 shown in Figure 22 in the display area 84 or display area 86. Image 90 displays an image 102 (e.g., a mark or icon) indicating that the beacon device 14 and the light generator 16 are not connected. Here, as an example, the light source is connected to the light generator 16 and the power to the light source is turned on. Image 90 displays images 98 and 100, similar to image 88. The control unit 30 may also display a message such as "Please check the device connection" on image 90. Alternatively, the control unit 30 may display a string of characters indicating that the beacon device 14 and the light generator 16 are not connected on image 90 instead of image 102.

[0134] If the light source is turned off, the control unit 30 displays the image 92 shown in Figure 23 in the display area 84 or display area 86. In this case, an image 104 (e.g., a mark or icon) indicating that the light source is turned off is displayed on image 92. The control unit 30 may also display a message prompting the user to check the power on image 92. Since the light source is turned off, no photoacoustic signal is received. Therefore, image 102 is displayed.

[0135] If no light source is connected to the light generator 16, the control unit 30 displays the image 94 shown in Figure 24 in the display area 84 or display area 86. In this case, an image 106 (e.g., a mark or icon) indicating that no light source is connected is displayed on image 94. The control unit 30 may also display a message on image 94 prompting the user to check the connection of the light source. Since no light source is connected, it is determined that the power to the light source is off, and no photoacoustic signal is received. Therefore, images 102 and 104 are displayed.

[0136] Figure 25 shows another example of how the judgment result is displayed. For example, the control unit 30 displays screen 108 on the display unit 34. Screen 108 includes display areas 110, 112, and 114.

[0137] Display area 110 displays an ultrasound image (e.g., a tomographic image or an image based on a photoacoustic signal). Display area 112 or display area 114 displays information indicating the judgment result. For example, display area 110 displays an image 116 based on a photoacoustic signal.

[0138] The control unit 30 may display a message in the display area 112 such as, "If an image based on a photoacoustic signal is displayed, proceed with the procedure." For example, if image 116 is displayed, the user, such as the surgeon, may determine that the beacon device 14 and the light generator 16 are connected and proceed with the procedure.

[0139] The control unit 30 may display information indicating the level (i.e., signal intensity) of the photoacoustic signal in the display area 114. For example, if multiple levels corresponding to the signal intensity are predetermined, the control unit 30 displays information indicating the level corresponding to the received photoacoustic signal in the display area 114. Specifically, if the intensity of the received photoacoustic signal is high, the control unit 30 displays information indicating "Photoacoustic signal level high" in the display area 114.

[0140] The signal determination unit 38 calculates the likelihood of the determination result, and the control unit 30 may display information indicating that likelihood on the display unit 34.

[0141] (Reception of photoacoustic signals from a region corresponding to the photoacoustic signal measuring instrument) The signal determination unit 38 may determine whether the beacon device 14 and the photogenerator 16 are connected based on the photoacoustic wave signal from a region corresponding to the photoacoustic signal measuring instrument. The region corresponding to the photoacoustic signal measuring instrument is the region corresponding to the position of the tip 14a of the beacon device 14 fixed by the fixing part. A specific example of this embodiment will be described below with reference to Figures 13, 15, and 26. Figure 26 shows screen 80.

[0142] As shown in Figures 13 and 15, a through-hole 64 is formed on the side of the photoacoustic signal measuring instrument 60 according to Embodiment 2. The through-hole 64 is formed at a depth d from the top surface of the container 62 (i.e., the top surface where the acoustic window 66 is installed). Therefore, when the tip 14a of the beacon device 14 is inserted into the container 62 through the through-hole 64, the tip 14a will be fixed at a depth d from the top surface of the container 62, or around the depth d.

[0143] The ultrasonic probe 18 is placed on the upper surface of the container 62 with its transmitting and receiving surface in contact with the acoustic window 66. Therefore, when the beacon device 14 is inserted into the container 62 through the through hole 64 and supported by the container 62, the tip 14a of the beacon device 14 will be positioned at a distance d from the transmitting and receiving surface of the ultrasonic probe 18, or around that position.

[0144] The signal determination unit 38 determines whether the beacon device 14 and the photogenerator 16 are connected based on the photoacoustic signal received from a position at a distance d from the transmitting / receiving surface of the ultrasonic probe 18 (i.e., at a depth d), or from the surrounding area including that position. The region 118 shown in Figure 26 is the region including the position at a distance d from the transmitting / receiving surface of the ultrasonic probe 18 (i.e., at a depth d). For example, region 118 is a region centered on the position at a distance d from the transmitting / receiving surface, and has a predetermined width in the vertical direction with respect to its center position.

[0145] The signal determination unit 38 determines whether the beacon device 14 and the photogenerator 16 are connected based on the photoacoustic signal received from region 118. The signal determination unit 38 may also determine whether the beacon device 14 and the photogenerator 16 are connected based on the difference ΔS obtained based on the photoacoustic signal received from region 118.

[0146] Region 118 is the region that includes the tip 14a of the beacon device 14. Therefore, it is presumed that the photoacoustic signal received from region 118 is a photoacoustic signal generated from the photoacoustic wave source 14d. Thus, by using the photoacoustic signal received from region 118, it is possible to determine whether or not the beacon device 14 and the photogenerator 16 are connected, excluding signals received from regions that do not include the tip 14a.

[0147] The signal determination unit 38 may determine whether the beacon device 14 and the photogenerator 16 are connected based on the ratio of photoacoustic signals from a region corresponding to the photoacoustic signal measuring instrument to photoacoustic signals from other regions.

[0148] In the example shown in Figure 26, region 118 corresponds to the region corresponding to the photoacoustic signal measuring instrument 60, that is, the region corresponding to the position where the through-hole 64 is formed (i.e., the position at depth d). Region 120 outside of region 118 corresponds to a region other than the region corresponding to the photoacoustic signal measuring instrument 60. In other words, region 120 is a region that does not correspond to the position at depth d.

[0149] Region 118 is the region that includes the position where the tip 14a of the beacon device 14 is located. Therefore, it is presumed that the photoacoustic signal received from region 118 is a photoacoustic signal generated from the photoacoustic wave source 14d. In this sense, region 118 can be defined as the S region from which the photoacoustic signal is obtained.

[0150] On the other hand, region 120 is a region that does not include the position where the tip 14a of the beacon device 14 is located. Therefore, it is presumed that the photoacoustic signal received from region 120 is not a photoacoustic signal generated from the photoacoustic wave source 14d, but rather a signal such as noise. In that sense, region 120 can be defined as region N from which signals such as noise are obtained.

[0151] The signal determination unit 38 determines whether the beacon device 14 and the light generator 16 are connected based on the ratio (which can be called the S / N ratio) of the photoacoustic signal (S signal) obtained from region 118, which is the S region, and the photoacoustic signal (N signal) obtained from region 120, which is the N region.

[0152] The signal determination unit 38 determines that the beacon device 14 and the light generator 16 are connected if the above ratio is greater than or equal to a threshold, and determines that the beacon device 14 and the light generator 16 are not connected if the above ratio is less than a threshold.

[0153] As described above, by separating the photoacoustic signal obtained from region 118 and the photoacoustic signal obtained from region 120 and using the ratio of the photoacoustic signals, it is possible to suppress the influence of signals received from regions that do not include the tip 14a and determine whether or not the beacon device 14 and the photogenerator 16 are connected. [Explanation of Symbols]

[0154] 10 Photoacoustic signal measurement system, 12 Ultrasonic imaging device, 14 Beacon device, 16 Photogenerator, 18 Ultrasonic probe, 40, 60 Instruments for photoacoustic signal measurement.

Claims

1. In a photoacoustic signal measuring instrument used to measure photoacoustic signals from a photoacoustic wave source installed at the tip of a device inserted into a subject, A retaining portion formed by a recess provided on one side of the packaging container, which accommodates the tip of the device and holds a material through which photoacoustic signals can pass; A space provided in the packaging container for positioning an ultrasonic probe toward the tip of the device held in the recess, outside the recess, A fixing part that fixes the relationship between the position where the ultrasonic probe is installed and the position of the tip of the device, without the tip of the device coming into contact with the ultrasonic probe that receives the photoacoustic signal, An instrument for measuring photoacoustic signals, characterized by including the following:

2. In the photoacoustic signal measuring instrument according to claim 1, It further includes a housing section for housing the aforementioned device, When the device is housed in the housing, the tip of the device is housed in the recess. The housing portion has a space formed outside the recess for installing the ultrasonic probe toward the recess. An instrument for measuring photoacoustic signals, characterized by the following features.

3. In the photoacoustic signal measuring instrument according to claim 2, The bottom surface of the recess includes an inclined surface. An instrument for measuring photoacoustic signals, characterized by the following features.

4. In the photoacoustic signal measuring instrument according to claim 1, The holding part is a container for containing the substance, The fixing portion is a through-hole formed on the surface of the container and leading to the inside of the container, into which the tip of the device is inserted. The container has an acoustic window on the outside of the container into which the ultrasonic probe is installed, and which allows photoacoustic signals from the photoacoustic wave source to pass through. An instrument for measuring photoacoustic signals, characterized by the following features.

5. A photoacoustic signal measuring instrument used to measure photoacoustic signals from a photoacoustic wave source located at the tip of a device inserted into a subject, The determination unit, Includes, The aforementioned photoacoustic signal measuring instrument is A retaining portion formed by a recess provided on one side of the packaging container, which accommodates the tip of the device and holds a material through which photoacoustic signals can pass; A space provided in the packaging container for positioning an ultrasonic probe toward the tip of the device held in the recess, outside the recess, A fixing part that fixes the relationship between the position where the ultrasonic probe is installed and the position of the tip of the device, without the tip of the device coming into contact with the ultrasonic probe that receives the photoacoustic signal, Includes, When light is irradiated from the light generator to the photoacoustic wave source via the device, a photoacoustic signal is generated from the photoacoustic wave source. The determination unit determines the connection status between the photo-generating device and the device based on the photo-acoustic signal generated from the photo-acoustic wave source and received by the ultrasonic probe. A photoacoustic signal measurement system characterized by the following features.

6. In the photoacoustic signal measurement system according to claim 5, The system further includes a control unit that controls the irradiation of light from the light generator to the photoacoustic wave source and the reception of photoacoustic signals from the photoacoustic wave source, The control unit controls the execution of a first process including the irradiation of light and the reception of a photoacoustic signal corresponding to that irradiation, and the execution of a second process including the reception of a photoacoustic signal when light is not irradiated. A photoacoustic signal measurement system characterized by the following features.

7. In the photoacoustic signal measurement system according to claim 6, The system further includes a signal processing unit that processes the photoacoustic signal received by the ultrasonic probe, The signal processing unit calculates the difference between the photoacoustic signal received by the execution of the first process and the photoacoustic signal received by the execution of the second process. The determination unit determines the connection status between the light generator and the device based on the difference. A photoacoustic signal measurement system characterized by the following features.

8. In the photoacoustic signal measurement system according to claim 5, The determination unit determines the connection status between the photo-generating device and the device based on the photo-acoustic signal from a region corresponding to the photo-acoustic signal measuring instrument. A photoacoustic signal measurement system characterized by the following features.

9. In the photoacoustic signal measurement system according to claim 8, The region corresponding to the photoacoustic signal measuring instrument is the region corresponding to the position of the tip of the device fixed by the fixing part. A photoacoustic signal measurement system characterized by the following features.

10. In the photoacoustic signal measurement system according to claim 9, The determination unit determines the connection status between the light generator and the device based on the ratio of the photoacoustic signal from the region corresponding to the photoacoustic signal measuring instrument to the photoacoustic signal from the other region. A photoacoustic signal measurement system characterized by the following features.

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