JPWO2013145711A1 - Diagnostic imaging apparatus and control method thereof - Google Patents

Abstract

The present invention does not require high positioning accuracy for the ultrasonic transmission / reception unit and the optical transmission / reception unit in the probe, and corrects the deviation based on the relative positions of the ultrasonic transmission / reception unit and the optical transmission / reception unit, It is possible to generate a tomographic image. For this reason, the probe distribution unit 101 having the ultrasonic transmission / reception unit and the optical transmission / reception unit includes the interval L in the rotation axis direction of the ultrasonic transmission / reception unit and the optical transmission / reception unit, and the rotation in the ultrasonic transmission direction and the optical transmission direction. An RFID chip 250 storing the direction angle difference θ is attached. The signal processing unit 528 of the operation control device 103 acquires information stored in the RFID chip 250 via the reading unit 570, and constructs an ultrasonic tomographic image and an optical tomographic image that absorb the interval L and the angle difference θ. ,indicate.

Description

  The present invention relates to a technique for generating a tomographic image of a biological tissue by ultrasonic cutting and light.

  2. Description of the Related Art Conventionally, diagnostic imaging apparatuses have been widely used for diagnosis of arteriosclerosis, preoperative diagnosis at the time of endovascular treatment using a high-function catheter such as a balloon catheter or stent, or confirmation of postoperative results.

  The image diagnostic apparatus includes an intravascular ultrasonic diagnostic apparatus (IVUS), an optical coherence tomography apparatus (OCT: Optical Coherence Tomography), and the like, each having different characteristics.

  Furthermore, recently, an image diagnostic apparatus that combines both the IVUS function and the OCT function has been proposed (see, for example, Patent Documents 1 and 2). According to such an image diagnostic apparatus, it is possible to generate a tomographic image taking advantage of the characteristics of IVUS that can be measured up to a high depth region and the characteristics of OCT that can be measured with high resolution, and more accurate diagnosis is expected. The

  In such an image diagnostic apparatus, generally, a tomographic image is generated by transmitting / receiving ultrasonic waves or light in a transmitting / receiving unit while operating a probe unit in an axial direction and a rotating direction in a blood vessel. However, each of the IVUS transceiver unit and the OCT transceiver unit requires a corresponding physical installation space, and therefore cannot be arranged at the same position. Inevitably, both are placed at different positions in the probe. Therefore, the respective vascular tomograms obtained by both are shifted by an amount corresponding to the arrangement position. Therefore, in order to be able to compare both tomographic images at the same position and the same viewpoint, it is necessary to adjust one tomographic image according to the difference in positioning.

JP 11-56752 A JP 2006-204430 A

  As described above, the higher the positioning accuracy of the IVUS transmission / reception unit and the OCT transmission / reception unit arranged in the probe, the better. However, it can be easily inferred that the higher the positioning accuracy, the worse the yield and the greater the cost problem.

  The present invention has been made in view of such a problem, and does not require high positioning accuracy for the ultrasonic transmission / reception unit and the optical transmission / reception unit in the probe, and is based on the relative positions of the ultrasonic transmission / reception unit and the optical transmission / reception unit. It is an object of the present invention to provide a technique that makes it possible to generate an ultrasonic tomographic image and an optical tomographic image corrected for the above.

In order to achieve the above object, the diagnostic imaging apparatus according to the present invention has the following configuration. That is,
An ultrasonic transmission / reception unit for transmitting / receiving ultrasonic waves, and an optical transmission / reception unit for transmitting / receiving light, the probe having a transmission / reception unit, and holding the probe rotatably and detachably, the ultrasonic transmission / reception unit An image diagnostic apparatus that generates an ultrasonic tomographic image and an optical tomographic image of a biological tissue using a reflected wave from the biological tissue received by the optical transmitter and a reflected light from the biological tissue received by the optical transceiver. ,
Read means for accessing a predetermined memory mounted on the probe, and reading information relating to the arrangement position of the ultrasonic transmission / reception unit and the optical transmission / reception unit from the memory;
Diagnostic information generating means for generating an ultrasonic tomographic image and an optical tomographic image in which the deviation according to the arrangement position is corrected from the information acquired through the reading means.

  According to the present invention, an ultrasonic tomographic image in which a deviation based on the relative positions of the ultrasonic transmission / reception unit and the optical transmission / reception unit is corrected without requiring high positioning accuracy for the ultrasonic transmission / reception unit and the optical transmission / reception unit in the probe. An optical tomographic image can be generated.

  Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are denoted by the same reference numerals.

The accompanying drawings are included in the specification, constitute a part thereof, show an embodiment of the present invention, and are used to explain the principle of the present invention together with the description.
1 is a diagram illustrating an external configuration of a diagnostic imaging apparatus 100 according to an embodiment of the present invention. It is a figure which shows the whole structure of a probe part, and the cross-sectional structure of a front-end | tip part. It is a figure which shows the cross-sectional structure of an imaging core, and arrangement | positioning of an ultrasonic transmission / reception part and an optical transmission / reception part. 2 is a diagram illustrating a functional configuration of the diagnostic imaging apparatus 100. FIG. It is a figure which shows the function structure of a signal processing part. It is a flowchart which shows the process sequence of the signal processing part 528. It is a figure which shows the cross-sectional structure of the imaging core in 2nd Embodiment, and arrangement | positioning of an ultrasonic transmission / reception part and an optical transmission / reception part.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings.

[First Embodiment]
1. FIG. 1 is a diagram showing an external configuration of an image diagnostic apparatus (an image diagnostic apparatus having an IVUS function and an OCT function) 100 according to an embodiment of the present invention.

  As shown in FIG. 1, the diagnostic imaging apparatus 100 includes a probe unit 101, a scanner / pullback unit 102, and an operation control device 103, and the scanner / pullback unit 102 and the operation control device 103 are connected by a signal line 104. Various signals are connected so that transmission is possible.

  The probe unit 101 is directly inserted into a body cavity such as a blood vessel and transmits an ultrasonic wave based on a pulse signal into the body cavity and receives a reflected wave from the body cavity, and transmitted light (measurement). An imaging core including an optical transmission / reception unit that continuously transmits light) into a body cavity and continuously receives reflected light from inside the body cavity is inserted. In the diagnostic imaging apparatus 100, the state inside the body cavity is measured by using the imaging core.

  The scanner / pullback unit 102 is detachably attached to the probe unit 101, and operates in the axial direction and the rotational direction of the imaging core inserted in the probe unit 101 by driving a built-in motor (the axial direction in the body cavity). And movement in the rotation direction). Further, the reflected wave received by the ultrasonic transmission / reception unit and the reflected light received by the optical transmission / reception unit are acquired and transmitted to the operation control apparatus 103.

  The operation control device 103 has a function for inputting various set values and a function for processing data obtained by the measurement and displaying the data as a tomographic image in the body cavity.

  In the operation control device 103, 111 is a main body control unit, which generates ultrasonic data based on the reflected wave obtained by measurement, and processes the line data generated based on the ultrasonic data, An ultrasonic tomographic image is generated. Further, interference light data is generated by causing interference between the reflected light obtained by measurement and the reference light obtained by separating the light from the light source, and line data generated based on the interference light data. To generate an optical tomographic image.

  Reference numeral 111-1 denotes a printer / DVD recorder, which prints a processing result in the main body control unit 111 or stores it as data. Reference numeral 112 denotes an operation panel, and the user inputs various setting values and instructions via the operation panel 112. Reference numeral 113 denotes an LCD monitor as a display device, which displays a tomographic image generated by the main body control unit 111.

2. Next, the overall configuration of the probe unit 101 and the cross-sectional configuration of the tip portion will be described with reference to FIG. As shown in FIG. 2, the probe unit 101 includes a long catheter sheath 201 inserted into a body cavity such as a blood vessel and a user's hand without being inserted into a body cavity such as a blood vessel for operation by the user. It is comprised by the connector part 202 arrange | positioned at the side. A guide wire lumen tube 203 constituting a guide wire lumen is provided at the distal end of the catheter sheath 201. The catheter sheath 201 forms a continuous lumen from a connection portion with the guide wire lumen tube 203 to a connection portion with the connector portion 202.

  Inside the lumen of the catheter sheath 201 is provided with a transmission / reception unit 221 in which an ultrasonic transmission / reception unit for transmitting / receiving ultrasonic waves and an optical transmission / reception unit for transmitting / receiving light, an electric signal cable and an optical fiber cable are provided. An imaging core 220 including a coil-shaped drive shaft 222 that transmits a rotational drive force for rotating the catheter sheath 201 is inserted over almost the entire length of the catheter sheath 201.

  The connector portion 202 includes a sheath connector 202a configured integrally with the proximal end of the catheter sheath 201, and a drive shaft connector 202b configured by rotatably fixing the drive shaft 222 to the proximal end of the drive shaft 222. Prepare.

  An anti-kink protector 211 is provided at the boundary between the sheath connector 202a and the catheter sheath 201. Thereby, predetermined rigidity is maintained, and bending (kink) due to a sudden change in physical properties can be prevented.

  The proximal end of the drive shaft connector 202b is detachably attached to the scanner / pullback unit 102.

  Next, a cross-sectional configuration of the tip portion of the probe unit 101 will be described. Inside the lumen of the catheter sheath 201 is a housing 223 in which an ultrasonic transmission / reception unit for transmitting / receiving ultrasonic waves and an optical transmission / reception unit for transmitting / receiving light are arranged, and a rotation for rotating the housing 223 An imaging core 220 including a driving shaft 222 that transmits a driving force is inserted through substantially the entire length to form the probe unit 101.

  The transmission / reception unit 221 transmits ultrasonic waves and light toward the body cavity tissue, and receives reflected waves and reflected light from the body cavity tissue.

  The drive shaft 222 is formed in a coil shape, and an electric signal cable and an optical fiber cable (single mode optical fiber cable) are arranged therein.

  The housing 223 has a shape having a notch in a part of a short cylindrical metal pipe, and is formed by cutting out from a metal lump, MIM (metal powder injection molding) or the like. The housing 223 includes an ultrasonic transmission / reception unit and an optical transmission / reception unit as a transmission / reception unit 221 inside, and a proximal end side is connected to the drive shaft 222. Further, a short coil-shaped elastic member 231 is provided on the tip side.

  The elastic member 231 is a stainless steel wire formed in a coil shape, and the elastic member 231 is arranged on the distal end side, thereby preventing the catheter core 201 from being caught when the imaging core 220 is moved back and forth.

  Reference numeral 232 denotes a reinforcing coil, which is provided for the purpose of preventing sudden bending of the distal end portion of the catheter sheath 201.

  The guide wire lumen tube 203 has a guide wire lumen into which a guide wire can be inserted. The guide wire lumen tube 203 is used to receive a guide wire previously inserted into a body cavity such as a blood vessel, and guide the catheter sheath 201 to the affected area using the guide wire.

  The drive shaft 222 can move the transmission / reception unit 221 in the axial direction and the rotation direction with respect to the catheter sheath 201, is flexible, and has a characteristic capable of transmitting rotation well, for example, from a metal wire such as stainless steel. It is comprised by the multilayer multilayer coil which becomes.

3. Next, the cross-sectional configuration of the imaging core 220 and the arrangement of the ultrasonic transmission / reception unit and the optical transmission / reception unit will be described. 3A is a cross-sectional configuration of the imaging core, and b and c are diagrams illustrating the arrangement of the ultrasonic transmission / reception unit and the optical transmission / reception unit.

  As shown to a of FIG. 3, the transmission / reception part 221 arrange | positioned in the housing 223 is provided with the ultrasonic transmission / reception part 310 and the optical transmission / reception part 320, and the ultrasonic transmission / reception part 310 and the optical transmission / reception part 320 are respectively Further, the drive shaft 222 is disposed along the axial direction on the rotation center axis (on the one-dot chain line a in FIG. 3).

  Among these, the ultrasonic transmission / reception unit 310 is disposed on the distal end side of the probe unit 101, and the optical transmission / reception unit 320 is disposed on the proximal end side of the probe unit 101, and the ultrasonic transmission / reception position of the ultrasonic transmission / reception unit 310 is It is attached in the housing 223 so that the distance between the optical transmission / reception unit 320 and the optical transmission / reception position becomes L.

  Further, the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 include an ultrasonic transmission direction (elevation angle direction) of the ultrasonic transmission / reception unit 310 and an optical transmission direction (elevation angle direction) of the optical transmission / reception unit 320 with respect to the axial direction of the drive shaft 222. ) Are respectively mounted in the housing 223 so as to be 90 °. Actually, this angle (angle γ) is not 90 ° but is shifted by 2 to 4 °. The reason is that if the angle is 90 °, a reflected wave and reflected light from the catheter sheath 201 are detected. However, it should be noted that the angle γ may be appropriately set according to the apparatus configuration and the like, and is merely an example, and the present invention is not limited thereby. Furthermore, the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 have a housing so that the angle difference between the transmission direction of the ultrasonic wave and the rotation direction of the optical transmission direction is 0 (but not limited to 0). 223 is mounted.

  As described above, the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 in the transmission / reception unit 221 arranged in the housing 223 are shifted by a relative distance L with respect to the axial direction, and the ultrasonic transmission / reception unit 310 transmits ultrasonic waves. The angle difference between the rotation direction in the direction and the light transmission direction of the optical transceiver 320 is set to zero. Therefore, when reconstructing a vascular tomographic image due to ultrasonic waves and optical interference, there is a deviation of the relative distance L in the axial direction between them, and the deviation of the angle with respect to the rotation axis is zero. One tomogram may be reconstructed to match the other tomogram according to an algorithm that is considered to be present.

  However, it is also true that variations occur in each of the actual manufacturing stages. That is, the axial distance between the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 in the actually manufactured transmission / reception unit 310 may be longer or shorter than L. Further, as shown in FIGS. 3B and 3C, the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 are attached with a shift of θ instead of 0 when the rotation direction of the optical transmission direction is used as a reference. There is also.

  The narrower the tolerance of these variations is, the smaller the axial and rotational shifts of the ultrasonic tomographic image and optical coherent tomographic image generated by the above algorithm are. You can compare the position and the viewpoint in the same rotation direction. However, in this case, the yield as a product is deteriorated, resulting in a high cost.

  On the other hand, the wider the tolerance of variation at the manufacturing stage, the better the yield and the cost problem is solved. However, on the contrary, the reliability when comparing the ultrasonic tomographic image and the optical coherent tomographic image from the viewpoint in the same axial direction and the same rotational direction is low.

The present invention solves the above problems. For this reason, in the embodiment, the following was dealt with.
First, in the algorithm for reconstructing an ultrasonic tomographic image and an optical coherent tomographic image, the axial distance L between the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 and the transmission direction thereof Instead of processing the angle difference θ in the rotation direction between them as fixed, they can be appropriately changed from the outside as “arguments (parameters)”.
Second, when the actually manufactured housing 223 is inspected, the axial measurement distance L between the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320, and the actual measurement angle difference θ between the rotation directions thereof. Is written on the RFID chip, and the RFID chip (also referred to as an RFID tag) is attached and fixed to an appropriate part of the probe 101 on the side where the scanner / pullback unit 102 is mounted. Reference numeral 250 shown in FIG. 2 is the RFID chip.
Thirdly, the scanner / pullback unit 102 operates under the control of the main body control unit 111, accesses this RFID chip, and reads information relating to the distance L and the angle difference θ stored therein. A reader (hereinafter referred to as a reading unit) is provided (reference numeral 570 in FIG. 4 described later). Note that since the communicable distance by the RFID communication technology is at least several centimeters, the distance between the RFID chip and the RFID reading unit when the probe 101 is set on the scanner / pullback unit 102 should be within that range. That is, high accuracy is not required for the installation position of the reading unit installed in the scanner / pullback unit 102.

  In addition, although explanation is mixed, if the distance L and the angle difference θ are written in the RFID chip at every inspection, a device for writing to the RFID chip is required separately, which is related to cost and manufacturing. It is disadvantageous in terms of time. Therefore, the following may be used.

  A fine distance ΔL and a fine angle difference Δθ are determined in advance, and {L−n · ΔL, L− (n−1) · ΔL,..., L,. , L + nΔL}, {θ−m · Δθ, θ− (m−1) · Δθ,..., Θ,..., Θ + (m−1) · Δθ with respect to the target angle difference θ (θ = 0 in the embodiment). , Θ + mΔθ}, a variety of RFID chips in which information indicated by the combination is already written are prepared in advance, and one of the values obtained from the inspection is selected, and the probe 101 is preset. Attach to the position. Such a procedure can be expected to reduce costs and manufacturing time. However, it should be noted that the examples other than the above are examples, and the present invention is not limited thereby.

  At the time of actual diagnosis, the scanning start timing for obtaining the vascular tomographic image or an appropriate timing before that (for example, when the probe 101 is fixed to the scanner / pullback unit 102), the probe 101 The RFID reader attached to the vicinity connected to the scanner / pullback unit 102 is read by the RFID reading unit, the read distance L and the angle difference θ are determined, and processing relating to tomographic image reconstruction using them as arguments Therefore, an ultrasonic tomographic image and an optical coherent tomographic image are reconstructed.

4). Functional configuration of diagnostic imaging apparatus Next, a functional configuration of the diagnostic imaging apparatus 100 will be described. FIG. 4 is a diagram illustrating a functional configuration of the diagnostic imaging apparatus 100 that combines the function of IVUS and the function of OCT (here, wavelength sweep type OCT). Note that the diagnostic imaging apparatus combining the IVUS function and the other OCT functions also has the same functional configuration, and thus the description thereof is omitted here.

  As shown in the figure, a scanner / pullback unit 102 is provided with a reading unit 570 that accesses an RFID chip 250 attached to the probe 101 and reads stored information. Note that the reading unit 570 is connected to the signal processing unit 528 in the operation control device 103.

(1) Function of IVUS The imaging core 220 includes an ultrasonic transmission / reception unit 310 inside the tip, and the ultrasonic transmission / reception unit 310 transmits ultrasonic waves based on the pulse wave transmitted from the ultrasonic signal transmitter / receiver 552. In addition to transmitting to the living tissue, the reflected wave (echo) is received and transmitted to the ultrasonic signal transmitter / receiver 552 as an ultrasonic echo via the adapter 502 and the slip ring 551.

  The rotational drive unit side of the slip ring 551 is rotationally driven by a radial scanning motor 505 of the rotational drive device 504. Further, the rotation angle of the radial scanning motor 505 is detected by the encoder unit 506. Further, the scanner / pullback unit 102 includes a linear drive device 507, and defines the axial operation of the imaging core 220 based on a signal from the signal processing unit 528.

  The ultrasonic signal transmitter / receiver 552 includes a transmission wave circuit and a reception wave circuit (not shown). The transmission wave circuit transmits a pulse wave to the ultrasonic transmission / reception unit 310 in the imaging core 220 based on the control signal transmitted from the signal processing unit 528.

  The reception wave circuit receives an ultrasonic signal from the ultrasonic transmission / reception unit 310 in the imaging core 220. The received ultrasonic signal is amplified by the amplifier 553 and then input to the detector 554 for detection.

  Further, the A / D converter 555 samples the ultrasonic signal output from the detector 554 for 200 points at 30.6 MHz, and outputs digital data of one line (line extending from the rotation center position onto the radiation) (super Sound wave data). Here, 30.6 MHz is assumed, but this is calculated on the assumption that 200 points are sampled at a depth of 5 mm when the sound speed is 1530 m / sec. Therefore, the sampling frequency is not particularly limited to this.

  The line-unit ultrasonic data generated by the A / D converter 555 is input to the signal processing unit 528. The signal processing unit 528 converts the ultrasonic data to gray scale to form an ultrasonic tomographic image at each position in the body cavity such as a blood vessel, and outputs it to the LCD monitor 113 at a predetermined frame rate.

  The signal processing unit 528 is connected to the motor control circuit 529 and receives a video synchronization signal from the motor control circuit 529. The signal processing unit 528 constructs an ultrasonic tomographic image in synchronization with the received video synchronization signal.

  The video synchronization signal of the motor control circuit 529 is also sent to the rotation drive device 504, and the rotation drive device 504 outputs a drive signal synchronized with the video synchronization signal.

(2) Function of Wavelength Sweep OCT 508 is a wavelength sweep light source (Swept Laser), which is an extended-cavity comprising an optical fiber 516 and a polygon scanning filter (508b) coupled in a ring shape with an SOA 515 (semiconductor optical amplifier). It is a kind of Laser.

  The light output from the SOA 515 travels through the optical fiber 516 and enters the polygon scanning filter 508b. The light whose wavelength is selected here is amplified by the SOA 515 and finally output from the coupler 514.

  In the polygon scanning filter 508b, the wavelength is selected by a combination of the diffraction grating 512 that separates light and the polygon mirror 509. Specifically, the light dispersed by the diffraction grating 512 is condensed on the surface of the polygon mirror 509 by two lenses (510, 511). As a result, only light having a wavelength orthogonal to the polygon mirror 509 returns through the same optical path and is output from the polygon scanning filter 508b. That is, by rotating the polygon mirror 509, time sweeping of the wavelength can be performed.

  As the polygon mirror 509, for example, a 32-hedron mirror is used, and the rotation speed is about 50000 rpm. A wavelength sweeping method combining the polygon mirror 509 and the diffraction grating 512 enables high-speed, high-output wavelength sweeping.

  The light of the wavelength swept light source 508 output from the coupler 514 is incident on one end of the first single mode fiber 540 and transmitted to the distal end side. The first single mode fiber 540 is optically coupled to the second single mode fiber 545, the third single mode fiber 544, and the sixth single mode fiber 546 at an intermediate optical coupler unit 541.

  An optical rotary joint (optical cup) that transmits light by coupling a non-rotating part (fixed part) and a rotating part (rotational drive part) to the tip side of the optical coupler part 541 of the first single mode fiber 540. A ring portion 503 is provided in the rotary drive device 504.

  Further, the fifth single mode fiber 543 of the probe unit 101 is detachably connected to the distal end side of the fourth single mode fiber 542 in the optical rotary joint (optical coupling unit) 503 via the adapter 502. Yes. As a result, the light from the wavelength swept light source 508 is transmitted to the fifth single mode fiber 543 that is inserted into the imaging core 220 and can be driven to rotate.

  The transmitted light is irradiated from the optical transmission / reception unit 320 of the imaging core 220 to the living tissue in the living body lumen while performing radial scanning. Then, a part of the reflected light scattered on the surface or inside of the living tissue is taken in by the optical transceiver 320 of the imaging core 220 and returns to the sixth single mode fiber 546 side through the reverse optical path. Further, a part of the light is moved to the second single mode fiber 545 side by the optical coupler unit 541 and emitted from one end of the second single mode fiber 545, and then received by a photodetector (eg, a photodiode 524). The

  Note that the rotational drive unit side of the optical rotary joint 503 is rotationally driven by a radial scanning motor 505 of the rotational drive unit 504. Further, the rotation angle of the radial scanning motor 505 is detected by the encoder unit 506. Further, the scanner / pullback unit 102 includes a linear drive device 507, and defines the axial operation of the imaging core 220 based on an instruction from the signal processing unit 528.

  On the other hand, an optical path length variable mechanism 532 for finely adjusting the optical path length of the reference light is provided at the tip of the third single mode fiber 544 opposite to the optical coupler portion 541.

  The optical path length changing mechanism 532 changes the optical path length to change the optical path length corresponding to the variation in length so that the variation in length of each probe unit 101 when the probe unit 101 is replaced and used can be absorbed. Means.

  The third single mode fiber 544 and the collimating lens 518 are provided on a uniaxial stage 522 that is movable as indicated by an arrow 523 in the optical axis direction, and form optical path length changing means.

  Specifically, when the probe unit 101 is replaced, the uniaxial stage 522 functions as an optical path length changing unit having a variable range of the optical path length that can absorb variations in the optical path length of the probe unit 101. Further, the uniaxial stage 522 also has a function as an adjusting means for adjusting the offset. For example, even when the tip of the probe unit 101 is not in close contact with the surface of the living tissue, the optical path length is minutely changed by the uniaxial stage so as to interfere with the reflected light from the surface position of the living tissue. Is possible.

  The optical path length is finely adjusted by the uniaxial stage 522, and the light reflected by the mirror 521 via the grating 519 and the lens 520 is supplied to the sixth coupler 541 provided in the middle of the third single mode fiber 544. The light obtained from the single mode fiber 546 side is mixed and received by the photodiode 524.

  The interference light received by the photodiode 524 in this manner is photoelectrically converted, amplified by the amplifier 525, and then input to the demodulator 526. The demodulator 526 performs demodulation processing for extracting only the signal portion of the interfered light, and its output is input to the A / D converter 527 as an interference light signal.

  The A / D converter 527 samples the interference light signal for 2048 points at 180 MHz, for example, and generates one line of digital data (interference light data). The sampling frequency of 180 MHz is based on the assumption that about 90% of the wavelength sweep cycle (12.5 μsec) is extracted as 2048 digital data when the wavelength sweep repetition frequency is 40 kHz. However, the present invention is not limited to this.

  The line-by-line interference light data generated by the A / D converter 527 is input to the signal processing unit 528. In the measurement mode, the signal processing unit 528 frequency-decomposes interference light data by FFT (Fast Fourier Transform) to generate data in the depth direction (line data), and coordinate-converts this to obtain a body cavity such as a blood vessel. An optical tomographic image at each position is constructed and output to the LCD monitor 113 at a predetermined frame rate.

  The signal processing unit 528 is further connected to an optical path length adjusting unit control device 530. The signal processing unit 528 controls the position of the uniaxial stage 522 via the optical path length adjusting unit controller 530.

5. Functional Configuration of Signal Processing Unit Next, a functional configuration of the signal processing unit 528 for constructing a tomographic image in the signal processing unit 528 of the diagnostic imaging apparatus 100 will be described with reference to FIG. The construction process described below may be realized using dedicated hardware, or may be realized by software (by a computer executing a program).

  FIG. 5 is a diagram illustrating a functional configuration and related functional blocks for realizing a construction process in the signal processing unit 528 of the diagnostic imaging apparatus 100.

  Prior to scanning, the control unit 605 controls the reading unit 570, controls the reading unit 570 of the scanner / pullback unit 102, the inter-sensor distance L stored in the RFID chip provided in the probe unit 101, and The angle difference θ in the transmission direction of the rotation direction of the sensor is read and set as a parameter in one of the ultrasonic tomographic constructing unit 613 and the optical tomographic image constructing unit 603. For example, if the tomographic image constructed by the optical tomographic image constructing unit 603 is used as a reference, the tomographic image to be generated is shifted in the axial direction by L with respect to the ultrasonic tomographic image 613, and θ is based on the axis of the blood vessel. Set to create a rotated tomogram.

  As shown in FIG. 5, the interference light data 621 generated by the A / D converter 527 is output from the motor control circuit 529 to the encoder of the radial scanning motor 505 in the line data generation unit 601 in the signal processing unit 528. Using the signal of the unit 506, processing is performed so that the number of lines per rotation of the radial scanning is 512.

  Here, as an example, an optical tomographic image is constructed from 512 lines, but the number of lines is not limited to this.

  The line data 622 output from the line data generation unit 601 is stored in the line data memory 602 for each rotation of the radial scan based on an instruction from the control unit 605. At this time, the control unit 605 counts the pulse signal 641 output from the movement amount detector of the linear driving device 507 and generates each line data 622 when the line data 622 is stored in the line data memory 602. The count value is stored in association with each other.

  The line data 623 stored in association with the count value is subjected to various processes (line addition averaging process, filter process, etc.) in the optical tomographic image construction unit 603 based on an instruction from the control unit 605, Sequentially output as an optical tomographic image 624.

  Further, the image processing unit 604 performs image processing for display on the LCD monitor 113 and then outputs the optical tomographic image 625 to the LCD monitor 113.

  Similarly, the ultrasonic data 631 generated by the A / D converter 555 is a signal of the encoder unit 506 of the radial scanning motor 505 output from the motor control circuit 529 in the line data generation unit 611 in the signal processing unit 528. Is used so that the number of lines per one rotation of the radial scanning is 512.

  The line data 632 output from the line data generation unit 611 is stored in the line data memory 612 for each rotation of the radial scan based on an instruction from the control unit 605. At this time, the control unit 605 counts the pulse signal 641 output from the movement amount detector of the linear driving device 507 and generates each line data 632 when storing the line data 632 in the line data memory 612. The count value is stored in association with each other.

  The line data 633 stored in association with the count value is subjected to various processes (line addition averaging process, filter process, etc.) in the ultrasonic tomographic image construction unit 613 based on an instruction from the control unit 605. Then, a shift by the distance L with respect to the axial direction and an Rθ-transformed ultrasonic tomographic image 634 are sequentially output to the image processing unit 604. The image processing unit 604 performs image processing for display on the LCD monitor 113, and then outputs the ultrasonic tomographic image 635 to the LCD monitor 113.

  Based on the above, the process of the control unit 605 eventually performs the process according to the flowchart shown in FIG.

  First, in step S101, it is determined whether or not there is a scan instruction. If it is determined that there is a scan instruction, in step S102, the control unit 605 controls the reading unit 570, the inter-sensor distance L stored in the RFID chip of the probe unit 101, and the transmission direction of the rotation direction of each sensor. Is obtained. Thereafter, in step S103, the acquired L and θ are set as parameters in the construction process of the ultrasonic tomographic image and the optical coherent tomographic image. Thereafter, each tomographic image reconstruction process is executed, and a display process is performed.

  Note that data obtained by scanning may be reused in the future. In this case, in addition to the setting information set at the time of scanning and the digital data obtained by the A / D conversions 527 and 555, in addition to the set L and θ, a file containing the angle γ in some cases is stored in the external storage device. (Hard disk etc.) can be stored.

  As described above, according to the embodiment, the ultrasonic wave transmission / reception unit and the light transmission / reception unit in the probe are not required to have high positioning accuracy, and the deviation based on the relative positions of the ultrasonic transmission / reception unit and the light transmission / reception unit is prevented. A corrected ultrasonic tomographic image and optical tomographic image can be generated. Moreover, the operator is not forced to perform special work.

  In the above embodiment, it has been described that both the distance L between the sensors and the angle difference θ between the sensor rotation direction and the transmission direction are stored in the RFID chip. However, either one is sufficiently high in terms of cost. If positioning is possible with accuracy and the other is not, the latter value may be stored in the RFID chip.

  In some cases, not only L and θ but also an angle γ may be written on the RFID chip. When the angle γ is written in the RFID, the angle γ can be taken into account when the angle γ is read, so that a more accurate tomographic image can be created.

[Second Embodiment]
In the first embodiment, the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 are arranged along the axial direction on the rotation center axis. However, when the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 are accommodated / fixed in the housing 233, a slight deviation from the rotation center position may be allowed. 7A in FIG. 7 shows a state in which the ultrasonic wave transmitting / receiving position in the ultrasonic wave transmitting / receiving unit 310 is shifted by r0 from the rotation axis. 7B in FIG. 7 shows a state where the light transmitting / receiving position in the light transmitting / receiving unit 320 is shifted by r1 from the rotation axis. 7A and 7B in FIG. 7 should be understood as corresponding to b and c in FIG. 3 shown in the first embodiment. Therefore, the illustrated θ has the same meaning as in the first embodiment.

  Since each tomographic image by ultrasonic waves and light is obtained by reconstructing the distance from each transmission / reception unit, when r0 and r1 shown in the figure are found, correction corresponding to the deviation is performed. It will be understood that a correct tomographic image can be obtained.

  Therefore, when the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 are accommodated / fixed in the housing 233, in the case where a slight deviation from the rotation center position is allowed, r0 and r1 of the probe obtained by manufacturing are illustrated. Is measured, and an RFID chip storing and holding θ and L together with r0 and r1 may be attached to the probe. Naturally, in step S102 in FIG. 6, not only L and θ but also r0 and r1 are acquired. In step S103, tomographic image reconstruction processing may be performed including r0 and r1 in addition to L and θ.

  As described above, according to the second embodiment, when the ultrasonic transmission / reception unit 310 and the optical transmission / reception unit 320 are accommodated / fixed in the housing 233, a slight deviation from the rotation center position is allowed. While maintaining the reconstruction of a tomographic image with high accuracy, the yield can be further improved as compared with the first embodiment described above.

  In the first and second embodiments, an RFID chip is shown as an example of the information storage medium. The RFID chip is a desirable form because it can be very small and useful. For example, a two-dimensional barcode including values of L and θ (and ro, r1 if applied to the second embodiment) This seal may be attached to an appropriate position of the probe unit 101. In this case, the reading unit 570 reads the barcode.

  In the first and second embodiments, the scan start instruction is given as the timing for reading the information in the RFID chip. However, when the main body control unit 111 is turned on or the scanner / pullback unit 102 is turned on. The timing at which the probe unit 101 is detected may be detected.

  Furthermore, although the processing of the signal processing unit 528 requires some hardware, most of the processing can be realized by an application executed by the control unit 605 in the signal processing unit 528. Therefore, it is obvious that the present invention includes a program for causing a computer to execute and a computer-readable storage medium storing the program.

  The present invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.

  This application claims priority based on Japanese Patent Application No. 2012-069144 filed on Mar. 26, 2012, the entire contents of which are incorporated herein by reference.

Claims (6)

An ultrasonic transmission / reception unit for transmitting / receiving ultrasonic waves, and an optical transmission / reception unit for transmitting / receiving light, the probe having a transmission / reception unit, and holding the probe rotatably and detachably, the ultrasonic transmission / reception unit An image diagnostic apparatus that generates an ultrasonic tomographic image and an optical tomographic image of a biological tissue using a reflected wave from the biological tissue received by the optical transmitter and a reflected light from the biological tissue received by the optical transceiver. ,
Read means for accessing a predetermined memory mounted on the probe, and reading information relating to the arrangement position of the ultrasonic transmission / reception unit and the optical transmission / reception unit from the memory;
An image diagnostic apparatus comprising: diagnostic information generation means for generating an ultrasonic tomographic image and an optical tomographic image in which a deviation corresponding to the arrangement position is corrected from information acquired through the reading means.   The diagnostic imaging apparatus according to claim 1, wherein the memory is an RFID memory chip, and the reading unit is an RFID reader.   The memory emits the interval L between the ultrasonic transmission / reception unit and the optical transmission / reception unit along the rotation axis of the rotation, or the transmission direction of the ultrasonic wave emitted by the ultrasonic transmission / reception unit and the optical transmission / reception unit. 3. The diagnostic imaging apparatus according to claim 1, wherein at least one information of an angular difference θ of the rotation direction in the light transmission direction is stored.   The image according to claim 3, wherein the memory stores information on a distance r0 from the rotation axis to the ultrasonic transmission / reception unit and a distance r1 from the rotation axis to the optical transmission / reception unit. Diagnostic device.   The ultrasonic transmission direction by the ultrasonic transmission / reception unit and the transmission direction of light by the optical transmission / reception unit are directions in which an elevation angle with respect to the axial direction is shifted by a predetermined angle with respect to 90 °. 4. The diagnostic imaging apparatus according to any one of items 3. An ultrasonic transmission / reception unit for transmitting / receiving ultrasonic waves, and an optical transmission / reception unit for transmitting / receiving light, the probe having a transmission / reception unit, and holding the probe rotatably and detachably, the ultrasonic transmission / reception unit A method for controlling an image diagnostic apparatus that generates an ultrasonic tomographic image and an optical tomographic image of a biological tissue using the reflected wave from the biological tissue received by the optical transmitter and the reflected light from the biological tissue received by the optical transceiver Because
An acquisition step of accessing a predetermined memory attached to the probe, and acquiring information relating to an arrangement position of the ultrasonic transmission / reception unit and the optical transmission / reception unit from the memory via a predetermined reading unit;
And a diagnostic image generation step of generating an ultrasonic tomographic image and an optical tomographic image in which the deviation according to the arrangement position is corrected from the information acquired in the acquisition step.

Images