JP5524549B2 - Optical probe - Google Patents

Description

  The present invention relates to an optical probe.

  Conventionally, for diagnosis of arteriosclerosis, preoperative diagnosis at the time of endovascular treatment with a high-function catheter such as a balloon catheter or a stent, or optical coherence tomography diagnostic apparatus (OCT) An optical coherence tomography diagnostic apparatus (OFDI) using wavelength sweep, which is an improved version of the optical coherence tomography diagnostic imaging apparatus (OCT), and light utilizing wavelength sweeping is used in this specification. The coherent tomographic image diagnostic apparatus (OFDI) is generically called “optical image diagnostic apparatus”).

  In such an optical diagnostic imaging apparatus, measurement light is emitted into the blood vessel while rotating the transmitting / receiving unit in a state where the optical probe unit including the transmitting / receiving unit that transmits and receives light and the optical fiber is inserted into the blood vessel. Radial scanning is performed by receiving reflected light from living tissue, and the tomographic image of the blood vessel based on the interference light is rendered by causing the reflected light obtained thereby to interfere with the reference light that has been divided from the measurement light in advance. doing.

  Because of this measurement principle, in order to draw a higher-quality tomographic image, the measurement light emitted from the transmitter / receiver efficiently reaches the living tissue and the reflected light reflected by the living tissue is efficiently It is essential to reach the transceiver.

  As a configuration for efficiently allowing the measurement light emitted from the transmission / reception unit to reach the living tissue, for example, a configuration for suppressing the measurement light emitted from the transmission / reception unit from being reflected on the inner surface of the catheter sheath. Can be mentioned. This is because the measurement light can reach the living tissue without waste by suppressing the reflection on the inner surface of the catheter sheath and improving the transmittance of the measurement light in the catheter sheath.

  On the other hand, in recent years, “non-reflective surface structure” has attracted attention as a surface structure for suppressing reflection of incident light on an object surface of an object that transmits light. “Non-reflective surface structure” refers to the fact that light reflection is caused by a sudden change in refractive index, and the surface of a transparent object is formed by an infinite number of cones to achieve a smooth refractive index distribution. Thus, the reflection on the surface of the transmissive object is suppressed. For this reason, by applying the non-reflective surface structure to the inner surface of the catheter sheath, a certain degree of effect is expected in realizing a higher-quality tomographic image.

“Development of surface anti-reflection structure fabrication technology”, [online], [searched on August 14, 2009], Internet <URL: http://www.ostec.or.jp/tec/area/a/a- 2 / a-2.html>

  However, in the case of a non-reflective surface structure formed by an infinite number of cones, the aspect ratio of the cones (the diameter of the circle on the bottom of the cone, the height of the cone, It is necessary to increase the ratio).

  On the other hand, in order to form an elongated cone having a higher aspect ratio, there is a problem that high processing accuracy is required and the feasibility is low. For this reason, development of a structure having a high effect of suppressing reflection while maintaining the aspect ratio is demanded.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve the effect of suppressing reflection on the inner surface of a catheter sheath in an optical probe used in an optical diagnostic imaging apparatus.

  One aspect of the present invention continuously transmits the light transmitted from the light source of the optical diagnostic imaging apparatus into the body cavity while moving in the axial direction while rotating in the circumferential direction in the catheter sheath. An optical probe in which a transmission / reception unit that outputs a signal for generating a tomographic image in a body cavity by continuously receiving reflected light from the inside is inserted, the inner surface of the catheter sheath, Square-convex convex portions having a convex shape toward the inner side of the catheter sheath are arranged in the axial direction and the circumferential direction at intervals shorter than the wavelength of light generated by the light source, and the convex portions The bottom surface is a square, and the cut surfaces when cut in a plane parallel to the bottom surface are all square, the area of the cut surface and the distance from the top of the convex portion to the cut surface The relationship is proportional And wherein the door.

  ADVANTAGE OF THE INVENTION According to this invention, in the optical probe used for an optical diagnostic imaging apparatus, it becomes possible to improve the effect of the reflection suppression in the catheter sheath inner surface.

It is a figure which shows the external appearance structure of the optical diagnostic imaging apparatus to which the optical probe part concerning the 1st Embodiment of this invention is applied. 2 is a diagram illustrating a functional configuration of the optical coherence tomography diagnostic apparatus 100. FIG. It is a figure which shows the function structure of the optical coherence tomography diagnostic apparatus 100 of wavelength sweep utilization. It is a figure which shows the structure of the front-end | tip part of an optical probe part. It is a figure which shows the cross-sectional structure of an imaging core. It is a figure which shows the shape of the inner surface of a catheter sheath. It is a figure which shows the shape of the inner surface of a catheter sheath. It is a figure which shows the shape of the inner surface of a catheter sheath. It is a figure which shows the shape of the inner surface of a catheter sheath. It is a figure which shows the shape of the inner surface of a catheter sheath. It is a figure which shows the shape of the inner surface of a catheter sheath. It is a figure which shows the shape of the inner surface of a catheter sheath.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings as necessary.

[First Embodiment]
1. External Configuration Figure 1 of an optical imaging diagnostic apparatus first embodiment the optical imaging diagnostic apparatus optical probe unit is applied according to the embodiment of the present invention (optical coherent tomography diagnosis apparatus for an optical coherent tomography diagnosis apparatus or a wavelength-sweeping) FIG.

  As shown in FIG. 1, the optical diagnostic imaging apparatus 100 includes an optical 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 include signal lines. 104 is connected.

  The optical probe unit 101 is directly inserted into a body cavity such as a blood vessel, and measures the state inside the body cavity using an imaging core described later. The scanner / pullback unit 102 is configured to be detachable from the optical probe unit 101, and regulates the radial operation of the imaging core inserted in the optical probe unit 101 when driven by a built-in motor.

  The operation control apparatus 103 has a function for inputting various setting values and a function for processing data obtained by measurement and displaying it as a tomographic image when performing an intra-body optical coherence tomographic diagnosis.

  In the operation control device 103, reference numeral 111 denotes a main body control unit that processes data obtained by measurement and outputs a processing result. 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 processing result in the main body control unit 111.

2. Functional configuration of optical coherence tomography diagnostic apparatus Next, the main functional configuration of the optical coherence tomography diagnostic apparatus (OCT) in the optical image diagnostic apparatus 100 according to the present embodiment will be described with reference to FIG.

  Reference numeral 209 denotes a low-coherence light source such as an ultra-bright light emitting diode. The low-coherence light source 209 outputs low-coherence light that exhibits coherence only in a short distance range in which the wavelength is about 1310 nm and the coherence distance (coherent length) is about several μm to several tens of μm. .

  Therefore, when this light is divided into two and then mixed again, the difference between the two optical path lengths from the divided point to the mixed point is within a short distance range of about several μm to several tens of μm. Is detected as interference light, and is not detected as interference light when the optical path length difference is larger than that.

  Light from the low-coherence light source 209 is incident on one end of the first single mode fiber 228 and transmitted to the distal end surface side. The first single mode fiber 228 is optically coupled to the second single mode fiber 229 and the third single mode fiber 232 at an intermediate optical coupler unit 208.

  The optical coupler unit is an optical component that can divide one optical signal into two or more outputs, or combine two or more input optical signals into one output, and has low interference. The light from the light source 209 can be transmitted by being divided into a maximum of three optical paths by the optical coupler unit 208.

  A scanner / pullback unit 102 is provided on the distal end side of the optical coupler unit 208 of the first single mode fiber 228. In the scanner / pullback unit 102, an optical rotary joint 203 that couples the non-rotating unit and the rotating unit and transmits light is provided.

  Furthermore, the distal end side of the fourth single mode fiber 230 in the optical rotary joint 203 is detachably connected to the fifth single mode fiber 231 of the optical probe unit 101 via the adapter 202. Thereby, the light from the low-coherence light source 209 is transmitted to the fifth single mode fiber 231 that is inserted into the imaging core 201 that repeatedly transmits and receives light and can be driven to rotate.

  The light transmitted to the fifth single mode fiber 231 is irradiated from the distal end side of the imaging core 201 to the living tissue in the blood vessel while performing a radial operation. Then, a part of the reflected light scattered on the surface or inside of the living tissue is taken in by the imaging core 201, returns to the first single mode fiber 228 side through the reverse optical path, and a part of the reflected light is reflected by the optical coupler unit 208. 2 moves to the single mode fiber 229 side. And it is radiate | emitted from the end of the 2nd single mode fiber 229, and is received by the photodetector (for example, photodiode 210).

  Note that the rotation drive unit side of the optical rotary joint 203 is rotationally driven by a radial scanning motor 205 of the rotation drive device 204. The rotation angle of the radial scanning motor 205 is detected by the encoder unit 206. Furthermore, the scanner / pullback unit 102 includes a linear drive device 207, and moves in the axial direction (the distal direction in the body cavity and the opposite direction) of the imaging core 201 based on an instruction from the signal processing unit 214 (axial operation). ). The axial movement is realized by the linear drive device 207 moving the scanner including the optical rotary joint 203 based on a control signal from the signal processing unit 214.

  At this time, the catheter sheath of the optical probe unit 101 is fixed in the blood vessel, and only the imaging core 201 inserted in the catheter sheath moves in the axial direction, so that the axial operation can be performed without damaging the blood vessel wall. Done.

  On the other hand, an optical path length variable mechanism 216 for changing the optical path length of the reference light is provided on the tip side (reference optical path) of the optical coupler unit 208 of the second single mode fiber 229.

  This optical path length variable mechanism 216 replaces the optical probe unit 101 with first optical path length changing means that changes the optical path length corresponding to the examination range in the depth direction of the living tissue (the direction in which the measurement light is emitted) at high speed. And second optical path length changing means for changing the optical path length corresponding to the variation in length so as to be able to absorb variations in length of the individual optical probe sections 101 when used.

  A grating 219 is disposed via a collimating lens 221 that is mounted on the uniaxial stage 220 together with the tip of the third single mode fiber 232 and that is movable in the direction indicated by the arrow 223. Further, a galvanometer 217 capable of turning by a minute angle is attached as a first optical path length changing means via a lens 218 corresponding to the grating 219 (diffraction grating). The galvanometer 217 is rotated at high speed in the direction of the arrow 222 by the galvanometer controller 224.

  The galvanometer 217 reflects light by a mirror of the galvanometer, and is configured to rotate the mirror attached to the movable part at high speed by applying an AC drive signal to the galvanometer functioning as a reference mirror.

  That is, a drive signal is applied from the galvanometer controller 224 to the galvanometer 217, and the optical signal is rotated in the direction of the arrow 222 at a high speed by the drive signal, so that the optical path length of the reference light is within the examination range in the depth direction of the living tissue. It will change at high speed by the corresponding optical path length. One period of the change in the optical path difference is a period for acquiring interference light for one line.

  On the other hand, when the optical probe unit 101 is replaced, the uniaxial stage 220 functions as a second 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 optical probe unit 101. Further, the uniaxial stage 220 also has a function as an adjusting means for adjusting the offset. For example, even when the tip of the optical 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 220, thereby setting the state to interfere with the reflected light from the surface position of the living tissue. It becomes possible to do.

  The light whose optical path length is changed by the optical path length variable mechanism 216 is mixed with the light obtained from the first single mode fiber 228 side by the optical coupler unit 208 provided in the middle of the third single mode fiber 232. The light is received by the photodiode 210 as interference light.

  The interference light received by the photodiode 210 in this way is photoelectrically converted and amplified by the amplifier 211.

  Thereafter, the signal is input to the demodulator 212, and the demodulator 212 performs demodulation processing for extracting only the signal portion of the interfered light, and the output is input to the A / D converter 213.

  The A / D converter 213 samples the interference light signal for 200 points, for example, and generates one line of digital data (“interference light data”). In this case, the sampling frequency is a value obtained by dividing the time of one scanning of the optical path length by 200.

  The line-by-line interference light data generated by the A / D converter 213 is input to the signal processing unit 214. The signal processing unit 214 converts the interference light data in the depth direction of the living tissue into a video signal to generate a tomographic image at each position in the blood vessel, and the LCD monitor 215 (see FIG. 1) at a predetermined frame rate. (Corresponding to number 113).

  The signal processing unit 214 is further connected to an optical path length adjusting unit control device 226. The signal processing unit 214 controls the position of the uniaxial stage 220 via the optical path length adjusting unit controller 226. The signal processing unit 214 is connected to the motor control circuit 225 and controls the rotational drive of the radial scanning motor 205.

  The signal processing unit 214 is connected to a galvanometer controller 224 that controls scanning of the optical path length of the reference mirror (galvanometer mirror), and the galvanometer controller 224 outputs a drive signal to the signal processing unit 214. The motor control circuit 225 synchronizes with the galvanometer controller 224 based on this drive signal.

3. Functional Configuration of Optical Coherence Tomographic Image Diagnosis Device Using Wavelength Sweep Next, FIG. 3 shows a main functional configuration of an optical coherence tomographic image diagnostic device (OFDI) using wavelength sweeping in the optical image diagnostic device 100 according to the present embodiment. It explains using.

  FIG. 3 is a diagram illustrating a functional configuration of the optical coherence tomographic image diagnosis apparatus 100 using wavelength sweeping. Hereinafter, the difference from the optical coherence tomography diagnostic apparatus (OCT) described with reference to FIG. 2 will be mainly described.

  Reference numeral 308 denotes a wavelength swept light source, and a sweep laser is used. A wavelength swept light source 308 using a swept laser is a type of extended-cavity laser composed of an optical fiber 316 and a polygon scanning filter (308b) coupled in a ring shape with an SOA 315 (semiconductor optical amplifier).

  The light output from the SOA 315 travels through the optical fiber 316 and enters the polygon scanning filter 308b. The light whose wavelength is selected here is amplified by the SOA 315 and finally output from the coupler 314.

  In the polygon scanning filter 308b, a wavelength is selected by a combination of a diffraction grating 312 for separating light and a polygon mirror 309. Specifically, the light split by the diffraction grating 312 is condensed on the surface of the polygon mirror 309 by two lenses (310, 311). As a result, only light having a wavelength orthogonal to the polygon mirror 309 returns through the same optical path and is output from the polygon scanning filter 308b. Therefore, the time sweep of the wavelength can be performed by rotating the polygon mirror 309. .

  As the polygon mirror 309, for example, a 32-hedron mirror is used, and the rotation speed is about 50000 rpm. High speed and high output wavelength sweeping is possible by a unique wavelength sweeping method combining the polygon mirror 309 and the diffraction grating 312.

  The light of the wavelength swept light source 308 output from the coupler 314 is incident on one end of the first single mode fiber 330 and transmitted to the distal end side. The first single mode fiber 330 is optically coupled to the second single mode fiber 337 and the third single mode fiber 331 at an intermediate optical coupler unit 334. Accordingly, the light incident on the first single mode fiber 330 is divided into a maximum of three optical paths by the optical coupler unit 334 and transmitted.

  An optical rotary joint 303 that couples the non-rotating part and the rotating part and transmits light is provided on the distal end side of the optical coupler part 334 of the first single mode fiber 330.

  Further, the distal end side of the fourth single mode fiber 335 in the optical rotary joint 303 is detachably connected to the fifth single mode fiber 336 of the optical probe unit 101 via the adapter 302. Thereby, the light from the wavelength swept light source 308 is transmitted to the fifth single mode fiber 336 that is inserted into the imaging core 301 and can be driven to rotate.

  The transmitted light is irradiated from the distal end side of the imaging core 301 to the living tissue in the body cavity while performing a radial operation. A part of the reflected light scattered on the surface or inside of the living tissue is taken in by the imaging core 301 and returns to the first single mode fiber 330 side through the reverse optical path. Further, a part of the optical coupler unit 334 moves to the second single mode fiber 337 side, is emitted from one end of the second single mode fiber 337, and is received by a photodetector (eg, a photodiode 319).

  Note that the rotational drive unit side of the optical rotary joint 303 is rotationally driven by the radial scanning motor 305 of the rotational drive device 304. Further, the rotation angle of the radial scanning motor 305 is detected by the encoder unit 306. Further, the scanner / pullback unit 102 includes a linear drive device 307 and regulates the axial operation of the imaging core 301 based on an instruction from the signal processing unit 323.

  On the other hand, an optical path length variable mechanism 325 for finely adjusting the optical path length of the reference light is provided at the tip of the third single mode fiber 331 opposite to the optical coupler section 334.

  The optical path length variable mechanism 325 changes the optical path length corresponding to the variation in length so that the variation in length of each optical probe unit 101 when the optical probe unit 101 is replaced and used can be absorbed. Optical path length changing means is provided.

  The third single mode fiber 331 and the collimating lens 326 are provided on a uniaxial stage 332 that is movable as indicated by an arrow 333 in the optical axis direction, and form optical path length changing means.

  Specifically, when the optical probe unit 101 is replaced, the uniaxial stage 332 functions as an optical path length changing unit having a variable range of optical path length that can absorb variations in the optical path length of the optical probe unit 101. Further, the uniaxial stage 332 also has a function as an adjusting means for adjusting the offset. For example, even when the tip of the optical 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, thereby setting the state to interfere with the reflected light from the surface position of the living tissue. It is possible.

  The light whose optical path length is finely adjusted by the optical path length variable mechanism 325 is mixed with the light obtained from the first single mode fiber 330 side by the optical coupler unit 334 provided in the middle of the third single mode fiber 331. The light is received by the photodiode 319.

  The interference light received by the photodiode 319 in this way is photoelectrically converted, amplified by the amplifier 320, and then input to the demodulator 321. The demodulator 321 performs demodulation processing for extracting only the signal portion of the interfered light, and its output is input to the A / D converter 322 as an interference light signal.

  The A / D converter 322 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 322 is input to the signal processing unit 323. The signal processing unit 323 generates a tomographic image at each position in the blood vessel by frequency-decomposing the interference light data by FFT (Fast Fourier Transform) to generate data in the depth direction and performing coordinate conversion on the data. The data is output to the LCD monitor 317 (corresponding to reference numeral 113 in FIG. 1) at a predetermined frame rate.

  The signal processing unit 323 is further connected to an optical path length adjusting unit control device 318. The signal processing unit 323 controls the position of the uniaxial stage 332 via the optical path length adjusting unit control device 318. The signal processing unit 323 is connected to the motor control circuit 324 and receives a video synchronization signal from the motor control circuit 324. The signal processing unit 323 generates a tomographic image in synchronization with the received video synchronization signal.

  The video synchronization signal of the motor control circuit 324 is also sent to the rotation drive device 304, and the rotation drive device 304 outputs a drive signal synchronized with the video synchronization signal.

4). Next, the configuration of the tip of the optical probe 101 will be described with reference to FIG. In FIG. 4, the imaging core 201 includes a housing 411 in which a transmitting / receiving unit 413 that transmits and receives measurement light is disposed inside a lumen of the catheter sheath 401 and a drive shaft 412 that transmits a driving force for rotating the housing 411. , 301 are inserted over almost the entire length, forming the optical probe portion 101.

  The transmission / reception unit 413 includes a side-irradiation type ball lens that reflects the optical axis of the measurement light transmitted by the optical fiber inserted through the drive shaft 412 to the side.

  The transmission / reception unit 413 transmits measurement light toward the biological tissue in the body cavity and receives reflected light from the biological tissue in the body cavity.

  The drive shaft 412 is formed in a coil shape, and a signal line (single mode optical fiber) is disposed therein.

  The housing 411 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 411 has a transmission / reception unit 413 therein, and the base end side is connected to the drive shaft 412. A short coil-shaped elastic member 403 is provided on the tip side.

  The elastic member 403 is a stainless steel wire formed in a coil shape, and the elastic member 403 is disposed on the distal end side, so that the stability during rotation of the imaging cores 201 and 301 is improved.

  Reference numeral 404 denotes a reinforcing coil, which is provided for the purpose of preventing sudden bending of the distal end portion of the catheter sheath 401.

  The guide wire lumen tube 402 has a guide wire lumen into which a guide wire can be inserted. The guide wire lumen tube 402 is used to receive a guide wire previously inserted into a body cavity and guide the catheter sheath 401 to the affected area by the guide wire.

  The imaging cores 201 and 301 can perform a rotational operation in the circumferential direction of the catheter sheath 401 and an axial operation in the axial direction, and the drive shaft 412 covering it is flexible and can transmit rotation well. For example, a multi-layered close-contact coil made of a metal wire such as stainless steel.

5). Next, the sectional configuration of the imaging cores 201 and 301 will be described. FIG. 5 is a diagram illustrating a cross-sectional configuration of the imaging cores 201 and 301. As shown in FIG. 5, a side-illuminated ball lens 501 serving as a transmission / reception unit is disposed in the housing 411, and an optical fiber including a clad unit 504 and a core unit 503 in the drive shaft 412. 502 is arranged.

  The side-illuminated ball lens 501 is melt-connected to the tip of the optical fiber 502, and the measurement light emitted from the tip of the optical fiber 502 is placed in a body cavity (not shown) located in a direction substantially orthogonal to the emission direction. The light is emitted toward the living tissue in a condensed state.

  The measurement light 510 emitted from the side irradiation type ball lens (transmission / reception unit) 501 passes through the inner surface / outer surface of the catheter sheath 401 and reaches the living tissue. The reflected light 511 reflected from the living tissue passes through the outer surface / inner surface of the catheter sheath 401 and is received by the side irradiation type ball lens (transmission / reception unit) 501.

6). Detailed structure of the inner surface of the catheter sheath Next, the structure of the inner surface of the catheter sheath 401 will be described. FIG. 6A is a view for explaining the structure of the inner surface of the catheter sheath 401.

  6A, (a-1) is a perspective view of the catheter sheath 401, and (a-2) is an enlarged perspective view of the inner surface of the catheter sheath 401. FIG. (B-1) is a view for explaining the axial and circumferential sectional shapes of the inner surface of the catheter sheath 401, and (b-2) is an axial direction and a circle of the inner surface of the catheter sheath 401. It is a figure which shows the detail of the cross-sectional shape of the circumferential direction.

  As shown in (a-2), on the inner surface of the catheter sheath 401, convex portions having a square conical shape convex toward the inner side are arranged at equal intervals in the circumferential direction and the axial direction. In this way, by arranging the rectangular conical convex portions at equal intervals in the circumferential direction and the axial direction, the adjacent convex portions are arranged without gaps.

  In other words, like the conventional non-reflective surface structure, when formed with a cone, the bottom circles cannot be arranged without gaps, and there is always a plane perpendicular to the incident light. As in this embodiment, in the case where the projection is formed by a square conical projection, there is no plane perpendicular to the incident light. As a result, it is possible to further improve the effect of suppressing reflection as compared with the case of forming with a cone.

  In addition, the said square-cone-shaped convex part is comprised so that the shape when it sees from a circumferential direction and the shape when it sees from an axial direction may become equal, and the circumference of each square-cone-shaped convex part is The interval between the direction and the axial direction is 0.1 μm to 1.0 μm. The interval is shorter than the wavelength λ of measurement light or reflected light transmitted through the catheter sheath 401 (for example, a wavelength (1310 nm) used in the optical coherence tomography diagnostic apparatus).

  In the case of the present embodiment, as shown in (b-1), each square-cone-shaped convex portion 600 has a midpoint (611 and 612 or 621 and 622) of opposing sides in the bottom square. The outer edge shape (631 or 651) of the cross section when cut by a plane (630 or 640) passing through the apex 601 of the top of the square-cone-shaped convex portion 600 is the shape shown in (b-2). (In (b-2), the length connecting the midpoints of the bottom squares is normalized to 1).

Specifically, the aspect ratio (ratio between the length connecting the midpoints of the bottom square and the height of the apex 601 of the square cone-shaped convex portion 600 when the bottom square is used as a reference) is a, When each position of the line connecting the midpoints of the square is X, the outer edge shape (631 or 651) Y at each position X of the line connecting the midpoints of the squares on the bottom surface is
(Expression 1) Y = −4aX (X−1).
However, the length connecting the midpoints of the bottom square is 1. Further, a = 1 to 10.

  Here, the effect | action of the convex part 600 which has the outer edge shape represented by Formula 1 is demonstrated using FIG. 6B. FIG. 6B (a) shows a convex portion using a plane parallel to the bottom surface at each height position (each position in the direction orthogonal to the square of the bottom surface) of the convex portion 600 having the outer edge shape represented by Formula 1. A cut surface when 600 is cut is shown.

  In FIG. 6B (a), reference numerals 661 to 663 denote planes parallel to the bottom surface of the rectangular conical convex portion 600 at each height position of the rectangular conical convex portion 600.

  Moreover, 665-667 represents the cut surface at the time of cutting the convex part 600 using the planes 661-663 parallel to a bottom face. Further, reference numeral 664 denotes a square on the bottom surface of the convex portion 600 having a square cone shape.

  As can be seen from (a) of FIG. 6B, the area of the cut surface (665, 666, 667) of the square cone-shaped convex portion 600 gradually increases toward the bottom surface direction (arrow 670). The ratio of the area of the cut surfaces (665, 666, 667) occupying the area of the square 664 (that is, the ratio of the convex portion occupying the space near the inner surface of the catheter sheath 401) gradually increases.

  FIG. 6B (b) shows the change in the area of the cut surface at this time. 6B shows the height position in the direction perpendicular to the square of the bottom surface (provided that the bottom surface is the bottom surface), with the ratio of the convex portions (members on the inner surface of the catheter sheath) occupying the space in the vicinity of the inner surface of the catheter sheath 401 on the horizontal axis. Is a graph in which the ratio of the length connecting the midpoints of the square is 1) on the vertical axis.

  As can be seen from (b) of FIG. 6B, the area of the cut surface increases in proportion to the distance from the apex to each height position in the direction orthogonal to the bottom surface of the square cone-shaped convex portion 600 (from the bottom surface). It decreases in proportion to the distance to each height position).

  That is, the outer edge shape represented by Equation 1 is such that the area of the cut surface when cut by a plane parallel to the bottom surface decreases in proportion to the distance between each height position of the plane parallel to the bottom surface and the bottom surface. It can be said that the shape is formed (a shape formed in proportion to the distance from the apex to each height position).

  Thus, when the convex part 600 is formed so that the area of the cut surface increases in proportion to the distance from the apex to each height position in the direction orthogonal to the bottom surface of the convex part 600 having a rectangular conical shape. In the light incident direction, the proportion of the convex portion 600 occupying the space (that is, the proportion of the catheter sheath inner surface member occupying the space) increases at a constant rate, thereby realizing a smooth refractive index distribution. It becomes possible.

  In other words, when it is formed of a cone like the conventional non-reflective surface structure, the area of the cut surface at each height position is a quadratic function with respect to the distance from the apex to each height position. However, by having the outer edge shape represented by Formula 1 as in this embodiment, the area of the cut surface at each height position with respect to the distance from the apex to each height position. However, it increases in proportion to a linear function, and a smoother refractive index distribution can be realized as compared with the conventional non-reflective surface structure.

  As a result, the reflectance on the inner surface of the catheter sheath 401 can be reduced.

[Second Embodiment]
In the first embodiment, the convex portions of the rectangular conical shape that are convex toward the inner side are arranged on the inner surface of the catheter sheath. However, the present invention is not limited to this, and the inside of the catheter sheath is not limited to this. You may make it arrange | position the concave part of a square-cone shape of a concave shape toward the inner side on the surface.

  FIG. 7A is a view for explaining the structure of the inner surface of the catheter sheath 401 according to this embodiment.

  7A, (a-1) is a perspective view of the catheter sheath 401, and (a-2) is an enlarged perspective view of the inner surface of the catheter sheath 401. FIG. Further, (b-1) is a view for explaining the sectional shape of the opening in the axial direction and the circumferential direction of the inner surface of the catheter sheath 401, and (b-2) is the axial direction of the inner surface of the catheter sheath 401. It is a figure which shows the detail of the opening part cross-sectional shape of the circumference direction.

  As shown in (a-2), on the inner surface of the catheter sheath 401, square conical concave portions that are concave toward the inner side are arranged at equal intervals in the circumferential direction and the axial direction. In this way, by arranging the rectangular conical concave portions at equal intervals in the circumferential direction and the axial direction, adjacent concave portions are arranged without gaps.

  In other words, like the conventional non-reflective surface structure, when formed with a cone, the bottom circles cannot be arranged without gaps, and there is always a plane perpendicular to the incident light. In the present embodiment, when the rectangular recess is formed, there is no plane perpendicular to the incident light. As a result, it is possible to further improve the effect of suppressing reflection as compared with the case of forming with a cone.

  The rectangular conical recesses are configured so that the shape when viewed from the circumferential direction is equal to the shape when viewed from the axial direction, and the circumferential direction of each rectangular pan-shaped recess and The interval in the axial direction is assumed to be 0.1 μm to 1.0 μm. The interval is shorter than the wavelength λ of measurement light or reflected light transmitted through the catheter sheath 401 (for example, a wavelength (1310 nm) used in the optical coherence tomography diagnostic apparatus).

  In the case of this embodiment, as shown in (b-1), each square-cone-shaped concave portion 700 has a midpoint (711 and 712, or 721 and 722) of opposing sides in the square opening on the upper surface. ) And a plane (730 or 740) passing through the apex (701) of the bottom portion of the rectangular pan-like recess 700, both of the outer edge shapes (731 or 751) of the cross section are (b-2) (In (b-2), the length connecting the midpoints of the square openings on the upper surface is normalized as 1).

Specifically, the aspect ratio (the ratio between the length connecting the midpoints of the square openings on the upper surface and the depth of the apex 701 of the rectangular conical recess when the square opening on the upper surface is used as a reference) is a. And each position of the line connecting the midpoints of the square openings on the top surface is X, and the outer edge shape (731 or 751) Y of the opening at each position of the lines connecting the midpoints of the square openings on the top surface is ,
(Expression 2) Y = 4aX (X-1).
However, the length connecting the midpoints of the square openings on the upper surface is 1. Further, a = 1 to 10.

  Here, the effect | action of the recessed part 700 which has the outer edge shape represented by Formula 2 is demonstrated using FIG. 7B. (A) of FIG. 7B uses a plane parallel to the upper surface at each height position (each position in the direction orthogonal to the square opening on the upper surface) of the recess 700 having the outer edge shape represented by Expression 2. The cut surface at the time of cut | disconnecting a recessed part is shown.

  In FIG. 7B (a), reference numerals 761 to 763 denote planes parallel to the upper surface of the rectangular conical recess 700 at each depth position of the rectangular conical recess 700.

  Moreover, 765-767 represent the cut surface at the time of cut | disconnecting the recessed part 700 using the planes 761-763 parallel to an upper surface. Furthermore, 764 represents a square opening on the upper surface of the rectangular conical recess 700.

  As can be seen from (a) of FIG. 7B, the area of the opening in the cut surfaces (765, 766, 767) of the rectangular conical recess 700 gradually decreases toward the apex direction (arrow 770). The ratio of the area of the opening of the cut surface (765, 766, 767) to the area of the square opening 764 on the upper surface (that is, the ratio of the space in the vicinity of the inner surface of the catheter sheath 401) gradually decreases ( In other words, the ratio of the members on the inner surface of the catheter sheath gradually increases toward the apex direction).

  FIG. 7B (b) shows the change in the area of the member on the inner surface of the catheter sheath at the cut surface at this time. FIG. 7B (b) shows the ratio of members on the inner surface of the catheter sheath occupying the space in the vicinity of the inner surface of the catheter sheath 401 on the horizontal axis, and the depth position in the direction perpendicular to the square opening on the upper surface (however, It is a graph in which the ratio (when the length connecting the midpoints of the square openings is 1) is plotted on the vertical axis.

  As can be seen from (b) of FIG. 7B, the area of the member on the inner surface of the catheter sheath at the cut surface is the distance from the opening on the top surface to each depth position in the direction perpendicular to the top surface of the rectangular conical recess 700. (Increase in proportion to the distance from the bottom vertex to each depth position).

  In other words, the outer edge shape represented by Equation 2 is such that the area of the member on the inner surface of the catheter sheath of the cut surface when cut by a plane parallel to the opening on the upper surface is each depth of the plane parallel to the opening on the upper surface. It can be said that the shape is formed in proportion to the distance between the position and the opening on the upper surface.

  Thus, the area of the member on the inner surface of the catheter sheath of the cut surface increases in proportion to the distance from the opening on the upper surface to each depth position in the direction orthogonal to the upper surface of the rectangular pan-like recess 700. When the concave portion 700 is formed in the light source, the ratio of the member on the inner surface of the catheter sheath occupying the space in the light incident direction increases at a constant rate, and a smooth refractive index distribution can be realized. It becomes.

  In other words, when it is formed of a cone like the conventional non-reflective surface structure, the area of the cut surface at each height position is a quadratic function with respect to the distance from the apex to each height position. However, by having the outer edge shape represented by Formula 2 as in this embodiment, the catheter of the cut surface at each depth position with respect to the distance from the upper surface to each depth position. The area of the member on the inner surface of the sheath increases in proportion to a linear function, and a smoother refractive index distribution can be realized as compared with the conventional non-reflective surface structure.

  As a result, the reflectance on the inner surface of the catheter sheath 401 can be reduced.

[Third Embodiment]
In the first and second embodiments, the inner surface of the catheter sheath is provided with either a square conical convex portion convex toward the inner side or a square conical concave portion concave toward the inner direction. Although the present invention is arranged, the present invention is not limited to this, and on the inner surface of the catheter sheath, a convex portion having a rectangular shape that is convex toward the inside, and a rectangular shape having a shape that is concave toward the inside. The recesses may be alternately arranged.

  FIG. 8A is a view for explaining the structure of the inner surface of the catheter sheath 401 according to this embodiment.

  8A, (a-1) is a perspective view of the catheter sheath 401, and (a-2) is an enlarged perspective view of the inner surface of the catheter sheath 401. FIG. Further, (b-1) is a view for explaining the axial and circumferential cross-sectional shapes (or opening cross-sectional shapes) of the inner surface of the catheter sheath 401, and (b-2) is a diagram of the catheter sheath 401. It is a figure which shows the detail of the cross-sectional shape (or opening part cross-sectional shape) of the axial direction and circumferential direction of an inner surface.

  As shown in (a-2), the inner surface of the catheter sheath 401 has a square conical convex portion that is convex toward the inner side and a square conical concave portion that is concave toward the inner direction. They are arranged at equal intervals alternately in the circumferential direction and the axial direction. In this way, by arranging the square conical convex portions and the square conical concave portions alternately at equal intervals in the circumferential direction and the axial direction, the adjacent convex portions and concave portions are arranged without gaps. Become.

  In other words, like the conventional non-reflective surface structure, when formed with a cone, the bottom circles cannot be arranged without gaps, and there is always a plane perpendicular to the incident light. As in the present embodiment, in the case of being formed by a rectangular conical convex portion and a rectangular conical concave portion, there is no plane perpendicular to the incident light. As a result, it is possible to further improve the effect of suppressing reflection as compared with the case of forming with a cone.

  In addition, the said square-cone-shaped convex part and the square-cone-shaped concave part are each comprised so that the shape when seen from the circumferential direction and the shape when seen from an axial direction may become equal, respectively. It is assumed that the circumferential and axial distances between the convex portion and the square conical concave portion are 0.1 μm to 1.0 μm. The interval is shorter than the wavelength λ of measurement light or reflected light transmitted through the catheter sheath 401 (for example, a wavelength (1310 nm) used in the optical coherence tomography diagnostic apparatus).

  In the case of this embodiment, as shown in (b-1), each square-cone-shaped convex part 800 and square-cone-shaped concave parts 810 and 830 are provided on each reference surface (the bottom surface of the convex part 800 and the concave part 810, 830) (the upper surface of 830), the midpoints of the opposing sides of the square (only (811 and 812, 841 and 842 are shown) in (b-1)), and the apex 801 and the square cone shape of the top portion of the quadrangular convex portion 800. The outer edge shape (821 or 851) of the cross section when cut by a plane (820 or 850) passing through the apex (802 or 803) of the bottom portion of the recess 810 or 830 of FIG. It has a shape (in (b-2), the length connecting the midpoints of the squares of the reference plane is normalized to 1).

Specifically, the aspect ratio (the ratio of the length connecting the midpoints of the squares of the reference plane to the heights (depths) of the vertices 801 or vertices 802 and 803 with reference to the square of the reference plane) is a. And each position of the line connecting the midpoint of the square of the reference plane is X, the outer edge shape (821, 851) Y at each position of the line connecting the midpoint of the square of the reference plane is
(Formula 3) Y = 2.67aX (X-1) (X-2).
However, the length connecting the midpoints of the squares of the reference plane is 1. Further, a = 1 to 10.

  Here, the action of the square-cone-shaped convex part 800 and the square-cone-shaped concave part 830 having the outer edge shape represented by Expression 3 will be described with reference to FIG. 8B. (A) of FIG. 8B shows each height (depth) position (the height (depth) in the direction orthogonal to the square of the reference plane) of the convex portion 800 and the concave portion 830 having the outer edge shape represented by Expression 3. (Position) shows a cut surface when a convex portion or a concave portion is cut using a plane parallel to the reference surface.

  In FIG. 8B (a), reference numerals 861 to 866 denote planes parallel to the reference plane at the respective height (depth) positions of the rectangular conical convex portion 800 and the concave portion.

  Reference numerals 871 to 876 denote cut surfaces when the convex portions 800 and the concave portions 830 are cut using planes 861 to 866 that are parallel to the reference plane. Further, 867 represents a square of the reference plane.

  As can be seen from (a) of FIG. 8B, the area of the cut surface (871, 872, 873) of the square-cone-shaped convex portion 800 gradually increases toward the apex direction (arrow 870) at the bottom. The ratio of the area of the cut surfaces (871, 872, 873) to the area of the square 867 of the reference plane (that is, the ratio of the convex portion in the space near the inner surface of the catheter sheath 401) gradually increases. Similarly, in the rectangular conical recess 830, the area of the opening of the cut surfaces (874, 875, 876) gradually decreases toward the apex direction (arrow 870) at the bottom, and the square shape of the reference surface is reduced. The ratio of the area of the opening of the cut surfaces (874, 875, 876) occupying the area of the opening (that is, the ratio of the space in the vicinity of the inner surface of the catheter sheath 401) gradually decreases (in other words, in the apex direction). As it goes, the proportion of members on the inner surface of the catheter sheath gradually increases).

  FIG. 8B (b) shows the change in the area of the member on the catheter sheath inner surface of the cut surface at this time. FIG. 8B (b) shows the ratio of the members on the inner surface of the catheter sheath occupying the space in the vicinity of the inner surface of the catheter sheath 401 on the horizontal axis, and the height (depth) position in the direction perpendicular to the square of the reference plane (however, FIG. 6 is a graph in which the ratio (when the length connecting the midpoints of the squares of the reference plane is 1) is plotted on the vertical axis.

  As can be seen from (b) of FIG. 8B, the area of the member on the inner surface of the catheter sheath of the cut surface is from the apex 801 of the convex portion 800 in the direction orthogonal to the reference surface of the rectangular conical convex portion 800 and the concave portion 830. It increases in proportion to the distance to each height (depth) position.

  In other words, the outer edge shape represented by Expression 3 is such that the area of the member on the catheter sheath inner surface of the cut surface when cut by a plane parallel to the reference surface is the height (depth) of the plane parallel to the reference surface. It can be said that the shape is formed in proportion to the distance between the position and the reference plane.

  Thus, the distance from the reference surface to each height (depth) position in the direction in which the area of the inner surface of the catheter sheath of the cut surface is orthogonal to the reference surfaces of the rectangular conical convex portion 800 and the concave portion 830 When the convex part and the concave part are formed in proportion to the ratio, the ratio of the member on the inner surface of the catheter sheath occupying the space in the light incident direction increases at a constant rate, and the smooth refractive index distribution Can be realized.

  In other words, when it is formed of a cone like the conventional non-reflective surface structure, the area of the cut surface at each height position is a quadratic function with respect to the distance from the apex to each height position. However, by having the outer edge shape represented by Expression 3 as in the present embodiment, each height (depth) with respect to the distance from the apex to each height (depth) position. The area of the inner surface of the catheter sheath at the position of the cut surface at the position will increase in proportion to a linear function, realizing a smoother refractive index distribution than the conventional non-reflective surface structure. It becomes possible to do.

  As a result, the reflectance on the inner surface of the catheter sheath 401 can be reduced.

[Fourth Embodiment]
In the first embodiment, the case where the shape of the cut surface is square has been described, but the present invention is not limited to this, and the area of the cut surface is proportional to the distance from the apex to each height position. As long as it is formed so as to increase, the shape of the cut surface is not limited to a square.

  FIG. 9 is a diagram illustrating the convex portion 900 when the shape of the cut surface is a circle. In FIG. 9A, reference numerals 961 to 963 are planes parallel to the bottom surface of the convex portion 900 at each height position of the convex portion 900.

  Reference numerals 971 to 973 denote cut surfaces when the convex portion 900 is cut using planes 961 to 963 parallel to the bottom surface. Further, 970 represents a circle near the bottom surface of the convex portion 900.

  As can be seen from FIG. 9A, the convex portion 900 gradually increases in area of the cut surfaces (971, 972, 973) toward the bottom surface direction (arrow 980), and a circle 970 near the bottom surface. The ratio of the area of the cut surfaces (971, 972, 973) to the area (that is, the ratio to the space in the vicinity of the inner surface of the catheter sheath 401) gradually increases.

  FIG. 9B shows the change in the area of the cut surface at this time. FIG. 9B shows the height position in the direction perpendicular to the square of the bottom surface (however, the bottom surface) with the ratio of the convex portion (member of the catheter sheath inner surface) occupying the space in the vicinity of the inner surface of the catheter sheath 401 on the horizontal axis. It is a graph in which the vertical axis represents the ratio when the length of the diameter of a nearby circle is 1.

  As can be seen from (b) of FIG. 9, the area of the cut surface increases in proportion to the distance from the apex to each height position in the direction orthogonal to the bottom surface of the convex portion 900 (from the bottom surface to each height position). Decreases in proportion to the distance to).

  In this way, when the convex portion 900 is formed so that the area of the cut surface increases in proportion to the distance from the apex to each height position in the direction orthogonal to the bottom surface of the convex portion 900, the incidence of light In the direction, the proportion of the convex portion 900 occupying the space (that is, the proportion of the member on the inner surface of the catheter sheath occupying the space) increases at a constant rate, and a smooth refractive index distribution can be realized. It becomes.

  In addition, if the shape of the bottom surface is circular, a gap is generated between adjacent convex portions, and a plane orthogonal to incident light exists. For this reason, the convex portion in the present embodiment is configured such that the bottom surface is a square and a smooth curved surface is formed from a circular shape to a square in the vicinity of the bottom surface.

[Fifth Embodiment]
In the fourth embodiment, the case of the convex portion has been described, but the case of the concave portion can be similarly formed. Moreover, it can be similarly formed when the convex portions and the concave portions are alternately arranged.

  Moreover, in the said 1st thru | or 3rd embodiment, although the shape of the cut surface was made into square, this invention is not limited to this, Other regular polygons may be sufficient.

Claims (12)

While moving in the axial direction while rotating in the circumferential direction within the catheter sheath, the light transmitted from the light source of the optical diagnostic imaging apparatus is continuously transmitted into the body cavity and the reflected light from the body cavity is continuously transmitted. An optical probe in which a transmission / reception unit that outputs a signal for generating a tomographic image in a body cavity is inserted,
On the inner surface of the catheter sheath, a rectangular pan-like convex portion having a convex shape toward the inner side of the catheter sheath is shorter than the wavelength of the light generated by the light source in the axial direction and the circumferential direction. Are arranged in
The convex portion is
The bottom surface is a square, and the cut surfaces when cut in a plane parallel to the bottom surface are all square,
Optical probe, characterized in that the relationship between the distance from the apex of the area before Symbol cut surface the convex portion to the cutting plane is proportional.   The optical probe according to claim 1, wherein the convex portions are arranged at equal intervals of 0.1 μm to 1.0 μm. The midpoint of the opposite sides of the square of the bottom surface, outer edge obtained by cutting the convex portions by a plane passing through said vertex, each position of the line connecting the center point and X, the aspect of the convex portion 3. The light according to claim 2, wherein when the ratio is a, the length of the line connecting the midpoints is 1, and Y = −4 × a × X (X−1). probe. While moving in the axial direction while rotating in the circumferential direction within the catheter sheath, the light transmitted from the light source of the optical diagnostic imaging apparatus is continuously transmitted into the body cavity and the reflected light from the body cavity is continuously transmitted. An optical probe in which a transmission / reception unit that outputs a signal for generating a tomographic image in a body cavity is inserted,
On the inner surface of the catheter sheath, a rectangular conical recess having a concave shape toward the inner side of the catheter sheath is provided at intervals shorter than the wavelength of the light generated by the light source in the axial direction and the circumferential direction. Are arranged,
The recess is
The opening on the upper surface is a square, and the cut surfaces when cut in a plane parallel to the upper surface are both square,
Optical probe, characterized in that the relationship between the distance from the apex of the recess and the area of pre-Symbol cut surface to the cut surface is proportional.   The optical probe according to claim 4, wherein the recesses are arranged at equal intervals of 0.1 μm to 1.0 μm. The midpoint of the opposite sides of the square opening of the upper surface, the outer edge shape obtained by cutting the recess by a plane passing through said vertex, each position of the line connecting the center point and X, of the recess 6. The light according to claim 5, wherein when the aspect ratio is a and the length of the line connecting the midpoints is 1, Y = 4 × a × X (X−1). probe. While moving in the axial direction while rotating in the circumferential direction within the catheter sheath, the light transmitted from the light source of the optical diagnostic imaging apparatus is continuously transmitted into the body cavity and the reflected light from the body cavity is continuously transmitted. An optical probe in which a transmission / reception unit that outputs a signal for generating a tomographic image in a body cavity is inserted,
On the inner surface of the catheter sheath, a rectangular conical convex portion convex toward the inner side of the catheter sheath and a rectangular conical concave portion concave toward the inner direction are provided in the axial direction and the circumference. Alternately arranged in directions, arranged at intervals shorter than the wavelength of the light generated by the light source ,
The convex portion is
The bottom surface is a square, and the cut surfaces when cut in a plane parallel to the bottom surface are all square,
Relationship between the distance from the apex of the area between the convex portion of the cut surface of the convex portion to the cut surface of the convex portion is proportional,
The recess is
The opening on the upper surface is a square, and the cut surfaces when cut in a plane parallel to the upper surface are both square,
Optical probe, characterized in that the relationship between the distance from the apex of the area between the recess of the cut surface of the recess up to the cut surface of the recess is proportional.   The optical probe according to claim 7, wherein the convex portions and the concave portions are alternately arranged at equal intervals of 0.1 μm to 1.0 μm. The midpoint of the opposite sides of the square opening of the midpoint and the upper surface of the opposing sides of the square of the bottom surface, the convex portion and the by a plane passing through said apex of said vertices and said recess of said protrusion The outer edge shape in the case of cutting the concave portion is that each position of the line connecting the middle points is X, and when the aspect ratio of the convex portion and the concave portion is a, respectively, the length of the line connecting the middle points is The optical probe according to claim 8, wherein each of the optical probes is represented by Y = 2.67aX (X−1) (X−2). While moving in the axial direction while rotating in the circumferential direction within the catheter sheath, the light transmitted from the light source of the optical diagnostic imaging apparatus is continuously transmitted into the body cavity and the reflected light from the body cavity is continuously transmitted. An optical probe in which a transmission / reception unit that outputs a signal for generating a tomographic image in a body cavity is inserted,
Conical convex portions having a convex shape toward the inner side of the catheter sheath are arranged on the inner surface of the catheter sheath at intervals shorter than the wavelength of light generated by the light source,
An optical probe characterized in that the relationship between the area of the cut surface when the convex portion is cut along a plane parallel to the bottom surface and the distance from the apex of the convex portion to the cut surface is proportional. While moving in the axial direction while rotating in the circumferential direction within the catheter sheath, the light transmitted from the light source of the optical diagnostic imaging apparatus is continuously transmitted into the body cavity and the reflected light from the body cavity is continuously transmitted. An optical probe in which a transmission / reception unit that outputs a signal for generating a tomographic image in a body cavity is inserted,
On the inner surface of the catheter sheath, conical concave portions having a concave shape toward the inner side of the catheter sheath are arranged at intervals shorter than the wavelength of light generated by the light source,
An optical probe characterized in that the relationship between the area of the cut surface when the recess is cut along a plane parallel to the upper surface thereof and the distance from the apex of the recess to the cut surface is proportional.   While moving in the axial direction while rotating in the circumferential direction within the catheter sheath, the light transmitted from the light source of the optical diagnostic imaging apparatus is continuously transmitted into the body cavity and the reflected light from the body cavity is continuously transmitted. An optical probe in which a transmission / reception unit that outputs a signal for generating a tomographic image in a body cavity is inserted,
Light generated by the light source is formed on the inner surface of the catheter sheath by a conical convex portion having a convex shape toward the inner side of the catheter sheath and a conical concave portion having a concave shape toward the inner direction. Are arranged at intervals shorter than the wavelength of
There is a proportional relationship between the area of the cut surface and the distance from the apex of the convex portion to the cut surface of the convex portion when the convex portion is cut along a plane parallel to the bottom surface thereof,
An optical probe characterized in that the relationship between the area of the cut surface when the recess is cut along a plane parallel to the upper surface thereof and the distance from the apex of the recess to the cut surface of the recess is proportional.

Images