JP4647327B2 - Probe unit for OCT diagnostic imaging equipment - Google Patents

Description

  The present invention relates to a probe unit for an OCT (Optical Coherence Tomography) diagnostic imaging apparatus, and more particularly to a probe unit characterized by coupling between a probe and a drive unit of the probe.

  In recent years, OCT diagnostic imaging apparatuses using low-coherence light, particularly OCT diagnostic imaging apparatuses that acquire optical tomographic images of tissues to be measured by measuring the light intensity of low-coherence interference light by heterodyne detection, have been used for medical diagnosis. It is being applied.

  This OCT diagnostic imaging apparatus divides low-coherence light emitted from a light source such as an SLD (Super Luminescent Diode) into measurement light and reference light, and slightly shifts the frequency of the reference light or measurement light by a piezo element or the like. The measurement light is incident on the tissue to be measured, the reflected light reflected at a predetermined depth of the tissue to be measured is interfered with the reference light, the light intensity of the interference light is measured by heterodyne detection, and tomographic information is acquired. The optical path length of the reference light is the same as the optical path length of the measurement light by slightly moving the movable mirror, etc., placed on the optical path of the reference light and slightly changing the optical path length of the reference light. Information at the depth of the tissue can be obtained.

  If such an OCT diagnostic imaging apparatus is used, the object to be observed can be observed with a high resolution of about several tens of μm. Therefore, since early cancer diagnosis is possible, a method for obtaining an optical tomographic image of a body cavity by guiding measurement light and reflected light of the measurement light with a probe that can be inserted into a forceps port of an endoscope apparatus Development is underway.

In addition, in order to perform radial scanning with the measurement light, a rotation shaft is provided in the sheath that covers the optical fiber in order to rotate the prism that emits the measurement light and the optical fiber that guides the measurement light to the prism. An OCT diagnostic imaging apparatus configured to rotationally drive a shaft is described in Non-Patent Document 1, for example.
Scanning single-mode fiber optic catheter-endoscope for optical coherence tomography: OPTICS LETTER Vol.21, No7 P543〜P545

  However, the structure of the probe that is long enough to be inserted into the forceps port of the endoscope apparatus, the mechanism for rotating the optical fiber in the sheath of the probe, the mechanism of the drive unit that drives the rotation of the optical fiber, and The concrete configuration and mechanism that lead to practical use, such as how to connect the drive unit and the probe, are still in the development stage, and the development of a probe unit that is easy to handle and highly accurate is required.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a probe unit that facilitates the operation of connecting the probe of the OCT diagnostic imaging apparatus to the drive unit.

The probe unit for an OCT diagnostic imaging apparatus according to the present invention is a probe in which an optical fiber rotating around an axis is accommodated in a cladding tube, and is detachably mounted between the probe and the apparatus main body to rotate the optical fiber. And a probe unit for an OCT diagnostic imaging apparatus comprising a drive unit that optically connects the optical fiber to the optical fiber extending from the apparatus main body side.
The drive unit includes a rotary connector connected to the optical fiber of the probe, and a drive unit having a gear train that rotationally drives the rotary connector in a housing fixed to the cladding tube side of the probe,
The rotary connector and the optical fiber are screwed together by rotation, and include a connecting portion made of an annular rotating member having a space through which the optical fiber passes.
The housing includes a rotation restricting member that prevents rotation of the gear train when operated from outside the housing.

  The rotation restricting member may be of any configuration as long as it can be operated from the outside and restricts the rotation of the gear train. For example, the operation restricting member protruding outside the housing and the inside of the housing And a restricting portion provided to be detachable from a part of the gear train by the operation of the operating portion, and by the operation, the restricting portion contacts or engages a part of the gear train. What prevents rotation of the gear train can be used.

  More specifically, for example, the rotation restricting member includes an urging member that urges the rotation restricting member so that the restricting portion is always located away from the gear train. A member that contacts or engages the part of the gear train by pushing the rotation restricting member into the housing against the urging of the urging member can be used.

  The rotation restricting member provided with the restricting portion prevents rotation of the gear train by contacting or engaging the restricting portion with a part of the gear having the largest diameter in the gear train. Is desirable.

  The probe can be inserted through the forceps opening of the endoscope.

  In the OCT diagnostic imaging probe unit according to the present invention, the probe and the drive unit are formed of an annular rotating member having a space through which the optical fiber is passed, in which the rotary connector and the optical fiber are screwed together by rotation. This connection portion rotates together with the gear train, but since the housing of the drive unit includes a rotation restricting member that prevents the rotation of the gear train, when attaching and detaching the probe and the drive unit, Since the rotation of the gear train is regulated and the connection portion between the optical fiber and the rotary connector is screwed in a state where the rotation is stopped, both can be easily screwed together. In the case where the rotation restricting member is not provided, there is a possibility that it cannot be screwed because it rotates when the connecting portion is screwed.

  Moreover, a screw-type fitting type rotary connector can be used, and compared with the case where a push-type fitting type connector is used, there is no backlash between the joining members, and the probe extends from the optical fiber and the apparatus main body side. The optical axis of the optical fiber can be matched with high accuracy. Furthermore, an inexpensive commercial product can be used as the rotary connector, and the overall cost can be suppressed.

  The rotation restricting member includes an operation part protruding outside the housing and a restriction part provided inside the housing so as to be detachable from a part of the gear train by the operation of the operation part. By using a member that prevents the rotation of the gear train by contacting or engaging a part of the gear train with the operation, the probe can be easily attached to the drive unit with a simple configuration. .

  Further, the rotation restricting member includes a biasing member that biases the rotation restricting member so that the restricting portion is always located away from the gear train, and the biasing member is biased by the operation of the operation portion. If the member that contacts or engages the part of the gear train by pushing the rotation restricting member against the housing is used, the rotation restricting member is normally opened without preventing the gear train from rotating. At the position, when the probe and the drive unit are fitted and detached, the position can be controlled by a simple operation so as to be a restricted position that prevents the rotation of the gear train.

  Further, if the rotation restricting member prevents the rotation of the gear train by contacting or engaging the restricting portion with a part of the gear having the largest diameter in the gear train, the force required for restricting the rotation is obtained. It can be made smaller, and a simpler operation becomes possible.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an OCT image diagnostic apparatus provided with a probe unit according to an embodiment of the present invention, FIG. 2 is a diagram showing a side cross section of a probe and a connection portion between the probe and a drive unit, and FIG. FIG. 4 is a side view of the drive unit, FIG. 4 is a perspective view of the schematic configuration inside the drive unit, and FIG. 5 is a VV cross-sectional view of the drive unit shown in FIG. .

  The OCT diagnostic imaging apparatus 1 includes an apparatus body 6 including a light source 2, an interferometer 3, a probe drive control circuit 4, and a signal processing unit 5, and is connected to the apparatus body 6 by an optical fiber 7 and an electric signal cable 8. It is comprised from the probe unit 9 which concerns on embodiment of invention.

  The probe unit 9 according to the present embodiment includes a long flexible sheath 11, a probe 10 having a base end portion 19 to which the sheath 11 is fixed, and the probe 10 to which the probe 10 is detachable. And a drive unit 30 for driving. The probe 10 is inserted into a body cavity via a forceps port of an endoscope, and has a length of, for example, about 3 m suitable for the purpose.

  The probe 10 according to the present embodiment includes a long flexible sheath 11 with a cap 12 attached to the distal end and the distal end closed, and a fixing member for a proximal end portion 19 to which the proximal end side of the sheath 11 is fixed. An optical fiber 13 that guides the measurement light L1 and the reflected light L2 of the measurement light L1 that extends from the sheath distal end to the base end 19 inside the cladding tube composed of the above, and a flexible disposed around the optical fiber 13 The optical fiber 13 rotates with the rotation of the flexible shaft 14. The flexible shaft 14 is composed of a close-contact coil in which a metal wire is wound in a closely wound spiral shape, and the close-contact coil is provided in a double manner. The winding direction of the outer contact coil and the winding direction of the inner contact coil are opposite to each other, so that even if the base end of the flexible shaft is rotated to the left or right, its rotation The force can be reliably transmitted to the optical fiber 13 disposed inside the close contact coil. Note that the flexible shaft is not limited to a double contact coil, but may be a single one if the rotation direction is one direction, or a triple or more multiple contact coils or a plurality of metals. It may be a multi-strand coil in which a wire is wound spirally, a multi-strand in which a plurality of metal wire rods are wound twice or more, a multiple coil, or the like.

  A ferrule 15 is attached to the tip of the optical fiber 13, and a GRIN lens (gradient refractive index lens) 16 and a prism 17 are further installed. The prism 17 emits the measurement light L1 guided by the optical fiber 13 in a direction intersecting with the optical axis of the optical fiber 13 (here, a direction substantially perpendicular to the optical axis) and receives the reflected light L2 to receive light. This is a reflective optical element that reflects toward the fiber 13 side. The optical fiber 13, the ferrule 15, the GRIN lens 16, and the prism 17 are connected to rotate integrally with the rotation of the optical fiber 13, and the prism 17 rotates to allow radial scanning with the measurement light L1. It has become.

  The base end portion 19 of the probe 10 is screwed and fixed with a sheath holding member 21 fitted to the base end side of the sheath 11, and the inner sleeve 20 and the inner sleeve 20 through which the optical fiber 13 and the flexible shaft 14 pass. The outer sleeve 22 slidably attached to the inner sleeve 20 in the optical axis direction of the optical fiber and the inner sleeve 20 are fitted and fixed to the outside of the inner sleeve 20 so as to surround the proximal end portion of the sheath 11 The fixing member comprising the provided rubber sleeve 29 for preventing bending and the flexible shaft 14 are fixed, the connecting member 23 through which the optical fiber 13 penetrates, and the base end of the optical fiber 13 are bonded and connected to the connecting member 23. Provided with a ferrule 24, a spring 25 that urges the connecting member 23 disposed around the base end side of the connecting member 23, and a connection ring portion that connects to a ring member of the drive unit described later 26, and a rotating member composed of a rotating cylinder 27 connected to the connection ring member 26 and disposed so as to surround the shaft holding member 23, and a bearing 28 that allows the rotating member to rotate with respect to the fixed member. I have.

  The drive unit 30 is disposed inside the housing 31 on the same axis as the optical fiber 13, and rotates a rotary connector 32 that rotates the optical fiber 13, a drive motor 33 that drives the rotary connector 32, and rotation of the rotary connector 32. The rotary encoder 34 for detecting the position is accommodated. The gears 32a, 33a, 34a of the rotary connector 32, the drive motor 33 and the rotary encoder 34 are engaged with the gear 33a of the drive motor 33 and the gear 32a of the rotary connector 32, and the gear 32a of the rotary connector 32 and the gear 34a of the encoder 34 are engaged. The gear train is configured as described above. The rotary connector 32 transmits the power of the drive motor 33 to the flexible shaft 14, rotates the flexible shaft 14, and rotates the optical fiber 13.

  The housing 31 guides the measurement light L1 emitted from the light source 1 and the cable insertion part 31a for inserting the electric signal cable 8 for transmitting the electric signal from the probe drive control circuit 4 of the apparatus body 6 into the housing 31. An optical fiber insertion portion for inserting a fixed optical fiber 7 that is light-guided and guides the reflected light L2 from the object to be observed to the interferometer 3 and whose tip is fixed coaxially with the rotary connector 32 inside the housing 31. 31b and a probe insertion portion 31c for attaching / detaching the probe 10 are provided. The probe insertion portion 31c receives the base end portion of the probe 10 in a non-rotatable manner.

  The rotary encoder 34 detects the rotation angle of the rotary connector 32 through the rotation of the gear 34a. The drive motor 33 is controlled by the probe drive control circuit 4 of the main body 6 via the electric signal cable 8, and the rotation angle signal detected by the rotary encoder 34 is fed back to the control circuit 4 via the electric signal cable 8. The

  A ring member 35 that rotates together with the rotary connector 32 is provided at the tip of the rotary connector 32 that is disposed in the vicinity of the probe insertion portion 31c. The ring member 35 is screwed into the connection ring member 26 at the base end of the probe 10 described above, and the ring member 35 and the connection ring member 26 constitute a connection portion. The probe 10 and the drive unit 30 are fitted by screwing the connection ring member 26 and the ring member 35 so that the optical axis of the optical fiber 13 of the probe 10 coincides with the optical axis of the fixed optical fiber 7. Is.

  Further, the drive unit 30 is provided with a rotation restricting member 50 having an operation portion 51 protruding outside the housing 31. The rotation regulating member 50 regulates the rotation of the rotary connector 32.

  FIG. 5 is a view for explaining the structure and operation of the rotation restricting member 50, and FIG. 5 (A) is a cross-sectional view taken along the line V-V in FIG. FIG. 5A shows the open position by the rotation restricting member, and FIG. 5B shows the restricting position by the rotation restricting member.

  The rotation restricting member 50 includes an operation part 51 protruding outside the housing 31, a resin restricting part 52, and a metal cylindrical connecting part 53 that connects the two, and the operating part 51 and the restricting part 52 are connected to each other. It is fixed integrally by 53. The housing 31 is provided with a cylindrical portion 55 into which the connecting portion 53 of the rotation restricting member 50 is inserted. As a biasing member that biases the operation portion 51 to the outside of the housing between the connecting portion 53 and the cylindrical portion. A back spring 56 is interposed. The restricting portion 52 may be made of rubber.

  Normally, the operating portion 51 is urged by the back spring 56 so that the restricting portion 52 is not in contact with the gear 32a, and the rotation restricting member 50 is positioned at the open position as shown in FIG. Yes.

  On the other hand, by pressing down the operating portion 51 against the urging force of the back spring 56, the restricting portion 52 is brought into contact with a part of the gear 32a of the rotary connector 32 as shown in FIG. The rotation of the connector 32 can be restricted. Specifically, the locking portion 52a of the restricting portion 52 is configured to engage with the gear of the gear 32a and lock the rotation.

  Here, the restricting portion 52 of the rotation restricting member 50 is brought into contact with a part of the gear 32a of the rotary connector having the maximum diameter among the gears of the rotary connector 32, the drive motor 33, and the rotary encoder 34 to rotate the gear 32a. Is regulated. By making it the structure which contacts the gear of the largest diameter, rotation of a gear can be prevented with a smaller force. However, the rotation restricting member is not limited to the configuration in contact with the gear of the rotary connector, and may be configured to stop the rotation of any gear.

  Next, a method for attaching the probe 10 to the drive unit 30 will be described.

  The outer sleeve 22 of the probe 10 is movable between a fitting position indicated by a solid line in the drawing and an open position indicated by a one-dot chain line, and when the probe 10 is attached to the drive unit 30, the outer sleeve 22 The connection ring member 26 and the ring member 35 on the drive unit 30 side are screwed together in a state where is in the open position. When the connection ring member 26 is screwed into the ring member 35, the operation part 51 of the rotation restricting member 50 is pushed inward of the housing 31, and the engaging part 52a of the restricting part 52 is engaged with the gear of the gear 32a. Thus, the rotation of the rotary connector 32 is stopped, and the rotation of the ring member 35 that rotates with the rotation of the rotary connector 32 is stopped. While maintaining the state where the operation part 51 of the rotation restricting member 50 is pressed down so that the ring member 35 does not rotate, the connection ring member 26 is screwed from the open position of the alternate long and short dash line position to the screwed position of the solid line position in the figure, The ring member 35 and the connection ring member 26 are screwed together.

  After the ring member 35 and the connection ring member 26 are screwed together, the pressing of the operation part 51 of the rotation restricting member 50 is released. Due to the action of the back spring 56 of the rotation restricting member 50, the operation portion 51 is biased toward the outside of the housing, the restricting portion 52 is separated from the gear, and the locked state is released.

  Thereafter, the outer sleeve 22 is slid to the drive unit side and fitted into the mounting port 31 c of the housing 31.

  As in this embodiment, by connecting the optical axis portions of the probe 10 and the drive unit 30 by screwing, the alignment accuracy of the optical axes of the fixed optical fiber 7 and the optical fiber 13 of the probe 10 is improved. Can do. Further, as the rotary connector provided with the screw type ring member 35, an inexpensive commercially available product can be used, so that the cost can be suppressed.

  When the drive motor 33 is driven with the probe 10 mounted on the drive unit 30 as described above, the gear 32a of the rotary connector 32 meshed with the gear 33a of the motor 33 rotates, and with this rotation, the ring member 35 is rotated. And the connecting ring member 26 of the probe 10 connected to the ring member 35 and the rotating member of the probe base end 19 connected to the connecting ring member 26 are rotated and fixed to one end of the rotating member. The rotation is transmitted to the shaft 14, and the optical fiber 13 rotates as the flexible shaft 14 rotates. As the optical fiber 13 rotates, the prism 17 connected to the tip of the optical fiber 13 rotates about the optical axis of the optical fiber 13, whereby the measurement light can be scanned radially.

  It should be noted that the method for detaching the probe 10 from the drive unit 30 may be performed in the reverse order of the mounting. First, the outer sleeve 22 is detached from the housing 31 to the open position, and the operation part 51 of the rotation restricting member 50 is pressed to restrict the rotation of the rotary connector 32 and the rotation of the ring member 35 is stopped. The probe 10 can be detached from the drive unit 30 by detaching the connection ring member 26 from the ring member 35 while the rotation of the ring member 35 is stopped. Note that after the ring member is detached, the pressing of the operation portion 51 of the rotation restricting member 50 is released.

  Thus, in the probe unit of the present embodiment, since the drive unit 30 includes the rotation restricting member 50, the probe 10 and the drive unit 30 can be attached and detached very easily, and the handleability is good. It is.

  The operation of the OCT image diagnostic apparatus provided with the probe unit according to the embodiment of the present invention will be briefly described below.

  First, the probe 10 is attached to the drive unit 30. When observing the inside of the patient's body cavity, the probe 10 is inserted into the forceps opening of the endoscope, the endoscope is inserted into the body cavity of the patient, and based on the image displayed on the monitor of the endoscope, Visually guide the distal end of the insertion portion of the endoscope to a desired site.

  The low coherence light emitted from the light source 2 is divided into reference light and measurement light L1 in the interferometer. The reference light is modulated by a piezo element or the like provided on the optical path, and a slight frequency difference Δf is generated between the reference light and the measurement light L. The modulated reference light is fed back to the interferometer through an optical path delay unit (not shown).

  The measurement light L1 is incident on the fixed optical fiber 7 that guides the probe unit through a fiber, a lens, and the like, and further incident on the optical fiber 13 of the probe 10 that is optically connected to the fixed optical fiber 7. The light is incident on the object to be observed from the tip of the optical fiber 13 via the GRIN lens 16 and the prism 17. Of the measurement light L1 incident on the object to be observed, the reflected light L2 reflected at a predetermined depth of the object to be observed is received by the prism 17 and reflected to the optical fiber side, and the GRIN lens 16, optical fiber 13 and light are reflected. It is fed back to the interferometer 3 via the fiber 7. In the interferometer 3, the reflected light L2 is combined with the reference light fed back to the interferometer 3 through the optical path delay unit.

  The combined reflected light L2 and reference light overlap again on the same axis, and the reflected light L2 and the reference light interfere to form interference light, generating a beat signal. Since the reference light and the reflected light L2 are low coherence light having a short coherence distance, the measurement light L1 (reflected light L2) until the low coherence light is divided into the measurement light L1 and the reference light and then combined. When the optical path length is equal to the optical path length of the reference light, both lights interfere with each other, and a beat signal is generated that repeats the intensity at the frequency difference (Δf) between the interfered lights.

  A light detector (not shown) detects the light intensity of the beat signal from the interference light, performs heterodyne detection, detects the intensity of the reflected light L2 of the measurement light reflected from a predetermined depth of the observed object, and the signal processing unit 5 Output to.

  Further, based on the instruction of the probe drive control circuit 4, the optical fiber 13 is rotated by the drive motor 33 to move the irradiation direction of the measurement light L1, and the radial scan about the longitudinal direction of the optical fiber 13 around the object to be observed is taken as an axis. I do. Note that if the optical path length of the reference light is changed by the optical path delay mechanism of the optical path delay unit, the optical path length of the reflected light that interferes with the reference light changes, so the depth at which tomographic information of the object to be observed is changed. Can do.

  The signal processing unit 5 generates an OCT image based on the tomographic information around the observed object detected by the light detection unit.

Schematic configuration diagram of an OCT diagnostic imaging apparatus provided with a probe unit according to the present invention The figure which shows the side cross section of the connection part of a probe and a probe unit Partial sectional view of the side of the drive unit The perspective view which shows the internal schematic structure of a drive unit (A) Drive unit sectional view showing the open position by the rotation restricting member, and (B) Drive unit sectional view showing the restricting position by the rotation restricting member.

Explanation of symbols

1 OCT diagnostic imaging equipment 9 Probe unit
10 Probe
11 sheath
13 Optical fiber
14 Flexible shaft
17 Prism
26 Connection ring member
30 Drive unit
31 Housing
32 Rotary connector
32a gear
33 Drive motor
33a gear
34 Rotary encoder
34a gear
35 Ring member
50 Rotation restricting member
51 Operation section
52 Regulatory Department
53 Connection
55 Insertion tube
56 Backspring

Claims (3)

A probe in which an optical fiber rotating around an axis is housed in a cladding tube, and a light that is detachably mounted between the probe and the apparatus main body to rotate the optical fiber and extend the optical fiber from the apparatus main body side In a probe unit for an OCT diagnostic imaging apparatus comprising a drive unit optically connected to a fiber,
The drive unit includes a rotary connector connected to the optical fiber of the probe, and a drive unit having a gear train that rotationally drives the rotary connector in a housing fixed to the cladding tube side of the probe,
The rotary connector and the optical fiber include a connection portion formed of an annular rotary member having a space through which the optical fiber is passed, which are screwed together by rotation,
The housing includes a rotation restricting member that prevents rotation of the gear train by being operated from outside the housing ;
The rotation restricting member is composed of an operation part protruding to the outside of the housing, and a restriction part provided inside the housing so as to be detachable from a part of the gear train by the operation of the operation part. A probe unit for an OCT diagnostic imaging apparatus, wherein the restricting portion contacts or engages a part of the gear train by the operation to prevent rotation of the gear train . The rotation restricting member includes an urging member that urges the rotation restricting member so that the restricting portion is always at a position away from the gear train. the probe unit according to claim 1, wherein the anti to one in which the restriction portion engaged contact or engagement with the portion of the gear train by pushing the rotation restricting member to the housing. The rotation regulating member, according to claim 1, characterized in that the regulating unit is intended to prevent rotation of the gear train by contact or engage a portion of the gear with the largest diameter of the gear train or 2. The probe unit according to 2 .

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