THERAPEUTIC LIGHT IRRADIATION UNIT, THERAPEUTIC LIGHT IRRADIATION APPARATUS, AND ENDOSCOPE

A therapeutic light irradiation device including a reflecting surface disposed on a path of a therapeutic light emitted in a first direction from an insertion section of an endoscope, and configured to switch an irradiation direction of the therapeutic light between the first direction and a second direction intersecting the first direction, and a connector configured to detachably connect the reflecting surface to the insertion section.

TECHNICAL FIELD

The present disclosure relates to a therapeutic light irradiation unit, a therapeutic light irradiation apparatus, and an endoscope.

BACKGROUND ART

Light therapy includes technique of accumulating photosensitive drugs in tumors and irradiating them with therapeutic light for treatment, such as PDT (photo-dynamic-therapy) and PIT (photo-immuno-therapy).

Light therapy inside the body under endoscopic observation involves difficulty in capturing treatment sites at a position on the display screen where the therapeutic light is readily radiated due to effects of blurring caused by patients' pulsations or the like. In particular, it is difficult to capture treatment sites that cannot be viewed from the front with an endoscope, such as tumors on the inner walls of gastrointestinal tracts, in the center of the display screen. This makes it difficult to reliably irradiate the treatment sites with the therapeutic light.

On the other hand, since tumors can occur in various sites inside the bodies, it is desirable to be able to irradiate affected areas both on the front side and lateral side with therapeutic light without changing the endoscope. Therefore, a light therapy apparatus capable of selecting an irradiation region of therapeutic light has been proposed (see, for example, PTL 1). An apparatus described in PTL 1 can change the irradiation position of the therapeutic light emitted from a window of a second sheath by rotating or longitudinally moving a second opaque sheath within a first translucent sheath.

SUMMARY

One aspect of the present disclosure is a therapeutic light irradiation device comprising a reflecting surface disposed on a path of a therapeutic light emitted in a first direction from an insertion section of an endoscope, and configured to switch an irradiation direction of the therapeutic light between the first direction and a second direction intersecting the first direction, and a connector configured to detachably connect the reflecting surface to the insertion section.

Another aspect of the present disclosure is a therapeutic light irradiation apparatus comprising an insertion section, a light source configured to radiate light in a first direction from the insertion section, and a reflecting surface disposed on a path of the light emitted in the first direction from the insertion section, and configured to switch an irradiation direction of the light between the first direction and a second direction intersecting the first direction.

Yet another aspect of the present disclosure is an endoscope comprising an insertion section, an illumination light source, arranged in the insertion section, configured to radiate illumination light in a first direction, a therapeutic light source, arranged in the insertion section, configured to radiate therapeutic light in the first direction, a reflecting surface disposed on a path of the illumination light and the therapeutic light emitted in the first direction from the insertion section, and configured to switch irradiation directions of both the illumination light and the therapeutic light between the first direction and a second direction intersecting the first direction, and a connector configured to detachably connect the reflecting surface to the insertion section.

DESCRIPTION OF EMBODIMENTS

A therapeutic light irradiation unit, a therapeutic light irradiation apparatus, and an endoscope according to one embodiment of the present disclosure is to be described with reference to the drawings.

FIG.1shows a first configuration example of a therapeutic light irradiation unit1according to the present embodiment. The therapeutic light irradiation unit1is a cap to be attached to the distal end of an elongated insertion section12of an endoscope11as necessary. The therapeutic light irradiation unit1may be disposable.

The therapeutic light irradiation apparatus10includes an endoscope11and a therapeutic light irradiation unit1.

The endoscope11is a front-view type and has, as well as an elongated insertion section12, an illumination optical system (light irradiation section)13and an objective optical system14that are provided at the distal end part of the insertion section12. The endoscope11also has a therapeutic light irradiation section (light irradiation section)15that emits therapeutic light L. A therapeutic light irradiation section15is, for example, an optical fiber probe that is inserted into a channel (lumen)12aof the insertion section12and emits therapeutic light L from a distal end thereof.

An illumination optical system13and the therapeutic light irradiation section15emit illumination light and therapeutic light L, respectively, in a first direction D1 along the longitudinal axis of the insertion section12. The objective optical system14receives observation light incident from an object in the first direction D1 and observes the field of view F in the first direction D1. The field of view F observed by the objective optical system14is imaged by an image sensor16, and the image of the field of view F is displayed on a display section20(seeFIG.10).

The therapeutic light irradiation unit1includes a connection section2to be attached to the distal end of the insertion section12, and an irradiation direction switching section3for switching the irradiation direction of the illumination light and the therapeutic light L.

The connection section2is a tubular member that is open at least on the proximal end surface. The distal end part of the insertion section12is inserted into the connection section2from the proximal end side, so that the connection section2is detachably attached to the distal end part of the insertion section12.

The irradiation direction switching section3includes a reflecting member4having a reflecting surface4a. The reflecting member4is disposed on the front side of the illumination optical system13, the objective optical system14and the therapeutic light irradiation section15. The reflecting surface4afaces the distal end surface of the insertion section12and is inclined with respect to the longitudinal axis of the insertion section12. The reflecting member4reflects all or substantially all of each of the illumination light and the therapeutic light L in a second direction D2 on the reflecting surface4a, and reflects the observation light, incident in the second direction D2, in a first direction D1. Thereby, the reflecting member4switches the irradiation direction of the illumination light and the therapeutic light L from the first direction D1 to the second direction D2, and switches the observation direction of the objective optical system14from the first direction D1 to the second direction D2. The second direction D2 is a direction intersecting the longitudinal axis of the insertion section12.

The connection section2may be entirely made of a transparent material or may have a window2aso that the illumination light, the therapeutic light L, and the observation light can travel in the second direction D2 between the inside and the outside of the connection section2. The window2ais formed by a hole or made of an optically transparent material.

Such a therapeutic light irradiation unit1is attached to the distal end of the insertion section12in a case in which the affected area A to be treated is located on the lateral side of the insertion section12, in particular, in a case in which the affected area A is located in the lumen B and on the side wall as shown inFIG.1. Thereby, the affected area A on the lateral side of the insertion section12can be irradiated with illumination light from the illumination optical system13and can be observed by the objective optical system14. In addition, the lateral side affected area A can be irradiated with the therapeutic light L from the therapeutic light irradiation section15to be effectively treated. In this manner, the treatment target A on the lateral side can be captured in the image, and can be reliably irradiated with the therapeutic light L.

Also, in a state in which the therapeutic light irradiation unit1is not attached to the distal end of the insertion section12, the affected area A on the front side of the insertion section12can be observed and treated. Therefore, attachment and detachment of the therapeutic light irradiation unit1enables both the light therapy for the treatment target A on the lateral side and the light therapy for the treatment target A on the front side.

In a state in which the therapeutic light irradiation unit1is attached to the distal end of the insertion section12, the object in the image acquired by the image sensor16is a mirror image. Therefore, when the therapeutic light irradiation unit1is attached to the distal end of the insertion section12, a mirror image correction mode for correcting a mirror image to a real image may be selected and executed. In the mirror image correction mode, the image corrected to a real image is displayed on the display section20. The operator may be allowed to select the mirror image correction mode.

FIGS.2A and2Bshow a second configuration example of the therapeutic light irradiation unit1according to the present embodiment. In the second configuration example, the reflecting member4is a thin flat plate member that is rotatable between a first angle for front view shown inFIG.2Aand a second angle for side view shown inFIG.2B.

The reflecting member4at the first angle is located at a position out of the front side of the optical systems13and14and the therapeutic light irradiation section15. InFIG.2A, the reflecting member4at the first angle is located radially outside the optical system13and parallel to the first direction D1.

The reflecting member4at the second angle is located on the front side of the optical systems13and14and the therapeutic light irradiation section15, like the reflecting member4in the first configuration example. At the second angle, the reflecting surface4afaces the distal end surface of the insertion section12and is inclined with respect to the longitudinal axis of the insertion section12.

The reflecting member4is rotatable about an axis of rotation between a first angle and a second angle with one end thereof as the rotation center. The axis of rotation extends in a direction orthogonal to the longitudinal axis of the insertion section12and intersecting the first direction D1 and the second direction D2 (in the referred drawing, the direction perpendicular to the paper surface). Rotation of the reflecting member4from the first angle to the second angle switches the illumination direction and the observation direction from the first direction D1 to the second direction D2.

A user such as an operator positions the reflecting member4at the first angle when inserting the insertion section12into the body cavity. This allows the user to advance the insertion section12to a region where the target affected area A may be located while observing the front-view image in the field of view F on the front side of the insertion section12. Moreover, the user positions the reflecting member4at the second angle when the user treats the affected area A on the lateral side. This allows the user to observe a side-view image in the field of view F on the lateral side of the insertion section12and irradiate the affected area A with the therapeutic light L when the affected area A on the lateral side is located substantially in the center of the field of view.

Thus, the user can observe and treat the treatment target A both on the front side and lateral side with the therapeutic light irradiation unit1attached to the distal end of the insertion section12.

The reflecting member4is mechanically rotated between the first angle and the second angle.FIGS.3A and3Bshow an example of a mechanism for rotating the reflecting member4. In this example, the irradiation direction switching section3further has a wire (operation member)5connected to the reflecting member4.

The wire5is longer than the channel12a, is disposed from the distal end side to the proximal end side of the insertion section12through the inside of the channel12a, and has the distal end connected to the reflecting member4.

When the therapeutic light irradiation unit1is attached to the distal end of the insertion section12, the wire5is inserted into the channel12auntil the wire5protrudes from the proximal end of the insertion section12, and the proximal end part of the wire5is exposed outside the channel12ato a length that can be pulled by an operation unit (not shown) or manually. Here, in a state in which the therapeutic light irradiation unit1is attached to the distal end of the insertion section12, as illustrated, the therapeutic light irradiation unit1is circumferentially positioned with respect to the insertion section12by the connection section2so that the channel12aand the window2aare positioned on opposite sides in the radial direction. Further, the distal end part of the wire5disposed inside the connection section2has a shape that curves toward the window2a, and can be elastically deformed into a linear shape in the longitudinal direction of the channel12a. Thus, the wire5, which is pulled toward the proximal end side, rotates the reflecting member4from the first angle to the second angle. The wire5, which is pressed toward the distal end side, rotates the reflecting member4from the second angle to the first angle.

FIGS.4A and4Bshow another example of a mechanism for rotating the reflecting member4. In this example, the reflecting member4is biased to a second angle by a spring6and is rotated from the second angle to the first angle with the wire5being pulled.

The operation member is not limited to the wire5, and may be any member that can apply a force to the reflecting member4to rotate it about the axis of rotation.

As shown inFIGS.5A and5B, the irradiation direction may be switched between the first direction D1 and the second direction D2 by changing the transmittance/reflectivity of the reflecting member4, instead of rotating the reflecting member4.FIG.5Ashows a state in which the reflecting member4has a low reflectivity (or a high transmittance), andFIG.5Bshows a state in which the reflecting member4has a high reflectivity (or a low transmittance).

In this case, a reflecting member4to be used has a transmittance and a reflectivity that change in response to electricity, light, or heat. For example, the reflecting member4to be used may be an optical plate containing an electrochromic crystal to electrically switch between transmission and reflection of light.

Another configuration may be such that the reflecting member4: is made of a material that is a substance whose transmittance changes with light or heat; is irradiated with laser beam to increase its reflectivity; and then irradiates the affected area A on the lateral side with the therapeutic light L.

FIG.6shows a third configuration example of the therapeutic light irradiation unit1according to the present embodiment. In the third configuration example, the reflecting member4transmits part of the light in the first direction D1 and reflects the other part of the light in the second direction D2.

For example, the reflecting member4switches the irradiation direction of the illumination light and the therapeutic light L between the first direction D1 and the second direction D2 depending on the wavelength. In one example, as shown inFIG.7, the reflecting member4is a dichroic mirror that transmits light in the blue band and reflects light that includes the therapeutic light L and has a longer wavelength than the blue band. In this case, the front-view image may be generated from the blue pixels of the image sensor16and the side-view image may be generated from the green and red pixels of the image sensor16.

In a case in which the endoscope11acquires images by a frame sequential method in which an object is sequentially irradiated with three colors of red, green, and blue light as the illumination light, the side-view image may be generated in synchronization with the red and green light irradiation, and the front-view image may be generated in synchronization with the blue light irradiation.

The side-view image and the front-view image may be displayed in parallel on the display section20, or may be alternatively displayed.

A user such as an operator can observe front-view images when inserting the insertion section12into the body, and can observe side-view images during treatment.

The reflecting member4may be a half mirror. In this case, half of each of the illumination light and the therapeutic light L is transmitted through the reflecting member4in the first direction D1, and the remaining half of each of the illumination light and therapeutic light L is reflected by the reflecting member4in the second direction D2.

In each of the above configuration examples, the position of the distal end of the insertion section12may be changeable within the connection section2in the first direction D1. For example, a stepped structure may be formed on the inner peripheral surface of the connection section2so that the position of the distal end of the insertion section12can be changed in multiple steps. Change in the position of the distal end of the insertion section12changes the distance in the first direction D1 from the distal end of the insertion section12to the reflecting member4. This can change the observation position and the irradiation position of the therapeutic light L in the first direction D1.

As shown inFIGS.8A and8B, the connection section2may have an inner peripheral surface provided with a plurality of projections (positioning portions)7projecting radially inward. The plurality of projections7are provided at a plurality of positions in the first direction D1.

The distal end surface of the insertion section12is abutted against the projection7, and thereby the insertion section12is positioned. Moreover, the projection7has elasticity, allowing the insertion section12to be inserted to a deeper position when the insertion section12is pushed in to bend the projection7.

In each of the above configuration examples, as shown inFIG.9A, the therapeutic light irradiation unit1may further include a fixture8that fixes the connection section2to the insertion section12at an arbitrary rotation angle about the longitudinal axis of the insertion section12.

For example, the fixture8is a ring-shaped member that is fixed to the proximal end part of the connection section2and disposed on the outer peripheral surface of the distal end part of the insertion section12. As shown inFIG.9B, the fixture8has an inner peripheral surface having a plurality of grooves arranged in the circumferential direction, and the distal end part of the insertion section12has an outer peripheral surface having a plurality of projections that fit into the plurality of grooves of the fixture8.

The user can integrally rotate the fixture8and the connection section2with respect to the insertion section12, to rotationally position the fixture8and the connection section2with respect to the insertion section12at any position where the grooves fit into the projections.

The connection section2is fixed to the insertion section12at a desired rotation angle outside the body, and then the insertion section12is inserted into the lumen B. This makes it possible to easily change the position of the affected area A to be subjected to light therapy within the lumen B.

FIG.10shows a configuration example of a therapeutic light irradiation system100including a therapeutic light irradiation unit1.

The therapeutic light irradiation system100includes a therapeutic light irradiation unit1, an endoscope11, a display section20and a processor30. A proximal end of the insertion section12is connected to the processor30. The processor30includes: an illumination light source31that supplies illumination light to the illumination optical system13; a therapeutic light source32that supplies therapeutic light L to the therapeutic light irradiation section15; and an image processing section33that processes an image acquired by the image sensor16. The correction of the mirror image may be performed by the image processing section33.

The therapeutic light irradiation system100may further include an irradiation direction detection section34that detects the irradiation directions of the illumination light and the therapeutic light L.

When the irradiation direction is detected to be the second direction D2, the mode switching section35may automatically switch to the mirror image correction mode. Alternatively, an indication20aindicating the detected irradiation direction may be displayed on the display section20, and the user may execute the mirror image correction mode based on the indication20a.

The irradiation direction detection section34may detect whether the therapeutic light irradiation unit1is attached to the distal end of the insertion section12. In the case of the reflecting member4of the first configuration example, it is possible to detect whether the irradiation direction is the first direction D1 or the second direction D2 based on the presence or absence of the therapeutic light irradiation unit1.

In the case in which the movable reflecting member4of the second configuration example is provided, the irradiation direction detection section34may have a sensor that detects the rotation angle (first angle or second angle) of the reflecting member4. The sensor may detect the rotation of the reflecting member4based on the movement amount of the wire5.

In each of the above configuration examples, the connection section2is a cap to be attached to the distal end of the insertion section12. Alternatively, as shown inFIG.11, the connection section2may be a tubular sheath that covers the insertion section12in the longitudinal direction. Rotation of the connection section2about the longitudinal axis with respect to the insertion section12can change the irradiation position and the observation position in the circumferential direction about the longitudinal axis.

The image may be three-dimensionally displayed on the display section20according to the rotation angle of the connection section2. As a result, the entire periphery of the lumen B can be observed, and can be irradiated with the therapeutic light L.

In each of the above configuration examples, the therapeutic light irradiation unit1may be provided as part of the endoscope11. That is, the endoscope11may include, at the distal end of the insertion section12, the illumination optical system13, the therapeutic light irradiation section15, and the irradiation direction switching section3. The irradiation direction switching section3may be detachably attached to the distal end of the insertion section12or may be integrated in the insertion section12.

The above examples describe cases in which the present disclosure is applied to PIT, but the following applications are also possible. In other words, the present disclosure can be applied not only to PIT but also to medical equipment using observation light and therapeutic light, such as PDT that performs light therapy while monitoring fluctuations in the intensity of light such as fluorescence similarly to PIT. In addition, the present disclosure can also be applied to a light therapy probe that exclusively irradiates therapeutic light. In this case, the therapeutic light irradiation unit, the therapeutic light irradiation apparatus, and the therapeutic light irradiation system of the present disclosure may be used as a device separate from the endoscope.