Laser therapeutic device

Abstract

A laser therapeutic device for a laser endoscope capable of relatively reducing the diameter of the endoscope while being capable of emitting a laser beam of a uniform intensity over a wide area is provided. An optical guide element (a square-shaped rod lens 15, a guide tube 2b) having a quadrangular cross section and guiding a therapeutic laser beam emitted from the tip of an optical fiber toward the tip side of a probe is used. On the tip side of a probe tube 2 being a barrel, using clearances C1 to C4 formed between the optical guide element and the inner circumferential surface of the probe tube, a camera unit 11 as imaging means and white-color LED units 12 and an ultraviolet LED unit 13 as illumination means are arranged.

Claims

1. A laser therapeutic device comprising: an optical fiber for guiding a therapeutic laser beam; a hollow probe tube being a barrel of an endoscope to which a tip of the optical fiber is connected, the hollow probe tube having an inner circumferential surface defining a cavity; an optical guide element having a quadrangular cross section arranged in the cavity of the hollow probe tube for guiding a laser beam emitted from the tip of the optical fiber toward a tip side of the hollow probe tube; and imaging means and illumination means both arranged in the cavity of the hollow probe tube within clearances formed between sides of the optical guide element and the inner circumferential surface of the hollow probe tube, wherein the clearances are separated from each other by corners of the optical guide element contacting the inner circumferential surface of the hollow probe tube.

2. The laser therapeutic device according to claim 1, wherein the optical fiber is a bare fiber having a circular cross section, and the optical guide element is a square-shaped rod lens.

3. The laser therapeutic device according to claim 2, further comprising a converging lens arranged at a tip of the square-shaped rod lens to enhance convergence of the laser beam emitted from the tip of the square-shaped rod lens.

4. The laser therapeutic device according to claim 1, wherein the optical fiber is a quadrangular optical fiber having a quadrangular cross section, and the optical guide element is a square tube whose inner surface is a reflective surface.

5. The laser therapeutic device according to claim 1, wherein the optical guide element has a square cross section, the clearances are ship-bottom shaped and formed at four locations around the optical guide element, and the imaging means and the illumination means are dispersedly arranged in the ship-bottom shaped clearances without leaving any of the ship-bottom shaped clearances unutilized.

6. The laser therapeutic device according to claim 1, wherein the illumination means is structured by a white-color LED unit and an ultraviolet LED unit.

7. The laser therapeutic device according to claim 1, wherein the imaging means is structured by a camera unit using a CCD image sensor.

8. The laser therapeutic device according to claim 2, wherein the optical guide element has a square cross section, the clearances are ship-bottom shaped and formed at four locations around the optical guide element, and the imaging means and the illumination means are dispersedly arranged in the ship-bottom shaped clearances without leaving any of the ship-bottom shaped clearances unutilized.

9. The laser therapeutic device according to claim 3, wherein the optical guide element has a square cross section, the clearances are ship-bottom shaped and formed at four locations around the optical guide element, and the imaging means and the illumination means are dispersedly arranged in the ship-bottom shaped clearances without leaving any of the ship-bottom shaped clearances unutilized.

10. The laser therapeutic device according to claim 4, wherein the optical guide element has a square cross section, the clearances are ship-bottom shaped and formed at four locations around the optical guide element, and the imaging means and the illumination means are dispersedly arranged in the ship-bottom shaped clearances without leaving any of the ship-bottom shaped clearances unutilized.

11. The laser therapeutic device according to claim 2, wherein the illumination means is structured by a white-color LED unit and an ultraviolet LED unit.

12. The laser therapeutic device according to claim 3, wherein the illumination means is structured by a white-color LED unit and an ultraviolet LED unit.

13. The laser therapeutic device according to claim 4, wherein the illumination means is structured by a white-color LED unit and an ultraviolet LED unit.

14. The laser therapeutic device according to claim 5, wherein the illumination means is structured by a white-color LED unit and an ultraviolet LED unit.

15. The laser therapeutic device according to claim 8, wherein the illumination means is structured by a white-color LED unit and an ultraviolet LED unit.

16. The laser therapeutic device according to claim 2, wherein the imaging means is structured by a camera unit using a CCD image sensor.

17. The laser therapeutic device according to claim 3, wherein the imaging means is structured by a camera unit using a CCD image sensor.

18. The laser therapeutic device according to claim 4, wherein the imaging means is structured by a camera unit using a CCD image sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an overall schematic diagram of an endoscope laser system for treating cervical cancer using a laser therapeutic device according to an embodiment of the present invention.

(2) FIG. 2A is a vertical cross-sectional view of the tip portion of a probe tube of the laser therapeutic device.

(3) FIG. 2B is an internal perspective view of the tip portion of the probe tube of the laser therapeutic device.

(4) FIG. 2C is a horizontal cross-sectional view of the tip portion of the probe tube of the laser therapeutic device.

(5) FIG. 3A is a vertical cross-sectional view of the tip portion of a probe tube of a laser therapeutic device according to a variation.

(6) FIG. 3B is an internal perspective view of the tip portion of the probe tube of the laser therapeutic device according to the variation.

(7) FIG. 3C is a horizontal cross-sectional view of the tip portion of a probe tube of a laser therapeutic device according to another variation.

(8) FIG. 4A is a diagram showing the tip surface of a temperature sensor arranged at the tip portion of the probe tube of the laser therapeutic device.

(9) FIG. 4B is a cross-sectional view of the temperature sensor shown in FIG. 4A.

(10) FIG. 4C is a cross-sectional view taken along line C-C in FIG. 4B.

(11) FIG. 5 is a block diagram of an endoscope laser system.

(12) FIG. 6A is a side view of the tip portion of the probe tube of the laser therapeutic device, being a side view of the type in which a laser emission unit is not projected.

(13) FIG. 6B is a side view of the tip portion of the probe tube of the laser therapeutic device, being a side view of the type in which the laser emission unit is projected.

(14) FIG. 7 is a diagram showing an example of use as a laser endoscope for uterine cervix cancer.

(15) FIG. 8A is a diagram showing the beam profile of a quadrangular laser beam.

(16) FIG. 8Ba is a conceptual diagram of the beam profile of a laser beam with a quadrangular fiber.

(17) FIG. 8Bb is a conceptual diagram of the beam profile of a laser beam with a bare fiber.

DESCRIPTION OF EMBODIMENTS

(18) In the following, with reference to the drawings, a description will be given of a laser therapeutic device according to an embodiment of the present invention. FIG. 1 is an overall schematic diagram of an endoscope laser system for treating uterine cervix cancer using a laser therapeutic device 1. The endoscope used in the system is a rigid endoscope, which can be used not only as the uterine cervix cancer endoscope but also as a laparoscope, a thoracoscope, a cystoscope and the like.

(19) The laser therapeutic device 1 includes a probe tube 2 being a barrel structured by a cylindrical body 2a having a circular cross section. A handpiece 3 is attached to the proximal end of the probe tube 2.

(20) To the proximal end of the handpiece 3, a cable 4 storing an optical fiber 10 and electrical lines (not shown) is connected. Via the cable 4, the laser therapeutic device 1 is connected to a laser oscillator 5 and a controller 6. The controller 6 outputs an image of a camera unit 11, which will be described later, on a liquid crystal monitor 7.

(21) The cylindrical body 2a structuring the probe tube 2 is cylindrically shaped to have a diameter of, for example, about 30 mm. At a substantially central position inside the cylindrical body 2a, as shown in FIG. 2A, a square-shaped rod lens 15 as an optical guide element is arranged. The tip of the optical fiber 10 is connected to the proximal end of the square-shaped rod lens 15 via a connector 16. Note that, though the cross section of the square-shaped rod lens 15 is square, it may be rectangle.

(22) An optical fiber 14 is a bare fiber that is available at low costs, and has a core 14a having a circular cross section and a clad 14b covering the outer circumference of the core 14a. The end surface of the core 14a is connected to the proximal end surface of the square-shaped rod lens 15.

(23) The tip portion of the cylindrical body 2a is a transparent laser emission unit 20. The tip portion of the square-shaped rod lens 15 extends to the position near the laser emission unit 20.

(24) A converging lens 17 is arranged in front of the tip portion of the square-shaped rod lens 15. The converging lens 17 enhances the convergence of a quadrangular laser beam emitted from the tip portion of the square-shaped rod lens 15. Note that, it is also possible to eliminate the converging lens 17 by arranging the tip portion of the square-shaped rod lens 15 close to the laser emission unit 20.

(25) In the present embodiment, as will be described later, imaging means and illumination means are arranged in a ship-bottom shaped clearance formed between the square-shaped rod lens 15 and the probe tube 2a.

(26) The laser therapeutic device 1 is structured as described above, and as shown by the lower illustration in FIG. 2A, a circular laser beam S1 (for example, of a diameter 600 m) emitted from the end of the optical fiber 14 enters the square-shaped rod lens 15. The circular laser beam S1 is shaped into a quadrangular shape while passing through the square-shaped rod lens 15, and emitted as a quadrangular laser beam S2 from the tip of the square-shaped rod lens 15.

(27) Thereafter, the quadrangular laser beam S2 further passes through the converging lens 17, and converges as a quadrangular laser beam S3 (for example, of 20 mm square) in the laser emission unit 20. With the quadrangular laser beam S3, a laser treatment such as hyperthermia can be performed.

(28) Next, with reference to FIGS. 3A to 3C, a variation of the present invention will be described. In the variation, in place of the above-described square-shaped rod lens 15, a quadrangular optical fiber 10 and a guide tube 2b as an optical guide element having a quadrangular cross section are used. The guide tube 2b is structured by a square tube whose inner surface is a reflective surface reflecting the laser beam.

(29) Specifically, as shown in FIG. 3A, the tip of the optical fiber 10 is connected to an optical system 30 in the handpiece 3. The optical fiber 10 has a core 10a having a quadrangular (square) cross section, and a clad 10b covering the outer circumference of the core 10a. The end surface of the core 10a is connected to the optical system 30.

(30) The emission side on the right side of the optical system 30 is connected to the guide tube 2b having a quadrangular (square) cross section and coaxially arranged in the cylindrical body 2a. The guide tube 2b extends to the tip portion of the cylindrical body 2a. The tip portion of the cylindrical body 2a is connected to the transparent laser emission unit 20.

(31) As shown in FIG. 3B, the four corners of the guide tube 2b are in contact with the inner circumferential surface of the cylindrical body 2a having a circular cross section. Accordingly, between the linear sides of the guide tube 2b and the inner circumferential surface of the cylindrical body 2a, ship-bottom shaped four clearances (a first clearance C1 to a fourth clearance C4) are formed.

(32) In the variation, as shown in the lower illustration in FIG. 3A, a quadrangular laser beam S4 (for example, of a diameter 600 m) emitted from the end of the optical fiber 10 enters the optical system 30. The quadrangular laser beam S4 output from the optical system 30 is enlarged maintaining the quadrangular shape while passing through the guide tube 2b, and emitted as a quadrangular laser beam S5 of a large area (for example, 20 mm square) from the tip of the guide tube 2b. With the quadrangular laser beam S5, a laser treatment such as hyperthermia can be performed.

(33) In the embodiment and the variation of the present invention, the ship-bottom shaped clearances formed around the square-shaped rod lens 15 as the optical guide element having a quadrangular cross section and the cylindrical body 2a are effectively used as the spaces for arranging the imaging means and the illumination means.

(34) That is, in the embodiment, as shown in FIGS. 2B and 2C, in the ship-bottom shaped clearance C1 formed on the upper side of the square-shaped rod lens 15, a temperature sensor unit 25 is arranged. Further, in the ship-bottom shaped clearance C3 formed on the lower side of the square-shaped rod lens 15, the camera unit 11 using a CCD image sensor as the imaging means and white-color LED units 12 and an ultraviolet LED unit 13 as the illumination means are arranged.

(35) The ultraviolet LED unit 13 is used for discerning the difference between normal tissue and abnormal tissue, based on the difference in intensity of autofluorescence emitted by the tissue when the tissue is irradiated with ultraviolet light. The wirings for supplying power to the camera unit 11 and others extend to the handpiece 3 through the clearances C1 and C3 around the square-shaped rod lens 15 (in FIG. 2A, only a wiring 11a of the camera unit 11 is shown).

(36) Further, in the variation shown in FIG. 3B, all the four ship-bottom shaped clearances C1 to C4 are used to dispersely arrange the imaging means and the illumination means. That is, the camera unit 11 using the CCD image sensor as the imaging means is arranged in the first clearance C1, and three white-color LED units 12 as the illumination means are arranged in the second clearance C2.

(37) Further, two white-color LED units 12 as the illumination means are arranged in the third clearance C3 opposing to the camera unit 11 having the optical fiber 10 interposed therebetween. One ultraviolet LED unit 13 as the illumination means is arranged in the fourth clearance C4. Note that, it goes without saying that the number of the white-color and ultraviolet LEDs can be changed as appropriate in accordance with the size of the clearances C2 to C4 and the type of the LEDs.

(38) Note that, as known in connection with the conventional endoscope, a cleaning nozzle unit may be arranged adjacent to the camera unit 11. By injecting saline from the cleaning nozzle unit to the camera unit 11, blood and the like adhered to the camera unit 11 can be removed.

(39) As shown in FIGS. 4A to 4C in detail, the above-described temperature sensor unit 25 is arranged at the laser emission unit 20 at the tip of the cylindrical body 2a. The temperature sensor unit 25 is structured with a coated thermocouple in which a measurement point 25a is exposed. In the drawings, 25b denotes a thermocouple wire, 25c denotes a thermocouple wire coating insulator, and 25d denotes a sheath insulator.

(40) The temperature sensor unit 25 is stored in a radial groove 20a formed from the central portion toward the periphery of the laser emission unit 20. The coated thermocouple of the temperature sensor unit 25 may be of an extremely thin size, which is immediately available from a plurality of manufacturers, even the one having a major axis of 0.5 mm or less. The coated thermocouple is desirably entirely gold plated, so as not to be affected by the laser beam L.

(41) The measurement point 25a is provided at the tip of the temperature sensor unit 25, and the measurement point 25a is positioned at the center of the laser emission unit 20. In connection with the temperature sensor unit 25, it is also possible that the radial groove 20a is not formed at the laser emission unit 20 and the temperature sensor unit 25 may be exposed at the laser emission unit 20 by being bonded by an adhesive agent or the like. Alternatively, only the measurement point 25a may be exposed at the laser emission unit 20 and the rest of the temperature sensor unit 25 may be embedded in the laser emission unit 20.

(42) In hyperthermia, a depth of about 5 to 10 mm from the surface of the tissue is heated to 42 C. or more. Accordingly, in order to surely attain this temperature, the wavelength and intensity of the laser beam are adjusted based on the output of the temperature sensor unit 25.

(43) FIG. 5 is a block diagram of the endoscope laser system for treating uterine cervix cancer. The small camera unit 11, the white-color LED units 12, and the ultraviolet LED unit 13 are controlled by the controller 6. The controller 6 includes a monitor control unit 6a , a light adjusting unit 6b, a control module 6c, and a power supply unit 6d. The output of the temperature sensor unit 25 is fed back to the laser oscillator 5, whereby the wavelength and intensity of the laser beam are adjusted.

(44) The cross-sectional shape of the optical fiber and that of the guide tube are not necessarily square as shown in FIG. 3B, and may be rectangular as shown in FIG. 3C. In this case, since relatively great first clearance C1 and second clearance C2 are respectively formed above and beneath the guide tube 2b, for example the camera unit 11 and the white-color LED units 12 are arranged in the first clearance C1, and the ultraviolet LED unit 13 is arranged in the second clearance C2.

(45) The laser emission unit 20 at the tip of the laser therapeutic device 1 may be arranged on the same plane as the tip surface of the probe tube 2 as shown in FIG. 6A, or may be arranged as being slightly projected from the tip surface of the probe tube 2 as shown in FIG. 6B. By arranging the laser emission unit 20 as being projected as shown in FIG. 6B, the laser emission unit 20 can be easily intimately attached to a tumor, and the laser beam can be effectively emitted easily.

(46) FIG. 7 shows an example of use of a endoscope for uterine cervix cancer in which the laser therapeutic device 1 according to the variation of the present invention is installed. The laser beam emitted from the laser emission unit 20 is projected over a wide quadrangular area, and as will be described later, has a laser profile of a top-hat type and of a uniform intensity. Therefore, the surface of a tumor can be heated over a wide area to a uniform temperature. Accordingly, for example in connection with uterine cervix cancer or the like, the uterine cervix cancer endoscope can be used to cover the entire tumor under an irradiation range, and completely destroy the cancer cells by one-time radiation. Note that, the laser therapeutic device 1 using the square-shaped rod lens 15 according to the embodiment of the present invention can be used in an identical manner, and similar operation and effect can be achieved.

(47) Irrespective of whether the cross-sectional shape of the square-shaped rod lens 15 as the optical guide elements and the cylindrical body 2a is square or rectangular, the quadrangular laser beams S3 and S5 emitted from the optical guide element each have a so-called top-hat type uniform beam profile as shown in FIG. 8A. While the output of the laser beam may be for example about 5 W in normal hyperthermia, depending on the content of the treatment, the output may be as low as several hundred mW.

(48) FIGS. 8Ba and 8Bb are conceptual diagrams comparing between the square-shaped rod lens and the bare fiber (bare core optical fiber). As shown, the square-shaped rod lens is capable of emitting a laser beam of a constant intensity over a wide area as compared to the bare fiber. Accordingly, the treatment effect of hyperthermia can be improved. Note that, when the quadrangular optical fiber 10 and the guide tube 2b are used also, a laser beam of a top-hat type and of a uniform intensity similarly to that shown in FIG. 8Ba can be obtained.

(49) In the foregoing, while one embodiment of the present invention has been described, the present invention is not limited to the above embodiment, and can be modified in various manners. For example, while the illumination units of the white-color LED units 12 and the ultraviolet LED unit 13 are exemplarily shown, the present invention is not limited to such LEDs and includes other illumination unit. For example, other illumination unit may be of an external light introduction type in which an illumination purpose external laser beam is introduced by an optical fiber.

REFERENCE SIGNS LIST

(50) 1: laser therapeutic device

(51) 2: probe tube

(52) 3: handpiece

(53) 4: cable

(54) 5: laser oscillator

(55) 6: controller

(56) 7: liquid crystal monitor

(57) 10, 14: optical fiber

(58) 11: camera unit

(59) 12: white-color LED unit

(60) 13: ultraviolet LED unit

(61) 20: laser emission unit

(62) 25: temperature sensor unit

(63) 30: optical system

(64) C1 to C4: ship-bottom shaped clearance