JP2003052842A - Photodynamic curing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photodynamic curing device capable of radiating light having substantially uniform distribution of power density in a wide range. SOLUTION: In this photodynamic curing device, photosensitive material dosed to a patient and staying in a lesion is excited by irradiation of light containing a specified wavelength to thereby cure the lesion. The device is provided with a plurality of light sources 3, a plurality of multi-reflecting members 12 respectively corresponding to the plurality of light sources, a plurality of condensing lenses 11 for guiding light from the plurality of light source to the plurality of the corresponding multi-reflecting members, and a plurality of projection lenses 13 for projecting the output light from the plurality of multi-reflecting members to an enlarged scale.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photodynamic therapy apparatus which treats an affected area by irradiating a patient with light having a specific wavelength to excite a photosensitizing substance accumulated in the affected area.

[0002]

[Prior Art] Photo Dynamic Therapy;
PDT) generates reactive oxygen species by a chemical reaction that occurs when a photosensitizer with tumor affinity is irradiated with light.
It is a treatment method that necroses tumors such as cancer by its power,
Since it selectively destroys tumors without damaging other organs or seriously damaging ecology, QOL (Q
Recently, much attention has been paid from the viewpoint of uality of Life.

By the way, a laser is mainly used as a light source. The reason for this is that the laser can effectively excite a photosensitizer having a monochromatic property and a narrow absorption band, has a high power density, and can generate pulsed light. Further, as the type of laser, an excimer die laser, a TAG-OPO laser, or the like having wavelength selectivity is adopted. This laser light is guided to an optical fiber, and the fiber is operated under the guide of an endoscope to aim the tip on the affected area and irradiate at the position.

However, the laser light is a spot light and the irradiation field is narrow, so that it is not suitable for the treatment of a relatively wide superficial disease.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photodynamic therapy device capable of irradiating light over a wide range with a substantially uniform power density distribution.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a photodynamic treatment apparatus for treating a diseased site by irradiating a patient with a light having a specific wavelength to excite a photosensitizing substance that remains in the affected site and treats the affected site. A plurality of multiple reflection members respectively corresponding to the plurality of light sources, a plurality of condensing lenses for guiding light from the plurality of light sources to the plurality of corresponding multiple reflection members, and the plurality of multiple reflection members And at least one projection lens for magnifying and projecting the output light from.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A photodynamic therapy apparatus according to the present invention will be described below with reference to the accompanying drawings. (First Embodiment) FIG. 1 shows a configuration diagram of a photodynamic therapy apparatus according to the present embodiment. There are multiple lamp houses 1,
For example, nine light source units 2 are provided. The nine light source units 2 are connected in 3 × 3 as shown in FIG. As shown in FIG. 3, each light source unit 2 has a light-shielding housing 41 having a light exit window 42 at its tip.
The light source 3, the condenser lens 11, the multiple reflection member 12, and the projection lens 13 are housed. Light source 3 is 400 nm to 4
It is composed of one or a plurality of semiconductor lasers that oscillate at a specific wavelength in the range of 20 nm or 600 nm to 700 nm. The light source 3 may be composed of one or a plurality of light emitting diodes that emit light with the specific wavelength as a peak.

The light from the light source 3 is guided to the incident surface of the multiple reflection member 12 by the condenser lens 11. The incident surface of the multiple reflection member 12 is arranged remote from the focal point of the light from the condenser lens 11. The distance between the condenser lens 11 and the incident surface of the multiple reflection member 12 is designed so that the area ratio of the incident field to the incident surface of the multiple reflection member 12 is, for example, 80%. Thereby, excessive heat generation on the incident surface of the multiple reflection member 12 can be avoided, and a margin for each alignment error between the light source 3 and the multiple reflection member 12 with respect to the optical axis of the condenser lens 11 can be provided.

As shown in FIG. 4 (a), the multiple reflection member 12 is a transparent quadrangular prism 13 made of, for example, quartz. The light incident from the incident surface is repeatedly reflected inside the multiple reflection member 12. Due to this multiple reflection, the power density distribution becomes substantially uniform on the emission surface orthogonal to the optical axis. The light whose power density distribution is substantially uniform is diffused and emitted from the entire emission surface of the multiple reflection member 12.

The multiple reflection member 12 is not limited to the quadrangular prism 13 and may be a regular hexagonal prism as shown in FIG. 4 (b). Further, the multiple reflection member 12 is not limited to a transparent prism, and may be a quadrangular or regular hexagonal cylinder whose inner surface is mirror-finished as shown in FIG. 4C. Furthermore, the multiple reflection member 12 may be a pyramid that spreads in a tapered shape from the incident surface toward the exit surface, or the entrance surface and the exit surface may have different shapes.

The light, the power density distribution of which is made substantially uniform in the multiple reflection member 12, is enlarged and projected on the irradiation surface through the projection lens 13 as shown in FIG. Projection lens 13
Has a fixed focal length and is fixed at a position separated from the exit surface of the multiple reflection member 12 by a predetermined distance. Projection lens 1
3, the distance between the multiple reflection member 12 and FIG.
As shown in FIG. 6B, a plurality of irradiation fields IF formed by a plurality of light source units 2 are connected to each other on an irradiation surface that is separated from the projection lens 13 by a predetermined distance dfix (hereinafter referred to as an appropriate distance dfix). , And is designed to image at that distance.

Incidentally, the connection means that a plurality of irradiation fields IF are not separated from each other as shown in FIG.
As shown in (b), the plurality of irradiation fields IF do not overlap with each other, and the plurality of irradiation fields IF are defined as being in continuous contact with each other at their respective contours. In this way, multiple irradiation fields IF
The area of the entire connected irradiation field (hereinafter referred to as the “connected irradiation field”) is linked to the area n of each irradiation field IF.
The power density distribution can be expanded twice (n is equivalent to the number of light source units 2), and the power density distribution can be made substantially uniform.

The appropriate distance dfix is designed on the basis of the light emission intensity of the light source 3 so that the power density on the irradiation surface separated from the projection lens 13 by the distance dfix becomes a predetermined value suitable for treatment. There is. Furthermore, the appropriate distance d
The distance between the multiple reflection members 12 of the adjacent light source units 2 is designed so as to secure the above-mentioned connected state by the fix.

In order to form the concatenated irradiation field as described above, it is important to accurately match the distance from the affected area to the projection lens 13 to the above-mentioned proper distance dfix. In order to support this alignment, a non-contact type distance sensor 5 using, for example, infrared rays or ultrasonic waves is arranged at the tip of the housing 41 of the lamp house 1 or the light source unit 2, and the distance sensor 5 measures the distance. An appropriate distance determination circuit 10 for determining whether or not the distance from the affected area to the projection lens 13 matches the appropriate distance dfix or whether or not the distance is within a predetermined range from the appropriate distance dfix based on the determined distance. There is.

According to the judgment result of the proper distance judgment circuit 10, the display control circuit 8 is displayed on the operation panel 9 as "there is a proper distance, please keep that position", "too close to the affected area, please separate a little. It has a function to display a message such as "Too far from the affected area, please bring it a little closer" as text information. If the distance from the affected area to the projection lens 13 does not match the proper distance dfix, or if it is not within the predetermined range from the proper distance dfix, a blinking message will be displayed, and at the same time a sound will be produced The color may be changed to call the operator's attention. Instead of or in addition to this message display, a voice message or a warning sound may be generated. If the distance from the affected area to the projection lens 13 does not match the appropriate distance dfix, or if it is not within the predetermined range from the appropriate distance dfix, the operator adjusts the position of the lamp house 1 with respect to the affected area according to these warnings. As a result, the appropriate distance dfix can be secured during the light irradiation to the affected area, and the continuous irradiation field can always be formed in the affected area to perform the appropriate light irradiation. For example, even if the patient moves, the operator can immediately understand how to adjust the position of the lamp house 1 by seeing the displayed text message, listening to the voice message, and the warning sound. Because it can be done, the appropriate distance d
The fix can be secured again and appropriate light irradiation can be continued.

Further, the distance sensor sees the difference between the proper distance dfix and the distance from the affected part to the projection lens 13, and if the distance from the affected part to the projection lens 13 is not the proper distance, how much more the lamp house 1 should be attached to the affected part. By letting the operation panel 9 display a distance indicating whether or not to move away from the patient or how close to the affected area, the operator is notified of the distance to be separated or the distance to be approached.
The operator can further facilitate operability of the device during the operation by using it as a guide. Instead of displaying the difference, the actual distance and the proper distance dfix may be displayed on the same screen (the proper distance dfix is predetermined and the operator has already grasped the proper distance). In this case, only the actual distance may be displayed). Further, the distance to be displayed is set to a numerical value in conjunction with the operator actually moving the lamp house 1 away from or near the affected area so that the distance sensor is turned on. It may be changed. At this time, when the distance sensor displays the difference between the proper distance dfix and the distance from the affected part to the projection lens 13, the operator may operate so that the displayed difference becomes zero. On the other hand, when displaying the actual distance, the operator may operate so that the actual distance becomes the proper distance dfix. in this way,
By performing the treatment with reference to the display on the display panel 9,
The operator can more accurately irradiate the affected area (useless irradiation can be suppressed), and the therapeutic effect can be further improved. Of course, the above operation may be automatically controlled based on the distance of the distance sensor as a system mechanism. Further, when the difference between the proper distance dfix and the distance from the affected area to the projection lens 13 becomes a certain value or more by the distance sensor, the current supply to the light source may be stopped and the irradiation may be stopped. Of course, when the patient moves during the light irradiation, the movement is grasped by the distance sensor, and the position of the lamp house 1 is automatically system-controlled in conjunction with the movement so that the patient can be appropriately and continuously connected to the affected area. An irradiation field can be formed, and appropriate continuous irradiation is possible. Further, when it is detected by the distance sensor that the patient has moved within a certain range, the current supply to the light source may be automatically stopped and the irradiation may be stopped. By doing so, the load on the patient can be reduced, and unnecessary irradiation can be prevented.

By the way, the shape and size of the affected area are not constant. Changing the shape and size of the connected irradiation field according to the shape and size of various affected areas is very useful in reducing unnecessary irradiation to a healthy part. The change in the shape and size of the connected irradiation field can be realized by driving the plurality of light sources 3 in any combination. Therefore, the power supply unit 6 is configured so that the plurality of light sources 3 can be turned on / off individually.
Is provided with a plurality of power supply units. Each power supply unit supplies a current to the corresponding light source 3 when a trigger signal is input from the irradiation time / irradiation pattern control circuit 7, and does not supply a current when the trigger signal is not input.

The combination pattern of the light sources 3 to be driven is
It is set by the surgeon. The display control circuit 8 causes the monitor of the operation panel 9 to superimpose and display a frame 20 schematically showing a plurality of irradiation fields, as shown in FIG. The operator sets the irradiation field on the affected area to the irradiation state (ON) through the touch panel arranged on the monitor or an arbitrary pointing device, and sets the irradiation field on the affected area to the non-irradiation state (OFF). ). Note that FIG.
As shown in (b), an image 18 including a lesioned part 19 captured from an external image diagnostic apparatus may be superimposed and displayed on this frame 20.

The irradiation time / irradiation pattern control circuit 7 outputs a trigger signal to the power supply unit of the light source 3 corresponding to the irradiation field set in the irradiation state, and the light source corresponding to the irradiation field set in the non-irradiation state. No trigger signal is output to the power supply unit of No. 3. This makes it possible to change the shape and size of the connected irradiation field according to that of the affected area.

In addition to controlling the irradiation pattern, the irradiation time / irradiation pattern control circuit 7 controls the irradiation time. The irradiation time / irradiation pattern control circuit 7 sets the irradiation time t to the irradiation energy J (=
I × t) and power density I (mW / cm ² ) in the irradiation field
And the duration of the trigger signal is adjusted according to the calculated irradiation time t.

By the way, in photodynamic therapy, it is important to strictly control the irradiation energy J. On the other hand, the light conversion efficiency slightly varies among the plurality of light sources 3, and even the same light source 3 slightly varies with time. In the present embodiment, the irradiation time of the plurality of light sources 3 is not uniformly controlled, but each light source 3 can be individually and finely controlled. In each light source unit 2, as shown in FIG. 3, an optical sensor 4 is arranged between the light source 3 and the condenser lens 11 and outside the light flux from the light source 3 to the condenser lens 11. . The optical sensor 4 is
When the multiple reflection member 12 is a transparent prism, it may be arranged between the condenser lens 11 and the multiple reflection member 12.

Most of the light generated by the light source 3 enters the condenser lens 11, but is slightly reflected by the lens surface. This reflected light (light loss) is measured by the optical sensor 4. This reflection ratio shows almost an eigenvalue in the condenser lens 11. Therefore, the intensity of the light actually generated by the light source 3 can be specified almost accurately from the intensity of the reflected light. Therefore, in the irradiation time / irradiation pattern control circuit 7, by individually controlling the duration of the trigger signal for each light source 3 according to the output of the plurality of optical sensors 4 provided in each of the plurality of light source units 2, The irradiation energy J can be made constant between irradiation fields.

As described above, according to this embodiment, it is possible to irradiate light with a substantially uniform power density distribution over a wide range.

(Second Embodiment) FIG. 9 shows the arrangement of a photodynamic therapy apparatus according to the second embodiment. 9, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the first embodiment, the projection lens 13 is fixed, and accordingly, the connection of a plurality of irradiation fields is adjusted to an appropriate distance dfi.
However, in the second embodiment, by adopting the zoom lens assay 22 in which the magnification and the focal length can be changed, the concatenated irradiation field can be formed with a substantially uniform power density distribution at an arbitrary distance. It is possible. In the present embodiment, by changing the magnification and the focal length in accordance with the variation of the distance d with the affected part, the connection of a plurality of irradiation fields is always ensured, that is, the connection irradiation field having a substantially uniform power density distribution. Can be formed.

Therefore, a magnification focal length control circuit 21 is provided. The magnification focal length control circuit 21 is shown in FIG.
As shown in FIG. 11, even if the distance changes, the distance sensor 5 does not change the size of the irradiation field on each irradiation surface.
The zoom lens assay 22 is controlled on the basis of the distances d1 and d2 measured in step 1 to change its magnification and focal length. As a result, even if the distance to the affected area (irradiation surface) changes, it is possible to maintain a state in which a plurality of irradiation fields are connected to each other while the power density distribution remains substantially uniform in the affected area.

As described above, according to this embodiment, it is possible to irradiate light in a wide range with a substantially uniform power density distribution,
Moreover, even if the distance to the affected part changes, it follows it,
It is possible to secure a state in which a plurality of irradiation fields are connected.

In the first and second embodiments, the size W of each irradiation field is fixed. This is to ensure the connected state of the irradiation field. The size W of each irradiation field for ensuring this connection state is determined depending on the interval between the multiple reflection members 12 of the adjacent light source units 2. Therefore, in order to make it possible to adjust the power density by changing the size W of each irradiation field for ensuring the connected state, the distance between the adjacent multiple reflection members 12 is variable with the light source unit 2. A support mechanism may be provided.

(Third Embodiment) In the above-described first and second embodiments, the size of the connected irradiation field is fixed in order to form a connected state of a plurality of irradiation fields. Therefore,
If the light source output is constant, the power density is also fixed at a constant value. In the third embodiment, the size of the concatenated irradiation field is made variable so that the power density can be freely changed.

FIG. 12 shows the internal structure of the lamp house of the photodynamic therapy system according to the third embodiment. Figure 1
2, the same parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 12 and 13, a feature of this embodiment is that a transparent body having a square or hexagonal prism shape is adopted as the multiple reflection member 12, and the multiple reflection members 12 are in contact with each other. It is that they are united together without any gaps. That is, in the first and second embodiments, since the lamp house 1 is an assembly of the light source units 2, it is inevitable that the multiple reflection members 12 are separated from each other. In order to eliminate the gap between the members 12 in the irradiation field and connect them to each other, the size of the irradiation field is made constant, or an appropriate distance is determined in order to obtain a constant size.

However, in the present embodiment, a plurality of multiple reflection members 12 are bound together in a state in which they are in contact with each other without any gap, so that FIG. 14 (a), FIG. 14 (b), and FIG.
As shown in (c), even if the irradiation field is enlarged / reduced, the connected state is secured.

For enlarging / reducing the irradiation field, a single projection lens 31 shared by a plurality of multiple reflection members 12 is supported by a moving mechanism 30 so as to be movable on the optical axis, and its magnification is determined by a position sensor 32. It is realized by setting according to the detected position of the projection lens 31. This one projection lens 3
As the No. 1, a large-diameter one is required, which is determined according to the overall diameter of the emission surfaces of the multiple reflection members 12 to be bound and the distance from the emission surfaces. A Fresnel lens having such a large aperture and being lightweight is suitable as the projection lens 31.

The moving mechanism 30 typically has a structure in which the lens holder 35 is movably supported by a holder guide 36, as shown in FIG. Holder guide 3
A plunger 37 is provided at 6 to stop the projection lens 31 at each position corresponding to several kinds of magnifications (for example, 2 times, 4 times, 8 times). Corresponding to these positions, a plurality of, here two, photosensors 38 are arranged at intervals along the optical axis. The position of the projection lens 31, that is, the current magnification can be detected by a combination of ON / OFF of the two optical sensors 38. When the optical sensor 38 is covered by the lens holder 35, the optical sensor 38 is in an off state, and when the optical sensor 38 is not covered by the lens holder 35, the optical sensor 38 is in the off state.
Is turned on. The position detection circuit 39 detects that the magnification is set to 2 when both the two optical sensors 38 are in the ON state, and when the two optical sensors 38 are both in the OFF state, It is detected that the magnification is set to 8 times, and when one is on and the other is off, it is detected that it is set to 4 times.

The detection result is displayed on the operation panel or the lamp house indicator so that the operator can visually recognize it.

As described above, according to this embodiment, it is possible to irradiate a wide range of light with a substantially uniform power density distribution,
Moreover, it is possible to change the energy density by enlarging / reducing while a plurality of irradiation fields are connected.

Instead of the optical sensor, a micro switch, a photo coupler, a magnetic sensor or the like may be used.

The present invention is not limited to the above-described embodiment, and can be carried out in various modifications at the stage of implementation without departing from the scope of the invention. Further, the above embodiment includes various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, some constituent elements may be deleted from all the constituent elements shown in the embodiment.

[0039]

According to the present invention, light irradiation can be performed in a wide range with a substantially uniform power density distribution.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a photodynamic therapy apparatus according to a first embodiment.

FIG. 2 is an external view of the lamp house in FIG.

3 is an internal structural diagram of each of the light source units in FIG.

FIG. 4 is an external view of each of the multiple reflection members in FIG.

5 is a diagram showing an appropriate distance peculiar to the lamp house of FIG.

FIG. 6 is a view showing a plurality of irradiation fields when the lamp house of FIG. 1 is installed at an appropriate distance.

FIG. 7 is a diagram showing a plurality of irradiation fields when the lamp house of FIG. 1 is installed at a position deviated from an appropriate distance.

8 is a diagram showing an example of a display screen of the operation panel of FIG.

FIG. 9 is a configuration diagram of a photodynamic therapy apparatus according to a second embodiment.

10 is a diagram showing the position of the projection lens when the lamp house of FIG. 9 is relatively far from the affected area.

11 is a diagram showing the position of the projection lens when the lamp house of FIG. 9 is relatively close to the affected area.

FIG. 12 is an internal structural diagram of a lamp house of the photodynamic therapy apparatus according to the third embodiment.

FIG. 13 is a view showing a plurality of bundled multiple reflection members of FIG. 12;

14 is a diagram showing a change in irradiation field size depending on the position of the projection lens in FIG.

FIG. 15 is a diagram showing the position of the projection lens of FIG. 12 when the magnification is 2 ×.

16 is a diagram showing the position of the projection lens in FIG. 12 when the magnification is 4 ×.

[Explanation of symbols]

1 ... Lamphouse, 2 ... Light source unit, 3 ... Light source, 4 ... Optical sensor, 5 ... distance sensor, 6 ... power supply unit, 7 ... Irradiation time / irradiation pattern control circuit, 8 ... Display control circuit, 9 ... Operation panel, 10 ... Appropriate distance determination circuit, 11 ... a condenser lens, 12 ... Multiple reflection member, 13 ... Projection lens.

Continued front page    F-term (reference) 4C026 AA04 AA10 BB08 FF33 HH02                       HH04 HH05 HH13                 4C082 RA02 RC09 RE34 RE35 RL02                       RL04 RL05 RL13

Claims (16)

[Claims] 1. A photodynamic therapy apparatus for treating a diseased site by irradiating a patient with light containing a specific wavelength to excite a photosensitizing substance accumulated in the diseased site to treat the diseased site. A plurality of corresponding multiple reflection members, a plurality of condensing lenses that guide light from the plurality of light sources to the corresponding plurality of multiple reflection members, and an enlarged projection of output light from the plurality of multiple reflection members. A photodynamic therapy device comprising at least one projection lens. 2. The photodynamic therapy apparatus according to claim 1, wherein each of the light sources comprises at least one light emitting diode or a semiconductor laser. 3. The photodynamic therapy apparatus according to claim 1, wherein the multiple reflection member is a substantially transparent prismatic body or a pyramidal body, or a cylindrical body whose inner surface is a mirror surface. 4. The power supply unit for driving the plurality of light sources, and the control circuit for controlling the power supply unit so as to drive the plurality of light sources in an arbitrary combination, further comprising: Photodynamic therapy device. 5. A display unit for displaying a schematic diagram of a plurality of irradiation fields corresponding to the plurality of light sources together with an image including the affected area, and a designating unit for designating the light source to be driven on the schematic diagram. The photodynamic therapy device according to claim 4, wherein 6. A light loss, which is arranged between the light source and the condenser lens or between the condenser lens and the multiple reflection member, and which measures an optical loss occurring at an incident surface of the condenser lens or the multiple reflection member. The photodynamic therapy apparatus according to claim 1, further comprising: a light sensor for controlling the irradiation time of the light based on an output of the light sensor. 7. A light loss, which is arranged between the light source and the condenser lens or between the condenser lens and the multiple reflection member, and which measures an optical loss occurring on an incident surface of the condenser lens or the multiple reflection member. The photodynamic therapy device according to claim 1, further comprising: a light sensor for controlling the irradiation time of the light for each light source based on an output of the light sensor. 8. The plurality of light emitting fields output from the plurality of multi-reflecting members are connected at a position apart from the projection lens by a predetermined distance so that the respective light emitting fields are connected without a gap and without overlapping. 2. The photodynamic therapy apparatus according to claim 1, wherein the multiple reflection member is arranged. 9. A distance sensor for directly or indirectly measuring the distance from the projection lens to the affected area, and whether or not the distance measured by the distance sensor matches the predetermined distance or the predetermined distance. 9. The photodynamic therapy apparatus according to claim 8, further comprising a determination circuit for determining whether or not it is within a predetermined range. 10. If the distance measured by the distance sensor does not match the predetermined distance or is not within a predetermined range from the predetermined distance as a result of the judgment by the judgment circuit,
10. The photodynamic therapy apparatus according to claim 9, further comprising an alarm unit that outputs an alarm. 11. A distance sensor for directly or indirectly measuring the distance from the projection lens to the affected area, a zoom lens assay including the projection lens, and light output from the plurality of multiple reflection members. And a control circuit for controlling the magnification and the focal length of the zoom lens assay based on the measured distances so that the irradiation fields of the two are connected without a gap and overlap at the position of the affected area. The photodynamic therapy device according to claim 1. 12. The photodynamic therapy device according to claim 1, wherein the plurality of multiple reflection members are substantially transparent prisms and are integrally united. 13. The photodynamic therapy apparatus according to claim 12, wherein the projection lens is shared by the plurality of multiple reflection members. 14. The photodynamic therapy apparatus according to claim 13, wherein the projection lens is a Fresnel lens. 15. The photodynamic therapy apparatus according to claim 12, further comprising a mechanism for movably supporting the projection lens in order to change a magnification. 16. The photodynamic therapy device according to claim 12, wherein the projection lens is a zoom lens assay or a telecentric optical system.