JP2014023598A - Irradiation device of terahertz light converted into microbeam and therapeutic apparatus using irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a terahertz light irradiation device being applicable to an extremely small-diameter transmission body just like an injection needle to be inserted into the body by converting terahertz light info an extremely small-diameter beam, and highly efficiently transmitting the terahertz light that has been converted into the beam.SOLUTION: The irradiation device includes: a terahertz light source 10 for generating terahertz light; a corrugated waveguide 11 that has protrusions on the inner surface along the advancing direction of the terahertz light and converges the terahertz light into a beam with a small diameter smaller than an incident diameter having Gaussian light intensity distribution, by the protrusions; and a transmission body 12 that transmits the terahertz light exited from the corrugated waveguide 11.

Description

  The present invention relates to a terahertz light irradiation apparatus that converts terahertz light generated by a terahertz light source into a microbeam with a very high density having a Gaussian-like light intensity distribution, and transmits the terahertz light with a transmission body having a diameter of μm with high efficiency, and the irradiation The present invention relates to a therapeutic apparatus that includes the apparatus and is effective particularly for the treatment of refractory cancer.

Terahertz light is generally considered to be light belonging to a frequency range of about 0.3 to 3 THz (wavelength range of 100 μm to 1000 μm), and has characteristics as light (for example, straight travel) and characteristics as radio waves ( Material permeability). Because of these characteristics, terahertz light has attracted a great deal of attention as a new light that replaces X-rays.
In particular, in the medical field, terahertz light is highly transmissive and safe. For example, the specified dislocation cancer cell fine tissue is irradiated with terahertz light to perform warming treatment. Development of treatment methods aiming at the complete cure of refractory cancer by simultaneous irradiation with quantum beams (neutrons, heavy particles, etc.) is underway. Attempts have also been made to warm the affected area by irradiating terahertz light to the body surface or the affected area in the body.

Yuji Matsuura, Eriko Takeda "Flexible hollow optical fiber for terahertz transmission:" (IEICE Technical Report OFT 2007-21 (2007-8))

However, when terahertz light is irradiated to the human body, it cannot be absorbed by the water molecules that make up the human body and reach the deep part of the body, and only the affected part of the body surface or a part close to it can be heated. There is a problem that it is not possible. For this reason, there is a demand to perform warming treatment with terahertz light even on an affected part in a deep part of the body. In addition, there is a demand to heat treatment by irradiating terahertz light at a pinpoint to affected parts scattered in various parts of the body such as metastatic cancer and minute affected parts such as early stage cancer. Furthermore, there is also a demand to perform a warming treatment by irradiation with terahertz light even on an affected part where bones and other important organs are localized and cannot be excised by surgery or the like.
In order to solve such problems, terahertz light is converted into a microbeam, and a technology for transmitting with high efficiency by a transmission body having a diameter of the order of μm is established. It is essential to establish technology that can transmit

Here, Non-Patent Document 1 proposes a technique for condensing terahertz light emitted from a terahertz light source with a lens and transmitting terahertz light with high efficiency using a hollow fiber having an inner diameter of about 3 mm.
However, with the technology described in this document, it is difficult to convert terahertz light into microbeams with high efficiency and high density down to the μm order, and it is also difficult to transmit terahertz light with high efficiency using a μm order transmitter. Moreover, there is a problem that it is not suitable for being inserted into the body like an injection needle and the amount of bending deformation is insufficient.

  The present invention has been made to solve such a problem. Terahertz light is converted into a micro beam having a very small diameter, and the micro beam is made to be transmitted with high efficiency by a transmission body having a diameter of μm order. It is an object of the present invention to provide a terahertz light irradiation device that can be applied to a transmitter that can be flexibly deformed, and a treatment device that includes this irradiation device and that is particularly effective for treating refractory cancer.

In order to solve the above problems, the present invention provides a terahertz light source that generates terahertz light, and a protrusion provided on the inner surface along the traveling direction of the terahertz light. The protrusion allows the terahertz light to have a Gaussian light intensity distribution. A corrugated waveguide condensing into a beam having a diameter smaller than the incident diameter and terahertz light emitted from the corrugated waveguide are transmitted.
According to this configuration, the terahertz light is converted into a very high density microbeam having a Gaussian light intensity distribution by the corrugated waveguide. Microbeam-generated terahertz light is transmitted with high efficiency by a transmission body having a diameter on the order of μm, and is irradiated onto an irradiation target.

  The diameter of the core of the transmission body is such that the cut-off frequency based on the shape, size and physical properties of the transmission body is smaller than the frequency of the terahertz light to be transmitted, as described in claim 2 , Size and physical properties (shape, size and physical properties satisfying “frequency of terahertz light to be transmitted> cutoff frequency based on shape, size and physical properties of the transmission body”). For example, when the frequency of the terahertz light to be transmitted is 1 THz when using an optical fiber made of quartz glass, the optical fiber having a circular section with a core diameter of about 0.1 mm having a cutoff frequency of about 0.9 THz Can be used.

  In the present invention, the corrugated waveguide is not particularly limited as long as the incident terahertz light can be converted into a very high density microbeam having a Gaussian light intensity distribution. As such a corrugated waveguide, for example, as described in claim 3, the width of the protrusion is about 1/3 to 1/5 of the wavelength of the terahertz light, and the height of the protrusion is 1 of the width. / 3 to 1/4, and the distance between the protrusions is about 1/3 to 2/3 of the wavelength of the terahertz light.

As the transmission body, as described in claim 4, an optical fiber composed of a core and a clad can be used. As described in claim 5, a gold coating layer for totally reflecting the terahertz light transmitted through the core may be formed on the outer peripheral surface of the clad.
The gold coating layer can totally reflect terahertz light to increase the transmission efficiency, and has no rejection when it is inserted into the living body of a human or animal, and has excellent ductility. There is also an advantage that the possibility of tearing in the coating layer is small and the safety is excellent.
Further, as another example of the transmission body, as described in claim 6, there is a coaxial two-core structure having a hollow tube and a metal wire arranged at the axial center of the hollow tube. it can. Such a coaxial two-core structure is advantageous in that it has no wavelength dependency and has high transmission efficiency, compared to a transmission body in which cut-off occurs due to wavelength dependency like an optical fiber.

The terahertz light source and the corrugated waveguide may be directly connected, or as described in claim 7, the terahertz light emitted from the terahertz light source is incident on the corrugated waveguide through a reflecting mirror. You may make it make it.
In this way, the terahertz light source, the corrugated waveguide, and the transmission body can be arranged apart from each other, and the positional relationship can be freely changed according to the position or posture of the irradiation target such as a human body. It becomes possible to do.
As described in claim 8, the distal end portion of the transmission body may be formed in a needle shape so that it can be inserted into an irradiation target in the body or other body such as a person or a plant or animal.

Moreover, you may provide the temperature sensor which measures the temperature of the local heating area | region in the front-end | tip part of the said transmission body. In this case, as described in claim 10, the temperature sensor may be provided at the tip of the transmission body. By doing in this way, since the temperature sensor for temperature measurement can be stabbed in the body with the said transmission body, the burden of a patient etc. can be eased.
Furthermore, as described in claim 11, the transmission body is held, the distal end of the transmission body is positioned at a predetermined position with respect to the irradiation target of the terahertz light by remote operation, and the distal end of the transmission body is positioned at the irradiation target There may be provided an operating means for puncturing to a predetermined depth.

  The above-described terahertz light irradiation apparatus of the present invention can be combined with an irradiation apparatus for quantum beams such as neutrons and heavy particles. In particular, when combined with an irradiation device of a quantum beam such as neutron beam, a high effect can be expected for cancer treatment, which has been difficult to treat. For example, a high therapeutic effect can be expected by using these in combination with treatment of intractable cancer that cannot be completely cured only by quantum beam irradiation or terahertz light irradiation alone. That is, as described in claim 12, a treatment apparatus of the present invention is characterized by including the terahertz light irradiation apparatus and the quantum beam irradiation apparatus described above which are microbeams.

Since the present invention is configured as described above, the terahertz light generated by the terahertz light source can be converted into a microbeam with a very small density and can be transmitted with high efficiency by a transmission body of μm order.
For this reason, the diameter of the transmission body can be reduced to an injection needle or less, for example, inserted into the patient's body, the distal end of the transmission body is brought close to the deeply affected area, and the affected area is irradiated with terahertz light for heating. It becomes possible to perform treatment. In addition, by using an optical fiber that can be deformed flexibly and a biaxial hollow tube, terahertz light is irradiated from the nearest position to the affected area where bones and other important organs are localized and cannot be excised by surgery. It becomes possible to do.

  The present invention is effective for refractory cancer that cannot be completely cured by single irradiation of terahertz light or single irradiation of a quantum beam such as a neutron beam. Such refractory cancers include (i) fixed cancers such as a mass, (ii) those that are localized on a small scale throughout the body, such as metastatic atypical cancers, and (iii) ) Although there are leftovers after excision of (i) by surgery, it is possible to cope with such refractory cancer by local heating with micro-beam terahertz light. Then, by performing simultaneous irradiation of the quantum beam and the terahertz light, advanced treatment corresponding to the above (i) to (iii) can be performed.

  Furthermore, in the present invention, the cancer affected area in the deep part of the body can be locally heated by puncturing the terahertz light that is made into a microbeam as thin as possible and making the microbeam into a small burden on the patient. In addition, it is possible to reduce the activation of the transmission body at the time of quantum beam irradiation by making the transmission body thin and long, and it is possible to control the heating condition by remotely inputting the terahertz light and the transmission body. Therefore, the practitioner can be protected from radiation exposure such as neutron radiation.

Hereinafter, preferred embodiments of a terahertz light irradiation device of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram illustrating a configuration of an irradiation apparatus according to an embodiment of the terahertz light irradiation apparatus of the present invention, FIG. 2 (a) is a schematic view of a corrugated horn, and (b) is a portion inside the corrugated horn. 3 is an enlarged view, FIG. 3 is a schematic cross-sectional view illustrating the configuration of the transmission body, FIG. 4 is a schematic view illustrating the embodiment when the present invention is applied to a treatment apparatus for cancer, and FIG. It is a conceptual diagram at the time of applying the terahertz irradiation apparatus of invention to human cancer treatment.

  As shown in FIG. 1, the terahertz light irradiation device 1 includes a terahertz light source 10 that generates terahertz light, a corrugated horn 11 that converts the terahertz light generated by the terahertz light source 10 into a microbeam, and the corrugated horn 11. The transmitter 12 is connected to one end and transmits terahertz light converted into a microbeam.

[Terahertz light source 10]
The frequency of the terahertz light is not clearly defined, but generally falls within the range of 0.3 to 3 THz (the wavelength is in the range of 100 μm to 1000 μm). As the terahertz light source 10 that generates such terahertz light, a gyrotron, a backward wave oscillator (BWO), a femtosecond laser, a far infrared laser, a quantum cascade laser, or the like can be used.

[Corrugated horn]
The corrugated horn 11 as the corrugated waveguide only needs to be able to convert the terahertz light generated by the terahertz light source 10 into a microbeam according to a transmission body 12 having a diameter on the order of μm to be described later. A material etc. do not ask | require. FIG. 2 shows an example of the corrugated horn 11, a main body 110 formed in a hollow cone shape having a through hole, and a flange that is formed on the large diameter side of the main body 110 and attaches the main body 110 to the terahertz light source 10. Part 111. The main body 110 has a terahertz light entrance 110a on the large diameter side and a terahertz light exit port 110b on the small diameter side.
The diameter of the incident port 110a of the corrugated horn 11 is adjusted to the diameter of the output port of the terahertz light source 10, and the diameter of the output port 110b is set to about 0.1 to 1.0 mm according to the diameter of the core 120 of the transmission body 12 described later. Is preferred.

[Corrugated structure]
A large number of projections 112 are formed on the inner surface of the main body 110 of the corrugated horn 11 along the traveling direction of the terahertz light as shown in FIG. The protrusion 112 makes the light intensity distribution of the terahertz light incident on the corrugated horn 11 Gaussian, and makes the terahertz light traveling in the corrugated horn 11 into a micro beam with a minimum density.
As an example of the protrusion 112, the width W is about 1/3 to 1/5 of the wavelength of the terahertz light, the interval S is about 1/3 to 2/3 of the wavelength of the terahertz light, and the height H is the width of the wavelength. Of about 1/3 to 1/4. For example, in the case of terahertz light having a frequency of 1 THz, the width W is about 75 μm, the interval S is about 150 μm, and the height H is about 20 μm.
The length of the corrugated horn 11 (the optical path length of the terahertz light) L is selected so that the terahertz light can be converted into a microbeam with the highest efficiency and high density, but depends on the diameter of the entrance 110a and the diameter of the exit 110b. . For example, when the diameter of the entrance 110a is about 28 to 30 mm and the diameter of the exit 110b is about 0.1 to 1.0 mm, the length L can be about 150 to 200 mm.

[Transmitter]
As a transmission body 12 for transmitting terahertz light converted into a Gaussian beam by the corrugated horn 11, a core part 120 made of quartz glass and a clad part 121 made of quartz glass formed around the core part 120. 3A having an optical fiber as shown in FIG. 3A and a hollow tube 123 and a metal wire 124 arranged at the axial center of the hollow tube 123 as shown in FIG. A hollow core tube can be used.
When an optical fiber is used as the transmission body 12, a coating layer 122 for totally reflecting terahertz light may be formed on the outer peripheral surface of the cladding portion 121. When the optical fiber transmission body 12 is inserted into the body, the coating layer 122 is preferably formed of gold. Gold is advantageous in that it does not react with a living body and has high ductility, making it difficult to tear the optical fiber.

  The relationship between the cut-off frequency and transmission loss when an optical fiber is used as the transmitter 12 is shown in the following table. The following table uses the terahertz light source 10 with an assumed output of 40 W · 0.4 THz, the dielectric constant of the core part 120 and the cladding part 121 is 3.806 to 3.814 (0.1 to 1 THz), and the cladding part 121. The case where the outer peripheral surface of this is gold-coated is shown.

  As can be seen from this table, terahertz light having a cut-off frequency or less corresponding to the diameter in the table cannot be transmitted with respect to the predetermined diameter of the core portion 120. For example, when the diameter of the core part 120 is 0.3 mm, the cut-off frequency is 0.3 THz. Therefore, terahertz light of 0.3 THz or less cannot be transmitted by an optical fiber having a core diameter of 0.3 mm. In other words, if the frequency is higher than 0.4 THz, the diameter of the core part 120 can be reduced to about 0.3 mm. If it is this diameter, since the diameter of the transmission body 12 can be made into the same magnitude | size or less than an injection needle, it can be used together with an injection needle or can be directly stabbed in the body.

  A temperature sensor or other sensor may be provided at the tip of the transmission body 12. For example, by providing a temperature sensor at the distal end of the transmission body 12, the temperature of the local heating region at the distal end portion of the transmission body 12 is measured, and the output of the terahertz light source and the irradiation position of the terahertz light are controlled based on the measurement result. The temperature of the irradiated part can be kept appropriate. Therefore, for example, in the field of cancer treatment or the like, it is possible to perform irradiation with terahertz light while maintaining the cancer affected part at an optimum temperature for killing cancer cells.

  The transmission body 12 and the corrugated horn 11 configured as described above can be connected via a connection member 13 such as a connector or an adapter. It is also possible to make the terahertz light emitted from the terahertz light source 10 enter the corrugated horn 11 via a reflecting mirror. In this way, the terahertz light source 10 and the corrugated horn 11 and the transmission body 12 can be arranged apart from each other, and the terahertz light source 10 and the corrugated horn 11 and the The positional relationship with the transmission body 12 can be freely changed.

FIG. 4 is a schematic view showing an embodiment when the present invention is applied to a treatment apparatus for cancer or the like.
In the illustrated treatment apparatus, a reflecting mirror 15 is arranged between the terahertz light source 10, the corrugated horn 11, and the transmission body 12, and terahertz light emitted from the terahertz light source 10 is incident on the corrugated horn 11 through the reflecting mirror 15. I try to let them. The distal end of the transmission body 12 is inserted into the irradiated body, and the affected part is irradiated with the terahertz light converted into a microbeam from the distal end of the transmission body 12. The temperature at which the affected area is heated by the irradiation of the terahertz light can be detected by the temperature sensor 16. The reflecting mirror 15 is preferably arranged in the waveguide 17. Although not shown, the distal end of the transmission body 12 may be held by an operating means such as a robot arm, and positioning and insertion of the transmission body 12 and irradiation of terahertz light and adjustment of heating conditions may be remotely operated. .
In addition to the terahertz light irradiation device, this treatment device is equipped with a quantum beam irradiation device such as neutrons and heavy particles for the purpose of treating refractory cancer, and the affected area is converted into a microbeam. Terahertz light irradiation and quantum beam irradiation may be performed simultaneously.

[Description of action]
The operation of the terahertz light irradiation apparatus having the above configuration will be described.
The terahertz light generated by the terahertz light source 10 is incident on the corrugated horn 11 and, while traveling through the corrugated horn 11, is converted into a Gaussian beam whose light diameter is reduced by the projection 112 of the corrugated structure. The terahertz light whose diameter has been reduced to about 0.1 to 1.0 mm at the exit port 110b is guided to the transmission body 12 by a connector or a reflecting mirror. If the tip of the transmission body 12 is formed in the shape of an injection needle, the tip of the transmission body 12 can be positioned near the affected part by being inserted into the body. Of course, it is also possible to irradiate the affected part with the terahertz light emitted from the exit port 110b of the corrugated horn 11 without using the transmission body 12 to the affected part on the body surface.

FIG. 5 is a diagram for explaining a model of cancer treatment in which terahertz light incident on the transmission body 12 is transmitted to a cancer affected part in a patient's body.
The direction of the terahertz light emitted from the terahertz light source 10 is changed by the reflecting mirror 15 and is incident on the corrugated horn 11 disposed in the vicinity of the patient's body. Then, the terahertz light that has been converted into a microbeam is irradiated toward the cancer affected area from the tip of the transmission body 12 that is inserted into the body of the patient. By irradiation with terahertz light, a certain region is heated around the irradiated portion, and cancer cells in the region can be killed.

  When the cancerous part is large, the transmitter 12 is inserted into a plurality of places and the terahertz light is irradiated. The heating temperature by the irradiation of the terahertz light is detected by a temperature sensor 16 provided in parallel with the transmission body 12 or integrally with the transmission body 12, and is adjusted to an optimum temperature for the heating treatment. By doing in this way, it becomes possible to perform cancer treatment of a deep part in the body by irradiation with terahertz light.

  Note that irradiation with a quantum beam such as a neutron beam may be used in combination with irradiation with terahertz light. In the present invention, since the transmission body can be made thin and long, the radiation of the transmission body 12 due to quantum beam irradiation can be reduced even in such a case, and the tip of the transmission body 12 can be operated by an operating means such as a robot arm. It is possible to remotely control positioning and insertion of the transmission body 12, irradiation of terahertz light and adjustment of heating conditions, and protect the operator from radiation exposure such as neutron radiation. .

Although a preferred embodiment of the present invention has been described, the present invention is not limited to the above description.
For example, the terahertz light has been described on the assumption that the frequency is in the range of 0.3 to 3 THz, but this range is a general guideline of “terahertz light” without a clear definition, and is equivalent to the present invention. Any device that exhibits an action and an effect is included in the “terahertz light” of the present invention even if it is outside this range.
In addition, the cross-sectional shape of the transmission body 12 is not limited to a circular shape, and may be an ellipse, a rectangle, or a polygon as long as the frequency of the terahertz light to be transmitted can be higher than the cutoff frequency based on the shape and physical properties of the transmission body. Other shapes may be used.

The apparatus of the present invention is suitable for the medical field such as the treatment of diseases such as cancer in humans and animals, as well as ultrasensitive solid nuclear magnetic resonance (NMR) by dynamic nuclear polarization (DNP) method, semiconductors, various examinations, It can be widely applied to engineering, chemistry and physical fields such as analysis and processing. In addition, the terahertz light irradiation apparatus and the quantum beam irradiation apparatus of the present invention can be combined and applied to a treatment apparatus such as a cancer treatment.
Furthermore, the apparatus combining the terahertz irradiation apparatus of the present invention and the irradiation apparatus of quantum beams such as neutrons and heavy particles is not limited to the above-mentioned medical field, for example, neutrons while exciting proteins with microbeam-ized terahertz light and proceeding photosynthesis The present invention can also be applied to the field of reaction analysis in which structural analysis is performed using a beam, and the field of engineering exploration to investigate internal mechanisms.

It is the schematic which concerns on one Embodiment of the irradiation apparatus of the terahertz light of this invention, and demonstrates the structure of an irradiation apparatus. 2A is a schematic view of the corrugated horn, and FIG. 2B is a partially enlarged view of the interior of the corrugated horn. FIG. 3 is a schematic cross-sectional view illustrating the configuration according to the embodiment of the transmission body. It is the schematic which shows embodiment at the time of applying this invention to treatment apparatuses, such as cancer. It is a conceptual diagram at the time of applying the terahertz irradiation apparatus of this invention to human cancer treatment.

DESCRIPTION OF SYMBOLS 1 Terahertz light irradiation apparatus 10 Terahertz light source 11 Corrugated horn (corrugated waveguide)
12 Transmitter 13 Connector 15 Reflector 16 Temperature Sensor

Claims (12)

A terahertz light source that generates terahertz light;
A corrugated waveguide is provided on the inner surface with projections along the traveling direction of the terahertz light, and the projections condense the terahertz light into a beam having a smaller diameter than the incident diameter having a Gaussian light intensity distribution;
A transmission body for transmitting terahertz light emitted from the corrugated waveguide;
A terahertz light irradiation apparatus in the form of a microbeam characterized by comprising: The shape, size, and physical properties of the transmission body are determined such that the cutoff frequency based on the shape, size, and physical properties of the transmission body is smaller than the frequency of the terahertz light to be transmitted. The irradiation apparatus of the terahertz light made into the micro beam of Claim 1. The width of the protrusion is in the range of 1/3 to 1/5 of the wavelength of the terahertz light, the height of the protrusion is 1/3 to 1/4 of the width, and the distance between the protrusions is 1 of the wavelength of the terahertz light. The irradiation apparatus for terahertz light in the form of a microbeam according to claim 1 or 2, wherein the irradiation apparatus is / 3 to 2/3. The terahertz light irradiation apparatus according to any one of claims 1 to 3, wherein the transmission body is an optical fiber including a core and a clad. 5. The microbeam-formed terahertz light irradiation apparatus according to claim 4, wherein a gold coating layer for totally reflecting terahertz light transmitted through the core is formed on an outer peripheral surface of the clad. The microbeam according to any one of claims 1 to 3, wherein the transmission body has a coaxial two-core structure including a hollow tube and a metal wire disposed at an axial center of the hollow tube. Terahertz light irradiation device. The terahertz light irradiation apparatus according to claim 1, wherein the terahertz light emitted from the terahertz light source is incident on the corrugated waveguide through a reflecting mirror. 8. The irradiation apparatus for terahertz light in the form of a micro beam according to claim 1, wherein a tip end portion of the transmission body is formed as a needle-like portion that is inserted into an irradiation target of terahertz light. . 9. The irradiation apparatus for terahertz light in the form of a micro beam according to claim 1, further comprising a temperature sensor for measuring a temperature of a local heating region at a distal end portion of the transmission body. 10. The irradiation apparatus for terahertz light in the form of a micro beam according to claim 9, wherein the temperature sensor is provided at a distal end portion of the transmission body. Operation means for holding the transmission body, positioning the distal end of the transmission body at a predetermined position with respect to the irradiation target of the terahertz light by remote operation, and inserting the distal end of the transmission body into the irradiation target to a predetermined depth The terahertz light irradiation apparatus in the form of a micro beam according to any one of claims 1 to 10. A treatment apparatus comprising the terahertz light irradiation apparatus and the quantum beam irradiation apparatus according to any one of claims 1 to 11.