The following provides a detailed explanation of embodiments of the present invention with reference to the attached drawings. Furthermore, the same reference symbols are indicated for the same constituent elements in the explanation of the drawings, and duplicate explanations are omitted.
The following provides an explanation of a treatment apparatus and treatment method as claimed in the present embodiment using the example of a dental treatment apparatus. Furthermore, the treatment apparatus as claimed in the present invention is not limited to a dental treatment apparatus.
The irradiation unit 10 is constituted by N number of first light emitting elements S1 to SN, N number of first focusing lenses L1 to LN, and N number of optic fibers (first output means) F1 to FN combined on a 1:1 basis. Here, N is an integer of 2 or more, and n to be appear later is an arbitrary integer of 1 to N. The first light emitting elements S1 to SN, the first focusing lenses L1 to LN and the optic fibers F1 to FN are preferably each the same. In addition, optic fibers Fn are bundled and held by a ferrule 12 on the output side of the dental treatment apparatus 1.
A first light emitting element Sn is an element which emits laser light at a specific wavelength λ1 within the range of 400 nm to 420 nm, and preferably includes a semiconductor laser element which outputs laser light having a specific wavelength λ1 within the range of 400 nm to 420 nm. A first focusing lens Ln is that in which both lenses are convex lenses, is arranged between the first light emitting element Sn and an optic fiber Fn, focuses light output from the first light emitting element Sn and causes said light to enter the incident end of the optic fiber Fn. The optic fiber Fn is provided on a 1:1 basis with respect to the first light emitting element Sn and the first focusing lens Ln, the incident end of the optic fiber Fn is optically connected to the first light emitting element Sn via the first focusing lens Ln, and the emergent end is bundled and held with the ferrule 12.
The temperature detection unit 20 is constituted by a non-contact temperature sensor 22 and a wire 24. More specifically, the non-contact temperature sensor 22 is attached to the emergent end of the optic fiber Fn of the irradiation unit 10, and detects in a non-contact manner far infrared light emitted from a site (irradiated site) irradiated with laser light output from the emergent end. In addition, the non-contact temperature sensor 22 is connected to the control unit 30 via the wire 24. Thus, temperature data detected with the non-contact temperature sensor 22 is transmitted to the control unit 30 through the wire 24.
The control unit 30 is provided on the side of the first light emitting element Sn of the dental treatment apparatus 1, and control the power of light output from each of the N number of the first light emitting elements S1 to SN. Namely, the control unit 30 adjusts the on/off time of laser light output from, for example, the first light emitting element Sn based on the temperature result of an irradiated site detected with the non-contact temperature sensor 22 and transmitted by the wire 24, and controls the power of output laser light by changing the irradiation intensity of the laser light output from the first light emitting element Sn over time.
Here, an explanation is provided of treating both dental hard tissue and soft tissue with laser light having a specific wavelength of 400 nm to 420 nm used in the dental treatment apparatus 1.
Dental hard tissue is composed of dentin, enamel and cementum, and the majority is composed of dentin and enamel. Dentin is the main component of dental hard tissue, and its components consist of 69% inorganic matter, 18% organic matter and 13% water. On the other hand, enamel is composed of 96% inorganic matter, 2% organic matter and 2% water.
On the other hand, 80% of the tissue components of dental soft tissue (such as the gingiva) is water. In order to incise soft tissue with laser light while effectively maintaining hemostasis, laser light having a wavelength at which absorption by water is to a certain extent low while having a certain extent of tissue penetrability is suitable. As shown in
The following provides an explanation of a dental treatment method using the above-mentioned dental treatment apparatus 1.
First, an explanation is provided of cutting dentin in the case of treating dental hard tissue. A dentin treatment site is irradiated with laser light having a specific wavelength of 400 nm to 420 nm using the dental treatment apparatus 1. At this time, the energy of the laser light is absorbed by protein in the dentin and is instantaneously transformed into thermal energy resulting in transpiration of the dentin. As a result, the dentin can be cut. Furthermore, it is preferable to intermittently irradiate the treatment site with the laser light so as to prevent the occurrence of cracks or carbonization in the tooth caused by the high level of heat at this time. Namely, the dentin of teeth is susceptible to the occurrence of cracking and carbonization by heat in the case of continuous irradiation of the dentin beyond that which is necessary. In order to prevent the occurrence thereof, it is preferable to adjust the on/off time of laser light output from, for example, the first laser emitting element Sn, or change the emergent intensity of laser light output from the first light emitting element Sn over time.
On the basis of the above results, the occurrence of cracking and carbonization at a treatment site during treatment of dentin is suppressed by a pulsed irradiation treatment method in which the irradiation on time t1 (t1=0.9 seconds) and the irradiation off time t2 (t2=2 seconds) are repeated at a fixed cycle to intermittently change the irradiation intensity as shown in
In addition, it is preferable to use the non-contact temperature sensor 22 of the temperature detection unit 20 to manage the temperature of the treatment site by detecting far infrared rays emitted from the treatment site with the non-contact temperature sensor 22. More specifically, far infrared rays emitted from the treatment site are detected with the non-contact temperature sensor 22, and the detected results are transmitted to the control unit 30 via the wire 24. The control unit 30 then adjusts the on/off time of the laser light output from, for example, the first light emitting element Sn based on the transmitted temperature results, and changes the emergent intensity of the laser light output from the first light emitting element Sn over time to control the average power of the output laser light. As a result, the temperature rise at the treatment site can be controlled more precisely, thereby making it possible to realize treatment with little damage to normal tissue. Furthermore, even in the case of the pulsed irradiation described above, it is not necessary to irradiate intermittently using fixed values for the irradiation on time t1 and the irradiation off time t2, but rather t1 and t2 may be suitably changed corresponding to the status (e.g., temperature) of the treatment site.
Similarly, when treating dental soft tissue as during, for example, incision into the gingiva, for example, an irradiated site of the gingiva is irradiated with laser light within the wavelength range of 400 nm to 420 nm sing the dental treatment apparatus 1. Since laser light in this wavelength range has high penetrability of soft tissue to a certain extent, in addition to the irradiated site being transpirated and incised as a result of irradiating with the laser light, a denatured layer of a suitable thickness is formed, thereby allowing the obtaining of satisfactory hemostatic effects.
According to the present embodiment, since the dental treatment apparatus 1 is provided with light emitting elements emitting laser light having a specific wavelength of 400 nm to 420 nm, and laser light within this wavelength range of 400 nm to 420 nm is effectively absorbed by protein in dentin, thereby demonstrating suitable penetrability into soft tissue, it is able to treat both dental hard tissue and soft tissue.
In addition, since the dental treatment apparatus 1 is provided with a first focusing lens Ln and an optic fiber Fn corresponding to a first light emitting element Sn on a 1:1 basis, the efficiency of photocoupling from the first light emitting element Sn to the incident end of the optic fiber Fn can be increased. Consequently, laser light output from the first light emitting element Sn is focused by the corresponding first focusing lens Ln, enters the incident end of the corresponding optic fiber Fn, is guided by the optic fiber Fn, and is efficiently emitted to the outside from the emergent end of the optic fiber Fn.
In addition, since the optic fiber Fn is bundled at the emergent end thereof, laser light output from the first light emitting element Sn is focused, the arrangement density of the optic fiber Fn at the emergent end increases, and laser light of a high power density can be obtained, thereby making it possible to anticipate effects which improve the performance and applicability of the dental treatment apparatus 1. The use of the optic fiber Fn not only facilitates propagation of light, but also makes it possible to suppress transmission loss occurring when the light is guided by the optic fiber Fn. In addition, as a result of the optic fiber Fn being bundled at the emergent end thereof, workability during production of the dental treatment apparatus 1 can be improved and handling of the apparatus during treatment becomes easy. Moreover, by using an inexpensive and compact semiconductor light emitting element for the first light emitting element Sn, the size and cost of the dental treatment apparatus 1 can be reduced.
The following provides a more detailed explanation of the first embodiment using examples thereof.
First, as shown in
As a result, although there were no changes observed in the appearance of the dentin attributable to irradiation under the conditions of Example 1, the dentin was confirmed to have been cut under the irradiation conditions of Examples 2 to 4.
According to the above results, laser light irradiated under the conditions of Examples 2 to 4 was verified to have the effect of being able to treat dental hard tissue. Under the irradiation conditions of Example 1, the power density of the laser light was excessively low, thus making these conditions inadequate for treatment.
In addition, soft tissue was cut under irradiation conditions of a laser light wavelength of 405 nm, power of 1.7 W, beam diameter of 270 μm, power density of 30 W/mm2, irradiation time of 1.0 second, and sweep rate of 1.0 mm/s using tuna as a typical example of soft tissue containing a large amount of lipids in Example 5, chicken white meat as a typical example of muscle tissue in Example 6, and liver as a typical example of tissue containing a large amount of hemoglobin in Example 7.
As a result, incisions into the samples were able to be confirmed in Examples 5 to 7 as shown in
Next, an explanation is provided of a second embodiment of a treatment apparatus as claimed in the present embodiment.
The first irradiation unit 40 is constituted by (1) five first light emitting elements 42, which emit laser light having a specific wavelength λ1 within the range of 400 nm to 420 nm, (2) five first focusing lenses 44, which focus laser light output from the first light emitting elements 42, and (3) five first optic fibers (first output means) 46, which guide laser light output from the first light emitting elements 42 and focused by the first focusing lenses 44, input the laser light to incident ends thereof and output the light from emergent ends thereof, respectively combined on a 1:1 basis.
The second irradiation unit 50 is constituted by (1) five second light emitting elements 52, which emit laser light having a specific wavelength λ2 within the range of 800 nm to 1000 nm, (2) five second focusing lenses 54, which focus laser light output from the second light emitting elements 52, and (3) five second optic fibers (second output means) 56, which guide laser light output from the second light emitting elements 52 and focused by the second focusing lenses 54, input the laser light to incident ends thereof and output the light from emergent ends thereof, respectively combined on a 1:1 basis.
The first light emitting elements 42 and the second light emitting elements 52 are elements that emit light, and preferably include semiconductor laser elements that output laser light. The first focusing lenses 44 and the second focusing lenses 54 are lenses in which both sides are convex, and focus laser light having a specific wavelength λ1 emitted from the first light emitting elements 42 and light having a specific wavelength λ2 emitted from the second light emitting elements 52, respectively. The first optic fibers 46 and the second optic fibers 56 are bundled at one end thereof (emergent end), are held by a ferrule 14, and the other ends are optically connected to the first light emitting elements 42 and the second light emitting elements 52 via the first focusing lenses 44 and the second focusing lenses 54, respectively.
In the treatment apparatus 2, the numerical aperture at each emergent end of the first optic fibers 46 and the second optic fibers 56 is preferably less than 0.14. In this case, since the laser light can be focused on a small area, the effect of transpirating a treatment site can be enhanced, and incision efficiency can be improved. Furthermore, although examples of irradiating tissue directly with light output from optic fibers are explained in the aforementioned first and second embodiments, lenses and so on may also be installed on the output ends of these optic fibers as necessary to adjust the laser light. In this case, the numerical aperture at the output ends of the light of the above-mentioned output means refers to the numerical aperture at the output end of the light of the output means immediately prior to irradiating tissue.
Since the structure, installation and so on of the temperature detection unit 20 are the same as the above-mentioned first embodiment, a duplicate explanation thereof is omitted. The control unit 30 is provided on the side of the first light emitting elements 42 and the second light emitting elements 52 of the treatment apparatus 2, and controls the power of laser light emitted from these light emitting elements based on temperature results at the irradiated site detected with a non-contact temperature sensor 22 and transmitted by a wire 24 so as to change the irradiation intensity of the respective laser light output from the first light emitting elements 42 and the second light emitting elements 52 over time.
Here, an explanation is provided of treatment of a treatment site with laser light having a specific wavelength λ1 within the range of 400 nm to 420 nm and laser light having a specific wavelength λ2 within the range of 800 nm to 1000 nm used in the treatment apparatus 2.
Thus, when irradiating a treatment site with laser light having a wavelength of 400 nm to 420 nm, the laser light of that frequency is absorbed by oxygenated hemoglobin contained in large amounts in the blood of soft tissue and is instantaneously transformed into heat, thereby enabling the soft tissue to be efficiently transpirated. As a result, the effect is obtained that allows soft tissue to be efficiently incised. In addition, since laser light of the wavelength indicated above is effectively absorbed by oxygenated hemoglobin, the blood can be made to coagulate easily, thereby enhancing hemostatic effects.
In addition, since laser light having a specific wavelength λ2 within the range of 800 nm to 1000 nm demonstrates a high tissue permeation rate, a denatured layer of a suitable thickness can be formed around the irradiated site, thereby also enhancing hemostatic effects.
The following provides an explanation of examples of using laser light having a specific wavelength λ1 within the range of 400 nm to 420 nm.
As shown in
As a result, as shown in
In addition, better incisability is obtained in the case of laser light having a wavelength of 400 nm to 420 nm with a narrow beam diameter and narrow beam spread angle. This is because, the threshold value of optical output power required for tissue transpiration can be lowered since a smaller beam diameter makes it possible to increase the optical power density of the irradiated portion, and since a narrower beam spread angle makes it possible locally irradiated to a greater depth, power density can be maintained at a high level even at locations deep below the tissue surface, thereby enabling tissue to be incised more efficiently.
Next, an explanation is provided for a treatment method using the treatment apparatus 2.
First, a treatment site is irradiated with laser light having a specific wavelength λ1 and laser light having a specific wavelength λ2 using the treatment apparatus 2. At this time, the treatment site is preferably irradiated first along the scanning direction of the laser light with the laser light having a specific wavelength λ1, followed by irradiating with the laser light having a specific wavelength λ2.
Namely, as shown in
When irradiating the treatment site while scanning with the laser light using the irradiated spot 60 formed in this manner, the treatment site is irradiated with laser light having a wavelength of 400 nm to 420 nm of the periphery 60b of the irradiated spot 60. Consequently, the treatment site is transpirated and incised. As a result of continuing to scan the irradiated spot 60, the treatment site is irradiated with laser light having a wavelength of 800 nm to 1000 nm of the center 60a of the irradiated spot 60. Since laser light having a wavelength of 800 nm to 1000 nm demonstrates a high tissue permeation rate, it demonstrates hemostatic effects on an incised treatment site. Since the treatment site is first irradiated with light having a wavelength of 400 nm to 420 nm in particular, the permeation rate of infrared light of the tissue decreases, while the absorption rate of near infrared light in the wavelength range of 800 nm to 1000 nm in the vicinity of the incision increases. As a result of then irradiating the treatment site previously irradiated with laser light at 400 nm to 420 nm with laser light having a specific wavelength λ2, the laser light having a specific wavelength λ2 is absorbed more effectively, thereby further enhancing hemostatic effects at the treatment site.
In this manner, by combining the use of laser light having a specific wavelength λ1 and laser light having a specific wavelength λ2, better treatment site incisability and hemostatic effects can be simultaneously obtained than in the case of irradiating with either laser light alone. Furthermore, when irradiating a treatment site, laser light having a specific wavelength λ1 and laser light having a specific wavelength λ2 may be irradiated simultaneously or alternately.
In addition, when irradiating with the laser light, the power of the laser light output from the first light emitting elements 42 and the second light emitting elements 52 is preferably respectively controlled by means of the control unit 30 based on the temperature at the treatment site detected by the temperature detection unit 20 in the same manner as in the first embodiment, or the irradiation intensity of the laser light output from these light emitting elements is preferably changed over time. In this case, by adjusting the irradiation intensity of the laser light in conformity with the treatment site, the occurrence of cracks and carbonization at the treatment site, which occur easily in the case of continuous irradiation, can be suppressed while also enabling damage to normal tissue at locations other than the treatment site to be suppressed.
The following provides an explanation of variations of the irradiated spot 60 formed by laser light output from the first optic fibers 46 and the second optic fibers 56 with reference to
In the variation shown in
In the variation shown in
Furthermore, the present invention is not limited to the above-mentioned embodiments. For example, although the explanation of the first embodiment used the example of a dental treatment apparatus 1 for the treatment apparatus, the treatment apparatus is not limited to the dental treatment apparatus 1, but rather can also be used as a semiconductor laser scalpel or other treatment apparatus.
In addition to being able to treat both hard tissue and soft tissue at a treatment site, the treatment apparatus and treatment method of the present invention also allows the obtaining of satisfactory hemostatic effects.
According to the present invention, a treatment apparatus and a treatment method can be provided which together with being able to treat both hard tissue and soft tissue at a treatment site, allow the obtaining of satisfactory hemostatic effects.
Number | Date | Country | Kind |
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P2006-112100 | Apr 2006 | JP | national |