JPH11267229A - Bone forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for promoting the treatment for a human being under the decrease of bone quantity or in the state of the possible occurrence of the decrease, for example, osteoporosis or bone fracture and for preventing the decrease in the bone quantity in the outer space where only few gravity is operated. SOLUTION: Concerning a device 1 for in radiating with laser beam at the bone forming device for forming the bone by irradiating a target part 3 with laser beam, in the case of a pulse wave oscillation laser device, the pulse width has several hundreds of microseconds to several picoseconds, the repeat frequency is 1 to 100 kHz, the wavelength is 400 nm to 11 μm and the irradiation energy is not more than 10J. In the case of a continuous wave laser device, the wavelength is similar to the pulse wave oscillation laser device, and the irradiation output is not more than 20 W.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

The present invention relates to the promotion of bone formation by laser light. One aspect of the present invention relates to the treatment of degenerative bone disease known as osteoporosis. Humans in which bone loss is occurring or is expected to occur, for example, devices that prevent or increase bone loss in osteoporosis. In the case of a fracture, the device that promotes healing is used. In the space where microgravity acts, it is concerned with a device to prevent bone loss.

[Prior art]

US Pat. No. 4,530,36 discloses a method for guiding fractures and pseudoarthritis by using a pulsed radio frequency signal applied to a patient's skin via a transducer to guide sound waves or the like to a bone lesion to be treated. Methods for treating bone injuries such as are described. This patent is based on the fact that bone has piezoelectricity, and the invention is constructed. Japanese Patent Application Laid-Open No. 7-8565 proposes a magnetic stimulator for treating a bone disease by stimulating a bone by an overcurrent generated in a living body due to a change in current in a coil means placed near the living body. In either case, bone disease is treated by generating electrical potential or current inside the bone by the transmission of mechanical energy generated externally or by direct means. Alternatively, it has been proposed to treat osteoporosis with drugs as seen in Japanese Patent Publication No. 6-49655. Alternatively, exercise therapy is being performed.
Electrical stimulation is used after surgery for early healing of fractures. In outer space, loss of bone mass is inevitable, and only exercises such as gymnastics are performed in the flying object.

[Problems to be solved by the invention]

[0003] Conventionally known methods using a pulsed radio frequency for a bone injured portion have a drawback that the device is large-scale or lacks portability. The laser beam which is a source of the elastic wave and the acoustic wave according to the present invention has a wide usable wavelength band. Therefore, it is a facility for full-scale treatment, a small device which can be used portablely, or an outer space. It is easy to select a laser light generator according to the conditions of use, such as ultra-small devices that can be used in a computer. In addition, various laser light sources, such as recent laser miniaturization technology and high output of semiconductor laser, have become easily available. In any laser bone forming apparatus, it can be realized by selecting the laser irradiation conditions within a certain range so as to generate the necessary elastic waves and acoustic waves.

[0004] The present invention is intended to prevent a decrease in bone mass in osteoporosis by irradiating a laser beam, and to maintain or increase the speed of bone regeneration. The purpose of the present invention is to provide a small, simple and inexpensive method for realizing the prevention of bone loss in space.

The present invention irradiates a living body with a laser beam, whereby an elastic wave or an acoustic wave generated directly at an irradiated site is propagated into the living body, so that a potential or a potential is applied to the inside of a bone lesion to be treated. By generating an electric current, or by causing a part of the laser light, which does not contribute to the generation of the elastic wave or the acoustic wave, to be propagated into the body and scattering and transmitting through the tissue in the living body, the bone damage is caused. The bones, osteoblasts and osteoclasts are transmitted to the bone and the laser beam is irradiated to the bone, thereby activating the bone regeneration mechanism and effectively treating bone injuries. It is what is done.

An object of the present invention is to provide a method and an apparatus for surgically and non-invasively utilizing elastic waves or acoustic energy by laser light irradiation for promoting repair of a bone loss part or a bone damage part such as an osteoporosis part. It is provided.

[0007] A general object of the present invention is to achieve the above object by using an inexpensive and small device which can be used safely and easily by a patient.

[Means for Solving the Problems]

According to the present invention, at least a body tissue adjacent to a bone loss part or a bone damage part is irradiated with a laser beam by irradiating an extracorporeal surface part with an elastic wave or an acoustic wave generated in a living body irradiation part. The above-mentioned object is achieved by irradiating a site or a plurality of sites with a laser beam and transmitting the elastic wave or acoustic energy surgically, non-invasively, and percutaneously. Alternatively, directly, the present invention can be diagnosed as having reduced bone mass in the lower limb, upper limb, and spinal column, or has good permeability in living tissue at sites expected to be reduced, such as the femoral neck, humeral neck, and vertebrae, and In the irradiating section, laser light having laser irradiation conditions that facilitate the generation of elastic waves or acoustic waves is radiated from above the skin to the vicinity of the above-mentioned portion, thereby preventing bone loss or preventing bone loss. The above objectives can be achieved by maintaining regeneration speed and increasing bone mass.

In the method of irradiating a laser beam, in a special treatment table, a bed or an irradiation device, a laser beam is irradiated downward from a target site.
This is achieved by providing means that can irradiate from above and from the side.

[Action]

It is well known that sound is generated when an object is irradiated with light. The fact that light is absorbed in an object is due to the fact that an absorbing substance corresponding to the wavelength of light is present in the substance. Such absorbers absorb light by free electrons in general metals and semiconductors, or by the natural vibration of the molecules that make up the object. Alternatively, it is also absorbed by inclusions that absorb a specific wavelength. In living tissues, water molecules or hemoglobin, melanin, oxyhemoglobin, etc. that absorb a specific wavelength are well known. The absorption of the laser beam having a high energy density in a short time by the absorber causes rapid thermal expansion of the irradiated portion, and as a result, generates mechanical stress in the living body.
It has been experimentally confirmed that intermittent irradiation of an object with a laser beam generates an elastic wave or an acoustic wave depending on the energy of the light (van Kessel).
and Siegel, Phys. Rev .. Let
t. 33: 1020, 1974). However, if the irradiation energy density exceeds a certain value in a short period of time to the absorber, rapid thermal expansion occurs at the irradiation site, resulting in an action such as destruction or loss of living tissue at the irradiation site. Close. Therefore, appropriate control of the laser beam energy density for such an irradiation part is an important requirement of the present invention.

Physiologically, bone is constantly resorbed and regenerated, called remodeling, to repair microfractures. Decreased momentum, reduced mineral intake, postmenopausal women, and microgravity spaces such as outer space cause bone resorption, resulting in bone loss.

It has been reported that calcium deposition is observed early when mechanical vibration is applied to osteoblasts, and that osteoblasts are activated by irradiating osteoblasts with low-power laser light. In addition, Nishisu et al. Mentioned that extracorporeal shock waves act on bone during growth, such as callus induction, osteocortical and diaphyseal width increase, overgrowth induction, and epiphyseal early closure. Annual Shock Wave Symposium Proceedings, pp. 429-432). Applications of extracorporeal shock waves in the field of orthopedic surgery include the treatment of pseudojoints (Valchanoue).
tal, Int. Ortho. 15: 181, 199
There is a report of 1).

According to an experiment using rabbits by the shock wave method, it is said that a shaved image of the bone cortex of the inner and outer periosteum appears, and a volcanic callus with a central depression is formed on the outer bone side of the outer cortical bone. He says that side effects include fractures. This phenomenon is evident from the destruction of gallstones and uroliths by extracorporeal shock waves and the consequent treatment, as the binding energy of the constituents that connect the bone tissues similar to gallstones and uroliths is increased by the shock waves. Of course, it is expected when it is powerful enough to be destroyed. Or, this fact indicates that shock waves emitted from outside the body surface easily pass through the body's constituents, such as muscles and organs, and directly act on hard tissue objects such as bones.

On the other hand, it is well known that when an acoustic wave, an elastic wave, a shock wave or a strain is transmitted to a bone, a potential is generated inside the bone. This suggests that part or all of the bone tissue is composed of components similar to the crystal structure that causes piezoelectricity, but the resulting microcurrent is affected by the metabolism of the bone tissue, As a result, it corresponds to the regeneration of bone tissue. Therefore, from another point of view, the present invention does not require that the mechanical energy applied to the bone be strong enough to destroy the binding energy of the bone tissue, and to generate a weak electric potential in the bone tissue. It is important that the transmission of mechanical energy to the extent that it occurs is sufficient.

In the present invention, the bone mass of the item is increased, and at the same time, the appearance of a scraped image of the cortex of the inner and outer periosteum of the item and the prevention of the formation of a volcanic callus with a central depression outside the outer cortical bone are realized. It provides a method for Laser irradiation can easily be performed from multiple directions, and can use elastic waves in multiple directions as a source, thereby overcoming the disadvantages of the shock wave method.

The present invention aims to prevent or increase bone loss in osteoporosis by irradiating a laser beam, to promote healing in fractures, or to reduce bone loss in space where microgravity acts. It is possible to realize prevention.

It can be experimentally confirmed that an elastic wave is generated by the irradiation of the laser beam. That is, a YAG laser with a pulse width of about 10 nanoseconds is embedded with a sensor that can detect weak pressure near the surface of the pig femur slightly away from the irradiated area and in the area slightly away from the transmitted light part on the back side of the irradiated area. Is irradiated. At this time, the laser energy density was 10 mJ / cm ² and the peak output was 1 MW. As a result, the sensor output near the irradiated surface showed a tensile displacement immediately after the irradiation, a compressive displacement after a lapse of time, and the sensor output at the back surface showed the opposite correspondence to the above sensor signal.

An outline of an animal experiment showing bone formation by laser light will be described. SD rats (10-week-old, female) were used as the animals, and the rats were reared for 17 days in a suspension-relieving device.
Pulse wave laser light (YAG laser: wavelength 1064)
nm, repetition frequency 10 Hz, irradiation time 10 minutes), the irradiation group (13 m
J / cm ² / pulsc), one irradiation group on day 8 (outside: 13 mJ / cm ² / pulse), two irradiation groups on day 8 (7.5 mJ / cm ² / pulse), and 17
The day suspension and non-suspension and non-irradiation groups were used as suspension control.
On the 18th day from the start of suspension, the femur of the rat was sliced to a thickness of 1 mm and the state of bone formation was observed. Tetracycline (1.0 mg / 100 g body weight) was used as an indicator of bone formation.
Intraperitoneal administration was performed on days 7 and 13 of the 7 days. Bone formation was assessed by microscopy, X-ray fluorescence microscopy, or by observing the fluorescence of tetracycline at the bone formation. As a result, the bone formation was highest in the irradiation group twice daily at both the central part of the femur and the end part of the femur.

Irradiation Method The method of irradiating the laser beam is as follows.
Alternatively, the light can be split or the light from another laser device can be irradiated from opposite or multiple directions. Alternatively, when irradiating two or more laser beams, each laser pulse can be emitted simultaneously or at a different time.
Optical fibers can also be used to guide light. Alternatively, when irradiating two or more laser beams, each laser beam can use the same or different wavelength.

BEST MODE FOR CARRYING OUT THE INVENTION

(1) As laser light as a source of elastic waves and acoustic waves to be propagated to bones, the laser light is absorbed in a living body,
Laser light in the wavelength band that causes thermal expansion of the tissue at the absorption site is used. (2) The typical absorption band of the tissue in the living body is OH in the ultraviolet region.
Absorption bands, hemoglobin and oxyhemoglobin in the visible region, and OH absorption in the infrared region are well known. (3) Various photosensitive dyes (porphyrins and their derivatives) administered from outside the body have absorption bands in the ultraviolet and visible regions. (4) Therefore, the usable laser light is from 400 nm to 11
It exists over a wide range of μm or more. However, laser light in the 2.94 μm or 10 μm band, which has extremely strong OH absorption, may cause problems such as evaporation and damage of the irradiated area if the laser energy per irradiation is increased, so care must be taken. . Therefore, in order to safely and easily generate elastic waves and acoustic waves on the surface of the irradiated living body, it is necessary to control the irradiation conditions of the laser beam appropriately. (5) As a simple method for defining the interaction between a laser beam and a substance, the energy density per irradiation (J / c
m ² ), laser output intensity (W / cm ² ), and action time. (6) As described above, it is important to generate an elastic wave and an acoustic wave in the living body irradiation part by the laser beam, and avoid generating excessive mechanical energy or causing damage to the irradiation part. There must be. Therefore,
As a means of selecting these irradiation conditions, it is necessary to appropriately select the energy density, laser output intensity, and operation time. (7) As a requirement for facilitating generation of elastic waves and acoustic waves, the magnitude of laser output intensity contributes more than the magnitude of energy density. Furthermore, in order to avoid damage to the irradiation site, it is necessary to select the action time as short as possible and the irradiation energy density as low as possible. (8) As a method of easily configuring such laser irradiation conditions, a method of selecting a laser light generating means as pulse light is useful. However, even for continuous light, the laser light output (w), irradiation area, and irradiation time are set so that the irradiation conditions can be appropriately selected and the prescribed energy density, laser light output intensity, and operation time can be set appropriately. Can be easily realized. (9) Another useful feature of the laser light is that the laser light can be easily guided to a fiber which is a thin glass medium. This feature enables multiple light guides to the target site, easy light guide to any location, and provides extremely simple means for irradiating the living body. (10) As another means of promoting the bone formation activity by the elastic wave and the acoustic wave by the laser beam irradiation, the irradiation method at a plurality of places is also effective to make the action on the target bone more effective. (11) The number of laser irradiations that promote bone formation can be achieved once or more times a day, or once or more times every few days, or by other means. These methods are not theoretically available; rather, it is practical to clinically determine the irradiation conditions for each target site, and therefore clearly define the number of actions that define their effects. You cannot do that.

[Brief description of the drawings] 【Example】

FIG. 1 shows a schematic view of an osteogenic device of the present invention.

FIG. 2 shows a schematic diagram of the irradiation method.

FIG. 3 shows the relationship between the laser light emission times.

FIG. 4 shows a schematic diagram of a method of irradiating a human. A is the limb, B is the style used for back and whole body irradiation

[Explanation of symbols]

FIG. 1 is a device for generating a laser beam having a wavelength of 400 nm to 11 μm, 2 is an optical fiber, and 3 is an object to be irradiated.

FIG. 2 is an irradiation target, and A-J are irradiation directions of a laser beam to a subject. A, G, C, B are directions of one-way irradiation. AB irradiation is irradiation on the same optical axis, AG, BG,
The combination of BC, GC and AC is off-axis irradiation.

FIG. 3 shows A, B, C, and D, each of which indicates a laser light emission time.
In B and C, the light is emitted with a delay of t ₁ and t ₂ from the light emission of A.

FIG. 4 is an irradiation target

Claims (5)

[Claims] 1. A bone forming apparatus characterized in that a bone is formed by irradiating a laser beam, wherein the apparatus for irradiating the laser beam has a pulse width of several hundred micrometers in a pulse wave oscillation laser apparatus. Seconds to several picoseconds, repetition frequency from 1 to 100 kHz, wavelength from 400 nm to 11
μm, irradiation energy of 10 J or less, and a continuous wave laser device having a wavelength and irradiation power of 20 W or less similar to that of a pulsed wave oscillation laser device. 2. The method of irradiating a living body with a laser beam in one direction with respect to a target part, or in two or more directions, on the same irradiation axis or off-axis, or on a semicircle or concentric circle. 2. An osteogenic device according to claim 1, wherein said device comprises an irradiating means. 3. A method of irradiating a plurality of laser beams, wherein each laser beam is different from the laser beam having the same wavelength, and each laser beam is irradiated at a different time from the method of simultaneous irradiation. An osteogenic device according to claim 1 or 2. 4. When irradiating a living body with a laser beam, an object which absorbs a small amount of the laser beam can be brought into contact with the surface of the living tissue, and is provided with means for preventing light reflection. An osteogenic device according to any one of claims 1 to 3. 5. An osteogenic device as claimed in claim 1, comprising an effective amount of laser light energy required for the osteogenic process to substantially restore and maintain the osteogenic rate.