Patent Abstract:
A laser therapy device, including: a laser diode that is adapted to produce a monochromatic laser beam; a lens that is adapted to receive the beam directly from the laser diode and exploit the natural divergence of the laser diode to form an essentially coherent monochromatic, collimated beam; wherein the formed beam is adapted to form on a plane perpendicular to the direction of propagation of the beam an elongated illuminated area in which the length of the illuminated area is at least twice the size of the width of the illuminated area; a controller that is adapted to control activation of the laser diode; an encasement enclosing the laser diode, the lens and the controller; wherein the encasement is adapted to be hand held by the user.

Full Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a handheld low energy laser device for treating people and animals. 
     BACKGROUND OF THE INVENTION 
     The use of light for treating people and animals is well known. Since the early history of mankind people have used the light from the sun to help cure ailments. In the mid 20&#39;Th century attempts were made to use concentrated light for treating wounded soldiers in World War II. In later years, the laser, which is based on the quantum phenomenon of stimulated emission, provided an excellent source of concentrated light for treating patients. The laser allows the use of a selected intensity of a monochromatic, and essentially coherent. This has been found to be effective in treating people for various ailments. 
     The use of a carefully selected wavelengths coherently directed toward a person provides energy for selectively stimulating processes in living cells. This can help increase blood flow; excite cell activity and intensify inter-cell communications. Laser light treatments have been applied to various ailments such as: 
     a. Various skeletal and tissue pains and injuries:
         1. Rheumatic and/or chronic joint inflammation;   2. Sport injuries, wounds, and fresh scars;   3. Lower and upper back pain; neck pains:   4. Plantar fasciitis and sprains;   5. Tennis elbow;   6. Achilles tendon infection:   7. Carpal tunnel syndrome;   8. Lymphedema-Edema;       

     b. Medical dermatology:
         1. Acne;   2. Burns;   3. Scars;   4. Hemorrhoids;   5. Vitiligo (e.g. discolored skin);   6. Herpes simplex;       

     c. Aesthetics:
         1. Aging and dermatolysis or the face:   2. Wrinkles;   3. Sensitive skin;   4. Post pregnancy stretch marks;       

     d. dental applications; 
     e. veterinary applications; 
     f. Acupuncture treatments; 
     and other applications. 
     The use of laser light in therapy has been shown to reduce pain, induce anti-inflammatory activity, induce healing processes and induce skin rejuvenation. 
     In the past light therapy has been applied by large, expensive and hazardous equipment which requires application by trained personnel. Thus miniature, user safe laser therapy devices, which can be used at home, are desirous. 
     SUMMARY OF THE INVENTION 
     An aspect of an embodiment of the invention, relates to an apparatus and method for treating people using a handheld low level laser therapy device. The device includes a laser diode that provides a monochromatic single phased laser beam that disperses with a small angle (e.g. between 5-7 degrees) in one direction) and with a larger angle (e.g. between 30-40 degrees) in the direction perpendicular to the first direction. The device exploits the natural divergence of the laser diode to produce a light beam that illuminate a larger area simultaneously with a monochromatic, essentially coherent and collimated light beam. 
     The device includes a lens that turns the laser beam into a collimated beam wherein the rays from the smaller dispersion angle provides a narrow illumination area and the rays from the larger dispersion angle provide an elongated illumination area. Optionally, the elongated illumination area is at least twice the size of the narrow illumination area. In some embodiments of the invention the illumination area forms a rectangular area. Alternatively, the illumination area is an ellipsoidal area. Optionally, the beam provides eye safety as a result of the dispersion, which provides less intensity per unit area. 
     In some embodiments of the invention, the monochromatic laser beam is an invisible infrared beam. Optionally, the wavelength of the laser beam is between 800 to 900 nm. In an exemplary embodiment of the invention, a visible light source (e.g. a LED) is used to provide a supplementary visible light beam to accompany the invisible light beam so that a user will be able to see that the device is active and will not point the device toward his eyes. In some embodiments of the invention, the visible light beam coincides with the invisible laser beam. Alternatively, the visible light beam illuminates an area that surrounds the laser beam forming a frame around the invisible laser beam to enhance user safety. 
     In some embodiments of the invention, the device is activated by an eye safety mechanism that is activated by pressing the light emitting end against the target that is to be illuminated, to prevent a user from shining the laser beam without precaution. Alternatively, or additionally, other activation switches are available on the device. 
     In some embodiments of the invention the laser diode is activated non-continuously when the device is activated, for example with a duty cycle of 50% or less. Optionally, the output power of the laser diode is continuously controlled by a servo loop that monitors the output of the laser diode and updates its duty cycle to maintain a constant power output by the laser beam, for example the pulse length or the frequency of turning on the laser diode are updated responsive to the detected intensity. 
     There is thus provided according to an exemplary embodiment of the invention, a laser therapy device, comprising: 
     a laser diode that is adapted to produce a monochromatic laser beam; 
     a lens that is adapted to receive the beam directly from the laser diode and exploit the natural divergence of the laser diode to form an essentially coherent monochromatic, collimated beam; wherein the formed beam is adapted to form on a plane perpendicular to the direction of propagation of the beam an elongated illuminated area in which the length of the illuminated area is at least twice the size of the width of the illuminated area: 
     a controller that is adapted to control activation of the laser diode; and 
     an encasement enclosing the laser diode, the lens and the controller; wherein the encasement is adapted to be hand held by the user. 
     In some embodiments of the invention, the lens is a toroidal lens having a different lens radius in the direction producing the length of the illuminated area and the direction producing the width of the illuminated area. Optionally, the beam produced by the laser diode is an infrared laser beam. 
     In an exemplary embodiment of the invention, the laser therapy device includes a visible light source that produces a visible light beam that is combined with the laser beam to provide a visible light as an indication of the presence of the invisible laser beam. Optionally, the visible light source is mounted, so that the image of the light source is in the focal plane of the lens. In an exemplary embodiment of the invention, the visible light beam is adapted to surround the invisible laser beam forming a frame enclosing the invisible light beam. 
     In an exemplary embodiment of the invention, the controller is adapted to control the duty cycle of the laser diode. Optionally, the controller is adapted to update the duty cycle of the laser diode to maintain a constant power output although the intensity of the laser diode changes over time. In an exemplary embodiment of the invention, the duty cycle of the beam produced by the laser diode is initially less than 50%. Optionally, the device includes a safety mechanism that activates the device by pressing the device against the illuminated object. In an exemplary embodiment of the invention, the illuminated area forms a rectangular or ellipsoidal shaped area. Optionally, the beam formed is an eye safe beam. 
     There is further provided according to an exemplary embodiment of the invention, a laser therapy device comprising: 
     a laser diode that is adapted to produce a monochromatic laser beam; 
     a lens that is adapted to receive the beam from the laser diode; 
     a controller that is adapted to control the duty cycle of the laser diode and maintain a constant power output; and 
     an encasement enclosing the laser diode, the lens and the controller; wherein the encasement is adapted to be hand held by the user. 
     There is further provided according to an exemplary embodiment of the invention, a laser therapy device, comprising: 
     a laser diode that is adapted to produce a monochromatic laser beam; 
     a lens that is adapted to receive the beam from the laser diode; 
     a controller that is adapted to control activation of the laser diode; 
     an encasement enclosing the laser diode, the lens and the controller; wherein the encasement is adapted to be hand held by the user; and wherein the device is activated by a safety mechanism by pressing the device against the illuminated object. 
     There is further provided according to an exemplary embodiment of the invention, a laser therapy device, comprising: 
     a laser diode that is adapted to produce a monochromatic laser beam; 
     a visible light source that is adapted to provide a light beam that surrounds the beam formed by the laser diode, forming a frame around the illumination pattern formed by the laser beam; 
     a lens that is adapted to receive the beam from the laser diode; 
     a controller that is adapted to control activation of the laser diode; 
     an encasement enclosing the laser diode, the lens and the controller; wherein the encasement is adapted to be hand held by the user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be understood and better appreciated from the following detailed description taken in conjunction with the drawings. Identical structures, elements or parts, which appear in more than one figure, are generally labeled with the same or similar number in all the figures in which they appear, wherein: 
         FIG. 1  is a schematic illustration of a handheld low-level laser therapy (LLLT) device for performing laser therapy, according to an exemplary embodiment of the invention; 
         FIG. 2  is a schematic illustration of an internal structure for manufacturing a low-level laser therapy device that demonstrates the use of the natural divergence of the laser diode and lens configuration, according to an exemplary embodiment of the invention; 
         FIG. 3  is a schematic illustration of an internal structure for manufacturing a low-level laser therapy device with a safety activation mechanism, according to an exemplary embodiment of the invention; 
         FIG. 4  is a schematic illustration of an internal structure for manufacturing a low-level laser therapy device with a combination mechanism to superimpose visible light beam over laser beam, according to an exemplary embodiment of the invention; and 
         FIG. 5  is a flow diagram of a method of controlling the duty cycle of a laser diode, according to an exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a schematic illustration of a handheld low-level laser therapy (LLLT) device  100  for performing laser therapy, according to an exemplary embodiment of the invention. In an exemplary embodiment of the invention, device  100  provides as output an elongated monochromatic coherent laser beam  170  that is collimated by a lens directly from the natural divergence of a laser diode embedded in device  100 . In contrast to prior art devices, instead of focusing the laser beam from the laser diode to a single spot to have a stronger illumination on a single spot, the natural tendency of the laser diode is exploited to form an elongated beam to cover a larger area. The standard laser diode typically has a divergence of about 5-7 degrees along its width and about 30 to 40 degrees along its length. Instead of using a lens to correct the beam to a narrow beam, device  100  uses a lens to form a collimated elongated beam to cover a larger area, for example an area of 3-6 cm by 0.5 to 1 cm. In an exemplary embodiment of the invention, the length of the illuminated area is at least twice the width of the illuminated area. In an exemplary embodiment of the invention, the resulting elongated beam is essentially coherent having a light beam with an essentially common phase as accepted for laser diode emission. 
     Optionally, by illuminating a large area each point is illuminated with a weaker and safer laser beam, for example an eye safe beam, having an intensity, which is not hazardous to a persons eye. More power can be delivered more accurately to a specific area by illuminating for a longer time or increasing the intensity of the laser diode without moving device  100 . In contrast in a single spot laser a single point is illuminated intensely and an area is processed by moving the beam across the user&#39;s skin and illuminating each point. 
     In an exemplary embodiment of the invention, the light sources and electronic circuitry for powering device  100  are encased in an ergonomic encasement  110  designed to fit into a user&#39;s hand. Optionally, device  100  includes an on/off switch  125 , which turns device  100  on and off. When device  100  is in the on state—it may be activated by pressing on an activation switch  130  located on the side of encasement  110 . Alternatively or additionally, device  100  may be activated by pushing eye safety activation switches  105  against the person or object being radiated, when using device  100 . Activation when pressing against the person being radiated increase the safety of device  100  since it will not accidentally allow a user to shine light into the user&#39;s eye. In some cases pressing against the user&#39;s skin is advantageous since it may reduce blood flow and enhance efficiency of the light absorption. Alternatively, in some cases the user may have a wound and it is preferable to not press against the user&#39;s skin. 
     In some embodiments of the invention, device  100  is powered by an internal power source (e.g. batteries  135 ). Alternatively or additionally, device  100  can be powered by an external power source via a power-cable (not shown) that is plugged into an external power source, such as a household power socket. Optionally, when the device is plugged into an external power source the batteries may be recharged. 
     In some embodiments of the invention, device  100  includes a display  115 , for example an LCD display, which shows various information, such as the status of the battery, and/or a timer/counter. In an exemplary embodiment of the invention, the timer on display  115  is set by the user to a pre-selected value using a selector  120 , the value may represent an amount of time in seconds during which the device will remain active when activated by the user. The device will count down and deactivate the device automatically once it counts the pre-selected amount of time. For example if the user whishes to illuminate an area for a specific amount of time, he sets the timer with the desired amount of time and activates device  100 . Device  100  will illuminate the area until the time runs out. 
       FIG. 2  is a schematic illustration of an internal structure for manufacturing device  100  that demonstrates the natural divergence of the laser diode and lens configuration, according to an exemplary embodiment of the invention. In an exemplary embodiment of the invention, a laser diode  210  is mounted onto a base  230 . In an exemplary embodiment of the invention, laser diode  210  is selected to emit infra-red radiation with a monochromatic wave length between 800-900 nm and a power output of at least 100 mw, so that it will be effective in healing the user. Optionally, the wavelength is selected to have optimal performance in providing power to the biological cells of the user, thus it is possible that other wavelengths may be used (e.g. visible light or ultra-violet light) if found to be more effective in dealing with a specific ailment. Additionally, laser diode  210  may be selected having a stronger or weaker power output. 
     In an exemplary embodiment of the invention, the light from laser diode  210  disperses with a small angle  260  in one direction, and with a larger angle  250  in the perpendicular direction. Optionally, a lens  220  is placed opposite laser diode  210  to make use of the natural divergence of the laser beam produced by laser diode  210  by collimating the dispersing laser beam and forming an illumination of the elongated monochromatic coherent laser beam  170  on the skin of the user. 
     In an exemplary embodiment of the invention, lens  220  is a toroidal lens having a different lens radius in two directions, so that the diverging beam formed from laser diode  210  will extend perpendicular to the lens and form an elongated illumination from monochromatic coherent laser beam  170 . In some embodiments of the invention, lens  210  has a rectangular or ellipsoidal shape and creates a rectangular or ellipsoidal illumination. Alternatively or additionally, lens  210  may be a single lens, a double lens or any other combination of lenses as long as it produces the elongated monochromatic coherent laser beam  170  to radiate the user. Optionally, elements other than lenses may affect the unity of phase and direction of the coherent laser beam  170 . 
       FIG. 3  is a schematic illustration of an internal structure for manufacturing device  100  with an eye safety activation mechanism  300 , according to an exemplary embodiment of the invention. As mentioned above, in an exemplary embodiment of the invention, when device  100  is turned on, it can be activated by pressing the eye safety activation switch  105  against the body of the user. Optionally, eye safety activation switch  105  is connected to two sliders  310  and 2 springs  330  are inserted on the sliders one for each side. When eye safety activation switch  105  is pushed into encasement  110  sliders  310  are move inward and depress on two micro-switches  320  that instruct controller  240  to activate laser diode  210 . The use of eye safety activation switch  105  prevents the user from activating laser diode  210  and aiming it toward his eyes or the eyes of another person. 
       FIG. 4  is a schematic illustration of an internal structure for manufacturing device  100  with a combination mechanism to superimpose visible light beam  160  over laser beam  170 , according to an exemplary embodiment of the invention. In an exemplary embodiment of the invention, a visible light source  410  (e.g. a LED) is mounted on a structure  430  above laser diode  210  to provide a visible light source. Optionally, structure  430  includes a polished back surface  420  (e.g. a mirror) to reflect the visible light towards lens  220 , so that it will be superimposed over the light rays originating from laser diode  210 . In some embodiments of the invention, only specific areas on the back surface are polished to control the resulting geometry of the visible light beam. In an exemplary embodiment of the invention, a cross section of the resulting beam includes an inner area formed by laser beam  170  and a larger area formed by visible light beam  160  that surrounds the inner area and provides a visible border around it, so that the user knows where the invisible laser beam is located. 
     Optionally, the visible light beam  160  serves as a safety measure, by providing the user with an indication that the invisible laser beam  170  is also there and may be dangerous if aimed at a person&#39;s eye. 
     LED  410  is preferably mounted, so that the image of the light source is in the focus of lens  220 . 
     In an exemplary embodiment of the invention, laser diode  210  is operated in short pulses at a constant frequency, for example of 10-20 μs with a frequency of 25 KHz providing a 25%-50% duty cycle, so that the resulting laser beam will have enough power to penetrate a users skin but the total energy output rate per area is low enough to maintain eye safety if accidentally shined into a persons eyes. In many devices the laser diode  210  is initially provided with a specific power output that deteriorates over time until the laser diode  210  must be replaced (e.g. after 3000-5000 hours of use). 
       FIG. 5  is a flow diagram  500  of a method of controlling the duty cycle of a laser diode, according to an exemplary embodiment of the invention. 
     In an exemplary embodiment of the invention, laser diode  210  is controlled by a controller  240  that detects ( 510 ) the power output of the laser diode. Optionally, controller  240  compares the power output to a stored value to determine if the power output is within a tolerance range ( 530 ) or if laser diode  210  has become weaker and is underperforming. 
     If the power output is within the tolerance range then the controller continues to periodically monitor the power output of laser diode  210 . Otherwise controller  240  calculates ( 540 ) an amended duty cycle that will provide the desired power output, for example by increasing the pulse length or by raising the activation frequency of laser diode  210 . Controller  240  changes ( 550 ) the duty cycle, so that device  100  maintains a constant power output. Optionally, controlling the duty cycle enables prolonging the lifetime of using device  100  without replacing laser diode  210 , although the intensity of laser diode  210  deteriorates over time. Optionally, the duty cycle may vary from less than 50% to more than 70%, for example from 10% to 100% to maintain a constant power output. 
     In an exemplary embodiment of the invention, a stronger laser diode (e.g. 100-900 mw) is used while providing the same power output as generated by a weaker laser diode (e.g. less than 100 mw) that is continuously on (100% duty cycle). As a result the laser beam is safer even though it is more intense since the beam is on intermittently and the target can cool off between pulses. When applying the beam to a user&#39;s skin the same overall power is delivered over the same amount of time. 
     Based on the above description it should be noted that device  100  includes a number of features that enhance user safety and/or enhance clinical efficiency: 
     1. A visible indication surrounding the laser beam to provide indication of the position of the laser beam; 
     2. A stronger laser beam with a controlled pulse length and duty cycle to prevent eye damage, since the beam is active only for a short period of time in every second; 
     3. A laser beam that is dispersed over a wide area to enable treating larger areas simultaneously with an eye safety light beam; 
     4. A secure activation switch that is only activated when pressing it against the target area. 
     It should be appreciated that the above described methods and apparatus may be varied in many ways, including omitting or adding steps, changing the order of steps and the type of devices used. It should be appreciated that different features may be combined in different ways. In particular, not all the features shown above in a particular embodiment are necessary in every embodiment of the invention. Further combinations of the above features are also considered to be within the scope of some embodiments of the invention. 
     It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined only by the claims, which follow.

Technology Classification (CPC): 1