Abstract:
A device for laser treatment of painful symptomatologies with a first laser source  1,  a conveying device for conveying the laser energy to a hand unit  5,  and optical structure  11, 13  for defocusing the laser beam.

Description:
This is a continuation-in-part of application Ser. No. 08/798,515 filed Feb. 10, 1997, and the entire disclosure of this prior application is considered to be part of the disclosure of the accompanying application and is hereby incorporated by reference therein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a device for local treatment of symptomatologies by means of laser application, for example for use in physiotherapy. 
     BACKGROUND OF THE INVENTION 
     Use of lasers in medical and aesthetic applications is known. 
     In the more strictly therapeutic sector, the laser is used, for example, for conveying, through an endoscope and an optical fiber, a high-density beam of energy to the inside of an organ for the destruction of polyps by hyperthermia. 
     In the aesthetic field, the laser is used with low energy levels for anti-ageing treatment of the skin. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     Essentially, the present invention is based on recognition of the fact that by applying an appropriately defocused laser beam within an appropriate range of wavelengths at given points of the epidermis of a patient afflicted by painful symptomatologies of various origins (deriving, for example, from past and recent traumas, arthrosis or rheumatism), the stimulation of the nerve ends by means of the incident energy causes a gradual reduction in, and in the end the disappearance, of the pain. 
     Therefore, the subject of the present invention is a device for laser treatment of painful symptomatologies, which comprises a first laser source, a first means of conveying the laser energy to a hand unit, and optical means of defocusing the laser beam which are positioned in the path of the laser beam. 
     Advantageously, the conveying means is constituted by an optical fiber, in front of the output end of which the optical means of defocusing are arranged. 
     It has been observed that particularly consistent effects and therefore rapid results in the reduction of painfll symptomatology are obtained by using a pulsed source which emits at a wavelength between 750 nanometers and 2.5 micrometers and preferably between 900 nanometers and 1.2 micrometers and with an energy level from 30 to 300 mjoules per pulse, and preferably between 100 and 200 mjoules per pulse. A particularly suitable laser source is the NDYAG laser with a wavelength of 1.06 micrometers. The frequency of the pulses as well as their duration are also parameters which have a considerable influence on the effectiveness of the treatment. It has been observed that the optimum frequency may optimally be selected between 10 and 40 Hz and preferably between 15 and 25 Hz for pulse durations which can vary between 100 and 200 microseconds. It is also preferable that only a single wavelength, for example 1.064 micrometers, be used to irradiate the body and treat the painful symptomatologies. 
     The hand unit can be held at the appropriate distance from the epidermis of the patient undergoing treatment by the operator. In order to make use safer and easier for the operator, however, the hand unit is in a preferred embodiment provided with a distance element to hold said optical means of defocusing at a predetermined distance from the body of a patient to whom the treatment is being applied, avoiding the necessity of determining and manually maintaining the optimum distance. 
     Again for the purpose of facilitating use of the device, it can be provided with a second laser source which emits at a wavelength in the visible range, and optical fiber or equivalent means for conveying the laser beam generated by said second source towards the hand unit. 
     The points where the application of the laser energy affords the major benefits, known as trigger points, are determined by the anatomical characteristics of the body. These are located, for example, in the region of the join between muscle and tendon. There is normally also a reduction in the thickness of the skin in this zone. Determination of the trigger point can be carried out on the basis of experience but this requires adequate knowledge of anatomy and can complicate the use of the device. Therefore, for the purpose of eliminating these disadvantages and of making the device easier to use, according to a particularly advantageous embodiment, a trigger point detector is provided, operating for example by measuring the resistance through the epidermis. In the region of the trigger points, in fact, resistance falls from normal values of around 200 kohms to values of a few kohms. 
     In one possible embodiment, the trigger point detector comprises a pair of electrodes associated with the hand unit, which during use are kept in contact with the body of the patient undergoing treatment and are connected to means for measuring the electric resistance between the electrodes. The measuring means bring about the generation of a control signal which orders the emission of a pulse or of a series of pulses from the laser source in the region of the detection of a trigger point. 
     The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS IN THE DRAWINGS: 
     The single FIGURE shows the hand unit of the device and, diagrammatically, the laser sources and the control systems. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the attached diagrammatic drawing,  1  indicates a laser source, for example, a NDYAG laser with emission at 1.06 micrometers, connected by means of an optical fiber  3  to a hand unit  5 . Inside the hand unit, the output end  3 A of the optical fiber  3  is fixed by means of an elastic sleeve  7  and a clamping nut  9 . Arranged facing the end  3 A of the optical fiber  3  is a defocusing optic  11 ,  13 . 
     The hand unit  5  ends in a converging end  5 A to which is fixed a distance piece  15  with a surface  15 A which is brought into contact with the epidermis E of the patient to whom the treatment is being applied. In this way, the defocusing optic  11 ,  13  is always held at a predetermined distance from the epidermis. In this way, once fixed, the energy is determined only by the energy density. 
     A second laser source  17  which emits continuously at a wavelength in the visible range introduces a laser beam into the fiber  3  by means of an auxiliary optical fiber  19 , a connector  21  and a mixer. As an alternative and equivalent, the second laser source can send the laser beam into a known device for coaxial mixing of the two laser beams. The two beams made coaxial are then sent to a known device for introduction into the fiber. 
     In this manner, the treatment zone is illuminated and can be seen by the operator in the presence of the distance piece  15  also if this is open or made of a transparent material. 
     Associated with the distance piece  15  are two electrodes  23 ,  25  connected to a resistance measuring device  27 . This measures the resistance of the epidermis in the region of the zone of application of the hand unit  5  and, by means of a trigger signal generator  29 , generates a control signal for the laser source  1  in such a manner that the latter emits pulses at the frequency and of the duration desired when the hand unit  5  is in the region of a trigger point, where the resistance measured by the measuring device  27  is lower. 
     It is intended that the drawing shows only an exemplary embodiment which is given only by way of practical demonstration of the invention, it being possible for the invention to vary in form and arrangement without moreover leaving the scope of the idea which forms the invention itself. 
     While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.