WO2004007023A1

WO2004007023A1 - A handpiece for tissue treatment

Info

Publication number: WO2004007023A1
Application number: PCT/DK2003/000491
Authority: WO
Inventors: Casper Dolleris
Original assignee: Asah Medico A/S
Priority date: 2002-07-11
Filing date: 2003-07-11
Publication date: 2004-01-22
Also published as: AU2003242517A1

Abstract

A handpiece for tissue treatment using a light source is provided wherein the handpiece only has an optical interconnection to the light source and no electrical interconnection to the light source. The handpiece comprises means for receiving a first light beam emitted from a light source, a sensor for measuring beam parameters of the first light beam, processing means for analyzing the measured beam parameters, and for producing one or more corresponding output, and means for deflecting the first light beam into a treating light beam and for directing the treating light beam towards a target area so that the handpiece is adapted to be operated on the basis of the one or more produced output from the processing means. Hereby, electrical adaptation between handpiece and light source is avoided. Furthermore, a method for tissue treatment using such a handpiece is provided.

Description

A HANDPIECE FOR TISSUE TREATMENT

TECHNICAL FIELD

The present invention relates to a handpiece for tissue treatment using a light source, the handpiece having only an optical interconnection to the light source and no electrical interconnection to the light source. Furthermore, the present invention relates to a method for tissue treatment using such a handpiece.

BACKGROUND OF THE INVENTION

It is known to use a handpiece, e.g. in combination with a scanning device, for tissue treatment, such as described in US 6,190,376, US 6,074,382, and in US 6,383,177 hereby incorporated by reference. However, in known handpieces information is transferred from the light source to the handpiece. The information is typically transferred as electrical signals from the light source to the handpiece and since the information provided is far from standardized between different suppliers of light sources, such as different laser suppliers, it is often a laborious task to modify a receiver positioned in the handpiece so as to be able to read and interpret the information provided by the specific light source.

The information transferred from the light source typically comprises all kinds of information about the light source and the interconnection itself, such as optical power, wavelength, dwell time, pulse duration, duty cycle, optical loss, such as attenuation, in the optical delivering fiber, etc. Furthermore, the light source may provide a start signal to the handpiece for activation of the treatment.

Furthermore, the light source is often used as the power supply for the handpiece incurring necessary modifications of the power supply set-up in the handpiece so as to correspond to the power supplied by the light source.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a handpiece comprising no electrical interconnection to the light source.

It is a further object of the present invention to provide a handpiece connected to a light source providing only a light beam to the handpiece. It is an even further object of the present invention to provide a handpiece having no information transferred from a connected light source.

It is a still further object of the present invention to provide a handpiece for tissue treatment wherein no electrical adaptation of the handpiece to the actual light source is necessary.

It is still another object of the present invention to provide a handpiece comprising sensors for obtaining information about the light beam emitted into the handpiece.

The above and other objects are obtained by the present invention, which according to a first aspect provides a handpiece for tissue treatment comprising:

means for receiving a first light beam emitted from a light source, - a sensor for measuring beam parameters of the first light beam, processing means for analysing the measured beam parameters, and for producing one or more corresponding output, and means for deflecting the first light beam into a treating light beam and for directing the treating light beam towards a target area,

wherein the handpiece is adapted to be operated on the basis of the one or more produced output from the processing means.

According to a second aspect of the present invention, a method of treating a tissue target area is provided, the method comprising the steps of:

receiving a first light beam emitted from a light source, measuring beam parameters of the first light beam, analysing the measured beam parameters and producing one or more corresponding output, and deflecting the first light beam into a treating light beam in accordance with the one or more produced output, thereby directing the treating light beam onto the target area.

The light source may comprise a coherent light source, such as a laser device, such as a C0₂ laser, a YAG laser, such as an Erbium YAG laser, a Holmium YAG lasers, a Nd YAG laser, etc., a semiconductor laser, such as a laser diode, a pulsed laser, a gas laser, a solid state laser, a Hg laser, an excimer laser, an Optical Parametric Oscillator (OPO) laser, a metal vapour laser, etc. Alternatively, the first light source may be a non-coherent light source, such as a lamp, a light bulb, a flash lamp, etc. Furthermore, the light source may comprise any number of coherent or non-coherent light sources.

It is preferred to adapt the components of the handpiece, such as the deflecting means, to the specific wavelength or the specific spectrum of the light source used. The light source may emit waves having a wavelength in the infrared part of the electromagnetic spectrum, such as in a wavelength range from 0.75 μm to 100 μm, such as in a near infrared part of the spectrum, such as from 0.75 μm to 1.5 μm, such as in a middle infrared part of the spectrum, such as from 1.5 μm to 30 μm, such as in a far infrared part of the spectrum, such as from 30 μm to 100 μm, in the visible part of the electromagnetic spectrum, such as in a wavelength range from 0.390 μm to 0.770 μm, and in the ultraviolet part of the electromagnetic spectrum, such as from 10 nm to 390nm, such as in the near ultraviolet part of the spectrum, such as from 300 nm to 390 nm, such as in the far ultraviolet part of the spectrum, such as from 200 nm - 300, such as in the extreme ultraviolet part of the spectrum such as from 10 nm to 200 nm.

Presently, lasers are a preferred light source and the light beam emitted from the laser is preferably coupled into an optical fiber delivering the light beam to the handpiece.

Present C0₂ lasers emit light at a wavelength of 10600 nm. The C0₂ laser is particularly well suited as a light source in an handpiece for ablating dermal cells as water has a high energy absorbance at 10600 nm and the C0₂ laser is capable of reliably delivering the required laser power.

Erbium YAG lasers emit light at a wavelength of 2930 nm. Water absorbs less energy at this wavelength that at 10600 nm. Therefore, the Erbium YAG laser may be preferred for ablating thinner layers of dermal cells than may be ablated with a C0₂ laser. Tissue having been treated with light emitted from an Erbium YAG laser may heal faster than tissue having been treated with C0₂ laser light as a thinner layer of dermal cells is influenced by Erbium YAG laser light. An Erbium YAG laser may also be preferred when photocoagulation of blood vessels is to be avoided.

A CO laser emits light in the 4500 nm to 5500 nm wavelength range. Water absorption at these wavelengths is somewhat less than water absorption at 10600 nm. A CO laser light source is presently preferred for dental treatment, e.g. for removal of carries, as dentine is not influenced by illumination of light from a CO laser. A Nd Yag laser emits light at a wavelength of 1060 nm and is well suited for hair epilation by selective photothermolysis, since light at this wavelength causes local heating of the hair bulb due to absorption of the light in the oxyhemoglobin contained in the capillaries.

A Nd YAG laser with a frequency doubled output beam in the 520-680 nm wavelength range is presently preferred as a light source for treatment of hypervasculation. Light in this wavelength range causes photocoagulation of blood without affecting surrounding tissue provided that an appropriate intensity of the light beam is directed towards the micro vessels for an appropriate period of time. Coagulation stops blood flow in the treated vessels whereby discoloration of the skin also stops.

A solid state diode laser emitting a wavelength of 810 nm is presently preferred for hair epilation by selective photothermolysis as this wavelength is absorbed by the melanin contained in the hair shaft. The hair bulb is thus damaged due to heat transportation through the hair shaft.

Typically, a power density greater than about 50 W/mm², such as a power density in the range from about 50 W/mm² to about 180 W/mm², is adequate for vaporizing cells with a minimum of damage to the surrounding tissue.

Generally, the power density is adapted to the wavelength and the intended treatment of tissue at the target area.

The deflecting means may comprise any optical component or components suitable for deflecting light emitted from the light source, such as mirrors, prisms, diffractive optical elements, such as holograms, grids, gratings, etc.

The deflecting means are preferably movably mounted for displacement of the deflecting means as a function of time, so that the light beam emitted from the handpiece, i.e. the treating light beam, may traverse a target area along a desired curve or path while the handpiece is kept in a fixed position. Preferably, the deflecting means are rotatably mounted, and the actual deflection of the light beam is determined by the current angular position of the deflecting means.

Deflecting moving means, such as actuators, such as piezo electric crystals, may be utilised to control positions of the deflecting means, the displacement of the deflecting means is controlled by applying a specific electric voltage to electrodes of the deflecting moving means. The deflecting moving means may comprise electromotors generating linear or rotational displacements, galvanometers, magnetically activated or controlled actuators, pneumatic actuators, hydraulic actuators, etc.

The positions of the deflecting means may be controlled by deflecting control means adapted to control the deflecting moving means so that the deflecting means deflect the light beam in such a way that the light beam traverses a target area along a desired curve or in a predetermined pattern, (see for example US 6,190,376).

The deflecting means may for example comprise two mirrors for deflecting of the light beam in two dimensions, and the deflecting moving means for the mirrors may be constituted by electromotors, e.g. each mirror may be directly connected to a shaft of a corresponding motor, whereby each motor is used for angular positioning of the corresponding mirror. Alternatively, the deflecting means may comprise a single mirror being able to move independently in two directions. The mirror may then be positioned facing downwards, thus reducing the amount of dust on the mirror surfaces since dust will not naturally settle on a mirror surface facing downwards.

When the handpiece is kept in a fixed position in relation to a target area, and is emitting a treating light beam towards the target area, changing of the position of the deflecting means causes the treating light beam to traverse or scan the target area along a curve. An area may be traversed or scanned by the treating light beam, e.g. by letting the treating light beam traverse or scan a meander-like curve substantially covering the area or, by traversing or scanning the area line by line. In the present context, the type, number and shape of curves traversed by the treating light beam in order to traverse a specific area are denoted the traversing pattern or the scan pattern. The area that is scanned or traversed by the treating light beam is denoted the scan area, the treatment area or the traversed area.

A light source for providing a visible aiming light beam may be provided, either in the handpiece or in combination with the first light source and be provided to the handpiece via a fiber. The aiming light beam may be adapted to be traversed around at least a part of the circumference of the target area thereby indicating the size, shape and position of the target area to be traversed with the treating light beam. When a polygonal shape of the target area has been selected, the visible light beam may, e.g. between traversing by the treating light beam, be traversed along one edge of the polygon. The aiming light beam is of particular interest when the treating light beam is invisible. The aiming light beam may then assist the operator by indicating areas towards which the invisible light beam is directed during traversing. A second light source may provide the aiming beam. A handpiece is a single unit for conveniently holding in one hand by an operator of the handpiece.

It is preferred to alert the user or operator of the handpiece by alerting means, so that e.g. a beep is emitted from the alerting means when the target area has obtained a predetermined irradiation, e.g. measured as treatment time, number of light pulses, accumulated light pulses, fluence, etc., or when the target area has been traversed by the treating light beam.

The handpiece may furthermore comprise means, such as a shutter, so that the first light beam or the treating light beam may be turned on and off at the handpiece, without turning on and off the light source. The shutter may be positioned in the beam path of the first light beam or the treating light beam, so that when the shutter is in a closed position, the beam is prevented from passing the shutter, thereby preventing unintended radiation, and when the shutter is in an open position, the beam is allowed to pass, thereby allowing treatment of the target area.

The shutter may, thus, be provided to shut off the first light beam when the target area has been traversed by the treating light beam according to the predetermined pattern.

Furthermore, the shutter may be operated on the basis of an output produced by processing means analysing measured beam parameters, such as wavelength, intensity, dwell time, pulse duration, duty cycle, etc., of the first light beam. The measured beam parameters may be provided by a sensor connected to the processing means. The sensor may for example be a sensor for measuring the power of the first light beam, and the processing means may analyse the measured power, the spot size irradiated by the treating light beam (which spot size may be predetermined), etc., and further operate the shutter according to a corresponding output, the output, in this specific example, controls the shutter so that the time of irradiation of the spot size is controlled to provide a specific fluence on the target area.

The sensor for measuring the power of the first light beam may be any power sensor, such as a silicon power sensor, a thermopile, a thermal volumetric power sensor, etc.

The shutter may then be opened, if the power of the first light beam increases above a predetermined power level. The measured power of the first light beam may, thus, be compared to a predetermined threshold value, and the shutter may be opened when the power of the first light beam exceeds the predetermined threshold value. The target area may then be treated according to predetermined settings and by means of the treating light beam. The shutter may be closed when the target area has been treated according to the predetermined settings.

The predetermined settings may comprise settings regarding the total duration of the treatment, and/or settings regarding the traversing pattern of the treating light beam on the target area, so that the shutter is closed when the treating light beam has performed the traversing pattern. Furthermore, the settings may comprise settings regarding the treatment time at each position to be treated.

For safety reasons a continuous comparison of the power of the light source and another predetermined threshold may be performed, so that the shutter may be closed if the power of the light source exceeds the other predetermined threshold.

It is an advantage of measuring the power of the first light beam in the handpiece that no information regarding the power of the first light beam need to be transferred to the handpiece from the light source. Further, any other parameters of the light source, such as wavelength, dwell time, pulse duration, duty cycle, etc. may be measured by one or more sensor(s) in the handpiece. This provides a very flexible handpiece which may be used with any light source without any pre-adjustment to make a receiver in the handpiece able to read the information transferred from the first light source.

Furthermore, the power for operating the handpiece may be supplied to the handpiece from a power supply being independent of the light source.

A user of the handpiece may manually tune parameters of the first light source according to the measured parameters of the light source so that for example the power and/or fluence of the first light beam is adjusted at the light source if the measured power and/or fluence do not corresponds to the power and/or fluence originally requested.

It is another advantage of measuring the power of the first light beam in the handpiece that the real value of the output power is known so that a consistent and uniform treatment is obtained, e.g. throughout the day or throughout the month, independently of the age and condition of the handpieces, light sources and interconnections used.

The shutter may also be used to optically and/or mechanically turn the light source on and off when the light source e.g. has slow turn on and turn off times. The on/off time for the shutter may be less than 150 ms, such as less than 100 ms, preferably less than 50 ms, such as less than 25 ms. The shutter turn on/off time will, naturally, be dependent on the mechanics of the shutter function. The user may be alerted when the shutter has been closed.

A temperature sensor may be provided at or near the shutter for measuring the temperature of the shutter and the user may be alerted if the temperature of the shutter exceeds a predetermined threshold temperature. In order to keep the shutter below such a predetermined threshold temperature, the handpiece may comprise cooling means, such as a cooling fan, a heatsink, etc. for cooling the shutter. The cooling means may further comprise means for providing a cooling fluid to the shutter, so that the shutter is cooled by a fluid, such as water, such as a cooling gel, etc.

The shutter may be coated by a reflective coating being adapted to reflect at least a part of the first light beam. The handpiece may then comprise absorbing means being adapted to absorb at least a substantial part of the light beam being reflected by the reflective shutter. The absorbing means may for example be positioned on an inner surface of the handpiece. The absorbing means may comprise a heat sink so that e.g. a stationary heat sink may be mounted on an inner surface of the handpiece or a heat sink may be mounted on the outside of the handpiece being in thermal contact with the absorbing means.

Especially when using high power light beams, it is an advantage to have a shutter coated with a reflective layer positioned in the beam path of the first light beam when measuring or shutting off the first light beam, so that the shutter is not excessively heated.

Alternatively, the deflecting means may comprise at least one mirror, said mirror(s) being movable between at least one position in which it directs the treating light beam onto the target area so as to allow treatment of the target area, and at least one position in which it directs the treating light beam away from the target area, e.g. towards an inner surface of the handpiece, so as to prevent treatment of the target area.

The information from the sensor, i.e. the measured beam parameters, or from the processing means analysing the measured beam parameters, i.e. the one or more produced output(s), may be displayed on a monitor or a display, such as a CRT, a VFD, an OLED, an LCD, a TFT display, etc. The display may be positioned on the handpiece or it may be an external display coupled to the handpiece. The predetermined pattern may be selected on the basis of the one or more produced output of the processing means. The external display may be connected to the handpiece via a wireless connection, such as a blue tooth connection. The display may comprise a touch screen for displaying e.g. predetermined treatment patterns stored in an electronic memory, such as an EEPROM, of the handpiece. An operator of the handpiece may select a desired predetermined treatment pattern by touching the corresponding pattern on the touch screen.

Alternatively, the user interface means may conventionally comprise a mouse or a track ball for moving a pointer on the display unit for pinpointing the predetermined treatment pattern to be selected.

The user interface means may further provide for setting of parameters, etc. The selection and setting of parameters may be performed by buttons, jog dials, etc. Furthermore, the buttons may be configurable soft-buttons allowing for future software upgrades so that for example implementation of new applications may be performed without any hardware changes.

The display may, for example, be mounted on an upper surface of the handpiece. Hereby, the user may be able to see the display irrespective of which hand is used. The image may be adapted to be rotated digitally, so that a rotation of 180 degrees when the hand is changed ensures that the image and any text on the display will turn upside down. Furthermore, soft buttons may be digitally (re)configured to the hand used by the operator. Alternatively, the display may be able to display information in a user specified direction by mechanical means, so that the display may be hinged or pivotally mounted in any other way so that the user may decide the position of the display, e.g. according to which hand is used to hold the handpiece.

The handpiece may further comprise an interconnection to operating means for manually operating the light source so that the manual operation may be overruled by a signal sent by the handpiece via the interconnection, thereby causing an interruption of the first light beam. The light source may for example be connected to a foot pedal to be operated by a user of the handpiece, so that activation of the foot pedal turn the light source on and deactivation of the foot pedal turns the light source off. It is, however, preferred to be able to overrule the operation of the foot pedal, so, therefore, an interconnection, electrical or optical, is formed between the handpiece and the foot pedal. Sending a signal, electrical or optical, to the foot pedal will then close the light source irrespective of the status of the foot pedal (activated or not). It is for example preferred to send a signal to the operating means when the target area has been traversed in a predetermined pattern by the treating light beam so that the light source is turned off immediately after the pattern has been traversed. Hereby, the safety is increased, since this construction ensures that the first light beam is not heating the shutter after the treatment has been performed. The handpiece may, still further, comprise a built-in light source for producing a treating light beam to be deflected onto the target area. The treating light beam produced by the built-in light source may be a highly focused light beam, such as a beam emitted from a laser diode, and may be adapted to form a spot on the target area, said spot having a high fluence and a small spot size. The power density may for example be in the range of 5-50 kW/cm², such as 10-30 kW/cm², such as preferably 20-25 kW/cm², and furthermore a spot size smaller than 1/5 mm, such as 1/10 mm may be provided by the built-in light source.

It is an advantage of the built-in light source that the light beam emitted from the built-in light source does not have to be led through an optical fiber from the light source to the handpiece. It is an advantage that the emitted light beam is not subjected to losses due to e.g. dispersion in the optical fiber, coupling losses in both ends of the optical fiber, absorption and attenuation in the optical fiber, etc. Hereby, the quality of the light beam emitted from the built-in light source may be maintained, so that a highly focused light beam may be deflected towards the target area.

It is a further advantage of providing a built-in light source that only a single external connection is necessary in order to provide for a power supply to the handpiece. The handpiece is hereby extremely flexible, in that not even a connection to an external light source is needed. Furthermore, a battery may be provided with the handpiece so that no power supply need to be provided from an external source.

The built-in light source may comprise a laser device, such as a laser diode, a LED, such as a high-power LED, a flash lamp, etc. or the light source may comprise any array(s) or matrix(ces) of such light sources, such as array(s) of laser diodes, array(s) of LED's, etc.

The built-in light source may be the first light source, so that no external light source has to be provided to the handpiece. Alternatively, the built-in light source may be an additional light source so that two light sources may be provided. Hereby different properties of the two light sources may be used to optimise the treatment. The first light beam emitted from the first light source may, for example, have a first wavelength and the treating light beam emitted from the built-in light source may have a second wavelength, and the first wavelength may be different from the second wavelength. Alternatively, the first and second wavelength may be substantially identical, so that the different optical properties of the two light beams are utilised or so as to provide a second or treating light beam having a higher power. BRIEF DESCRIPTION OF THE DRAWING

Fig. 1 shows a handpiece for tissue treatment having only a light beam interconnection to a light source,

Fig. 2 shows a handpiece for tissue treatment according to the present invention.

DETAILED DESCRIPTION OF THE DRAWING

Fig. 1 shows a handpiece for tissue treatment comprising only a light beam interconnection to the light source 2. Typically, interconnections between the light source 2 and the handpiece for tissue treatment 3 comprises all kinds of information about the light source and the interconnection itself, such as power, wavelength, dwell time, pulse duration, duty cycle, optical loss, such as attenuation, in the optical delivering fiber, etc. Furthermore, interconnections between the light source 2 and the handpiece for tissue treatment 3 typically comprises a power connection supplying power to the handpiece.

The handpiece for tissue treatment 3 of a target area is not provided with any electrical interconnections to the light source 2. The only interconnection is an optical fiber 4 delivering a light beam to the handpiece.

The light source 2 is provided with a footswitch or foot pedal 5. When the foot pedal 5 is activated, the light source 2 starts emitting a light beam, such as a pulsed laser light beam, through optical fiber 4 to receiving means 6 in the handpiece 3. An operator may, thus, depress the foot pedal 5 when the operator is prepared to start the treatment.

The handpiece 3 comprises a shutter 7 to be inserted in a light path of the light beam being emitted from the light source 2. When the shutter 7 is closed, emission of the light beam towards the target area is prevented or interrupted. When the handpiece is initially connected to the light source, the shutter will be closed at least during a predetermined time interval, such as at least during emission of a first laser pulse.

The shutter is coated with an at least partly reflective coating so that at least a part of the light beam is reflected from the shutter 7 onto a beam pick-up sensor 10. The beam pick- up sensor 10 is positioned in such a way that at least a part of the light beam being reflected from the shutter is received by the beam pick-up sensor.

When an operator activates the foot pedal 5, a light beam is emitted form the light source 2 and the beam pick-up sensor 10 measures relevant beam parameters of the light beam, e.g. power, wavelength, etc. The measured parameters are analysed by processing means 22 and an output controlling the treatment of the target area is produced. The treatment pattern, parameters, etc. have been determined before the foot pedal 5 is activated so that the treatment is performed on the basis of the output of the processing means and of the input provided by the operator. The processing means may be adapted to perform necessary changes of the settings in order to perform the predetermined treatment by the specific light beam emitted from the light source 2. When the treatment settings have been determined, the shutter 7 is opened, the light beam is deflected towards the target area by deflecting means 8, the treatment is performed, and the shutter 7 is closed again. The operator is notified by alerting means 25 emitting sound and/or light signals when the treatment is done so that the foot pedal may be released and the light source turned off.

The handpiece further comprises an overruling interconnection 1 to operating means 5 for manually operating the light source so that the manual operation may be overruled by a signal sent by the handpiece to the foot pedal interrupt relay 9 via the overruling interconnection 1, thereby causing an interruption of the first light beam. Normally, activation of the foot pedal 5 turn the light source on and deactivation of the foot pedal turns the light source off. It is however preferred to shut the light source off immediately after the treatment has been performed. When for example a predetermined irradiation of the target area has been performed, the overruling signal will overrule the operation of the foot pedal, and turn the light source 2 off, irrespective of the status of the foot pedal 5 (activated or not).

Preferably, the handpiece comprises a display or a read-out 23 so that an operator is able to see the measured and/or analysed parameters. The handpiece may furthermore comprise a user interface means 24 where settings of the treatment, such as treatment time, treatment pattern, etc. may be chosen.

In another embodiment, the operator decide which settings of the treatment, such as treatment time, treatment pattern, etc. to select on the basis of these measured parameters.

Alternatively or additionally, the beam pick-up sensor 10 may be used to ensure that the beam has a correct or desired power level before the shutter 7 is opened and the treatment is commenced. This is very useful in case the light source is a laser which is relatively slow when turning on/off. In this case, it is desirable to monitor the power of the light beam before opening the shutter 7 in order to ensure that the light source is fully turned on and stable before starting the treatment. Fig. 2 shows a handpiece for tissue treatment comprises a circular selector device 12, a deflecting mirror 14 and an output lens 13. A light beam is delivered from a light source by an optical fiber 4 and through an outlet end 15 of the fiber 4. The light beam then passes through the circular selector device 12, is deflected by the deflecting mirror 14 towards a target area, and exits the handpiece through the output lens 13. The circular selector device is a movably mounted disc which may comprise a number of components to be positioned in a light path of the light beam. A desired component of the circular selector device 12 may be selected by rotating the circular selector device 12 about an axis of symmetry 16 by means of motor 21. In Fig. 2, two components are shown on the selector device 1, that is a shutter 17 and a collimating lens 18. When the shutter 17 is opened, i.e. removed from the beam path of the first light beam by rotating the selector device, the collimating lens 18 may be positioned in the light path of the first light beam.

In the figure, the shutter 17 has been selected. When the shutter 17 is closed, it absorbs the energy of the light beam, and thereby heat is dissipated in the shutter 17. Therefore, the shutter 17 is provided with cooling fins 19 for cooling the shutter 17 in order to prevent overheating. Furthermore, a temperature sensor 20 is positioned at or near the shutter 17 in order to monitor the temperature of the shutter 17. In case the temperature exceeds a predetermined level above which the shutter 17 may be damaged, the cooling may be increased and/or the user alerted. Furthermore, the beam may be interrupted in order to prevent additional dissipation of heat if an additional interconnection is made between the handpiece and the foot pedal so that a 'stop emitting¹ signal is send by the handpiece, e.g., when a treatment pattern has been traversed.

To avoid positioning large cooling fins 19, etc. at the backside of the shutter 17 in the beam path of the light beam, a reflective component can be inserted in the beam path, preferably so that the shutter is coated with an at least partly reflective coating. The shutter will then reflect the light beam towards beam pick-up sensor 10 for measuring beam parameters. Alternatively, the light beam is reflected towards an absorbing media positioned for example on an inner surface of the handpiece. The absorbing media may be in thermal contact with cooling fins on the outside of the handpiece reducing the overall size of the handpiece and allowing for smaller cooling fins due to the natural air-flow on the outside of the handpiece.

Claims

1. A handpiece for tissue treatment comprising:

means for receiving a first light beam emitted from a light source, a sensor for measuring beam parameters of the first light beam, processing means for analysing the measured beam parameters, and for producing one or more corresponding output, and - means for deflecting the first light beam into a treating light beam and for directing the treating light beam towards a target area,

2. A handpiece according to claim 1, further comprising deflecting moving means for moving the deflecting means and deflecting control means for controlling the moving means and being adapted to control the deflecting means so that the treating light beam traverses the target area in a predetermined pattern.

3. A handpiece according to claim 1 or 2, further comprising means for alerting the user when a predetermined irradiation of the target area is obtained.

4. A handpiece according to claim 2 or 3, further comprising means for alerting the user when the predetermined pattern has been traversed.

5. A handpiece according to any of the preceding claims, further comprising means for interrupting the first light beam when a predetermined irradiation of the target area is obtained.

6. A handpiece according to any of claims 2-5, further comprising means for interrupting the first light beam when the predetermined pattern has been traversed.

7. A handpiece according to any of claims 2-6, wherein the predetermined pattern is selected on the basis of the one or more produced output.

8. A handpiece according to any of the preceding claims, further comprising a shutter positioned in the beam path of the first light beam or the treating light beam, so that when the shutter is in a closed position, the beam is prevented from passing the shutter, thereby preventing treatment of the target area, and when the shutter is in an open position, the beam is allowed to pass, thereby allowing treatment of the target area.

9. A handpiece according to claim 8, wherein the shutter is operated in accordance with 5 the one or more produced output.

10. A handpiece according to claim 8, wherein the shutter is operated in accordance with the predetermined pattern.

10 11. A handpiece according to claim 9 or 10, further comprising cooling means for cooling the shutter.

12. A handpiece according to claim 11, wherein the cooling means comprises a cooling fan.

15 13. A handpiece according to claim 11 or 12, wherein the cooling means comprises means for providing a cooling fluid to the shutter.

14. A handpiece according to any of claims 8-13, further comprising means for alerting the user when a temperature of the shutter exceeds a predetermined level.

20

15. A handpiece according to any of claims 1-7, wherein the deflecting means comprises at least one mirror, said mirror(s) being movable between at least one position in which it directs the treating light beam onto the target area so as to allow treatment of the target area, and at least one position in which it directs the treating light beam away from the

25 target area so as to prevent treatment of the target area.

16. A handpiece according to claim 15, wherein the treating light beam is directed towards an inner surface of the handpiece when it is directed away from the target area.

30 17. A handpiece according to any of the preceding claims, wherein the measured beam parameters comprise power.

18. A handpiece according to any of the preceding claims, wherein the output of the processing means comprises fluence.

35

19. A handpiece according to any of the preceding claims, further comprising a display for displaying one or more of the measured beam parameters and/or one or more of the produced output.

20. A handpiece according to any of the preceding claims, wherein power is supplied to the handpiece from a power supply being independent of the light source.

21. A handpiece according to any of the preceding claims, wherein the light source

5 comprises means for manually operating the light source, the handpiece further comprising an interconnection to the operating means, so that the manual operation may be overruled by a signal send by the handpiece via the interconnection, thereby causing an interruption of the first light beam.

10 22. A handpiece according to claim 21, wherein the interconnection is an electrical connection, and wherein the signal is an electrical signal.

23. A handpiece according to claim 21, wherein the interconnection is an optical connection, and wherein the signal is an optical signal.

15

24. A handpiece according to any of claims 21-23, wherein the signal is sent when a predetermined irradiation of the target area is obtained.

25. A handpiece according to any of claims 21-24, wherein the signal is sent when the 20 target area has been traversed in a predetermined pattern by the treating light beam.

26. A handpiece according to any of claims 21-25, wherein the means for manually operating the light source comprises a foot pedal.

25 27. A handpiece according to any of the preceding claims, wherein the means for deflecting comprises the means for directing.

28. A method of treating a tissue target area, the method comprising the steps of:

30 - receiving a first light beam emitted from a light source, measuring beam parameters of the first light beam, analysing the measured beam parameters and producing one or more corresponding output, and deflecting the first light beam into a treating light beam in accordance with the one or 35 more produced output, thereby directing the treating light beam onto the target area.

29. A method according to claim 28, the method further comprising the step of moving the deflecting means so as to cause the treating light beam to traverse the target area in a predetermined pattern.

30. A method according to claim 29, further comprising the step of alerting the user when a predetermined irradiation of the target area is obtained.

5 31. A method according to any of claims 28-30, further comprising the step of alerting the user when the predetermined pattern has been traversed.

32. A method according to any of claims 28-31, further comprising the step of interrupting the first light beam when a predetermined irradiation of the target area is obtained.

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33. A method according to any of claims 28-32, further comprising the step of interrupting the first light beam when the predetermined pattern has been traversed.

34. A method according to any of claims 29-33, further comprising the step of selecting a 15 pattern to be traversed, said selection being performed on the basis of the one or more produced output.

35. A method according to any of claims 28-34, further comprising the step of operating a shutter function in accordance with the one or more produced output, so as to prevent the

20 beam from passing or allowing the beam to pass in accordance with the one or more produced output.

36. A method according to claim 35, further comprising the step of cooling the shutter.

25 37. A method according to claims 35 or 36, further comprising the step of alerting the user when the temperature of the shutter exceeds a predetermined level.

38. A method according to any of claims 28-34, further comprising the step of operating at least one mirror in accordance with the one or more produced output, so as to prevent the

30 beam from passing or allowing the beam to pass in accordance with the one or more produced output.

39. A method according to any of claims 28-38, further comprising the step of displaying one or more of the one or more produced output on a display.

35

40. A method according to any of claims 28-39, further comprising the step of interrupting the beam, said step being performed by sending a signal via an interconnection between the handpiece and means for manually operating the light source, thereby overruling the manual operation of the light source.

41. A method according to claim 40, wherein the interrupting step comprises sending an electrical signal.

5 42. A method according to claim 40, wherein the interrupting step comprises sending an optical signal.

43. A method according to any of claims 40-42, further comprising the steps of:

10 - causing the treating light beam to traverse the target area in a predetermined pattern, and performing the interrupting step when a predetermined irradiation of the target area is obtained.

15 44. A method according to any of claims 40-43, further comprising the steps of:

causing the treating light beam to traverse the target area in a predetermined pattern, and performing the interrupting step when the predetermined pattern has been traversed.