reference will be made to the above figures in the following description of the present invention . with initial reference to fig1 a and 1b , the structural similarity between a conventional resector 1 and an accessory 10 according to the present invention is shown , both of these being capable of directly reaching a target tissue with one or more operating tips . the conventional resector 1 acts , as is known to those skilled in the art , in such a way that the operation is performed solely by means of the contact of the loop 2 with the tissue concerned . one of the advantages of the present invention , which will be made clear by the following description , is that it can act even when it is not in contact with the target tissue . in particular , a first subject of the present description is an accessory 10 designed to simulate the action of the resector loop , while allowing the operator to act also at a distance not close to the tissue . the subsequent fig2 to 4b are views of an accessory 10 according to the present invention . the accessory 10 can be used to optimize the processes for cutting , ablation , resection , vaporization of the tissues and simultaneously for the effective control of the haemostasis of the blood vessels which may be damaged during the operation . the accessory 10 according to the present invention is therefore an accessory for a medical device in which said device is suitable for the laser cutting , ablation , resection , vaporization and / or coagulation of a tissue , preferably by endoscopy . the accessory 10 comprises , in the first place , a supporting element 11 and at least two guide elements 12 and 13 . the guide elements 12 and 13 are capable of carrying corresponding optical fibres , preferably one optical fibre in each guide element . as shown in the drawings , the guide elements 12 and 13 are mounted on the supporting element 11 which can be connected to a medical device 20 . this connection is provided by the presence of means 21 for connecting the support 11 to the medical device 20 . these connecting means 21 may include — but are in no way limited to — engaging , sliding , bayonet - type or male and female systems . fig4 c , which is a rear view of an accessory according to the present invention , shows by way of example a bayonet - type connection . clearly , connecting means which are not explicitly described herein , but which are considered suitable by persons skilled in the art for ensuring co - operation between the accessory 10 and a medical device using the support 11 , are to be considered as part of the present description . as stated above , the accessory 10 is preferably used in the surgical procedures of laser cutting , ablation , resection , vaporization and / or coagulation of a tissue , preferably performed by endoscopy . for this reason the accessory 10 may further comprise first optical means 30 for endoscopic viewing of the target tissue . these first optical means 30 can be placed inside a first housing 31 in order to align the endoscopic view with the resection area and protect the optical elements from direct laser radiation which would damage them . a person skilled in the art will be able to determine which optical means should be used in the construction of the accessory 10 described herein , as well as determine the type of housing most suitable for them . by way of non - limiting example , these optical means 30 may comprise at least one lens and / or an objective . the accessory 10 is apt to carry at least two optical fibres 17 and 18 . these fibres , which are preferably sterile , can be mounted inside the guide elements 12 and 13 . clearly , the presence of at least one entrance to the guide elements allows the optical fibres to be introduced into the guide elements . in other words , in the preferred embodiment of the accessory 10 , these guide elements 12 and 13 are hollow tubular elements . the function of the optical fibres is to convey laser radiation to the target tissue or site . the length and thickness of the tubular elements can therefore be determined easily by a person skilled in the art , without the need for further details , according to the structural characteristics of the fibres chosen as being suitable for the embodiment of the present invention . the accessory 10 may also comprise locking elements 16 for each of the optical fibres 17 and 18 . these securing elements 16 allow the optical fibres to be locked after their insertion into the guide elements , thus preventing them from accidentally sliding . this is because excessive sliding would expose the fibres to rapid deterioration , due , for example , to continual direct contact with the tissue and / or with the guides . the integrity of the fibres is important in order to maintain optimal functionality of the resection accessory 10 . as shown in fig4 d , the accessory 10 according to the present invention may advantageously comprise protective elements 19 , similar to caps for example , which can be fitted on the operating tip of each guide element 12 and 13 . these caps 19 may be advantageously used during the operations of transport and / or autoclaving , and , more generally , whenever the instrument is to be protected . they also allow precise definition of the degree to which the fibres are inserted into the elements . each optical fibre can therefore be inserted , when its protective element has been applied to the guide element , until it touches said element , and can then be fixed by means of suitable securing devices which will be described more fully below . the dimensions , characteristics and materials of the protective elements 19 can be determined by a person skilled in the art according to the purposes of the operation . the accessory 10 is designed essentially for use in the medical field and it is therefore preferable that it should satisfy certain requirements , such as that of sterility . for this purpose , at the end of each treatment the optical fibres may be removed for sterilization or for replacement with new fibres to be used for the next treatment . additionally , in order to improve the effect on the tissue and thus achieve effective processes of cutting , ablation , resection , vaporization and / or coagulation , it is advantageously possible to provide means for regulating the position , and particularly the inclination , of one or more optical fibres . in one embodiment of the present invention , the accessory 10 may comprise first means for regulating the position of at least one guide element with respect to the tissue . in the construction of the device , a person skilled in the art may use any regulating means or system which enable at least one guide element to be positioned differently according to the requirements of use . by way of a non - limiting example these first regulating means ( not shown in the drawings ) may include pairs of rotating collars which , acting on one or both of the guide elements , may modify their positions . advantageously , these first regulating means can be integrated into the securing elements 16 , 16 ′ and / or integrated into the elements 12 , 13 themselves . fig4 e shows , by way of example , a possible embodiment of these first regulating means , integrated with the guide elements 12 , 13 and provided in the form of rotating collars 14 . since the focusing of the laser emission can be regulated by regulating the position and / or inclination of the guide elements , it is possible to regulate the effective distance from the tissue , thus enabling the instrument to be used both in contact with the tissue and at a distance . suitable arrangements are provided on the output elements to protect the tips of the delivery fibres . however , it is considered unnecessary to describe these arrangements in greater detail , as they will be evident to persons skilled in the art . in one embodiment of the present invention , a lens 15 may also be provided at an operating end of each of the guide elements 12 , 13 . this lens 15 , preferably of the converging type , is useful for concentrating the laser radiation in the proximity of the target tissue . the subsequent fig5 a and 5b relate to two medical devices 20 , 20 ′ according to the present invention , each provided with an accessory 10 as described hitherto . in particular , two medical devices 20 , 20 ′ for the laser cutting , ablation , resection , vaporization and / or coagulation of a tissue , preferably by endoscopy , are shown . the devices 20 and 20 ′ are characterized by the presence of an accessory 10 as described above and at least one interface element which can co - operate with the connecting means 21 present in the accessory . a person skilled in the art will be able to design the interface element of the device in accordance with the type of connecting means which are included in the accessory 10 and with which the element is required to co - operate . each of the devices 20 and 20 ′ comprises two inputs 22 , 22 ′ for the optical fibres , located on the main body of the device . securing elements 16 , 16 ′ as described above may be provided at the inputs 22 , 22 ′. advantageously , the medical devices 20 and 20 ′ may also be provided with second regulating means for controlling and / or defining the inclination of at least one of the guide elements 12 , 13 included in the accessory 10 . these second regulating means may be considered to be structurally and functionally similar to the first regulating means , as described above , included in the accessory 10 . the devices 20 and 20 ′ are essentially designed for use in surgical procedures , preferably by endoscopy . the viewing of the target site and / or tissue can be facilitated by the presence of second optical means suitably connected to the eyepiece 33 , 33 ′ of the first means 30 . these optical means may comprise , for example , lenses and / or objectives and / or video cameras . the structure and further technical details for the construction of devices according to the present description , of which the devices 20 and 20 ′ are only some of the possible embodiments , are well known to persons skilled in the art and therefore do not need to be detailed more fully in this description . the laser radiations to be conveyed by the optical fibres 12 and 13 are emitted by one or more laser sources , as will be readily understood . these laser sources may be advantageously incorporated in the accessory 10 . fig5 d shows the accessory associated with a schematic resector . the optical supply devices 17 , 18 depart from one or more laser sources and terminate at the tip of the device which focuses their emission beam . said fibres are fixed by the elements 16 , 16 ′ and are carried and protected by the elements 12 , 13 . the whole instrument can be introduced and retracted as required by the operator , using the translation device . this operation can also be carried out by moving the whole instrument without using the resector . it is also possible to produce instruments completely dedicated to laturp . with reference now to fig6 a and 6b , these show , in schematic form , two possible connections of the accessory according to the present invention to two different laser sources 40 , 41 . the device is intended to be used with laser sources emitting beams at any wavelength , with any energy , in continuous or pulsed emission . with reference now to fig6 a and 6b , these show , respectively , a first constructional layout of the present invention , in which two separate laser sources 40 , 41 are used . in particular , according a first embodiment , shown in fig6 a , the accessory 10 may comprise a first source 40 for emitting a first laser radiation and a second source 41 , separate from the first , for emitting a second laser radiation . each of said first and second sources supplies a respective one of the two optical fibres 17 and 18 . in order to activate selectively one or other or both of the laser sources 40 , 41 , an activator of the laser emission 60 may advantageously be provided . the specific embodiment of this activator can be chosen freely by a person skilled in the art . for example , it may comprise one or more pedals by means of which the surgeon can select the laser source to be activated . for example , the activator may permit the following combinations : ( first optical fibre 17 )/( first laser source 40 ) and ( second optical fibre 18 )/( second laser source 41 ); ( first optical fibre 17 )/( first laser source 40 ) and ( second optical fibre 18 )/( first laser source 40 ); or ( first optical fibre 17 )/( second laser source 41 ) and ( second optical fibre 18 )/( second laser source 41 ). thus the operator may , at his / her discretion , combine sources which emit radiation with different or uniform effects on the tissue . in fact , the effects of vaporization and / or vaporesection and / or cutting and / or ablation and haemostasis ( coagulation ) may be necessary during surgical operations , as already pointed out above . accordingly , the presence of two sources makes it possible to carry out cutting , ablation , resection and vaporization by using one specific radiation and coagulation of the target tissue by using the other radiation . for example , purely by way of example , the first laser radiation may have a wavelength close to the water absorption peak , particularly within the spectral region from 1900 to 2100 nm and with a variable power of up to 200 w . the first laser radiation may operate in either continuous or pulsed mode . this choice is preferable , in particular , when vaporesection of the target tissue must be performed . the radiation - tissue interaction in the 1900 - 2100 nm spectral region essentially takes place by the absorption of the water . the penetration length is extremely small , at l1 & lt ; 0 . 5 mm . when the volumetric power density levels are sufficiently high , simultaneous vaporization and resection ( vaporesection ) of the tissue takes place . when the vaporization rate is high , bubbles are present , indicating the high effectiveness of the treatment . the vaporization rate can also be controlled by varying the angle of incidence of the radiation on the tissue or by suitably modulating the power of the laser source . because of the high power and short absorption length ( less than 0 . 5 mm ), it is possible to operate in conditions of high volumetric power density , thus achieving effective vaporization . the second laser radiation may , for example , have a wavelength close to the water absorption peak in the spectral region from 1400 nm to 1540 nm , with an output volumetric power density which promotes the haemostasis process . in this case also , the interaction is with water , but the absorption length is greater ( 1 . 5 mm ). fig6 b shows a second variation of embodiment of the present invention , again using two separate laser sources 40 , 41 . in this case , while the above description is still applicable , the device further comprises a modulator 50 interposed between the outputs of the laser sources 40 , 41 and the input of the instrument . this is because , as mentioned above , different stages of operation , such as a cutting stage which may or may not be followed by a stage of haemostasis , can be identified in a surgical operation . however , it might sometimes be necessary , during an operation , to carry out the cutting stage and the haemostasis stage simultaneously . consequently , the laser radiation conveyed by the optical fibres may , in the accessory according to the present invention , be laser radiations which can be modulated temporally and spatially by any type of modulator in the accessory . fig7 a , 7 b and 7 c show a second constructional layout of the present invention , in which a single laser source 70 is used . in this case , the device comprises a single source 70 for emitting a laser radiation . the radiation emitted by the single source 70 is then divided between the two optical fibres 17 , 18 . the three variants shown in fig7 a , 7 b and 7 c show three different methods of dividing the single laser radiation between the optical fibres 17 , 18 . in particular , fig7 a shows the use of a splitter 80 , in other words an optical fibre - to - fibre coupler which can divide the radiation from the output optical fibre 71 of the single laser source . fig7 b shows the use of a single laser source 70 which , however , already has two separate outputs which can therefore directly supply the two optical fibres 17 and 18 . fig7 c shows the use of a doubler 90 of the output optical fibre 71 of the laser source , this device being made , for example , in the form of a y - shaped optical fibre . the single laser source 70 can be activated by means of the normal actuator provided by the manufacturer . the laser device according to the present invention is suitable for use in surgery , particularly in surgical procedures for laser cutting , ablation , resection , vaporization and / or coagulation of a tissue . vaporesection is the term used to refer to vaporization and resection carried out simultaneously ( bach t et al ., revolix vaporesection of the prostate : initial results of 54 patients with a 1 - year follow - up . world j urol . 2007 ; 25 : 257 - 62 .). preferably , said tissues are soft tissues such as prostate , liver , kidney , or lung tissue , or the like . even more preferably , said tissue is prostate tissue . the possibility of a continuous - wave ( cw ) emission mode associated with the first laser radiation enables a precise incision to be made , promoting a significant effect in combination with the vaporization of prostate tissue in urology ( t . back et al ., thullium : yag 2 micron cw laser prostatectomy , where we stand . world j . urol . 28 : 163 - 168 ; wendt - nordhal g ., et al ., systematic evaluation of a recently introduced 2 - μm continuous - wave thulium laser for vaporesection of prostate , journal of endourology , 22 , n . 5 , may 2008 ). in urology , the main treatments in which the device according to the invention can be used are , by way of non - limiting example , benign prostate hyperplasia ( bph ), recurrent bladder tumours , contracture of the neck of the bladder , stricture of the urethra and urethral stenosis , and urethral tumours . the diameter of the optical fibres is preferably within a range of 100 to 1000 microns . laser radiation may generally be modulated and may therefore be emitted in continuous or alternating mode . the presence of an emission modulator enables the radiation from the single laser to be divided between both optical fibres carried by the instrument 10 when only one of the emitting sources is suitably activated by the pedal system . when both of the connected laser sources are used simultaneously , each of the fibres carried by the device is intended for the conveying of only one of the two emitting laser sources . as described above , it is possible to use an emission modulator 50 which , acting on the incoming laser sources , controls the emission modes of each of the single fibres carried in the instrument . examples of output combinations are shown in fig8 a to 8f , for example : simultaneous emission of the terminals of the instrument connected to laser supply sources with pulsed and / or continuous emission . alternating emission of the terminals of the instrument connected to laser supply sources with pulsed and / or continuous emission . continuous emission of the first terminal and alternating emission of the second terminal of the instrument connected to laser supply sources with pulsed and / or continuous emission . alternating emission of the first terminal and continuous emission of the second terminal of the instrument connected to laser supply sources with pulsed and / or continuous emission . these combinations can produce different types of action on the tissue according to the wavelengths and the power supplied by the individual supply sources . the operating modes of the aforementioned modulator are not described herein because they will be familiar to the average person skilled in the art . it is to be understood that the modulator may be used in all cases , including the configuration of the invention in which there is a single laser source . it is also to be understood that , generally , in all the embodiments described above the surgical and / or haemostatic procedures can be carried out with the output optical fibres in contact with or in the proximity of the tissue . fig9 is a schematic exemplary view of the insertion of the device through a resector , used for action on prostate tissue . the following fig1 a to 10c show , in sequence , the use of the device for performing , for example , vaporization of tissue , using a particular inclination and distance from the tissue during operation , while maintaining a sufficient degree of haemostasis and coagulation . finally , fig1 a to 11d show the use of the device for performing , for example , tissue resection , using a particular inclination and bringing the ends of the optical fibres into contact with the tissue , the translational movement being the same as that used in ordinary turp . by using laturp it is also possible to maintain a sufficient haemostatic and coagulating action . the present invention has been described hitherto with reference to its preferred embodiments . it is to be understood that there may be other embodiments based on the same inventive concept , all such embodiments being included within the scope of the claims provided below .
a device for supplying laser radiation is described . the device has adjustable focusing or a fixed geometry . the device can be connected as required to cystoscopes or endoscopes including those provided with a translation element commonly used for resection . the device is also connected to separate laser sources or to a single laser source whose emission is suitably divided and conveyed in two or more outgoing fibres . the device can be used for the purposes of resection , vaporization and / or cutting and / or ablation , and / or for haemostasis , providing results similar to those of conventional resection procedures using an electrosurgical scalpel / resector .