Abstract:
There is disclosed a medical handpiece, in particular a dental handpiece, having a lighting device which includes at least one optical semiconductor element, whereby the at least one optical semiconductor element is arranged at least partially in the interior of the handpiece and is detachably connected to the handpiece. On account of this design, it is possible for the user to easily connect the handpiece to an optical semiconductor element that is needed for a certain treatment and has, for example, a certain desired power level and/or emits a desired wavelength. The handpiece may thus be used for different applications without requiring any additional components such as switches, etc., that take up space. The outside dimensions of the handpiece remain substantially unchanged in comparison with known handpieces.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority from pending European Patent Application No. 06024780.6, filed Nov. 30, 2006, which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     The present application relates to a medical handpiece, in particular a dental handpiece, having a lighting device comprising at least one optical semiconductor element. 
     2. Description of Prior Art 
     Japanese Patent Application JP 10165419 A describes a dental handpiece having a lighting device capable of emitting radiation of different wavelengths to thereby be able to perform different treatments. The handpiece therefore comprises multiple light sources in the form of LEDs and a switch by means of which optionally one or more LEDs can be operated so that green or blue light, for example, is emitted for treatments or white light is emitted for illuminating the treatment site. 
     One disadvantage is that the design of this handpiece is complicated and requires a great deal of space because multiple LEDs, a switch and electronic or mechanical switch elements have to be accommodated in the handpiece. Because of a wide variety of components contained in the handpieces with a connection for tools that can be set in motion, e.g., drive elements, tool receptacles, media lines, etc., integration of additional elements is not possible to an unlimited extent or would be possible only if the outside dimensions of the handpiece could be enlarged. However, the space available in the oral cavity is very limited, especially for dental applications, and the user&#39;s vision is often limited to the preparation site, so larger outside dimensions are not desirable. 
     One object is thus to create a medical handpiece, in particular a dental handpiece, having a receptacle for tools that can be set in motion and having a lighting device with which treatments can be performed under different operating parameters, e.g., different wavelengths, whereby the handpiece should have the simplest possible design and there should not be any increase in the outside dimensions of the handpiece. 
     SUMMARY 
     According to one embodiment, the medical handpiece, in particular dental handpiece, has a lighting device with at least one optical semiconductor element, whereby the at least one optical semiconductor element is arranged at least partially in the interior of the handpiece and whereby it is detachably connected to the handpiece. Due to this design, it is possible for the user to easily connect the handpiece to the optical semiconductor element, which is needed for the respective treatment and has, for example, a certain desired power level and/or emits a desired wavelength. The handpiece may thus be used for different applications without requiring additional components that take up space, such as switches, etc. The outside dimensions of the handpiece thus remain unchanged in comparison with known handpieces. 
     Due to the arrangement of the at least one optical semiconductor element at least partially in the interior of the handpiece, this also ensures that the optical semiconductor element does not hinder or impair the handling of the handpiece. In a preferred embodiment, the electric components which supply electricity to the optical semiconductor element, in particular cables and contacts, are accommodated in the handle, thereby further improving the handling of the handpiece. 
     Another advantage of the inventive handpiece is that the at least one optical semiconductor element can easily be replaced if it is damaged and no longer functional. This may occur in particular due to the penetration of particles, liquids or gases, e.g., liquid or gaseous cleaning media through the lighting device to the optical semiconductor element. In replacement, thus only the optical semiconductor element that is no longer functional is replaced, whereas the functional handpiece may remain in use. 
     In addition, the inventive handpiece may be used for various treatments for which users have previously required multiple handpieces. Thus the cost of acquisition as well as the cleaning and maintenance cost for the user are reduced. 
     The detachable connection of the at least one optical semiconductor element to the handpiece can be established by all known detachable connecting means, e.g., by a form-fitting or frictionally locking connection, or by clamped, screw or plug connections. 
     To be able to detach the at least one optical semiconductor element from the handpiece and remove it, the handpiece may be designed in two pieces, with the separation point between the two handpiece parts preferably being provided approximately at the location where the semiconductor element is arranged, so that it is readily accessible. The head and handle part of the handpiece in particular may be detachable from one another and the at least one optical semiconductor element may be arranged in the area of the separation point. 
     In a preferred embodiment, an opening which is provided in the outer sleeve of the handpiece is designed so the at least one optical semiconductor element can be passed through this opening. This eliminates the need for a two-piece design of the handpiece with an additional separation point and with corresponding connecting means and sealing means. The opening in particular must be large enough so that the at least one optical semiconductor element can be passed through it, and it must be arranged at a location on the outer sleeve to which the optical semiconductor element has access in particular from the interior of the handpiece or toward which it moves, e.g., toward which it can be pushed, and it should also be provided at a location on the handpiece that is readily accessible from the outside, so that the optical semiconductor element can be passed through the opening in a manner that is easy for the user. 
     An opening which also fulfills another function is especially preferably used as the opening for passing the optical semiconductor element through, so that no additional opening for passing an optical semiconductor element through need be provided in the outer sleeve of the handpiece. Such an opening may be, for example, the light-emitting opening or the coupling opening. If the handpiece includes an accommodation for a battery with an opening through which a battery can be inserted, then the optical semiconductor element may also be inserted into the handpiece or removed from it through this opening. 
     In another embodiment, the handpiece is designed so that the at least one optical semiconductor element can be moved through an interior space of the handpiece, in particular to an opening provided in the outer sleeve of the handpiece through which the optical semiconductor element can be passed, i.e., can be removed from and inserted into the handpiece. To this end, either corresponding passages, openings or clearances may be provided in the interior of the handpiece and between components arranged therein and/or one or more components arranged in the handpiece may be removed from the handpiece or may be movably arranged therein, so that the optical semiconductor element can be moved through the interior of the handpiece after removing these components. 
     In particular, it is possible to provide for the head part of the handpiece to be arranged movably, e.g., displaceably in relation to the handle part so that the optical semiconductor element which is clamped in place in the handpiece by the head part is movable in the handpiece. In addition, one or more components, e.g., coupling elements for connection of the handpiece to a power supply or drive unit or media lines, may be arranged on the handpiece or in the interior of the handpiece, so that they are displaceable or can be removed from the handpiece, thereby permitting or facilitating access to the optical semiconductor element to be replaced or its removal from the handpiece. 
     In a preferred embodiment, the at least one optical semiconductor element is designed as part of a lighting module, in particular a lighting module that is hermetically sealed from the outside, whereby the at least one optical semiconductor element is releasable from the handpiece jointly with the lighting module. Integration of the at least one optical semiconductor element into a lighting module has several advantages. For example, the lighting module may be provided with additional function elements, e.g., one or more fastening means for detachable connection of the lighting module to the handpiece. In addition, a rotational lock or form-fitting elements may also be provided to prevent twisting of the lighting module and/or facilitate the insertion and/or attachment of the lighting module and the optical semiconductor element in only one selected position. This is important in particular for a correct connection of the optical semiconductor element to the power source. Sealing elements or means, e.g., for sealing the interior space of the handpiece from the environment, waveguides, light-emitting windows, protective glasses or a casting material that encases, connects and seals the electric contacts of the at least one optical semiconductor element and the electric lines or contacts connected to them may also be provided on the lighting module. 
     The lighting module is preferably hermetically sealed from the outside and/or comprises a hermetically sealed interior space in which the at least one optical semiconductor element is accommodated. Therefore, the optical semiconductor element is protected from damage, penetration of substances, etc. The hermetic seal is especially preferably designed so that the optical semiconductor element is sterilizable, i.e., can withstand repeated introduction into an environment at temperatures of at least 120° C., preferably 130° C., especially preferably 134° C. and/or with steam or chemicals or gases, in particular disinfectants, and/or pressure fluctuations of approximately 1 bar without being damaged. The hermetic seal may be provided by encapsulation of the at least one optical semiconductor element with metallic and/or plastic elements. It may also be achieved by covering the at least one optical semiconductor element with curable plastics or resins, e.g., epoxy resins. 
     In addition, multiple optical semiconductor elements may also be present in the lighting module, so that a higher light output is achievable. At the same time, the use of the optical semiconductor elements is facilitated because most of the optical semiconductor elements can be handled jointly, e.g., are replaceable. 
     In a preferred embodiment, the lighting device of the handpiece is connected to other components, e.g., to a waveguide and/or to an optical element, e.g., a lens, and in particular to electric or electronic components such as an electric line and/or electric contacts and/or a carrier device, preferably a circuit board, and/or electric coupling elements and/or electric or electronic components such as rectifiers, resistors, transformers, etc., at least one of these components can be released from the handpiece together with the at least one optical semiconductor element or the lighting module. 
     The component that is replaceable and jointly attachable together with the optical semiconductor element or the lighting module is especially preferably the electric lines or contacts that are used for connecting the optical semiconductor element or the lighting module to an electric power source. If the optical semiconductor element or the lighting module can be released from the handpiece together with the electric lines or contacts, then the optical semiconductor element or the lighting module and the electric lines or contacts are joined together fixedly, i.e., undetachably, e.g., by soldering, welding and/or by an encasing material, e.g., a casting material, in particular being inseparably encased by a synthetic resin such as epoxy resin or silicone resin. 
     This nonreleasable connection has the advantage that the optical semiconductor element or the lighting module can be introduced into the handpiece only in a certain position, namely in such a way that a connection to the power supply or electric current source can be established via the lines or contacts, in particular so that the lines or contacts are facing the current source. This creates a possibility for inserting the optical semiconductor element into the handpiece in such a way that it is correctly connected to the power supply, i.e., the positive and negative poles of the optical semiconductor element are each connected to the positive and negative poles, respectively, of the d.c. current source, so that the connection to the current source is established according to the direction of current flow of the optical semiconductor element. This advantageously makes it possible to prevent the user of the optical semiconductor element or the lighting module from inserting the optical semiconductor element or the lighting module into the handpiece in a random position and then having to check on whether the optical semiconductor element or the lighting module has been attached correctly, i.e., in the correct direction of current flow in the handpiece, and if this is not the case, the optical semiconductor element or the lighting module having to be removed from the handpiece again and reinserted in another position. 
     The introduction of the lighting module in a predetermined position into the handpiece has other advantages, e.g., if the lighting module comprises an optical element, preferably a lens that focuses the radiation generated by the optical semiconductor element at a specific point, in particular the point of the tool chucked in the handpiece. If the lighting module can be inserted into the handpiece in only one position, this also reliably ensures that the lens is arranged in the handpiece in such a way that it deflects the radiation in the desired direction and onto the desired point. 
     In another embodiment, a circuit, in particular an electronic circuit, may additionally be provided in the handpiece, so that the electronic circuit receives the energy supplied by the current source and adapts it to the requirements of the at least one optical semiconductor element. In particular it receives the current of the current source regardless of its polarity and delivers it with a defined polarity, which is suitable for the optical semiconductor element connected to the circuit. To do so, a polarization protection circuit, for example, consisting of a plurality of diodes and optionally additional elements, in particular a so-called bridge circuit or a bridge rectifier circuit may be provided. The circuit may also contain other elements such as rectifiers, transformers, converters, resistors, etc., to process the amperage or voltage in particular in such a way that it is suitable for the connected semiconductor element. Such an optical semiconductor element, e.g., an LED is usually operated with a d.c. current of approximately 2-3 V and at least 20 mA, preferably more than 50 mA. 
     However, the circuit need not necessarily be provided in the handpiece but instead may also be contained in other instruments or devices that are or can be connected to the handpiece so that the electric current reaching the handpiece already has a defined polarity and suitable current parameters, respectively. 
     The above embodiments and others are explained in greater detail below and with reference to the accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a first preferred embodiment of a medical handpiece, in particular a dental handpiece, partially in section, with a lighting device comprising at least one optical semiconductor element that can be detached from the handpiece. 
         FIG. 2  shows an enlargement of the front section of the handpiece according to  FIG. 1 . 
         FIG. 3  shows the front section of a second embodiment of a medical handpiece, in particular a dental handpiece with a lighting device that is detachable from the handpiece and comprises at least one optical semiconductor element. 
     
    
    
     DETAILED DESCRIPTION 
     The medical handpiece  1 , in particular the dental handpiece illustrated in  FIGS. 1 and 2 , comprises a handle part  14  and a head part  13  at an angle to the former. A tool receptacle which can be set in motion, namely rotatably here, is arranged in the head part  13  and can accommodate a tool, e.g., a rotatable drill. The tool is driven by at least one drive element that is connected to the tool, whereby the drive element is preferably designed as a rotating shaft. The drive element may have other components depending on the type of handpiece, e.g., one or more additional rotating or oscillating shafts, one or more gearwheels or gears, a motor, a rotor, a vibration generator, etc. 
     A pushbutton  15  is provided at one end of the head part  13  for operation of a tool release mechanism, so that a tool which is held or chucked in the tool receptacle can be released from said tool receptacle. A tool opening is provided on the end of the head part  13  opposite the pushbutton  15 , so that a tool can be inserted through it into the tool receptacle. The tool thus protrudes out of the head part  13  at an angle to the longitudinal axis of the handle part  14 . 
     A lighting device  3  for emitting radiation onto a preparation site is arranged on the end of the handle part  14  facing the head part  13 . The lighting device  3  comprises a lighting module  7  with at least one optical semiconductor element. The lighting module  7  is situated in a light-emitting opening  5  of the outer sleeve  2  of the handpiece  1 , whereby most of the lighting module and/or the optical semiconductor element is accommodated in the interior of the handpiece  1 . Therefore, the lighting module  7  does not interfere with the handling of the handpiece  1 . Due to the arrangement of the lighting module  7  in the immediate vicinity of the head part  13 , no waveguide is needed for emitting radiation onto the preparation site. 
     The at least one optical semiconductor element is accommodated in an interior of the lighting module  7 , whereby according to a preferred embodiment, the interior is hermetically sealed with respect to the environment, so that the optical semiconductor element can be subjected to various cleaning and care measures, in particular sterilization, jointly with the handpiece. The hermetically sealed interior is formed by a socket  16  and a cap  17  tightly connected to the former, e.g., by welding. In addition a light-emitting window is provided on the cap  17  through which the radiation generated by the optical semiconductor element can pass. Instead of or connected to the light-emitting window, additional optical elements such as waveguides or lenses may be provided. These optical elements may be designed as part of the lighting module  7  or as separate parts. 
     The lighting module  7  also comprises a lampholder  18  having a cylindrical, essentially sleeve-shaped form through which a borehole passes. The lampholder  18  is preferably made of a material that does not conduct electricity. The socket  16  and the cap  17  are accommodated in the borehole. In addition, a casting compound body  22 , which is made of a synthetic resin, e.g., epoxy resin or silicone resin in particular, is provided in the end of the lampholder  18  facing the interior  4 . The casting compound body  22  sheaths the front end of the electric line  10 , which is connected to the electric current source, in particular the section of the line  10  that is free of any insulating protective sheath. The casting compound body  22  also surrounds the electric contacts  23  of the optical semiconductor element formed as an LED. The line  10  and the contacts  23  are inseparably joined together by the casting compound body  22 . The line  10  and the contacts  23  are preferably additionally soldered, welded or crimped (pinched) together. The casting compound body  22  also seals the lighting module  7  and the contacts  23 . 
     A sealing element  9 , e.g., a sealing ring, which is accommodated in a groove on the outer sheath of the lampholder  18 , is pinched between the outer sleeve  2  of the handpiece  1  and the outer sheath of the lampholder  18 . The sealing element  9  seals the interior  4  of the handpiece  1  and the components contained therein from the environment, preventing the penetration of particles, dirt, treatment media, cleaning agents, etc., into the handpiece  1  or leakage of lubricant out of the interior of the handpiece  1 . Alternatively or additionally, such a seal may also be provided on the handpiece  1  itself. 
     In addition, the fastening device or means  8 , which serve to fasten the lighting device  3  to the handpiece  1 , are also provided on the lampholder  18 . These fastening means may comprise a flange  19 , which is arranged on one end of the lampholder  18  and the outer sheath of the lampholder  18 . The lighting module  7  is inserted into the light-emitting opening  5 , whereby the outer sheath of the lampholder  18  is of such dimensions that it forms a crimped connection to the outer sleeve  2  of the handpiece  1 . The outer sleeve  2  has a fastening element  20 , e.g., in the form of protrusions, ring shoulders, etc., that extend into the interior  4 , to increase the frictional or pinching contact area with the outer sheath of the lampholder  18 . If the lampholder  18  is inserted completely into the light-emitting opening  5 , then the flange  19  comes in contact with the free end of the fastening element  20 , so that on the one hand, additional fixation and, on the other hand, accurate positioning of the lighting module  7  in the light-emitting opening  5  are both achieved. 
     The fastening of the lighting module  7  in the light-emitting opening  5  is additionally accomplished by the head part  13 . The head part  13  has a protrusion  21  on its end facing the handle part  14 , said protrusion  21  being insertable into the interior  4  for connecting the head part  13  to the handle part  14 . The protrusion  21  is of such dimensions that, when inserted into the interior  4 , it contacts the lighting module  7  and presses in the direction of the light-emitting opening  5 , so that the lighting module  7  is fixedly secured in the light-emitting device  5 . 
     The power supply to the at least one optical semiconductor element is provided via the electric pins or contacts  23 , the electric line  10  and an electric coupling element  12  which includes additional electric contacts  11 . Connection of the handpiece  1  to the power source is accomplished in a known way via a coupling  24 , which is preferably designed as a rotary coupling. Other devices such as drive motors, couplings, adaptors, control units, dental units, treatment units, etc., may of course also be provided in a known way between the handpiece  1  and the power source. The electric contacts  11  may be designed differently, depending on the type of coupling  24 , e.g., as sliding contacts, spring contacts or pin contacts. 
     Between the electric coupling element  12  and the contacts  23 , other electric or electronic components may be provided in the handpiece  1 , in particular a circuit that receives the power supplied by the current source and adapts it to the requirements of the at least one optical semiconductor element. The circuit preferably receives the current of the current source regardless of its polarity and delivers it with a defined polarity to the optical semiconductor element. 
     The electric coupling element  12 , the contacts  11  and optionally also the additional electric or electronic components may likewise be nondetachably connected to the lighting device  3 , in particular the lighting module  7 , so they can be removed from the handpiece together with the lighting device  3  when the latter is removed. This is an advantage in particular when the additional electric or electronic components perform specific functions, e.g., pulsating delivery of light, which are necessary or appropriate only for certain applications and thus only for certain optical semiconductor elements. Alternatively, the electric coupling element  12 , the contacts  11  and optionally also the additional electric or electronic components may also be designed to be detachable from the lighting device  3 , so they remain in the handpiece  1  when the lighting device  3  is replaced. 
     The lighting module  7  is released and replaced via the interior  4  of the handpiece  1  and the coupling opening  6 . The light emitting opening  5  which accommodates the lighting module  7  is connected to the coupling opening  6  via the interior  4  of the handpiece  1 . To release the lighting module  7 , the user must first separate one or more components in the handpiece  1  and/or one or more components of the coupling  24  from the handpiece  1 , in particular the coupling pipe  25 . In the next step, the user releases the head part  13  of the handpiece  1  from the handle part  14 , so that the lighting module  7 , which has been forced by the head part  13  into the light-emitting opening  5 , can be released from the light-emitting opening  5 . The user then exerts pressure on the lighting module  7  from the outside with his finger or an auxiliary tool, so that the lighting module is displaced into the interior  4 . Finally, the user removes the lighting module  7  through the coupling opening  6  and preferably also removes the line  10  from the handpiece  1 . 
     The insertion of the lighting module  7  into the handpiece  1  is also accomplished via the interior  4  and the coupling opening  6  in the opposite order from that described for releasing the lighting module  7  from the handpiece  1 . 
     The handpiece  1 ′ depicted in  FIG. 3  corresponds in many features to the handpiece  1 , so that the differences in particular are described below. Handpiece  1 ′ has a head part  13 ′ and a handle part  14 ′. Again a light-emitting opening  5 ′ is provided in the outer sleeve  2 ′, with a lighting device  3 ′ and a lighting module  7 ′ having at least one optical semiconductor element accommodated therein being detachably inserted into the light-emitting opening  5 ′. The lighting module  7 ′ and in particular the at least one optical semiconductor element are arranged essentially in the light-emitting opening  5 ′ of the outer sleeve  2 ′ and thus in the interior of the handpiece  1 ′. 
     The power supply of the lighting module  7 ′ is provided via the electric contacts  23 ′ of the LED and an electric line  10 ′ which are connected to one another by a spring-mounted electric contact element  27 . The connection between the contacts  23 ′ and the contact element  27  is detachable, so that on removal of the lighting module  7 ′ from the handpiece  1 ′, the line  10 ′ and the contact element  27  remain in the handpiece  1 ′. An electrically insulating contact holder  28  which is made of a plastic or synthetic resin, for example, surrounds and connects line  10 ′ and contact element  27  and seals the interior  4 ′ of the handpiece  1 ′ from the environment. 
     In contrast with the handpiece  1  from  FIGS. 1 and 2 , in the case of the handpiece  1 ′ the lighting module  7 ′ and in particular the at least one optical semiconductor element are replaced through the light-emitting opening  5 ′. This allows the user an extremely convenient and rapid means of replacing the lighting module  7 ′. 
     To replace the lighting module  7 ′, a screw ring  26  is provided having an outside thread on its outside. The outer sleeve  2 ′ is provided with a corresponding inside thread in the area of the light-emitting opening  5 ′, so that the screw ring  26  can be screwed onto the outer sleeve  2 ′. The lighting module  7 ′ in turn comprises a socket  16 ′ and a cap  17 ′, whereby the socket  16 ′ has a slightly larger diameter than the cap  17 ′. If the socket  16 ′ and the cap  17 ′ have been joined together, then the outside area of the socket  16 ′ protrudes beyond the cap  17 ′ and forms a ring collar that is secured in the outer sleeve  2 ′ by the screw ring  26  screwed into it. A sealing element  9 ′ is in turn provided in the area of the socket  16 ′, sealing the interior  4 ′ of the handpiece  1 ′ from the environment. 
     The invention is not limited to the embodiments described here but instead comprises all possible embodiments that do not alter the basic appropriate function principle of the invention. Thus, the shape of the handpiece may differ significantly from the shape shown in  FIGS. 1-3 ; for example, it may be designed to be straight or shaped like a gun. Likewise, the application and functioning of the handpiece may also differ from those in the examples shown here and may pertain to any medical field, in particular dental, surgical or orthopedic field. The type and direction of movement of the tool are also variable and may include, for example, not only rotating tools but also oscillating tools and tools that move back and forth and/or up and down, as well as files, saw blades, chisels, vibrating dental plaque removing tools, rotatable brushes, caps and other prophylactic devices. 
     There is also the possibility of operating the at least one optical semiconductor element with alternating current above the so-called flicker frequency (corresponding to approximately 25 Hz a.c. voltage), so this gives the human eye the impression of a constant uninterrupted light emission. The a.c. current source may be provided inside the handpiece or outside the handpiece.