one embodiment of the deflector shield 40 is shown in use in fig1 as an element of device 10 . the device 10 consists of an ultrasound generator 11 producing a signal to drive an ultrasound transducer 14 . the ultrasound transducer 14 produces ultrasound waves and is attached to an ultrasound tip 20 to transmit the ultrasound energy to a distal end 21 . the ultrasound transducer may be covered with a housing 17 to isolate the operator &# 39 ; s hand from the transducer . the housing 17 may extend over the ultrasound tip 20 . the ultrasound tip 20 may have an interior passage 12 to deliver fluid 15 to the distal end 21 . the fluid may serve as a coupling medium 16 to transmit ultrasound waves from the ultrasound tip 20 to a wound surface . the ultrasound energy and fluid 15 may be discharged from a radiation surface 24 located on the radial surface 23 of the distal end 21 of the ultrasound tip 20 . the radiation surface 24 may be in the form of a parabolic chamber or spoon shape on the radial surface 23 . the use of a device without the deflector shield 40 is described in u . s . patent application ser . no . 11 / 857 , 162 filed sep . 18 , 2007 which is incorporated by reference in its entirety . as shown in fig1 , the housing 17 may be attached to a deflector shield 40 that covers portions of the ultrasound tip 20 . the deflector shield may optionally be attached to the housing 17 through a shield adapter 30 that surrounds the tip as a ring . the deflector shield 40 and the shield adapter 30 are preferably physically isolated from the tip to reduce the transmission of vibrations to the housing 17 . fig2 discloses an alternative embodiment of the device 10 shown in fig1 in which the ultrasound energy is being transmitted through a distal surface 22 . in this embodiment , ultrasound waves are emitted with from the radiation surface 24 with a longitudinal orientation parallel to the axial centerline of the ultrasound tip 20 . the fluid 15 , used as a coupling medium 16 is directed to the wound using a radiation surface 24 with a defined shape on the distal surface 24 . in some embodiments , the ultrasound tip 20 may contain a portion of the interior passage 12 as a chamber 13 to allow mixing , activation and / or additional holding time of the fluid within the ultrasound tip 20 . various embodiments of the radiation surface 24 , the ultrasound tip 20 and methods for using and focusing the ultrasound radiation are described in u . s . patent application ser . no . 11 / 959 , 577 filed dec . 17 , 2007 the teachings of which are hereby incorporated by reference in its entirety . the use of a device and various embodiments for using and focusing the ultrasound radiation in a device for the cryogenic ablation of tissue without the deflector shield 40 are described in u . s . patent application ser . no . 11 / 250 , 870 filed oct . 13 , 2005 the teachings of which are hereby incorporated by reference in its entirety . an exploded view of the hand - piece of an embodiment of the invention is shown in fig3 . optionally , the shield adapter 30 is used to cover portions of the ultrasound tip 20 and may be used to position the deflector shield 40 . the shield adapter 30 is particularly useful when patients are known to have blood or tissue born communicable disease . the shield adapter 30 may attach to the housing 17 through mechanical means such as for example , an o - ring , threaded connection or mechanical tabs . the deflector 40 shield may attach to the shield adapter 30 through alternative mechanical means , examples of which may include an o - ring , threading or mechanical tabs . one embodiment of the removable shield adapter 30 is shown in fig4 . the shield adapter allows easy installation of alternative shield configurations . to create a press fit the shield adapter 30 may have a protruding ring 31 slightly raised from the exterior surface of the shield adapter 30 to interlock with the deflector shield 40 and a mechanical attachment tab 32 or threaded connection for attachment to the housing 17 . the shield adapter 30 is preferably of a generally open cylindrical shape to provide isolation from the ultrasound tip 20 . fig5 is an elevational view of an alternative embodiment of the shield adapter 30 showing its use as an extension piece with an alternative mechanical attachment tab 32 . a hand piece may be used with or without a deflector shield 40 . the deflector shield 40 is preferably a disposable unit and therefore preferably constructed of a plastic material that generally maintains its shape during use , but exhibits sufficient flexibility in use to allow deformation when necessary for manipulation of the hand piece next to the patients skin without causing discomfort to the patient . typical materials of use include ; pvc , polyethylene or teflon . a silicone elastomer is preferred because of its optical clarity , mechanical characteristics and its low cost allow its economical use as a single - use item . when a deflector shield 40 is used , the deflector shield 40 may be directly coupled to the ultrasound tip 20 or it may be isolated from the ultrasound tip and directly coupled to the housing 17 , or it may be directly coupled to the shield adapter 30 . an embodiment of the deflector shield 40 is shown in fig6 . the deflector shield 40 may include a hub portion 50 located at the proximal end of the deflector shield 40 and a conical portion 60 located at the distal end of the deflector shield 40 the hub portion 50 may be preferably a hollow cylindrical surface with a length 53 and an outer diameter 56 . a conical portion 60 is located at the deflector shield 40 distal end . the conical portion 60 is preferably frusto conical with the profile of an outer surface being a concave surface 61 . the conical portion 60 has an upper base 62 with an upper diameter 63 adjacent the hub portion 50 . the upper diameter 63 is preferably approximately equivalent to the hub diameter 56 . the conical portion 60 distal end preferably has an elliptical or circular outline with a lower diameter 65 and may include a raised lip 69 that includes a ribbed edge to provide structural strength with minimal increased material and weight . fig7 is a cross - sectional view of an embodiment of the deflector shield as shown in fig6 . a central aperture 41 is sized to at least contain the ultrasound tip 20 . it may also be provided with adequate clearance to prevent direct contact with the ultrasound tip 20 . the deflector shield 40 may contain a receiving cavity 51 located near the interface between the hub portion 50 and the conical portion 60 . the conical portion 60 extends radially from the central aperture 41 . the receiving cavity 51 , formed by the protrusion of the hub portion 50 into the conical portion 60 provides improved performance of the deflector shield 40 by enhancing capture of sprayed fluids and reducing backsplash . furthermore , the receiving cavity 51 prevents contact of the splashing fluid and debris with the vibrating surface of the ultrasound tip 20 radial portion . this of course reduces reatomization of the backsplash fluid from the radial surface . the cavity also allows channeling of the splashing fluid for effective removal of the collected fluid away from ultrasound tip 20 so that it will not build up and be resuspension or reflection of the fluid back into the air . the receiving cavity 51 also further isolates the conical portion 60 from the ultrasound tip 20 . as the device is positioned during use on a patient , the conical portion 60 may deform when contacted against skin surface . the receiving cavity 51 allows the conical portion 60 to deform without contacting the ultrasound tip 20 . even with substantial deformation , the conical portion 60 that exceeds the open space provided in the conical portion 60 , the conical portion 60 will contact the hub portion 50 surrounding the ultrasound tip 20 and not contact the ultrasound tip 20 directly . this will prevent excessive unwanted ultrasound energy from being transferred to the patient tissues through the conical portion 60 of the deflector shield 40 . cylindrical surfaces are optionally provided with a relief of 1 . 6 degrees to improve manufacturability , assembly and detachment of the deflector shield 40 to the hand piece . the hub may also have a groove 54 located on an inner hub diameter 57 to accept the adapter ring 31 or an o - ring . fig8 is a distal end view of an embodiment of the deflector shield showing a circular embodiment with a lower diameter 65 . fig9 is a distal end view of an embodiment of the deflector shield 40 in an elliptical embodiment with a mechanical tab or snap coupling feature embodiment . under the preferred embodiment , the deflector shield 40 may have the following dimensions . the embodiment disclosed is not intended to be exhaustive or to limit the invention to the precise form disclosed in the detailed description . rather , the embodiments are chosen and described such that others skilled in the art might utilize their teachings . while this invention has been described as having an exemplary design , the present invention may be further modified within the spirit and scope of this disclosure . this application is therefore intended to cover any variations , uses , or adaptations of the invention using its general principles . further , this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains .