GB2373443A - Apparatus for removing surface portions of human tissue - Google Patents

Abstract

A single piece end piece (20) for a hand tool (1) of a tissue removal apparatus has a cylindrical portion terminating in a first dome shaped end (22), the first dome shaped end (22) defining a first hollow portion (24) delimited by an internal wall of the dome shaped end, and a central core (25) arranged within the body of the end piece. A second end of the cylindrical portion has a centrally arranged, cylindrical indentation defining a second hollow portion. The central core has a first and second bore (28, 29) passing therethrough and connecting the first hollow portion (24) with the second hollow portion. The second bore (29) terminates in a nozzle shaped end (30) opening into the first hollow portion (24) and the central core (25) is so shaped where it delimits the first hollow portion (24) as to provide a greater separation between the end of the second bore (29) and the inner wall of the dome than between the end of the first bore (28) and the inner wall of the dome. The dome shaped end has an eccentrically positioned orifice (31).

Description

IMPROVEMENTS IN AND RELATING TO APPARATUS FOR REMOVING SURFACE PORTIONS OF HUMAN TISSUE This invention relates to apparatus for the controlled removal of surface portions of human tissue, most particularly the outer layers of human skin tissue.

Various apparatus for the removal of surface tissue are known. Examples are given in WO 99/37229, EP 564392, US 5971999 and EP 318042. Generally these apparatus comprise a source of abrasive material which is directed, under pressure, via a conduit to a nozzle where it is directed against the tissue surface. A second conduit is connected to a suction device and draws exfoliated debris and used abrasive material away from the tissue surface for disposal.

The abrasive material is typically a hard particulate solution in an aqueous carrier.

A hand tool is generally used to direct the abrasive material at the tissue surface.

These hand tools take various forms but typically comprise a handle portion configured to be gripped by a surgeon performing the treatment; two conduits carried by and extending from the distal end of the handle, each having an open end, one for carrying and releasing the abrasive material under pressure and one for withdrawing debris.

Surmounted over the ends of the conduit and handle is a dome shaped cap having a shaped orifice cut off-centre of the dome. This orifice is used to direct the abrasive material at the tissue surface.

It will be appreciated that the use of such apparatus as has been described above proposes a potential health risk in that biological material removed from one subject may potentially be transferred to another subject if suitable hygiene procedures are not followed. In particular, infectious agents such as the HIV virus or Hepatitis virus which are carried in the blood may potentially be transferred where skin abrasion leads to bleeding. In order to prevent such transfers of infection, the hand tools of the known arrangements have a removable cap which can easily be disposed of and replaced. The exposed ends of the conduits are typically removable from the handle and can be sterilised before re-use by, for example, an autoclave. After cleaning, the conduits are replaced and a new cap is placed over the handle ready for treatment of the next patient.

Whilst such procedures, if used properly, are generally effective in preventing cross infection, the task of disassembling the hand tool, cleaning, sterilising and reassembling the tool is cumbersome and time consuming, hence, there is a temptation for the user simply to replace the disposable cap which has direct contact with the surface tissue to be treated without thoroughly sterilising other components of the hand tool. Whilst this significantly reduces the risk of cross infection, it does not provide the same level of protection as is provided if the correct procedure is followed.

The present invention aims to simplify the procedures for sterilising the hand tools described with a view to improving hygiene in clinics using the above mentioned tissue removal apparatus and minimising any risk of cross infection between subjects receiving the treatment.

In accordance with the present invention there is provided an end piece for a hand tool of a tissue removal apparatus comprising a single piece having an external surface comprising a cylindrical portion terminating in a first dome shaped end and a second flat, circular end; the first dome shaped end defining a first hollow portion delimited by an internal wall of the dome shaped end and a central core arranged within the body of the end piece; the second flat, circular end having a centrally arranged, cylindrical indentation defining a second hollow portion delimited by the internal wall of the cylindrical portion and the central core; the central core having a first and second bore passing therethrough and connecting the first hollow portion with the second hollow portion, the first bore terminating in a nozzle shaped end opening into the first hollow portion; the central core being so shaped, where it delimits the first hollow portion, as to provide a greater separation between the end of the first bore and the inner wall of the dome than between the end of the second bore and the inner wall of the dome; and, the dome shaped end having an eccentrically positioned orifice.

An illustration of an apparatus for removing surface portions of human tissue of the type described in EP 318 042 is shown in Figure 1. As can be seen from the figure, the apparatus has a hand tool for applying the treatment to the tissue surface which generally comprises a cylindrical body (1) surmounted by a dome shaped cap (2). The body (1) houses first and second parallel tubes (3,4) which connect respectively with a source of abrasive material and a suction pump (not shown). A nozzle (5) is seated on the end of the second parallel tube (4) and is held in position by a block (6) which is mechanically fixed to the cylindrical body (1) by a screw (7). The cap (2) sits atop the block and has a hole (8) arranged eccentrically of the domed surface.

The end piece of the invention may be attached directly to the cylindrical body of a hand tool of any existing tissue removal apparatus. In the illustrated case of the apparatus of EP 318 042, the end piece is used in place of the nozzle, block and spherical cap of the apparatus described therein. The cylindrical indentation receives the end of the hand tool and the first and second bore are configured to align with the exits of the parallel tubes housed in body of the hand tool. The end piece may be suitably proportioned to provide a firm push fit onto the end of the hand tool and may optionally be fastened by other means. The external surface of the end piece which positions adjacent the hand tool body is preferably provided with a ridged or otherwise roughened surface for better grip by the user.

After use on one subject the nozzle of the invention can be quickly and easily removed as a single piece for cleaning, sterilising and replacing. Alternatively, the end piece can be disposed of and replaced with another, similar end piece.

The end piece of the invention may conveniently be manufactured inexpensively by moulding, either as a single piece or as two pieces which can be bonded together to form a single piece. Where two pieces are moulded these may conveniently be the cylindrical portion and the central core. If the tolerance of manufacture of the pieces is sufficiently good, the central core may optionally be force fitted into the cylindrical portion without the need for bonding.

The end piece may be manufactured from any material which is non-toxic to human tissues. Suitable materials are plastics which are generally inexpensive and easy to mould enabling the end piece to be manufactured on a large scale at low cost and thereby saleable as a disposable product.

An embodiment of the invention will now be described by way of example with reference to the Figures in which; Figure 1 is a schematic sectioned view of the hand tool of a prior art apparatus for the removal of tissue as disclosed in EP 318 042; Figure 2 is a perspective view of one embodiment of an end piece according to the present invention; Figure 3 is a schematic sectioned view of the end piece of Figure 2 incorporated with the hand tool of Figure 1.

Figure 2 shows an end piece according to the present invention. The end piece of the embodiment is manufactured from a partially transparent plastics material and is shown in a perspective view (b) with the view from either end (a) and (c) also shown.

As the material is transparent, the outline of the internally arranged features are shown in broken lines for clarity.

As can be seen from the figure, the end piece comprises a single piece generally indicated as (20). The external surface of the piece (20) comprises a cylindrical portion (21), the terminating at one end in a dome shaped end (22) and at the other in a flat, circular end (23).

The dome shaped end defines a first hollow portion (24) which is delimited by an internal wall of the dome shaped end and a central core (25) arranged within the body of the end piece (20). The flat, circular end has a centrally arranged, cylindrical indentation (26) defining a second hollow portion (27) delimited by the internal wall of the cylindrical portion and the central core (25).

The central core (25) has two bores (28,29) passing therethrough and connecting the first hollow portion (24) with the second hollow portion (27). The first bore (28) terminates in a nozzle shaped end (30) opening into the first hollow portion (24). The central core has a stepped surface where it delimits the first hollow portion (24) arranged so that a greater separation is provided between the end of the first bore (28) and the inner wall of the dome than between the end of the second bore (29) and the inner wall of the dome. The dome shaped end (22) is provided with an eccentrically positioned orifice (31). The outer surface (32) of the cylindrical portion (21) adjoining the flat, circular end (23) is provided with a ribbed texture for improved grip by the user.

In Figure 3, the nozzle (5), block (6), screw (7) and cap (8) of the hand tool of the prior art have been removed and replaced with an end piece (20) according to the present invention. In use an abrasive substance is provided through first tube (3) of the hand tool and into bore (29) of the end piece (20). The substance flows into the hollow cavity (24) and exits through orifice (31) which is positioned adjacent the tissue to be exfoliated. Spent abrasive substance and removed tissue is drawn back through the orifice (31) by the action of the suction pump (not shown). The pump draws these materials through nozzle (30) into bore (28) and into tube (4) of the hand tool from where it is drawn by the suction pump into a suitable container for later disposal.

It is to be understood that the foregoing represents just one embodiment of the invention and is not intend to detract from the true scope of the invention as claimed in the appended claims.

Claims (7)

1. CLAIMS 1. An end piece for a hand tool of a tissue removal apparatus comprising; a single piece having an external surface comprising a cylindrical portion, the cylindrical portion terminating in a first dome shaped end and a second flat, circular end; the first dome shaped end defining a first hollow portion delimited by an internal wall of the dome shaped end and a central core arranged within the body of the end piece; the second flat, circular end having a centrally arranged, cylindrical indentation defining a second hollow portion delimited by the internal wall of the cylindrical portion and the central core; the central core having a first and second bore passing therethrough and connecting the first hollow portion with the second hollow portion, the first bore terminating in a nozzle shaped end opening into the first hollow portion; the central core being so shaped where it delimits the first hollow portion as to provide a greater separation between the end of the first bore and the inner wall of the dome than between the end of the second bore and the inner wall of the dome; and, the dome shaped end having an eccentrically positioned orifice.
2. 2. An end piece as claimed in claim 1 wherein the end piece comprises a rigid plastic material.
3. 3. An end piece as claimed in claim 1 or claim 2 wherein the end piece is manufactured by a moulding process.
4. 4. An end piece as claimed in any preceding claim wherein the end piece is disposable.
5. 5. An end piece as claimed in any preceding claim wherein there is provided specific means for attachment to the body of the hand tool.
6. 6. An end piece as claimed in any preceding claim wherein the external wall of the cylindrical portion is provided with an easy grip surface.
7. 7. An end piece substantially as described herein with reference to Figures 2 and 3.