GB2249962A - "Puncture apparatus" - Google Patents

Abstract

The apparatus, which is used for administering vaccines such as BCG, is provided with a head unit comprising an outer housing 10 having apertures 12 through its end face 24 which is placed against a patient's skin for administration of the vaccine. Needles 16 mounted on a needle block 14 are disposed within the housing and, on actuation by an actuating body 30, 32, the needles are projected through the apertures and into the patient's skin. The actuating body is attached to the head unit and is guided during attachment by an end portion 29 of the outer housing of increased diameter. Once the vaccine has been administered the needle block remains in its extended position. The head unit is removed to be replaced by a sterile head unit and the used head unit is discarded. <IMAGE>

Description

"Puncture Apparatus" This invention relates to an improved puncture apparatus for use with vaccines in such areas as the administration of BCG.

At present there are two basic forms of apparatus used for the Heaf test for tuberculosis. One such form has an interchangeable needle block with stainless steel needles mounted separately in the block and individually disposable. The block is mounted on a body which has a heat resistant handle and a stainless steel shaft and all parts can be sterilised by autoclaving. In addition the needles may be sterilised by soaking them with methylated spirit which is then ignited and burned off, but this form of sterilisation can be dangerous in its use of a naked flame in close proximity to volatile spirit, and indeed accidental fires have on occasion occurred. Further, disquiet has been expressed about the repeated use of the same apparatus.

The other form of the apparatus has a stainless steel plate with a number of raised points, the plate being held in position by a magnetic head. After sterilisation, which is effected by autoclaving, the plate is easily picked up by holding the magnetic head directly over the plate or by placing the plate in position on the head using sterile forceps.

This latter form of the apparatus allows a separate plate to be used for each patient, and overcomes the above-described disadvantages of the first form.

However, recent results have shown that the results are not as effective as with the first form possibly due to the head of the gun being annular and holding the skin down only at its edges, thus allowing the skin to flex under impact of the points. Also, the stainless steel plate attached to the head has a central hole through which the magnet may become contaminated by splashing of vaccine or blood. The rim of the magnetic head, which is not sterilised between each use, can also give rise to contamination on touching the skin of the patient.

According to the present invention there is provided puncture apparatus comprising a housing having an end face for contact with the skin of a patient, a block slidable within the housing between a first position spaced from the end face and a second position adjacent the end face, at least one needle extending from the block towards the end face and contained within the housing in the first position, the needle extending through an aperture in the end face when the block is in the second position.

Preferably means are provided for releasably attaching the apparatus to an actuating body so that the block is movable between its first and second positions on actuation of the body.

Preferably, stainless steel needles are used, but moulded plastic needles may be satisfactory.

The aperture in the end face of the housing is preferably of a size allowing through passage of the needle with only a small clearance.

Preferably, the needle is of round cross-section.

The block may be made from any suitable material; moulded plastics materials may be preferred as being inexpensive.

Preferably, the apertured end face is planar so as to apply even pressure across the engaged area of the patient's skin.

Preferably also, the portion of the housing which engages the body is shaped to act as a guide for ease of fitting the apparatus to the body and to provide a mask to protect the end of the body from contamination during the test.

Preferably the position of the needles can be altered to allow a different number and formation of needles to be used during the test.

The introduction of the outer housing combats the problems of the aforementioned existing forms of the apparatus. It does this by providing a bearing surface for the apparatus against the skin and by keeping the actuating body out of contact with the patient. When the end face of the housing is planar, the needle is aligned with and extends through the aperture, providing a more accurate test.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a cross-sectional side view of one embodiment of apparatus in accordance with the present invention; Fig. 2 is a plan view of the end face of the needle block of the apparatus of Fig. 1; and Fig. 3 is a partial section through the needle block of Fig. 2 on line A-A.

Referring to the drawings, this embodiment of the apparatus of the invention is a head unit for multiple puncture apparatus, and comprises a cup-shaped outer housing 10 with apertures 12 through the end face 24.

A cylindrical moulded plastics needle block 14 in which needles 16 are mounted is disposed within the outer housing 10. The block 14 has one or more orientation projections 17 along its length to maintain it in a predetermined attitude relative to the housing 10 which has corresponding guides on its inner face 18. It also has one or more annular projections 19.

The needle block 14 has two concentric arrays of through holes 20, 22 in which the needles 16 are secured and from which they project at one end towards the end face 24 of the housing 10. The needle block 14 has attached to its opposite end face a magnetic plate 26 and is held in the outer housing 10 by locating projection 19 between annular ridges 27 and 28 on the housing 10, or by clips. An actuating body in the form of a handle assembly 30 has a magnet 32 and is attached onto the head unit, being guided during attachment by an end portion 29 of the outer housing 10 of increased diameter. The magnet 32 is slidable within the handle assembly 30.

In use the apparatus provides a means of administering vaccines such as BCG. The end face 24 of the housing 10 is placed against a patient's skin. The outer housing 10 with the apertures 12 in its end face aligned to the needles 16 in the needle block 14 extends around the end portion of the handle assembly 30 and protects it against contamination during use.

The handle assembly 30 is then operated in conventional manner to fire the magnet 32 forwardly towards the end face 24, overcoming the friction of the ridge 28, thus projecting the needles 16 mounted on the needle block 14 through the apertures 12 and into the skin. The end face 24 lies against the skin during this operation, ensuring uniformity of penetration.

After use, the needle block 14 is held forward by ridge 27 and cannot be re-set. The protruding needles give a positive indication that the head unit has been used.

The head unit is therefore removed from the handle assembly and replaced with a sterile head unit. The used head unit is then discarded.

For a standard Heaf test the needle block 14 mounts only six needles on the inner array 20. Where a BCG vaccination is to be administered a further twelve needles can be mounted on the outer array 22, giving an eighteen puncture pattern. Other patterns of needles may be arranged in the holes 20, 22 in the needle block 14, if desired.

The throw of the needles 16 can be reduced if desired by introducing an insert 34.

Modifications and improvements may be incorporated without departing from the scope of the invention. For example the plastics needle block 14 and separate magnetic plate 26 can together be replaced by a stainless steel needle block.

Claims (10)

1. Puncture apparatus for use with vaccines comprising a housing having an end face for contact with the skin of a patient, a block slidable within the housing between a first position spaced from the end face and a second position adjacent the end face, at least one needle extending from the block towards the end face and contained within the housing in the first position, the needle extending through an aperture in the end face when the block is in the second position.

2. Apparatus as claimed in Claim 1, in which means are provided for releasably attaching the apparatus to an actuating body so that the block is movable between its first and second positions on actuation of the body.

3. Apparatus as claimed in Claim 2, in which an area of attachment of the actuating body to the block is enclosed by the actuating body, the block and a wall oJ the housing.

4. Apparatus as claimed in Claim 1, 2 or 3, in which said at least one needle is of stainless steel.

5. Apparatus as claimed in Claim 1, 2 or 3, in which said at least one needle is of moulded plastics material.

6. Apparatus as claimed in any one of the preceding Claims, in which said at least one needle is of round cross-section.

7. Apparatus as claimed in any one of the preceding Claims, in which the block is made from moulded plastics material.

8. Apparatus as claimed in any one of the preceding Claims, in which the apertured end face is planar.

9. Apparatus as claimed in any one of the preceding Claims, in which said at least one needle is removable from the block, and the block includes means for receiving said at least one needle in a plurality of alternative positions.

10. Puncture apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.