GB2324469A

GB2324469A - Sterile envelope for medical equipment

Info

Publication number: GB2324469A
Application number: GB9708400A
Authority: GB
Inventors: John Francis Cockburn
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-04-24
Filing date: 1997-04-24
Publication date: 1998-10-28
Also published as: GB9708400D0

Abstract

A sterile envelope (2) for providing a sterile covering over an item of medical equipment (1) such as an ultrasound probe has a sterile inner surface (3) and an unsterile outer surface (4) and is rupturable and evertable over the probe (1) so that the sterile inner surface (3) becomes the outer surface. Before eversion the envelope is sealed and is ruptured (8) at one end by pressure build-up as the probe (1) is applied. Ultrasound jelly (6) is contained in the sterile interior of the envelope. In another embodiment the envelope is attached by its open mouth to the interior of a cardboard tube which facilitates insertion of the probe, in this case without eversion of the envelope.

Description

Sterilising arrangement and method The present invention relates to an arrangement and method of providing a sterile exterior surface over an item of medical equipment. The item of medical equipment may for example be a hand-held item such as an ultrasound probe.

The invention is applicable particularly but not exclusively to relatively complex electronic or electromechanical items of equipment which cannot be reliably and safely sterilised by conventional means such as heating or gas sterilisation.

Accordingly, such items are normally covered with an elongate sterile envelope so that any surface which comes into contact with a patient is the sterile outer surface of the covering envelope.

At present, ultrasound probes are sterilised by sliding an open-mouthed elongate tubular envelope over the probe. The envelope is packed in a sterile package, together with rubber bands which are used to attach the envelope to the probe. Additionally, the package includes a sachet of sterile ultrasound coupling jelly which is smeared over the exterior of the envelope after the latter has been opened and fitted over the probe.

Since both an unsterile item of medical equipment and a package containing sterile materials must be handled in order to fit the envelope over the equipment, the doctor (wearing sterile gloves) requires an assistant for this somewhat cumbersome operation.

An object of the present invention is to overcome or alleviate at least some of the above disadvantages.

In one aspect the invention provides an arrangement for providing a sterile exterior surface over medical equipment, the arrangement comprising a flexible envelope having an inner surface and an outer surface, one of said surfaces being sterile and being separated from the other surface by a closure, said other surface being contactable in use with the medical equipment.

Preferably said other surface is unsterile.

In one embodiment said other surface is initially the outer surface and the envelope is arranged to be evertable over the probe or other item of medical equipment. In this embodiment the closure is preferably a rupturable closure (of a suitable medical adhesive for example) which seals an edge region of the envelope which after eversion becomes the open mouth of the envelope at the proximal end of the probe or other item of medical equipment.

In another embodiment the arrangement comprises means for supporting the envelope in an open or expanded configuration so as to facilitate introduction of such medical equipment into the envelope. For example the supporting means could comprise a generally tubular support attached to a mouth region of the envelope.

Preferably the supporting means comprises a gas-permeable container, which enables the exterior surface of the envelope to be sterilised with a conventional sterilising gas. The gas-permeable container may for example be a cardboard container, cardboard being sufficiently gas-permeable for sterilisation but the pores being sufficiently small to protect the envelope against bacterial contamination.

In this embodiment the closure preferably comprises a cap over said mouth region.

In another aspect the invention provides a method of providing a sterile exterior surface over an item of medical equipment comprising the steps of providing an envelope having an inner surface and an outer surface separated by a closure, one of said surfaces being sterile, removing or rupturing the closure and enveloping the item of medical equipment by introducing it against the other of said surfaces.

In another aspect the invention provides a method of providing an exterior sterile surface over an item of medical equipment comprising the step of everting a flexible envelope over the item of medical equipment, the inner surface of the envelope before inversion being sterile and becoming the exterior sterile surface on eversion.

Preferred features are defined in the dependent claims.

Preferred embodiments are described by way of example only with reference to Figures 1 to 7 of the accompanying drawings, wherein: Figure 1 is a diagrammatic longitudinal cross-section of an item of hand-held medical equipment together with an envelope in accordance with the invention; Figure 2 is a diagrammatic longitudinal cross-section showing the arrangement of Figure 1 with the envelope's closure ruptured by pressure from the item of equipment; Figure 3 is a diagrammatic longitudinal cross-section showing the envelope of Figure 1 fitted over the item of medical equipment following eversion of the envelope; Figure 4 is a diagrammatic longitudinal cross-section of apparatus similar to that of Figure 3 showing a sterile needle inserted through a wall of the envelope into a holder in the item of medical equipment; Figure 5 is a diagrammatic longitudinal cross-section of another embodiment of the invention; Figure 6 is a diagrammatic longitudinal cross-section of the embodiment of Figure 5 with one end cap removed and an item of medical equipment inserted into the envelope, and Figure 7 is a diagrammatic longitudinal cross-section of the embodiment of Figure 5 showing a later stage in the insertion of the item of medical equipment in the envelope with the envelope about to be removed from the supporting tube.

Referring to Figure 1, the envelope 2 comprises an inner sterile surface portion 3 and an outer unsterile surface portion 4, which are each suitably composed of polyethylene or thin latex. The envelope is scaled at a closure 5 which could for example be a thermal seal or comprise an appropriate medical adhesive.

The envelope is at least partially inflated and is sterilised with a suitable sterilising gas such as ethylene oxide. The envelope optionally contains a quantity of sterile jelly such as ultrasound coupling jelly for example (if the item of medical equipment 1 is an ultrasound probe).

As shown in Figure 2, the item of medical equipment 1 is grasped in one hand and applied against one end of the envelope 2 (which is grasped in the other hand), increasing the pressure in the envelope and rupturing the closure 5.

The regions of the envelope 2 around the closure 5 are folded in the directions indicated by arrows 7 to evert the envelope and roll it over the item of medical equipment with the unsterile surface region 4 on the inside facing the outer surface of the item of medical equipment and the sterile surface region 3 on the outside of the envelope, the latter surface region being smeared with a layer of the sterile jelly 6. This state is shown in Figure 3.

As shown in Figure 4, a further, preferably sterile item of medical equipment 20 (eg a drill or a needle) can be inserted through the envelope wall (eg by piercing the wall with item to 8) and located at the distal end of item 1.

Referring to Figure 5, the arrangement shown comprises a cardboard tube 8 about 150 to 200 mm in length, of 0.5mm wall thickness and about 75 mm in diameter which is permeable to a sterilising gas such as ethylene oxide but impermeable to bacteria. It is capped at each end by removable caps or closure members 9 and 10 and has an open tubular envelope 2' (which may for example be similar to envelope 2 of the embodiment of Figures 1 to 4) removably attached at its mouth to the left hand end of the interior of the tube. A blob of sterile jelly 6 (which may be ultrasound coupling jelly for example) is adhered to the distal tip (right hand end) of the outer surface of envelope 2' and the interior of the envelope (which may contain unsterile ultrasound coupling jelly - not shown) is unsterile. The length of the envelope 2' is about 600 to 900mm - ie considerably longer than the tube 8.

As shown in Figure 6, in use an item of unsterile medical equipment such as an ultrasound probe 1 is inserted into the open mouth of envelope 2, after removing cap 9.

The other cap 10 is then removed and the probe 1 is inserted further as shown in Figure 7, extending the envelope 2' until it ruptures the bond between the mouth of the envelope 2' and the bore of the tube 8, enabling the latter to be separated from the assembly.

The above operations shown in Figures 6 and 7 are performed by the user before he or she has donned sterile gloves, grasping the outside of the tube 8 in one hand and an unsterile proximal (left hand end in the view shown in Figure 6) region of the probe 1 in the other, In use the probe 1 is held by the user gripping a sterile outer region of envelope 2' with a sterile glove.

Claims

1. An arrangement for providing a sterile exterior surface over medical equipment, the arrangement comprising a flexible envelope having an inner surface and an outer surface, one of said surfaces being sterile and being separated from the other surface by a closure, said other surface being contactable in use with the medical equipment.

2. An arrangement as claimed in claim 1 wherein said other surface is unsterile.

3. An arrangement as claimed in claim 1 or claim 2 wherein said other surface is initially the outer surface and the envelope is arranged to be evertable over the medical equipment.

4. An arrangement as claimed in any preceding claim comprising means for supporting the envelope in an open or expanded configuration so as to facilitate introduction of such medical equipment into the envelope.

5. An arrangement as claimed in claim 4 comprising a generally.tubular support attached to a mouth region of the envelope.

6. An arrangement as claimed in claim 5 wherein said closure comprises a cap over said mouth region.

7. An arrangement as claimed in any of claims 4 to 6 wherein said supporting means comprises a gas-permeable container.

8. An arrangement as claimed in claim 5 wherein said tubular support is capped at each end to enclose the envelope and is removable from the envelope.

9. An arrangement as claimed in claim 3 or claim 4 wherein said envelope is sealed in an at least partially inflated condition and the seal is rupturable in use as the envelope is everted over the medical equipment.

10. An arrangement as claimed in any preceding claim wherein said sterile surface is in contact with sterile jelly.

11. An arrangement as claimed in claim 10 wherein said jelly is an ultrasound coupling medium.

12. A method of providing a sterile exterior surface over an item of medical equipment comprising the steps of providing an envelope having an inner surface and an outer surface separated by a closure, one of said surfaces being sterile, removing or rupturing the closure and enveloping the item of medical equipment by introducing it against the other of said surfaces.

13. A method as claimed in claim 12 when performed using an arrangement as claimed in any of claims 1 to 1 1.

14. A method of providing an exterior sterile surface over an item of medical equipment comprising the step of everting a flexible envelope over the item of medical equipment, the inner surface of the envelope before inversion being sterile and becoming the exterior sterile surface on eversion.

15. A method as cured in claim 14 when performed using an arrangement as claimed in any of claims 4 to 10 as dependent on claim 3.

16. A method as claimed in claim 14 or claim 15 wherein a further item of medical equipment is attached to the first-mentioned item of medical equipment by insertion through the wall of the envelope.

17. A method as claimed in claim 16 wherein said further item of medical equipment is a needle.

18. An arrangement for providing an exterior sterile surface over an item of medical equipment substantially as described hereinabove with reference to Figures 1 to 4 or Figures 4 to 7 of the accompanying drawings.

19. A method of sterilising an item of medical equipment substantially as described hereinabove with reference to Figures 1 to 4 or Figures 4 to 7 of the accompanying drawings.