GB2436148A

GB2436148A - Portable glove tester used within the confines of an isolator

Info

Publication number: GB2436148A
Application number: GB0605424A
Authority: GB
Inventors: Richard Nathan Williams
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-03-17
Filing date: 2006-03-17
Publication date: 2007-09-19
Also published as: GB0605424D0

Abstract

A portable glove tester used within the confines of a glove-box / isolator 13 to check for leaks in the glove 14 without the glove or the hand having to be removed from the isolator, and without the glove having to be turned inside out, the glove tester surrounding the glove, sealing against it and introducing a vacuum between itself and the glove. The cuff ring on the glove forms a seal with a corresponding part on the tester unit. The glove tester is electronically controlled and battery operated. A glove size sensor 5 may cut off the vacuum pump 3 when the glove has reached a certain size. A leak in the glove will cause the glove to deflate and disengage the glove-size sensor. LEDs 8 will indicate if a hole is present in the glove. A valve 2 may be provided to reduce the vacuum to enable the glove to be removed.

Description

GLOVE INTEGRITY TESTER

Technical field

This invention relates to a high pressure glove testing apparatus in the main applicable to but not restricted to the hospital and pharmaceutical isolation technologies and more particularly to the methods employed to provide a quick, automatic and and simple system of testing without removing the glove (or hand) from its operative position WITHIN an isolation system or glove box.

Background

Isolation technology is now a vast, expanding and responsible field of industry with many of it's activities controlled by strict laws of protocol calling for many new systems and devices to im-prove on existing technology to more accurately and safely speed up production of all sorts of processing of products, medicines, vaccines, sterility testing and research.

To carry out any of these processes, a more sterile environment is called for beyond the normal clean-room facilities to safeguard the operators and also the consumers of the products, by way of an effectively controlled barrier from which the operator can work without being contaminated (toxic), or contaminating the products (sterile). This is achieved by way of the Isolator.

lsolators come in many forms, shapes and sizes mainly to satisfy the type of processing required of them, from the small two-glove type to large systems accommodating forty gloves or more.

Many Isolators consist of stainless steel cabinets with glass or polycarbonate visor panels, but mostly, a less expensive construction of a box shaped canopy of flexible plastic film sealed to a stainless steel base tray and the whole mounted taut within a stainless steel frame with suitable airflow through HEPA filters to offer positive or negative pressure within the isolator according to whether the application is aseptic or toxic respectively.

Gloves are generally attached to sleeves at the wrist on specially designed rings, and the shoulder end of the sleeve mounted sealingly to rings on the faces of the isolator below or in the visor panels.

Other types of isolators contain one or more half-suits attached sealingly at the waist to turret-like structures sealed to the floor of the isolator and fed with air to the suit helmet and body for breathing and cooling. Gloves are once again attached to the wrists of the suits on standard rigid sealing rings (our reg. design 3013656), or in a situation calling for a higher standard of integrity during glove changing, may require the safety-change ring system (our reg. design 3021444) where little or no risk is encountered.

Whatever form the Isolator takes, GLOVES of one sort or another have to be used for human manipulation. Consequently these are the most used, stressed and weakest link of the whole iso-lator system and the most feared as vulnerable and suspect to leaks, so much so that due to the absence of a suitable in-isolator tester, thousands of perfectly good gloves are discarded each day on a pure suspicion of a leak perhaps after a "snagging" on a sharp or an abrasive area of a mechanism. Or, a glove inadvertently damaged merely by the stresses of over stretching whilst removing the hand from the glove previously (always a highly probable possibility) and only dis-covered on start-up or after contamination has occurred. Meanwhile precious time is lost in changing gloves and proving isolator integrity. In some applications the complete system has to be shut down and products have to be tested or rejected and the financial loss can be extreme, apart from the possible danger to the operator in toxic or pathogenic situations.

There are already a number of glove testing facilities on the market and some of these use a system of prior art in placing a glove sealingly to a vacuum chamber and slightly raising air pressure inside the glove by way of creating a small negative pressure within the chamber by various means until the glove has reached a definite low pressure which is controlled by using a pressure switch to cut off the supply vacuum. The loss in this small pressure is then noted over a long period of time, signifying the extent of a leak, which could extend to 15 minutes or more before even a significant leak is indicated.

The main disadvantage in using such a system is that the pressure applied to the glove is fixed to a pre-determined minimal amount and is therefore not universal inasmuch that it does not test by expanding the glove according to it's structure. i.e. if set for a thin glove, it may expand slightly, whereas if the glove is quite thick there is virtually no expansion at all of the material and the glove merely straightens.

Also, as only a low fixed pressure is used, the time to detect a leak can reach well beyond practicability.

Again, pressure switches are often unpredictably erratic and lack sensitivity for small ratios of pressure differences rendering them totally unsuitable for the type of tester greatly required in the industry. Man-ual control of pressure is also fraught with problems within the small time-frames required and lacks accuracy and consistency, as a minor distraction could cause a far greater catastrophe by converting a mere pinhole to an exploding glove and therefore would not pass the Safety Standards tests.

Another disadvantage in some present systems is that they are bulky and cumbersome, and some have to be wheeled on castors to the locality of an isolator to test "in situ" where a gloved sleeve has to be turned from inside the isolator to the outside (hardly an in situ test) and applied to a test chamber with the sleeve and glove inside-out in a vertical position and going through a long and tedious routine in-volving evacuation of air, injection of gas, an expensive gas analyser etc. and then manually releasing and inverting the sleeve back into it's working position in the isolator-the whole procedure taking any-thing up to 15 minutes. Also, at no time is the glove subjected to any effective true test (a pressure purely sufficient to form a seal is inadequate to test a glove) for the potential leak area is never stretched as it could well be in normal use, so self sealing is quite possible under little or no tension, thus no leak detected. Also problems of undue stress can arise at the glove/sleeve and shoulder joints during turning of the sleeve back into the isolator, possibly even creating a leak after the test has been completed.

In the case of a serious leak, sterilization would have to be included if dangerous pathogens infiltrate the external testing apparatus before removing the glove, as the vacuum draws contaminated air through the glove from the isolator and thus to the atmosphere In order to test a glove thoroughly and in a reasonable time (say within one minute) it is necessary for a Tester to have the capability of inflating any thickness of flexible glove very quickly (say three seconds) to a definite predetermined SIZE of at least twice it's normal volume, thus also expanding any potential leak area, and this along with the automatically and accurately controlled increased pressure required to achieve this, effectively reducing the time required for leak detection. (Some of the thicker variety of gloves used, require up to 15 times the pressure of the thinnest gloves used). The Tester must also be SMALL, LIGHTWEIGHT and PORTABLE in order for the test to be carried out WITHIN THE ISO-LATOR, rendering it unnecessary to remove the glove (or indeed the hand, but very easily done whilst inflated) from the isolator. Thus the whole test is conducted WITHIN THE SAFETY OF THE ISOLA-TOR and in the event of a leak, pathogens would be contained and not released to the glove interior or the atmosphere.

These criteria coupled to an extremely sensitive leak detector system and high efficiency high pressure vacuum pump, was the ultimate goal of the present inventor. The GloveTester must also be produced and sold at less than 5% of some of the more expensive Testers (which at present can cost up to 15,000) in order to be within a realistic price range for all operators for this very essential safety test.

Hitherto, no facility to meet these criteria has yet emerged, but this is now about to change, forming a very useful and important step in glove testing technology, as from henceforth all gloves within Isolator situations can at last be cheaply and safely tested under TRULY IN SITU conditions, and will soon be declared mandataty by the HSE and other bodies for many isolator applications.

Such a device for carrying out an IN-ISOLATOR HIGH PRESSURE GLOVE TEST and methods of procedure for this and other facilities are disclosed and claimed herein.

Essential technical features According to the present invention there is essentially provided A Glove Integrity Tester comprising in the main a clear vacuum chamber of a size suitable to accommodate a gloved hand introduced through an aperture at the front end, the chamber being mounted onto a sealed plastic control box, housing the electronic control system for actuating and regulating a vacuum pump mounted to the rear of the vacuum chamber.

Th,cntr-l Ict flln'tnnc cprpc Af,llI int1ii'tnrc fitted th frnnt nf the nntrnI hn, with addi-Another important feature of the invention is the neccessity for some of the thinner gloves to have their stretch on inflation to be more evenly distributed throughout the glove as there is a tendency for higher inflation to occur in the larger areas, i.e. the wrist/palm, and less in the finger area. This is achieved by way of a cylinder 15 of flexible open cell plastic foam to form a buffer placed to the inside wall within the first 10 cms or so of the vacuum chamber 1 glove aperture, and with an aperture of corresponding size. This can remain in position for the testing of all gloves and can easily be removed for routine cleaning, but should be periodically renewed.

Glove sensor 5 and release valve 2 can also be easily removed from their slots in chamber I for routine cleaning and swabbing out manually, but normal purging of the isolator would in most cases serve admirably.

Thus, it can readily be seen from this description, that as the testing of gloves can be en-tirely carried out within the safe confines of the glove-box or isolator, with a capability of detecting a small pin- hole within one minute (hitherto undetectable in some gloves by a standard water test) which can be equally applicable to both simple sleeve systems and half-suits, involving a minimum of skill requirement to routinely produce reliable results quickly, and peace of mind for the operator.

Claims

CLAIMS

I A completely portable battery operated, automatic and electronically controlled HIGH PRESSURE Glove In-tegrity Tester, capable of detecting a small pinhole in less than one minute TRULY IN SITU, WITHIN the normal working confines of an isolator system without removing the glove (or hand) from within the isolator and without having to turn the glove inside-out.

2A Glove Integry Tester as defined in Claim 1, whose electronic control system indicates the integrity of the