WO2016009204A1

WO2016009204A1 - Methods and devices for testing the effectiveness of an automated apparatus for the cleaning of medical instruments

Info

Publication number: WO2016009204A1
Application number: PCT/GB2015/052047
Authority: WO
Inventors: Lawrence Ralph Dawson
Original assignee: Medisafe Uk Limited
Priority date: 2014-07-16
Filing date: 2015-07-15
Publication date: 2016-01-21
Also published as: GB201412601D0

Abstract

Disclosed is a process challenge device for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments. The PCD is flexible and defines a main body having a test soil material disposed thereon. A plurality of attachment formations project from the main body which may be used to mount the PCD directly to an instrument carrier for an automated cleaning apparatus by cooperation with a mesh of the instrument carrier. Also disclosed is a method for testing the effectiveness of an automated apparatus for the cleaning of medical instruments wherein the PCD is directly mounted to the instrument carrier.

Description

METHODS AND DEVICES FOR TESTING THE EFFECTIVENESS OF AN AUTOMATED APPARATUS FOR THE CLEANING OF MEDICAL INSTRUMENTS The present invention relates to methods and devices for testing the effectiveness of an automated apparatus for the cleaning of medical instruments. The present invention also extends to methods of manufacturing a device for testing the effectiveness of an automated apparatus for the cleaning of medical instruments.

The invention is particularly, although not exclusively, applicable to methods and devices for testing the effectiveness of an automated apparatus for the cleaning of surgical instruments, and to methods of providing such devices. However the methods and devices of the invention in its various aspects may also be applied to testing the effectiveness of an automated apparatus for the cleaning of other types of medical instrument. The medical instruments may be for use in any medical field, including dental and veterinary fields.

The methods and devices of the invention are applicable to testing the effectiveness of an automated apparatus that may used to clean any medical instruments that are being reprocessed subsequent to use to enable them to be reused. While the medical instruments may be constructed to be non-disposable, the present invention is also applicable to apparatus that are used to clean disposable instruments, which in many cases are too expensive to be disposed of after a single use. For example, the invention may be applied to automated apparatus used to clean so-called "reposable" instruments, which are limited to a certain number of uses e.g. 10 uses. Thus, the invention may be applied to automatic apparatus for cleaning non-disposable, disposable or semi-disposable or reposable instruments. Thus, the invention is broadly applicable to providing methods and devices for testing the effectiveness of an automated apparatus for the cleaning of reusable medical instruments.

It is important that all external surfaces of the instruments are thoroughly cleaned to remove any body fluids, proteins, tissue or bone fragments etc prior to reuse of the instrument. In particular it is important to remove all traces of blood from an instrument surface before any disinfection and/or sterilisation that occurs prior to reuse. Dried blood is particularly difficult to remove from surfaces due to the presence of fibrin which can strongly adhere to particular instrument features and surfaces e.g. of stainless steel instruments. Blood can become even more difficult to clean when it is heated as the proteins therein denature and become insoluble in water.

It is often desirable to disinfect and/or sterilise instruments following a cleaning process to reduce the risk of transmitting infection between patients. For example, instruments may undergo disinfection and then sterilisation as a final decontamination stage following cleaning. If an instrument is not sufficiently cleaned prior to disinfection, contaminants e.g. blood or other organic matter may become more firmly fixed to the instrument during the disinfection process, as a result of the high temperatures and chemicals used. Similarly, if sterilisation is carried out on an instrument that has not been sufficiently cleaned, whether or not disinfection is first performed, the sterilisation may be ineffective if contaminants remain on the instrument following cleaning.

Cleaning of an instrument involves contacting the instrument with a cleaning fluid i.e. liquid. The cleaning fluid is a cleaning liquid, and may comprise water, and may further comprise one or more cleaning agents e.g. detergents. Cleaning may involve forcing pressurised cleaning fluid over the instruments to achieve cleaning. This so-called "deluge cleaning" is typically carried out in large deluge washer machines which spray fluid over the instruments in a similar manner to a dishwasher machine. Medisafe UK Limited's Niagara® range washers, e.g. the Niagara ® Express, are examples of deluge cleaning systems. Disinfection may also be carried out in this way using fluid at an elevated temperature.

Alternatively or additionally, cleaning of medical instruments may involve the use of ultrasonic waves. In an ultrasonic cleaning process, the instrument is immersed in a bath of cleaning liquid. Ultrasonic transducers are used to excite liquid in the bath, causing ultrasonic waves to propagate through the liquid. The ultrasonic waves cause small, high pressure bubbles to form and collapse in the liquid at high frequency. This "cavitation" effect gives rise to pressure waves in the liquid, which acts to "scrub" the surfaces of the immersed instrument. In this way, debris attached to the surfaces of the instrument may be loosened. Cleaning fluid i.e. liquid may be supplied to internal surfaces of the instruments during ultrasonic cleaning. Instruments may also be subjected to soaking in which they are immersed in liquid e.g. provided in an ultrasonic reservoir, but without the application of ultrasonic waves.

Ultrasonic cleaning may be carried out alone, or in combination with deluge cleaning. Deluge cleaning may be used to help flush debris dislodged by the ultrasonic cleaning from the surfaces of the instrument. Combined ultrasonic and deluge cleaning washers are known. Examples include Medisafe UK Limited's

Niagara® SI ultrasonic® and Niagara® SI PCF® machines. These machines include an ultrasonic reservoir situated in the base of a cleaning chamber, with deluge sprayers arranged above the reservoir. Instruments are inserted into the chamber at various levels. This may be achieved by placing the instruments directly on a carrier of the machine, or by first placing them in baskets which are then placed on the carrier. The lowermost instruments may be immersed in the ultrasonic reservoir to enable ultrasonic cleaning to be carried out. This may be achieved by lowering the carrier appropriately and/or filling the ultrasonic reservoir with liquid to cover the instruments. The bath may or may not then be drained and/or the deluge sprayers operated. Operation of the deluge sprayers may provide deluge cleaning of those instruments situated in the upper parts of the cleaning chamber, and in some cases, the ultrasonically cleaned instruments in the reservoir if drained. In other situations, cleaning may involve ultrasonic cleaning without deluge cleaning. Examples of such ultrasonic cleaning machines include Medisafe UK Limited's Sonic Irrigator® range e.g. the Sonic Irrigator® SA® and Sonic Irrigator® PCF®.

In general cleaning may include any or all of deluge cleaning, which may include pre wash, wash and rinsing stages; ultrasonic cleaning; and soaking. The cleaning may be followed by disinfection and/or sterilization.

The devices and methods of the present invention are applicable to automated cleaning apparatus that are used to implement any cleaning process or processes for the cleaning of medical instruments. It will be appreciated that the apparatus is for the automated cleaning of medical instruments, and may be arranged to perform an automated cycle for the cleaning of medical instruments. The cleaning performed by the apparatus e.g. cleaning cycle may include any one or ones of the above cleaning processes, and optionally may form part of a

decontaminating process e.g. cycle including one or more additional decontamination processes e.g. disinfection and/or sterilisation. The apparatus is arranged to bring a cleaning fluid, i.e. a liquid, into contact with the instruments to be cleaned. The apparatus is preferably arranged to carry out deluge cleaning, although may additionally or alternatively be arranged to carry out ultrasonic cleaning. The apparatus may be configured to carry out additional decontaminating processes such as disinfection and/or sterilisation. The invention is particularly applicable to a cleaning apparatus that is an automated washer or washer-disinfector.

Automated medical instrument cleaning apparatus may be subject to faults which could affect the ability of the apparatus to function effectively. Such faults could occur, for example, in the water pump(s), detergent delivery system, heating system, water delivery system, water treatment system or computer control or software upgrade. These faults might not be immediately apparent to the operator of the apparatus resulting in ineffective cleaning of instruments. Ineffective cleaning can cause serious risk to washer operators, medical personnel and patients.

In order to detect faults of the apparatus, regular tests need to be performed in order to monitor its effectiveness. In some cases tests need to be performed daily, while in other cases tests need to be performed weekly or monthly.

For hospital equipment in particular, such tests need to meet strict standards, such as those of ISO 15883 or equivalent.

Known tests include painting a test soil material, which simulates blood or organic material, on inside surfaces of the cleaning chamber of the apparatus. A cleaning cycle is then conducted and the interior of the chamber inspected to detect any remaining soil material which would indicate ineffective cleaning. Painting the inside of a cleaning chamber is, however, time consuming and impractical for regular testing.

Process challenge devices (PCDs) have been developed in order to streamline the testing process. PCDs are devices which incorporate a soil material to simulate an instrument to be cleaned. The invention relates to such PCDs. PCDs have become widespread in the field of testing automated apparatus for cleaning medical instruments, and come in a variety of configurations in order to simulate particular scenarios for cleaning. Typically, known PCDs include a substrate painted with a test soil material and mounted into a dedicated PCD carrier, such as a box or container, which is placed in an instrument tray or basket of the cleaning apparatus usually together with a load of instruments to be cleaned, although sometimes the PCD in its carrier may be disposed in instrument tray or basket in the cleaning apparatus without a load of instruments to be cleaned e.g. to verify the settings of the apparatus prior to use. After the end of automated cleaning, the carrier is removed from the instrument tray or basket, and the substrate inspected for residual test soil material. Various PCD carriers have been developed in order to create a tortuous path for the cleaning fluid. The PCD carriers, and PCDs arranged to cooperate with the carriers, can be intricate and complex to manufacture and therefore expensive. Furthermore, their complexity can make them difficult to use in a consistent manner.

Thus, the present invention provides improved methods and devices for testing the effectiveness of an automated cleaning apparatus for medical

instruments.

In accordance with a first aspect of the invention there is provided a a method for testing the effectiveness of an automated apparatus for the cleaning of medical instruments, the method comprising:

providing an instrument carrier in the cleaning apparatus together with a process challenge device (PCD) comprising a test soil material,

wherein the process challenge device is directly mounted to the instrument carrier.

The abbreviation "PCD" will be used in place of "Process Challenge Device" herein.

In accordance with the invention, therefore, as is known in the art, a process challenge device (PCD) is provided in the cleaning apparatus i.e. in a cleaning chamber thereof, together with an instrument carrier. The instrument carrier may or may not be loaded with one or more medical instruments. However, in contrast to prior art techniques, the PCD is directly mounted to the instrument carrier. In this way, the device is associated directly with the instrument carrier, such that it will be subject to cleaning conditions which more closely reflect those experienced by, or that would be experienced by, instruments loaded in the carrier. The condition of the device after operation of the cleaning apparatus may therefore be more accurately be indicative of effectiveness of the apparatus. As the device is directly mounted to the instrument carrier, a more reliable test of cleaning function may be achieved, as the test soil material of the device may be exposed to the same conditions as would be experienced by medical instruments within the apparatus during cleaning, i.e. without being protected by a process challenge device carrier.

Mounting the device directly to the instrument carrier also provides improved ease of use for user performing the test, allowing the user to more readily perform reliable and consistent testing of the cleaning apparatus. As the device is mounted directly to the instrument carrier, the device can interact directly with the structure of the instrument carrier to form an attachment thereto. The need to use an additional PCD carrier or other fixing means is avoided. This reduces the number of components required when performing a test, resulting in lower costs, and greater ease of use for the user. The greater simplicity of the device may allow more repeatable and reliable testing to be achieved, as there is less scope for variation or error in use of the device. Inspection of the PCD after use is also facilitated, as the user does not need to remove it from a PCD carrier. In embodiments at least, the method provides a PCD which is simpler and more cost effective to manufacture.

In accordance with the invention, the instrument carrier with the PCD directly mounted thereto, and optionally loaded with one or more medical instruments, is provided in the cleaning apparatus. The steps of mounting the PCD to the carrier, and, where applicable loading the carrier with the one or more instruments, and/or locating the instrument carrier in the cleaning apparatus, may be carried out in any order, and some or all of the steps may be carried out simultaneously.

The step of providing the instrument carrier having the PCD mounted thereto, and optionally loaded with one or more instruments, in the cleaning apparatus, may comprise providing the instrument carrier having the PCD mounted thereto, and optionally loaded with one or more instruments in a cleaning chamber of the apparatus.

References to providing or locating the instrument carrier or other

components in the cleaning apparatus, or removing an item therefrom, should be understood to refer to locating or providing the carrier or component in the cleaning chamber thereof, or removing an item therefrom, unless the context demands otherwise. The cleaning apparatus thus defines a cleaning chamber.

The step of providing the instrument carrier in the cleaning apparatus e.g. chamber may comprise locating the instrument carrier in the cleaning apparatus e.g. chamber. The step of locating the instrument carrier in the apparatus e.g. chamber may comprise loading the carrier into the cleaning apparatus e.g. chamber. The step of locating the instrument carrier in the cleaning apparatus or cleaning chamber e.g. loading the instrument carrier into the cleaning apparatus or chamber may involve the use of a loading trolley or any other equipment which may be used in the art. The step of locating the instrument carrier in the cleaning apparatus e.g. cleaning chamber may comprise loading the instrument carrier onto a further carrier configured to hold the instrument carrier in the cleaning apparatus e.g. cleaning chamber as described in more detail below. The further carrier may or may not also be an instrument carrier which is configured to directly carry instruments. The further carrier may already be disposed in the apparatus, or the method may involve locating the further carrier together with the instrument carrier in the apparatus e.g. cleaning chamber. It will be appreciated, however, that the step of providing the instrument carrier, optionally loaded with the one or more medical instruments, and together with the PCD, in the cleaning apparatus e.g. cleaning chamber may not involve locating i.e. inserting the instrument carrier in the cleaning apparatus e.g. chamber thereof. For example, the method may involve mounting the PCD to an instrument carrier which is already located in the cleaning apparatus e.g. chamber. In these arrangements the instrument carrier may be a fixed part of the apparatus, or may be removable therefrom.

In accordance with any of its embodiments, the method preferably comprises the step of loading the instrument carrier with one or more medical instruments. The method may comprise loading the instrument carrier with the one or more

instruments and locating the instrument carrier in the cleaning apparatus (e.g.

cleaning chamber thereof). The method may comprise loading the instrument carrier into the cleaning apparatus (e.g. cleaning chamber). The step of locating the instrument carrier in the cleaning apparatus e.g. chamber is preferably carried out after loading the carrier with the one or more instruments. The method therefore preferably comprises locating the instrument carrier loaded with the one or more medical instruments in the cleaning apparatus e.g. chamber. The method may comprise loading the instrument carrier loaded with the one or more medical instruments into the cleaning apparatus e.g. cleaning chamber. However, it is envisaged that depending upon the nature of the cleaning apparatus, the method may comprise loading an instrument carrier already disposed in the cleaning apparatus e.g. cleaning chamber with the one or more instruments. For example, the cleaning apparatus might be a "reach-in" type apparatus e.g. chest style. Testing of the apparatus with one or more medical instruments located therein e.g. in a cleaning chamber thereof, may be performed to verify the performance of the apparatus at any stage, and to provide an indication of the extent to which instruments are being cleaned by the apparatus.

In other embodiments, the instrument carrier provided in the cleaning apparatus e.g. cleaning chamber, and having the PCD mounted thereto, may not be loaded with one or more medical instruments. Thus the instrument carrier having the PCD mounted thereto may not comprise any medical instruments. The instrument carrier having the PCD mounted thereto is then subjected to automated cleaning by the cleaning apparatus without any medical instruments being loaded in the carrier. The cleaning apparatus may be operated to perform automated cleaning without any medical instruments being located therein e.g. in a cleaning chamber thereof. Testing of the cleaning apparatus without medical instruments being located therein may be carried out to verify a set up of the apparatus e.g. at the start of a day, prior to its use to clean instruments.

In accordance with the invention, the PCD is directly mounted to the instrument carrier. Thus, the instrument carrier when disposed in the cleaning apparatus e.g. cleaning chamber thereof, optionally loaded with the one or more medical instruments, has the PCD directly mounted thereto. The method comprises the step of directly mounting the PCD to the instrument carrier. The step of mounting the PCD to the instrument carrier may be carried out before, after or during loading of the instrument carrier with the one or more instruments, where this step is carried out, and/or before, during or after locating the instrument carrier in the cleaning apparatus e.g. chamber in embodiments in which such a step is performed. The method may comprise directly mounting the PCD to the instrument carrier when the instrument carrier is disposed in the cleaning apparatus e.g. cleaning chamber. In these embodiments the carrier may or may not be loaded with one or more medical instruments. However, whether or not the instrument carrier is loaded with one or more medical instruments at any stage, preferably the method comprises mounting the PCD to the instrument carrier and then locating the instrument carrier with the PCD directly mounted thereto in the cleaning apparatus e.g. cleaning chamber.

In embodiments in which the carrier is loaded with one or more medical instruments, the method may comprise loading the instrument carrier with one or more medical instruments before, during or after mounting the PCD thereto, and preferably before locating the instrument carrier in the cleaning apparatus e.g.

cleaning chamber. For ease of use, the step of mounting the PCD to the instrument carrier is preferably carried out before loading the instrument carrier with one or more instruments, and locating the loaded instrument carrier in the cleaning apparatus e.g. cleaning chamber. The instrument carrier is preferably loaded, and the PCD mounted thereto, outside the cleaning apparatus.

In some preferred embodiments the method comprises loading the instrument carrier with one or more medical instruments and directly mounting the PCD to the instrument carrier, and locating the instrument carrier loaded with the one or more medical instruments and with the PCD directly mounted thereto in the cleaning apparatus e.g. in a cleaning chamber of the apparatus. The steps of loading the instrument carrier with one or more medical instruments and directly mounting the PCD to the instrument carrier may be carried out in any order, although preferably the PCD is mounted to the carrier before it is loaded with instruments.

In accordance with any of the embodiments of the invention, the step of directly mounting the PCD to the instrument carrier, and where appropriate, removing the PCD from the carrier, is carried out by a user, and is preferably carried out manually. By manually, here, and in accordance with any other references herein, it is meant that the user is able to carry out the action e.g. mounting or removing by hand, without the need for any tools. The step of directly mounting the device to the instrument carrier, and, where appropriate, removing the device from the instrument carrier, may advantageously be carried out by the user with one hand. Removal of the PCD from the carrier may be referred to as "demounting" the PCD from the carrier.

The present invention extends to a PCD that may be used in accordance with any of the methods herein claimed. It is believed that these PCDs are advantageous in their own right. In accordance with a further aspect of the invention there is provided a Process Challenge Device for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, wherein the PCD comprises a test soil material, the PCD being configured such that it may be directly mounted to an instrument carrier of an automated apparatus for the cleaning of medical instruments by a user in a manner such that the PCD may remain securely in place during automated cleaning by the apparatus, preferably while being removable from the instrument carrier by a user after completion of automated cleaning.

The present invention in this further aspect may include any or all of the features described by reference to any of the other aspects or embodiments of the invention to the extent they are not mutually exclusive. For example, the construction and configuration of the PCD may be in accordance with any of the embodiments discussed below. The PCD may be configured to permit its use in accordance with any of the methods herein described.

In accordance with the invention in any of its aspects, the PCD is preferably directly mounted or mountable to the instrument carrier so as to allow removal i.e. demounting of the PCD from the instrument carrier by a user, preferably manually. The PCD is therefore preferably releasably directly mounted to the instrument carrier. This enables the PCD to be removed from the instrument carrier for inspection after use e.g. after completion of automated cleaning by the apparatus. Any references herein to the PCD being mounted to the instrument carrier, or to a mounting engagement between parts of the PCD and the instrument carrier etc. therefore preferably refer to a mounting that is releasable by a user (preferably manually). In these embodiments the PCD is removable from the instrument carrier in a manner such that the PCD remains intact. Thus the PCD is removable without destruction of the PCD. In accordance with any of the embodiments of the invention described herein, the automated cleaning performed by the apparatus may comprise an automated cleaning cycle.

In accordance with the invention, the PCD is directly mounted or mountable to the instrument carrier in a manner such that the PCD may be, or is, securely retained in place during operation of the cleaning apparatus to perform automated cleaning. The PCD is configured such that it is directly mountable in this manner. It will be appreciated that the device may be subjected to considerable turbulence and other forces during automated cleaning e.g. through the incidence of cleaning fluid etc. The PCD is retained in place by virtue of the direct mounting to the carrier i.e.

through the direct interaction between the PCD and the carrier.

Accordingly, the PCD may be directly mounted to the instrument carrier in a manner such that the PCD may be, or is, securely retained in place during operation of the cleaning apparatus to perform automated cleaning while allowing removal i.e. demounting of the PCD from the instrument carrier by a user following completion of automated cleaning e.g. for inspection. It will be appreciated that the instrument carrier may be, and preferably is removed from the cleaning apparatus e.g. cleaning chamber with the PCD mounted thereto before the PCD is removed from the instrument carrier.

The PCD is separately formed from and releasably mountable to the instrument carrier. The PCD does not form part of the carrier before being mounted thereto. The PCD is a discrete component. The PCD is not attached to the carrier before being mounted thereto. In embodiments, after removal from the carrier, the PCD is not attached thereto. Thus, the PCD is fully removable from the carrier.

The PCD is directly mounted or mountable to the instrument carrier in a manner such that it is attached to the instrument carrier through direct interaction e.g. cooperation between the PCD and the instrument carrier. It will be appreciated that the term "mounting" as used herein requires the components that are mounted to one another to cooperate with one another to provide an attachment between the components. The PCD may be fixed to the instrument carrier when mounted thereto. The mounting involves an engagement between the components. This is more than simply a placing of one component on or in the other component. The PCD and the instrument carrier cooperate directly with one another to provide an attachment between the PCD and the instrument carrier. The cooperation may be between respective parts of the PCD and instrument carrier e.g. between attachment portions of the PCD and a part or parts of the instrument carrier. The direct mounting between the PCD and the instrument carrier involves an engagement between the PCD and the instrument carrier. The PCD and the instrument carrier are in direct contact with one another to provide the direct mounting. The mounting is provided through a mechanical interaction between the instrument carrier and the PCD. The direct mounting may be such that substantially no relative movement is possible between the PCD and the instrument carrier when mounted thereto.

The direct mounting between the PCD and the instrument carrier refers to a mounting that is achieved without the need for any additional mounting device or component(s). Thus the direct mounting does not involve any additional carrier or fixing means for the PCD, such as a frame, box or clip. The PCD is directly mounted to the instrument carrier without first being disposed in a PCD carrier. The PCD is directly mounted to the instrument carrier without first being disposed in a PCD carrier and without the need for an additional, separate intermediate attachment component (i.e. additional and separate to the device and the carrier). Thus, in accordance with any of the aspects or embodiments of the invention, when mounted to the instrument carrier, no intermediate carrier is disposed between the PCD and the instrument carrier. No additional, separate intermediate attachment component is provided between the PCD and the instrument carrier for mounting the PCD to the instrument carrier. The mounting may be achieved without the use of adhesive.

In accordance with the invention in any of its embodiments therefore, only the PCD (which is preferably a unitary device) i.e. one or more parts thereof and the instrument carrier are involved in providing the direct mounting between the PCD and the instrument carrier. The instrument carrier to which the PCD is mounted may be of any suitable type. An instrument carrier refers to a carrier which may, and preferably does, hold one or more medical instruments to be cleaned during cleaning in the automated cleaning apparatus. The instrument carrier is arranged to retain the one or more medical instruments during operation of the apparatus to perform automated cleaning. The instrument carrier is disposed in a cleaning chamber of the apparatus during operation of the apparatus to perform automated cleaning. Thus the instrument carrier is located or locatable in a cleaning chamber of the apparatus. The instrument carrier is configured such that it permits the one or more instruments to be subjected to the cleaning action(s) of the cleaning apparatus while held by the carrier. The instrument carrier may be configured to do this in any suitable manner. The instrument carrier is arranged to directly hold the instrument(s). An instrument carrier may be arranged such that the or each instrument with which the carrier is loaded in use is disposed in, on, around or over the instrument carrier. Preferably the instrument carrier is arranged such that an instrument or instruments held by the carrier are disposed in or on the carrier. The instrument carrier is preferably arranged to directly contact the or each medical instrument with which it is loaded. It will be appreciated that if not explicitly stated, references to the "instrument carrier" herein refer to a medical instrument carrier unless the context demands otherwise. Likewise, references to an "instrument" refer to a "medical instrument" e.g. a surgical instrument, unless the context demands otherwise.

As described above, in preferred embodiments, the instrument carrier to which the PCD is mounted is loaded with one or more medical instruments, and will then hold the or each instrument in any of the manners described. Where the instrument carrier is not loaded with one or more instruments, then it is configured such that it may be loaded with one or more instruments such that they are retained in any of the manners described. Thus the instrument carrier that is loaded with, or which may be loaded with one or more medical instruments, may be of any in accordance with any of the embodiments described herein.

The instrument carrier is preferably of a defined shape. The instrument carrier may be substantially rigid. The instrument carrier may be formed of any suitable material. For example, the instrument carrier may be constructed of metal and/or plastic.

The instrument carrier may be an instrument container. An instrument container may be an instrument tray, basket or rack. The container may be an open or a closed container. An instrument container may define a base and one or more sidewalls. An instrument container of this type may be an instrument tray or basket. An instrument container may define an interior space for holding medical

instruments. In some embodiments the instrument carrier may be configured such that the or each instrument with which the instrument carrier is loaded is disposed within an interior space of the instrument carrier. A step of loading the instrument carrier with the or each instrument may comprise disposing the or each medical instrument within the interior space.

The instrument carrier may be selected from; an instrument rack, an instrument shelf, an instrument tray or an instrument basket. Of course, the instrument carrier might alternatively be of any other suitable form e.g. an instrument ramp or instrument cart. The instrument carrier may be any form of instrument container. Preferably the instrument carrier is an instrument container such as an instrument tray or an instrument basket. An instrument tray or basket may or may not be provided with a removable lid. The instrument carrier may be configured to retain, or may retain, one or more medical instruments. The instrument carrier may be adapted to hold a single instrument. The carrier may then be shaped to receive a particular type of instrument. In other arrangements the carrier may not be specifically adapted to receive a particular type of instrument.

The instrument carrier may be loaded with one or more instruments to be cleaned in any suitable manner such that they are held thereby. The step of loading one or more medical instruments into the instrument carrier if performed may comprise locating the medical instrument(s) in, on, around or over the instrument carrier, and preferably in or on the carrier. Of course, the instrument carrier may be loaded with a plurality of instruments, which may be loaded in the same or different manners, including any of the manners described above, and combinations thereof.

Loading a medical instrument or instruments may involve placing the, each or an instrument in, on, around or over the instrument carrier (preferably in or on the carrier) or mounting the, each or an instrument to the carrier. As described in relation to the mounting of the PCD, as used herein, mounting between two components involves cooperation between respective parts of the components, i.e. the instrument carrier and instrument in this case, to provide an attachment therebetween. This is more than merely a placing of one component on or in another. The way in which an instrument is loaded will depend upon the type of instrument carrier and instrument. For example, in embodiments in which an instrument is mounted to an instrument carrier, the instrument carrier may comprise instrument connecting means arranged to cooperate with the instrument to retain the instrument. The instrument connecting means may comprise means for supplying a cleaning fluid to an interior of an instrument. In some embodiments in which the instrument carrier is an instrument tray, basket or rack, the method may comprise loading the instrument carrier by placing the or each instrument on or in the instrument carrier.

In preferred embodiments the instrument carrier is configured to be removable from the cleaning apparatus and/or cleaning chamber thereof, and is removably located or locatable in the cleaning apparatus and/or cleaning chamber. The instrument carrier may be only partially removable from the apparatus and/or cleaning chamber or more preferably is fully removable from the apparatus and/or cleaning chamber. The instrument carrier may then be loaded with instruments outside the cleaning apparatus and/or cleaning chamber and then inserted therein prior to operation of the cleaning apparatus. Such arrangements are commonplace e.g. with cabinet or chest style apparatus.

Preferably the instrument carrier loaded with the one or more instruments and with the PCD directly mounted thereto that is provided in the cleaning apparatus e.g. cleaning chamber thereof is a removable instrument carrier. The step of locating the instrument carrier in the cleaning apparatus may therefore comprise removably locating the carrier in the cleaning apparatus e.g. cleaning chamber. Preferably the instrument carrier may be removed entirely from the cleaning apparatus and/or cleaning chamber. The method may comprise the step of locating the instrument carrier in the cleaning apparatus e.g. in a cleaning chamber thereof prior to operation of the apparatus to perform automated cleaning, and preferably removing the instrument carrier from the cleaning apparatus e.g. a cleaning chamber thereof, subsequent to completion of cleaning. Of course, it is envisaged that the instrument carrier could be a fixed instrument carrier i.e. fixed in the cleaning apparatus e.g. in a cleaning chamber thereof. The step of mounting the PCD to the carrier, and, in embodiments, removing it therefrom, may then comprise mounting the PCD to the carrier, or removing it therefrom while the carrier is disposed in the cleaning apparatus e.g. cleaning chamber. Similar comments would apply to the loading or unloading of instrument(s) where performed.

In some embodiments the instrument carrier is loaded with a plurality of medical instruments, and the method may comprise loading the carrier with a plurality of medical instruments. The instruments may be the same or different. The instrument carrier may directly contact the or each medical instrument with which it is loaded. In other embodiments the instrument carrier is loaded with a single medical instrument.

The cleaning apparatus may, when loaded, comprise one or more carrier which is configured to be loaded with one or more, and preferably a plurality of, instrument carrier(s). The carrier may be located in a cleaning chamber of the apparatus. The carrier may be an instrument carrier that is configured to directly receive an instrument as well as one or more instrument carriers. The carrier may or may not be removable from the cleaning apparatus or cleaning chamber. Such an instrument carrier may be a shelf. Thus, the apparatus e.g. cleaning chamber thereof may, when loaded with an instrument carrier or carriers, comprise one or more primary instrument carrier that is configured to be loaded with one or more secondary instrument carriers. The primary instrument carrier may or may not be removable from the cleaning apparatus or cleaning chamber. The instrument carrier to which the PCD is mounted may be a primary instrument carrier configured to be loaded with one or more secondary instrument carrier, or more preferably is a secondary instrument carrier that is loaded onto a primary instrument carrier in the cleaning apparatus e.g. cleaning chamber thereof. References to a secondary instrument carrier being loaded onto a primary instrument carrier encompass the secondary instrument carrier being located in, on, around, or over the primary instrument carrier. For example, the instrument carrier to which the PCD is mounted may be an instrument container such as a tray or basket that is disposed upon an instrument shelf in the cleaning apparatus, or may be an instrument rack onto which an instrument carrier such as an instrument tray may be loaded.

The method of providing the instrument carrier to which the PCD is mounted in the cleaning apparatus e.g. chamber may comprise loading the instrument carrier onto another carrier e.g. an instrument carrier, optionally together with one or more additional instrument carriers. The carrier e.g. instrument carrier to which the instrument carrier having the PCD is mounted may be located in the cleaning apparatus e.g. chamber prior to loading with the instrument carrier having the PCD and any additional instrument carrier, or preferably the method may comprise loading a carrier e.g. instrument carrier with the instrument carrier to which the PCD is mounted, and preferably with one or more additional instrument carrier, and locating the carrier e.g. instrument carrier having the instrument carrier to which the PCD is mounted, and the or each additional instrument carrier, in the cleaning apparatus e.g. cleaning chamber. Thus, in these embodiments, the instrument carrier to which the PCD is mounted, and any additional instrument carrier, may be referred to as a secondary instrument carrier, and an instrument carrier that is loaded with the instrument carrier to which the PCD is mounted and the any additional instrument carrier may be referred to as a primary instrument carrier. The PCD may be mounted to the instrument carrier before, after or during loading of the instrument carrier onto another instrument carrier.

The PCD may be mounted to any part of the instrument carrier. The PCD should be mounted in a manner such that the test soil material will experience conditions as close as possible to those experienced by or that would be experienced by instruments of a load. The PCD may be mounted to a surface or surfaces of the carrier, preferably to a surface that faces instrument(s) loaded in the carrier or that is arranged to face instrument(s) when loaded in the carrier. The surface or surfaces may be an interior surface or surfaces. For example, if the instrument carrier is a shelf, the PCD may be mounted to an instrument facing side of the carrier. If the instrument carrier is an instrument container having an interior space in which instrument(s) to be cleaned are disposed, the PCD may be mounted to an interior surface or surfaces of the carrier. The PCD is preferably mounted with the test soil material exposed i.e. facing away from the surface or surfaces to which the PCD is mounted. The surface or surfaces may be provided by a wall or walls of the carrier. In accordance with the invention in any of its embodiments, the instrument carrier may define a base and one or more sidewalls. The PCD may be mounted to the base and/or to one or more of the sidewalls. The PCD may be mounted to the sidewall or sidewalls of the instrument carrier, preferably such that the PCD is spaced from the base of the carrier. The PCD may be mounted in a corner defined between sidewalls of the carrier. The carrier may be an instrument container e.g. a basket or tray. In some preferred embodiments in which the instrument carrier is an instrument container e.g. an instrument tray or basket, the PCD is directly mounted to the instrument carrier within the interior space of the instrument container, and the method may comprise mounting the PCD in this manner. One or more instruments may be located within the container. The PCD may be mounted to the instrument carrier with the test soil material of the PCD facing the interior space of the instrument container. These arrangements enable the test soil material to directly be subjected to the same cleaning action as a load of instruments to be cleaned. In some preferred embodiments the PCD is mounted in a corner of the instrument carrier e.g. in a corner of an instrument container e.g. instrument basket or tray. Mounting to a corner of an instrument carrier may provide a good indicator of cleaning apparatus effectiveness as cleaning in corners can be more challenging. The PCD is then mounted in a corner of the instrument carrier within the carrier e.g. within an interior space thereof.

In accordance with the invention in any of its aspects or embodiments, therefore, the PCD may be mounted in an instrument holding space of the instrument carrier and/or to an instrument holding surface of the instrument carrier. One or more medical instruments may be located within the space or on the surface with the PCD.

The present invention extends to an instrument carrier and a PCD, the PCD being directly mounted or mountable to the instrument carrier. In these further aspects of the invention, the instrument carrier, PCD and/or mounting may be in accordance with any of the embodiments of the invention described herein. The instrument carrier may be located in a cleaning apparatus. The instrument carrier may be loaded with one or more medical instruments.

In accordance with the invention in any of its aspects or embodiments, the direct mounting of the PCD to the instrument carrier may be achieved in any suitable manner. The PCD is suitably configured to enable it to be directly mounted to an instrument carrier. The way in which the PCD is configured may depend upon the type of instrument carrier or carriers with which it is intended to be used.

Advantageously the PCD is configured to enable it to be directly mounted to a plurality of different types and/or sizes of instrument carrier. In other words, a PCD is preferably not adapted to be mounted only to a specific instrument carrier. It is envisaged that different standard size PCDs may be produced for use with different sets of one or more, and preferably a plurality of instrument carriers e.g. of differing type and/or size.

The PCD is advantageously configured to be directly mounted to the instrument carrier without the need to specifically adapt the instrument carrier to enable it to cooperate with the PCD to allow direct mounting of the PCD thereto. In accordance with any of the aspects or embodiments of the invention, the PCD is preferably configured to cooperate with the structure of the instrument carrier to be directly mounted thereto. The PCD mechanically cooperates with the structure. The method may comprise manipulating the PCD to cause it to cooperate with the structure of the instrument carrier or otherwise to become directly mounted to the carrier.

It will be appreciated that an instrument carrier typically comprises a plurality of openings to render the carrier permeable to a cleaning fluid i.e. liquid. This enables cleaning fluid i.e. liquid to reach instruments with which the instrument carrier is loaded during cleaning of the instruments e.g. when located in a cleaning chamber of the apparatus, and to allow the fluid i.e. liquid to pass through the carrier, avoiding it pooling within the carrier. It has been found that these openings may be exploited to allow direct mounting of the PCD to the carrier.

In preferred embodiments the instrument carrier comprises a structure having a plurality of openings, and the PCD is configured to be directly mounted to the instrument carrier through direct cooperation between the PCD and the structure having the plurality of openings. The openings are preferably openings to allow the passage of cleaning fluid i.e. liquid to reach one or more medical instruments carried by the carrier when the carrier is located in a cleaning apparatus e.g. cleaning chamber thereof loaded with one or more medical instruments and the cleaning apparatus is operated to perform automated cleaning in use. The PCD may be directly mounted to the instrument carrier through cooperation of the PCD with the openings of the structure (i.e. with one or more of the openings, and preferably with a plurality of the openings). The PCD may cooperate with any portion of a structure of the carrier that defines a plurality of openings.

The openings may be of any configuration e.g. shape or size, and may be of the same or differing configurations. The openings may be arranged in a regular array. It will be appreciated that an "opening" as used herein refers to an opening through or in the structure of the instrument carrier over an above any inherent pores in the material of the structure.

In particularly preferred embodiments, the instrument carrier comprises a mesh, and the PCD is directly mounted to the instrument carrier through direct cooperation of the PCD with the mesh of the instrument carrier. Thus, in these embodiments, the structure having the plurality of openings is a mesh. The PCD may cooperate with one or more, or preferably a plurality of openings of the mesh. The PCD may cooperate with any portion of a mesh defined by the instrument carrier.

The term "mesh" as used herein refers to any structure of a mesh-like configuration. The mesh comprises a plurality of openings. The openings may, for example, be defined between strands or struts, or by perforations in a substrate.

It will be appreciated that the mesh is not limited to a structure that is defined by a plurality of interwoven strands. The mesh may be defined by a perforated plate, or by a framework of the instrument carrier. For example, the mesh may be provided by a plurality of wires, which may be interwoven to provide a mesh, or may be bent into a framework defining a mesh, or may be provided by a perforated substrate e.g. plate. The mesh may be rigid or flexible. The mesh may be in the form of a net or a grill type structure.

The mesh may be of any scale, ranging e.g. from a sieve-like e.g. mesh to a framework of a larger scale. The openings of mesh may e.g. have a diameter of the order of millimeters, centimeters or inches. For example, a mesh may be defined by an instrument carrier in the form of a framework, along the lines of a dishwasher rack. In other arrangements the instrument carrier may be in the form of a basket that comprises the mesh. The mesh structure may then be similar to a deep fat fryer type basket. In other arrangements the mesh may be defined by a colander type structure, in which a substrate is perforated to define the mesh.

The mesh may be a plastic and/or metal mesh. The mesh may define a regular or irregular array of openings. The mesh may define any part or parts of the instrument carrier, or the instrument carrier may be entirely of a mesh structure.

The method may comprise directly mounting the PCD to the instrument carrier by causing the PCD to cooperate with the structure of the carrier having the plurality of openings or mesh to directly mount the PCD thereto. The step of causing the PCD to cooperate with the structure in this way may comprise manipulating the PCD to cause it to interact with the structure or mesh. In these embodiments the instrument carrier is an instrument container comprising the structure having the plurality of openings or mesh, and is most preferably an instrument basket or tray. However, the instrument carrier could be of other forms e.g. an instrument shelf.

The structure having the plurality of openings or mesh may define any part or parts of the carrier, or the entirety of the carrier. In embodiments the structure having the plurality of openings or mesh defines at least a portion of one or more side walls of the instrument carrier, and optionally a base thereof. The PCD may cooperate with such a structure or mesh of one or more of the sidewalls and/or the base to be directly mounted thereto.

It will be appreciated that references to the "structure having a plurality of openings" herein may be replaced by a reference to the preferred structure i.e. a mesh.

The PCD may be mountable to the carrier in any one of a plurality of different orientations.

The PCD may comprise one or more, or preferably a plurality of attachment portions which cooperate with the instrument carrier e.g. with a structure having a plurality of openings or a mesh of the carrier, e.g. with one or more, or a plurality of openings thereof, to directly mount the PCD thereto. The method may comprise using at least some of the attachment portions to mount the PCD to the instrument carrier. One or more, or preferably a plurality, or each attachment portion may be used. Thus "at least some" should be understood to refer to the attachment portion if only one is provided, or any or all of the attachment portions where multiple portions are provided. The PCD may cooperate with one or more, or preferably a plurality of openings of a structure or mesh of the instrument carrier. Where the PCD comprises one or more attachment portion(s), each attachment portion that cooperates with the structure or mesh preferably cooperates with a different respective opening or openings, although it is envisaged that a plurality of attachment portion(s), which may be some or all of the attachment portion(s) involved in cooperating with the structure or mesh, may cooperate with the same opening. Preferably a plurality of attachment portions involved in cooperating with the structure or mesh cooperate with different respective openings in the structure or mesh, and most preferably each attachment portion cooperates with a different opening or openings.

The structure having the openings may be of any of the types described above, such as a mesh. The attachment portion(s) are preferably provided at the periphery of the PCD. Preferably an attachment portion is provided at least at each end of the PCD. The attachment portion(s) are preferably integral with a remainder of the PCD. Thus the PCD is preferably unitary.

The method may comprise causing at least some of the attachment portion(s) of the PCD to cooperate with the carrier e.g. with a structure having a plurality of openings e.g. a mesh thereof, to directly mount the PCD to the carrier. The method may comprise causing at least some of the attachment portion(s) to cooperate with opening(s) of the structure or mesh. The attachment portions may be of any suitable form. The step of directly mounting the PCD to the instrument carrier may comprise manipulating the PCD to result in the PCD being directly mounted to the instrument carrier by cooperation of at least some of the attachment portions with the instrument carrier e.g. with a structure having a plurality of openings e.g. a mesh thereof, or more particularly with openings in the structure or mesh. The method may comprise mounting the PCD to the instrument carrier by causing at least some of the attachment portions of the PCD e.g. one or more, a plurality, or each attachment portion, to be inserted into an opening of the structure of the instrument carrier. A plurality of the attachment portions, or each attachment portion, may be inserted in a different respective opening of the structure.

In embodiments the PCD may be configured to be caught in the structure having the plurality of openings e.g. the mesh structure of the instrument carrier to directly mount the PCD to the instrument carrier. The method may comprise mounting the PCD to the structure of the instrument carrier such that it is caught in the structure. In embodiments in which the PCD comprises one or more attachment portions, at least some of the attachment portions, or each attachment portion, may be caught in an opening of the structure.

It will be appreciated that any step of causing the PCD or an attachment portion or portions thereof to interact with the structure of the carrier e.g. with an opening thereof in order to mount the PCD to the carrier may comprise manipulating the PCD to cause the PCD or an attachment portion or portions thereof to interact with the carrier in this way.

The or each attachment portion may be of any suitable configuration that enables it to cooperate with a instrument carrier to achieve direct mounting of the PCD thereto. The or each attachment portion is preferably an attachment formation. To facilitate mounting of the PCD to the carrier e.g. to a mesh thereof, it is

advantageous for the attachment formations to project from a main body of the PCD. Thus, the or each attachment portion in any of the embodiments described above is preferably an attachment formation projecting from a main body of the PCD.

Preferably the PCD comprises a main body, with one or more attachment formations projecting therefrom. The main body is preferably integrally formed with the or each attachment formation. The term "main body" refers to the part of the PCD from which the attachment formation(s) project. Thus the PCD is preferably a unitary PCD comprising the main body and one or more attachment formations. The or each attachment formation preferably projects from a periphery of the main body. The or each attachment formation is therefore located at a periphery of the PCD. The attachment formation(s) may be elongate. The attachment formation(s) are discrete formation(s).

In accordance with a further aspect of the invention there is provided a

Process Challenge Device for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, the PCD having a test soil material disposed thereon, wherein the PCD is flexible and comprises a main body and one or more, and preferably a plurality of attachment formations projecting from the main body which may be used to mount the device directly to an instrument carrier for an automated apparatus for the cleaning of medical instruments in use.

Preferably the PCD is unitary. Preferably the attachment formations are arranged to be able to cooperate with a structure of the instrument carrier having a plurality of openings e.g. a mesh structure of the instrument carrier to directly mount the PCD thereto.

In accordance with a further aspect of the invention there is provided a unitary Process Challenge Device for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, the PCD having a test soil material disposed thereon, wherein the PCD is flexible, and preferably resiliently flexible, and comprises a main body having the test soil material disposed thereon, and one or more, and preferably a plurality of attachment formations projecting from the main body which may cooperate with a mesh structure of an instrument carrier for an automated apparatus for the cleaning of medical instruments to enable the PCD to be directly mounted to the instrument carrier. Preferably the PCD is cut from a sheet. Preferably the PCD is provided by a piece of a substrate cut from a sheet and having the test soil material disposed thereon. The test soil material may be disposed on the PCD or substrate before or after the PCD or substrate is cut from a sheet.

Preferably an attachment formation is provided at each end of the PCD i.e. projects from each end of the main body. Any one or ones of these preferred features may be combined in a given embodiment.

The PCD in accordance with these further aspects of the invention may comprise any or all of the features described in relation to the other aspects of the invention, and may be configured to be used in accordance with any of the methods described herein. The method of the invention in accordance with any of its aspects or embodiments may use a PCD in accordance with any of the aspects or embodiments described.

The PCDs of the invention in any of its aspects or embodiments are for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments. The method extends to the use of the PCD in accordance with any of the aspects or embodiments of the invention described herein to test the

effectiveness of an automated apparatus for the cleaning of medical instruments. The method comprises directly mounting the PCD to an instrument carrier of the cleaning apparatus as described herein. The method may include any of the steps described herein.

In accordance with any of the aspects of the invention, whether relating to the PCD itself or a method using the PCD, in embodiments in which the device comprises a main body having one or more attachment formation(s) projecting therefrom, the or each attachment formation may have dimensions that are small relative to the dimensions of the main body of the device. The length and width of an attachment formation may be small relative to a length and width of the main body and of the device as a whole. The attachment formation(s) are preferably configured to allow them to cooperate with openings of a structure of an instrument carrier to mount the PCD thereto e.g. of a mesh, and may be configured such that they may be caught in openings of the structure. A given attachment formation is preferably configured to interact with a single opening. Each attachment formation may interact with a different opening.

The or each attachment formation may have a length that is less than a length of the main body, and is preferably less than 50%, or less than 30%, or less than 20%, or less than 10 % of the length of the main body. Alternatively or additionally, the length of an attachment formation may be at least 5% of the length of the main body. Alternatively or additionally, the or each attachment formation may have a length that accounts for less than 50%, or less than 30%, or less than 20 % or less than 10 % of a length of the PCD (i.e. including the contribution to the length provided by the attachment formations). Alternatively or additionally, the length of an attachment formation may account for at least 5% of the length of the PCD. The length of an attachment formation is measured in the direction that it extends away from the main body. The main body or PCD defines a length and a width. The length of the PCD or main body is a longest dimension thereof. The length of an attachment formation may lie in any range that is defined by a combination of the above subranges.

Alternatively or additionally, the or each attachment formation may have a width that is less than a width of the main body, and is preferably less than 50%, or less than 30%, or less than 20%, or less than 10% of the width of the main body. Alternatively or additionally, the width of an attachment formation may be at least 5% of the width of the main body. Alternatively or additionally, the or each attachment formation may have a width that accounts for less than 50%, or less than 30%, or less than 20 %, or less than 10% of a width of the PCD. Alternatively or additionally, the width of an attachment formation may account for at least 5% of the width of the PCD. The width of an attachment formation may lie in any range that is defined by a combination of the above subranges. It will be appreciated that any of the above length and width ranges may be combined.

Of course, depending upon the nature of the instrument carrier with which the PCD is to be used, or at least the structure e.g. mesh of the carrier with which the PCD is to interact, the length and/or width of the attachment formation (s) relative to the main body or PCD, and/or the shape of the formation (s) may be varied. The configuration of the attachment formation (s) should enable the device to be directly mounted to the instrument formation (s) with which it is intended to be used. The attachment formation (s) may be configured to allow them to interact with a particular structure of the carrier e.g. a mesh. In preferred embodiments in which the PCD interacts with a structure of the carrier having a plurality of openings e.g. mesh, the configuration of the attachment formation(s) may be chosen by reference to the configuration of the openings, and their density etc.

In preferred embodiments the or each attachment formation is in the form of an attachment tab projecting from the main body. Of course, longer attachment formation(s) could be used. It is envisaged that multiple attachment formation where provided may be the same or different in configuration. The attachment tab(s) may be in the form of teeth. Preferably the attachment formations are each of the same configuration.

It will be seen that in embodiments at least, the PCD may be mounted to an instrument carrier through insertion of the attachment portion(s), e.g. attachment formation(s) such as tabs, through opening(s) of a structure of the instrument carrier e.g. a mesh thereof, as described above. In embodiments the or each attachment portion, e.g. attachment formation, such as a tab, does not include a clip for mounting the PCD to an instrument carrier. In general, the PCD may not include any clips for mounting the PCD to an instrument carrier.

In accordance with the invention in any of its embodiments, the main body may be of any shape. The main body may comprise a plurality of edges. An attachment formation may project from any point along an edge of the main body. The main body may comprise an attachment formation projecting from an end or ends of one or more edges thereof, and/or from an edge or edges thereof between the ends of the edge.

In some embodiments the main body comprises a plurality of corners connecting edges of the main body. An attachment formation may project from an edge or corner of the main body. The main body may be elongate, and may comprise a pair of longitudinal extending edges connecting the opposite longitudinal ends thereof, and a pair of transverse edges connecting the longitudinal edges at the longitudinal ends thereof.

The main body may be in the shape of a polygon, such as a quadrilateral. The main body may be square or rectangular in shape. The or each attachment formation may project from an edge of the main body in a direction perpendicular thereto.

The main body of the PCD may comprise any number of attachment formations projecting therefrom, and preferably comprises a plurality thereof. In preferred embodiments the PCD comprises one or more attachment formation projecting from one or more edges thereof, and preferably comprises one or more attachment formation extending from a plurality of edges, or each edge thereof. It is envisaged that only one attachment formation may project from a given edge.

The PCD preferably comprises a plurality of attachment formation(s) projecting from a main body of the PCD. In some embodiments the PCD comprises up to 8 attachment formations, or up to 6 attachment formations projecting from a main body of the PCD. The main body may comprise at least 2 attachment formations or at least 4 attachment formations projecting therefrom. The number of attachment formations may lie within a range corresponding to any combination of these sub ranges, and e.g. may be from 2-8 or 2-6. In these embodiments the main body is preferably a quadrilateral.

In some preferred embodiments in which the main body of the PCD comprises a plurality of corners connecting edges thereof, an attachment formation projects from each corner. Of course, the PCD may alternatively or additionally comprise one or more attachment formations projecting from an edge of the main body thereof between the ends of the edge.

Preferably, in accordance with any of the embodiments of the invention, one or more attachment formation projects from each end of the main body of the PCD. Thus one or more attachment formation is preferably provided at each end of the PCD. The ends are opposite ends e.g. opposite longitudinal ends of the device or main body. The PCD may comprise attachment formations projecting from each of one or both ends of the main body in both transverse and longitudinal directions.

Although it is preferred that the PCD comprises attachment formation(s) projecting therefrom, it is envisaged that this may not necessarily be the case. For example, the PCD may define one or more edges and/or one or more corners which may act as attachment portion(s). In these arrangements, the PCD may itself be of the shape described by reference to the main body used in those embodiments described in relation to arrangements having projecting attachment formations. In such embodiments the PCD preferably comprises a plurality of corners and/or edges, and may be in the shape of a polygon such as a quadrilateral. The PCD may be elongate. It is envisaged that the attachment portions of the PCD may then be provided by corners and/or edges of the PCD. The PCD may comprise a number of attachment portion(s) lying in any of the ranges disclosed with respect to embodiments in which the attachment portions are attachment formations that project from the main body.

Preferably the PCD does not comprise any opening extending therethrough. In accordance with any of the aspects or embodiments of the invention, the PCD device is preferably capable of being deformed by a user facilitate direct mounting of the device to the instrument carrier. This will also facilitate removal i.e. demounting of the device from the instrument carrier. Preferably the PCD is flexible, and most preferably resiliently flexible. The PCD is flexible or resiliently flexible to enable the device to be deformed by a user, preferably manually, to facilitate direct mounting thereof to the instrument carrier. References to the device being flexible or resiliently flexible may refer to the entire device being flexible or resiliently flexible, or at least a portion thereof. The resilience and/or flexibility refers to the properties of the PCD when deformed manually. In preferred embodiments in which the device comprises a main body and one or more attachment formations projecting therefrom, preferably at least the main body is flexible or resiliently flexible. This enables the device to be more readily manipulated by manipulating the main body, without needing to handle the attachment formations. However, in preferred embodiments the main body and the or each attachment formation is flexible or resiliently flexible. The entire PCD is therefore preferably flexible, or resiliently flexible. This may be achieved readily in the preferred embodiments in which the PCD is unitary.

In preferred embodiments, whether or not the PCD comprises a main body and attachment formations projecting therefrom, the PCD may be provided by a substrate having the test soil material disposed thereon. The substrate is preferably a flexible or resiliently flexible substrate

In accordance with any of these embodiments in which the PCD is flexible, the PCD, or portion thereof, or the substrate, is preferably resiliently flexible. The resilience of the device, part thereof, or substrate, may allow the device to recover to some extent after deformation during the mounting process to engage more securely with the instrument carrier, and may also allow the device to recover following removal from the carrier after use, to facilitate inspection.

The step of directly mounting the device to the instrument carrier, and optionally removing the device therefrom, may therefore comprise manipulating the device to deform the device to facilitate mounting or, where appropriate, removal of the device. Deformation of the device involves a change in shape of the device. Deformation of the device may involve deformation of the entire device or at least a portion thereof. Preferably this is carried out manually. For example a user may be able to manually manipulate the PCD by pressing each longitudinal end with their thumb and forefinger so that the device bends or deforms under manual pressure into a shape that facilitates mounting to the instrument carrier or removal therefrom.

Any steps involving deforming the PCD refer to deformation by a user, preferably manually. In embodiments in which the device comprises a main body and one or more attachment formations projecting therefrom, deforming the device may comprise deforming the main body and/or the one or more attachment formations. Preferably the method comprises deforming at least the main body. Such arrangements provide greater ease of use, avoiding the need to manipulate individual attachment formations. In some embodiments in which the device comprises multiple attachment formations extending from a main body, the method comprises deforming the main body to vary a spacing between attachment formations. The deformation is preferably an elastic deformation.

In preferred embodiments, the PCD, in its initial state i.e. prior to being mounted to the instrument carrier is substantially planar. The PCD may therefore be substantially planar in a form in which it is supplied to the user e.g. when packaged prior to use. Thus, the PCD in accordance with the device aspects of the invention is preferably substantially planar. The step of mounting the PCD to the instrument carrier may comprise deforming the PCD out of a plane defined initially by the PCD. The method may comprise deforming the PCD such that it defines a convexly curved shape when mounted to the instrument carrier in use. The PCD may be arranged to recover toward the planar configuration after removal from the instrument carrier. The PCD is preferably flexible or resiliently flexible to facilitate mounting in these manners.

It will be appreciated that the PCD being substantially planar refers to the substrate of the PCD being substantially planar. This does not exclude some surface undulation as a result of the presence of the test soil substance disposed thereon.

In embodiments in which the PCD comprises a main body and one or more attachment formations projecting therefrom, at least the main body of the PCD is preferably substantially planar (in an initial state before being mounted to the instrument carrier), and preferably the PCD including the main body and attachment formation(s) is substantially planar (in the initial state). Thus the entire PCD may be substantially planar. The method may comprise deforming at least the main body thereof out of the plane initially defined to mount the PCD to the instrument carrier. At least the main body may then recover toward the planar configuration after removal from the instrument carrier. The main body of the PCD of the further aspects of the invention is therefore preferably substantially planar and is deformable out of the plane by a user to directly mount the PCD to an instrument carrier in use.

The PCD of the present invention in accordance with any of its aspects or embodiments comprises a test soil material. The test soil material may be any test soil material as is known in the art. The test soil material should be selected appropriately by reference to the type of test of effectiveness that is to be performed e.g. to conform to any standards governing the test, and with regard to the type of the cleaning apparatus and/or medical instruments. A test soil material typically comprises substances that reflect the types of material that are to be removed from the medical instruments to be cleaned, and is arranged to adhere to the PCD with a degree of stubbornness selected such that removal of the material from the PCD is an adequate test of the effectiveness of the cleaning performance of the apparatus. Materials having differing levels of adherence to substrates that may be used to provide the PCD of the invention are known in the art, and the skilled person will understand how to vary the level of adherence as required. In some preferred embodiments the test soil material comprises blood or other organic material, or a blood or other organic material simulant. The test soil material is a solid material. The test soil material may be a dried material. Preferably the test soil material is a material that has been applied to the PCD and allowed to dry thereon. Exemplary test soil materials may be the Edinburgh soil test available from SVMS Ltd., United Kingdom or the Browne soil test available from Medical World Ltd., United Kingdom or any other soil test material that meets the requirements of ISO 15883 or equivalent standards for testing washer-disinfectors. These standards are only mentioned by way of example. It will be appreciated that a suitable test soil material may be in accordance with any current or future test standard. Of course, depending upon the nature of the test, the test soil material may not necessarily be in accordance with a particular standard, instead being chosen appropriately for the particular test that is to be performed and/or the apparatus that is being tested.

The test soil material is disposed on a surface of the PCD. The surface may be referred to as a test surface. The test surface is an exterior surface of the PCD. The test surface is preferably a surface of the PCD which is directly exposed to the cleaning actions of the apparatus during operation thereof e.g. which is exposed to a cleaning fluid etc. The test surface is preferably a planar surface at least prior to mounting of the PCD to the instrument carrier. This may facilitate inspection. The method may comprise mounting the PCD to the instrument carrier such that the test soil material is directly exposed to the action of the cleaning apparatus. By avoiding the need to provide an additional carrier for the PCD, the present invention allows, through the direct mounting of the PCD to the instrument carrier, the test soil material to be directly exposed to the cleaning effects of the apparatus in the same manner as the instruments loaded in the carrier, providing a more reliable test as to how well the instruments are being cleaned, or would be cleaned if loaded in the carrier. The test soil material is disposed on a surface of the PCD. Preferably the PCD defines a front and a back surface, and the test soil material is provided on only one of the front and back surfaces. The surface with the test soil material may define the front surface. In preferred embodiments the test soil material is provided on only one side or surface of the PCD.

In embodiments in which the PCD comprises a main body and one or more attachment formation(s) projecting therefrom, the test soil material is disposed on the main body. The test soil material may be disposed only on the main body or may also be disposed on the attachment formation(s). Preferably the main body of the PCD defines a front and a back surface, and the test soil material is provided on only one of the front and back surfaces of the main body. The surface with the test soil material may define the front surface. In preferred embodiments the test soil material is provided on only one side or surface of the main body.

The test soil material may be applied to the PCD in any suitable pattern. The pattern may be regular or irregular, and may be continuous or discontinuous. The pattern may be chosen appropriately to provide a desired degree of difficulty of removal e.g. depending upon test standards etc. The pattern is a predetermined pattern.

The test soil material provides a coating on the PCD i.e. on a substrate of the PCD. The test soil material may be provided in the form of a layer of the material. The layer may or may not be of uniform thickness or composition. The test soil material is preferably printed on the PCD, although it is envisaged that the material could be applied by other means involving contact or non contact processes.

The PCD is preferably a unitary device. The PCD is thus preferably a single piece device.

In accordance with the invention in any of its aspects or embodiments, the

PCD may be provided by a substrate having the soil test material disposed thereon. The PCD may comprise or consist of the substrate having the soil test material disposed thereon. The PCD is preferably provided by a single or unitary piece of a substrate having a test soil material disposed thereon. The substrate is preferably continuous over the extent of the device. The test soil material is disposed on a surface of the substrate. Preferably the PCD defines a front and a back surface, and the test soil material is provided on only one of the front and back surfaces. The surface with the test soil material may define the front surface. In preferred embodiments the test soil material is provided on only one surface of the substrate. The substrate is preferably a sheet substrate. Thus the test soil material is preferably disposed on only one side of the sheet. .

The substrate provides the PCD with its structural properties. The substrate may have any of the properties described above in relation to the PCD. The substrate is preferably flexible or resiliently flexible. In embodiments in which the PCD comprises a main body and one or more attachment formation(s) projecting therefrom, the main body and the or each attachment formation are preferably provided by a unitary piece of a substrate.

For the avoidance of doubt, in preferred embodiments, the substrate of the PCD, in its initial state i.e. prior to being mounted to the instrument carrier is substantially planar. The substrate of the PCD may therefore be substantially planar in a form in which it is supplied to the user e.g. when packaged prior to use. Thus, the substrate of the PCD in accordance with the device aspects of the invention is preferably substantially planar. The step of mounting the PCD to the instrument carrier may comprise deforming the substrate of the PCD out of the plane defined initially by the the substrate of the PCD. The method may comprise deforming the substrate of the PCD such that it defines a convexly curved shape when mounted to the instrument carrier in use. The substrate of the PCD may be arranged to recover toward the planar configuration after removal from the instrument carrier. The substrate of the PCD is preferably flexible or resiliently flexible to facilitate mounting in these manners.

In embodiments in which the substrate defines a main body and one or more attachment formations projecting therefrom, at least the main body is preferably substantially planar (in an initial state before being mounted to the instrument carrier), and preferably the main body and attachment formation (s) is substantially planar (in the initial state). Thus the entire substrate may be substantially planar.

The material or materials of the substrate of the PCD may be selected as desired to provide the PCD with the necessary or desired properties to enable it to be used in the manner of the present invention. The PCD should have a degree of rigidity to enable it to be directly mounted to the instrument carrier. The PCD is of a defined shape.

The substrate may be a laminate or more preferably is a single layer of a material. Whether or not it is a laminate or single layer material, preferably the substrate comprises a metallic material. The substrate may consist of a metallic material. For example the substrate may comprise or consist of a layer of the metallic material or may comprise or consist of a composite material containing metallic material. The metallic material may be aluminium or stainless steel. In some embodiments the substrate may comprise or consist of stainless steel or aluminium. In some embodiments the substrate comprises aluminiumised polyester. The substrate may be a metal substrate e.g. a stainless steel or aluminium substrate. Of course, in other embodiments, the substrate may be a plastic substrate.

However, the use of a substrate that comprises or is a metallic material has been found to be particular advantageous in providing a more attractive PCD upon which the test soil material may be more easily disposed e.g. by printing, and which may provide a degree of flexibility facilitating direct mounting of the device in accordance with the invention.

The thickness of the substrate may be in the range of between 0.1 mm and 1 mm, or between 0.1 mm and 0.5mm. The thickness may be less than 1 mm, or less than 0.5 mm, or less than 0.3 mm. The thickness may lie in a range defined between any of the end points defined with respect to these various sub ranges. The thickness of the substrate should be chosen as appropriate having regard to the substrate material to provide a substrate with desired flexibility, and ideally resilience, while also being capable of being used in the manner described.

In accordance with any of the aspects or embodiments of the invention, the PCD in preferably unitary, and cut from a sheet. In embodiments in which the PCD comprises a substrate having the test soil material disposed thereon, the substrate of the PCD is preferably provided from, and most preferably cut from a sheet of the substrate. Of course, it is envisaged that the PCD may be constructed in other manners. For example, it may be moulded. For example it may be cast or injection moulded. However, forming the PCD from a sheet of a substrate is considered to be particularly advantageous in facilitating manufacture.

In accordance with the invention in any of its aspects or embodiments, preferably the PCD comprises or is in the form of a plate. The test soil material is disposed on a surface of the plate. Where the PCD comprises a substrate having the test soil material disposed thereon, the substrate of the PCD is, in these embodiments, in the form of a plate. In preferred embodiments in which the PCD comprises a main body and one or more attachment formations projecting therefrom, at least the main body, and preferably the main body and attachment formation(s), are provided by a plate. Thus the entire PCD may be in the form of a plate having the test soil material disposed thereon. The PCD is preferably able to be deformed as described above to facilitate mounting or demounting thereof. Preferably the plate is a flexible plate, and most preferably, a resiliently flexible plate. By providing a PCD in the form of a flexible plate, the PCD may be constructed to be preferably substantially planar in the initial state of the PCD before use, while permitting deformation out of the plane in order to permit mounting of the PCD as described above. By providing the test soil material on a plate, inspection of the device is also facilitated after use, as any remaining soil material may be more readily apparent.

Embodiments in which the PCD (i.e. the substrate thereof) is in the form of a plate are advantageous as they may facilitate manufacture of the PCD. The PCD may simply be cut from a sheet substrate. This also facilitates application of the test soil material to the substrate e.g. through a printing process.

Preferably the PCD is provided by a single piece cut from a sheet of a substrate and having the test soil material disposed thereon.

The test soil material may be applied to a substrate of the PCD in any suitable manner to provide a coating thereon. The test soil material may be applied to the substrate either by a contact process, such as screen printing or slot coating, or a non-contact process, such as inkjet printing or spraying. The test soil material is preferably applied using a printing process, which may be a contact or non contact process. Preferably a contact printing process is used, and most preferably a screen printing process. It is envisaged that application may alternatively be achieved e.g. using a painting type process, which may be implemented using a robotic arm or similar.

The present invention extends to a method of manufacturing a PCD for use in accordance with the methods of the invention in any of its aspects or embodiments, or of manufacturing a PCD in accordance with the invention in any of its aspects or embodiments. The method may comprise the steps of cutting a piece from a sheet of a substrate, a test soil material being applied to the substrate before or after cutting the piece therefrom in order to provide a unitary PCD having the test soil material disposed thereon. Preferably the test soil material is applied to the substrate before the piece is cut therefrom to provide the PCD. The method may comprise applying the test soil material to the substrate before or after cutting the piece therefrom.

It is believed that these methods of manufacturing a PCD are advantageous in their own right.

In accordance with a further aspect of the invention there is provided a method of manufacturing a unitary Process Challenge Device for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, wherein the PCD comprises a substrate having a test soil material disposed thereon, the method comprising;

providing a sheet of a substrate having a test soil material applied thereto, and cutting a piece of the substrate having the test soil material applied thereto from the sheet to provide a unitary PCD.

It will be appreciated that the methods in these further aspects may be used to mass produce PCDs. The method may comprise cutting a plurality of pieces from the substrate having the test soil material applied thereto to provide a plurality of

PCDs. The method may comprise providing the sheet of the substrate, and applying the test soil material thereto. The test soil material is preferably applied to only one surface or side of the sheet, and the method may comprise applying the test soil material to only one side of the sheet.

providing a sheet of a substrate,

cutting a piece of the substrate from the sheet of the substrate,

and applying a test soil material to the cut piece to provide a unitary PCD. It will be appreciated that the methods in these further aspects may be used to mass produce PCDs. The method may comprise cutting a plurality of pieces from the substrate, and applying the test soil material to the or each cut piece to provide a plurality of unitary PCDs. The method preferably comprises applying the test soil material to only one surface or side of the cut piece.

The present invention in accordance with these further aspects or

embodiments may include any of the features described by reference to any of the other aspects of the invention. The PCD produced may be in accordance with any of the embodiments described and/or suitable for use in accordance with any of the methods described.

The methods in which the test soil material is applied to the substrate sheet before the piece is cut therefrom to provide the PCD are preferred for reasons of manufacturing simplicity. The substrate sheet may be pre-printed with the test soil material avoiding the need to handle and print individual pieces. In these further aspects or embodiments of the invention, the PCD may be in accordance with any of the aspects or embodiments of the invention earlier described. Preferably the PCD comprises a main body and one or more attachment formations projecting therefrom. The method preferably comprises cutting a piece of the substrate that defines a main body and one or more attachment formations projecting therefrom. The piece may be cut, or the test soil material applied to a cut piece, in such a manner to be disposed at least on the part of the piece providing the main body of the PCD, and, in embodiments, only on such a part. The test soil material may be of any of the types earlier described.

The test soil material may be applied to the cut piece or the sheet in any suitable manner to provide a coating thereon. The material may be applied by printing or painting. The test soil material may be applied to the substrate either by a contact process, such as screen printing or slot coating, or a non-contact process such as inkjet printing or spraying. In some preferred embodiments the test soil material is applied to the substrate by contact printing. It has been found that the use of a sheet material to provide the substrate facilitates printing in this manner, and allows the test material to be applied in a more consistent manner, allowing a device to be provided that results in a more reliable test of the apparatus. In a particularly preferred embodiment a screen printing process is used. This may allow desired deposition patterns to be achieved, in particular more irregular patterns which have been found to be useful in providing realistic test scenarios.

The substrate may of any of the materials described above, and preferably comprises a metallic material, and may be a metal substrate. The substrate is preferably flexible or resiliently flexible.

In accordance with the invention in any of its aspects or embodiments, the

PCD may be of any suitable dimensions. The dimensions of the PCD may be chosen as appropriate with regard to an instrument carrier to which the PCD is to be mounted. However, certain ranges have been found to be particularly suitable for use with a range of different carriers, in particular instrument trays or baskets. In the ranges below, the length and width of the PCD is with respect to the entire device, including the main body and any projecting attachment formations.

The PCD may define a length and a width. The length may be measured between longitudinal edges of the device, and the width between transverse edges of the device.

The PCD may have a length of between 20mm and 100mm, or between

30mm and 70mm, or between 40mm and 70 mm. The length may be at least 20cm, or at least 30 cm, or at least 40 cm. Alternatively or additionally, the length may be less than 100 cm, or less than 80 cm, or less than 70 cm, or less than 65 cm. The length may lie in a range defined between any of the end points defined with respect to these sub ranges e.g. 30mm and 70 mm etc.

Alternatively or additionally, the PCD may have a width of between 10mm and 60mm, or between 20 mm and 50 mm, or between 25 mm and 45 mm. The width may be at least 20 cm, or at least 30 cm. Alternatively or additionally, the width may be less than 60 cm, or less than 50 cm, or less than 45 cm. Again, the width may lie in a range defined between any of the end points defined with respect to these sub ranges.

Alternatively or additionally, the thickness of the PCD may be in the range of between 0.1 mm and 1 mm, or between 0.1 mm and 0.5mm. The thickness may be less than 1 mm, or less than 0.5 mm, or less than 0.3 mm. Again, the thickness may lie in a range defined between any of the end points defined with respect to these various sub ranges. The thickness refers to the overall thickness of the PCD including the test soil material disposed thereon. However, the thickness of the substrate having the test material thereon which defines the PCD may alternatively or additionally be within any of the ranges described for the PCD. The skilled person will recognise that the thickness of the PCD may be selected having regard to a desired deformability and/or resilience of the device, taking into account also the substrate used.

In one example, the length of the PCD is around 50mm, the width around 35 mm, and the thickness around 0.2 mm. In another example, the length is around 60 mm, the width around 40mm, and the thickness around 0.2 mm. Therefore the skilled person would be able to select a substrate thickness that resulted in a particular deformability. For example, in a particular embodiment the substrate may be stainless steel and the thickness of the substrate about 0.2mm.

Alternatively or additionally, in embodiments in which the PCD comprises a main body and one or more attachment formations e.g. tabs projecting therefrom, each attachment formation may have a length of at least 3 mm or at least 5mm. Each attachment formation may have a length of less than 10 mm, or less than 7 mm or less than 6 mm. Alternatively or additionally, each attachment formation may have a width of less than 5 mm and/or a width of greater than 3 mm. The length of an attachment formation is measured in the direction that the attachment formation extends away from the main body of the PCD, and the width in the direction perpendicular thereto e.g. along an edge of the main body from which the formation projects. In some exemplary embodiments each attachment formation has a width of around 4 mm and a length of around 6 mm. In other embodiments each attachment formation has a width of around 3.5 mm and a length of around 5 mm.

The width of the PCD may be at least 40%, or at least 50% or at least 60% of the length of the PCD. Alternatively or additionally, the width of the main body of the PCD in embodiments having a main body and projecting attachment formation(s) may be at least 40%, or at least 50%, or at least 60% of the length of the main body. Alternatively or additionally, the width of the PCD or main body is preferably less than the length thereof, or less than 90%, or less than 80% or less than 70% of the length thereof. Any one of these ranges may be combined.

Any of the above dimensions, whether absolute or relative, for the PCD in its various embodiments may be used alone or combined. Ranges expressed for the overall PCD may be combined with those for the main body and/or attachment formations in embodiments having such portions.

The test soil material may cover any suitable portion of a surface of the PCD to which it is applied. The test soil material may cover no more than 65%, or no more than 60%, or no more than 55% of a surface of the PCD to which it is applied. The test soil material may cover at least 1 % or at least 5% of the surface. In some exemplary embodiments the test soil material covers at least 10% and no more than 50% of the surface. However, coverage may be as low as 1 %. Where the PCD comprises a main body and attachment formations extending therefrom, the coverage of the main body may alternatively or additionally be in these ranges.

For the avoidance of doubt, where there is variation in the length, width or thickness, or indeed any other dimension of a component e.g. of the PCD, main body, attachment formation etc, the ranges herein are with respect to a maximum dimension, i.e. a maximum length, width or thickness.

It will be appreciated that the scale of the PCD, and its components may vary depending upon the instrument carrier with which it is to interact. Thus, a PCD for use with a carrier in the form of a larger framework e.g. rack may be larger than one for use with a small instrument basket.

The method of the invention in any of its aspects or embodiments may comprise the step of sealing a cleaning chamber of the cleaning apparatus with the instrument carrier and PCD mounted to the carrier therein, optionally with one or more medical instruments loaded in the carrier e.g. by closing a door of the apparatus.

In accordance with the invention in any of its aspects or embodiments, the method extends to the steps involved in testing the effectiveness of the cleaning apparatus using the PCD.

The method may further comprise the step of operating the cleaning apparatus to cause the apparatus to perform automated cleaning with the instrument carrier having the PCD directly mounted thereto in the cleaning apparatus e.g. in a cleaning chamber of the apparatus. The instrument carrier may be loaded with the one or more medical instruments. However, as mentioned above, the apparatus may be operated without any medical instruments being loaded in the carrier, and, in embodiments, without any medical instruments being located in the cleaning apparatus or cleaning chamber.

It will be appreciated that "use" of the PCD refers to the use of the PCD in a test, involving locating the PCD in the cleaning apparatus e.g. cleaning chamber, and operating the cleaning apparatus to perform automated cleaning, and optionally inspecting the PCD after completion of automated cleaning.

The method in any of its aspects or embodiments may comprise the step of removing the PCD from the cleaning apparatus, e.g. from a cleaning chamber thereof, and preferably from the instrument carrier subsequent to completion of automated cleaning by the cleaning apparatus e.g. for inspection. The step of removing the PCD from the instrument carrier is carried out by a user, preferably manually. The PCD may or may not be removed directly after completion of cleaning. For example, the apparatus may be arranged to carry out a

decontamination process that includes disinfection and/or sterilisation after cleaning, and the PCD (and instrument carrier if appropriate) may be removed from the apparatus after completion of all decontamination processes carried out by the apparatus. The PCD may be removed before, during or after unloading of the carrier if it was loaded with instrument(s).

The method may comprise the step of removing the instrument carrier from the apparatus e.g. from a cleaning chamber thereof, after completion of automated cleaning with the PCD directly mounted thereto, and preferably together with one or more medical instruments loaded in the carrier in those embodiments in which the carrier is so loaded. The method may comprise then removing the PCD from the instrument carrier e.g. for inspection. Of course the PCD may be inspected in situ while mounted to the carrier. The PCD would, however, be removed prior to reuse of the carrier.

The method may extend to the step of inspecting the PCD subsequent to cleaning by the cleaning apparatus. The step of inspecting the PCD may be carried out in any manner, and may involve subjecting the PCD to some form of interrogation which may involve the use of inspection equipment e.g. a PCD reader device such as a sensor. The most appropriate form of inspection will depend upon the nature of the PCD and the test soil material. Any suitable technique in the art may be used.

However, preferably the step of inspecting the PCD comprises visually inspecting the PCD. This step may be performed by a user. The visual inspection is preferably carried out with the naked eye.

The method may comprise inspecting the PCD to assess the efficacy of the cleaning apparatus. The step is preferably carried out by a user. The method may comprise using the visual appearance of the PCD to make the assessment. The method may comprise inspecting the PCD to determine whether any test soil material remains on the PCD. If no test soil material remains, it may be inferred that the apparatus is working adequately. If test soil material remains, the quantity and/or pattern of material remaining may be observed. This information may be used to determine whether the cleaning of the medical instruments of that load is sufficient, or whether further cleaning is needed and/or to determine what actions are need to improve the performance of the apparatus e.g. changing operating settings, requesting maintenance etc.

The PCD is preferably intended to be used only once before disposal.

The method may comprise the step of disposing of the PCD after use.

In accordance with a further aspect, the present invention further extends to a medical instrument carrier for an automated apparatus for the cleaning of medical instruments in combination with a PCD, the PCD being directly mounted or mountable to the medical instrument carrier. The instrument carrier is preferably loaded with one or more medical instruments. The PCD is preferably directly mounted or mountable to the carrier through cooperation with a mesh of the carrier.

In accordance with a further aspect of the invention there is provided an automated apparatus for the cleaning of medical instruments comprising a medical instrument carrier with a PCD directly mounted to the medical instrument carrier, and optionally loaded with one or more medical instruments. These further aspects of the invention may comprise any of the features described by reference to the other aspects of the invention. Thus, the medical instrument carrier, cleaning apparatus and/or PCD may be in accordance with any of the embodiments described herein.

In accordance with the invention in any of its aspects, the PCD is a hand held device. The PCD is preferably disposable.

As discussed above, the methods and devices of the present invention are applicable to testing the effectiveness of any type of automated apparatus for the cleaning of medical instruments. The apparatus is preferably arranged to perform an automated cleaning cycle in use. References herein to operating the apparatus to perform automated cleaning may refer to operating of the apparatus to perform an automated cleaning cycle. References to carrying out a step before operation of the apparatus to carry out automated cleaning, e.g. mounting the PCD to the carrier etc. may refer to carrying out the step(s) before operation of the apparatus to carry out an automated cleaning cycle. Alternatively or additionally, references to carrying out a step after completion of automated cleaning by the apparatus or after operation of the apparatus to perform automated cleaning e.g. removal of the carrier and/or PCD therefrom etc. may refer to carrying out the step(s) after completion of an automated cleaning cycle by the apparatus.

The apparatus may be semi-automatic or automatic.

The apparatus comprises a cleaning chamber in which the instrument carrier and PCD, and any medical instruments are disposed for cleaning.

The cleaning apparatus may be arranged to, and preferably does, clean medical instruments therein, e.g. in a cleaning chamber thereof, by bringing a cleaning fluid i.e. liquid into contact with instruments to be cleaned. The cleaning fluid is a liquid, and may comprise or be water, and optionally may include one or more cleaning agents e.g. detergents.

The apparatus may be arranged to force pressurised cleaning fluid i.e. liquid over instruments to achieve cleaning. The apparatus may be arranged to spray instruments with cleaning fluid i.e. liquid. The cleaning apparatus may be arranged to provide deluge cleaning of medical instruments. Alternatively or additionally, the apparatus may be arranged to provide ultrasonic cleaning of medical instruments. In an ultrasonic cleaning process, the or each instrument is immersed in a bath of cleaning liquid. Ultrasonic transducers are used to excite liquid in the bath, causing ultrasonic waves to propagate through the liquid. The ultrasonic waves cause small, high pressure bubbles to form and collapse in the liquid at high frequency. This "cavitation" effect gives rise to pressure waves in the liquid, which acts to "scrub" the surfaces of the immersed instrument. In this way, debris attached to the surfaces of the instrument may be loosened. Cleaning fluid i.e. liquid may be supplied to internal surfaces of the instruments during ultrasonic cleaning.

Alternatively or additionally the apparatus may be arranged to provide cleaning of instruments by subjecting the instruments to soaking. For example, the apparatus may be arranged to immerse instruments to be cleaned in liquid. The liquid may be provided in an ultrasonic reservoir of the apparatus. Soaking is then carried out in the ultrasonic reservoir, but without the application of ultrasonic waves.

It will be appreciated that ultrasonic cleaning may be carried out alone, or in combination with deluge cleaning. Deluge cleaning may be used to help flush debris dislodged by the ultrasonic cleaning from the surfaces of an instrument.

The cleaning apparatus may include an ultrasonic reservoir situated in the base of a cleaning chamber, with deluge sprayers arranged above the reservoir. In these arrangements, the lowermost instruments may be immersed in the ultrasonic reservoir to enable ultrasonic cleaning to be carried out. This may be achieved by lowering an instrument carrier appropriately and/or filling the ultrasonic reservoir with liquid to cover the instruments. The reservoir may or may not then be drained and/or the deluge sprayers operated. Operation of the deluge sprayers may provide deluge cleaning of those instruments situated in the upper parts of the cleaning chamber, and in some cases, the ultrasonically cleaned instruments in the reservoir if drained. In other situations, cleaning may involve ultrasonic cleaning without deluge cleaning.

In general the apparatus may be arranged to provide cleaning that includes any or all of deluge cleaning, which may include pre wash, wash and rinsing stages; ultrasonic cleaning; and soaking. The apparatus may carry out any of these types of cleaning when operated e.g. as part of a cleaning cycle. The cleaning preferably involves the use of a cleaning liquid e.g. water optionally with one or more cleaning agents e.g. detergents.

In embodiments in which the method includes the step of operating the apparatus to provide automated cleaning with the instrument carrier having the PCD mounted thereto therein, optionally loaded with one or more instruments, the cleaning may include any or all of the above types of cleaning. Thus the method may comprise the apparatus performing any of the above types of cleaning that it is described as being able to perform in embodiments. It will be appreciated that where no instruments are located in the apparatus, it may still be considered to perform "cleaning" i.e. those processes that are involved in a cleaning cycle, and which would be experienced by an instrument if located therein. The apparatus is arranged to perform the processes for the cleaning of instruments. The instrument carrier and PCD will be subjected to such cleaning.

The apparatus may be arranged to be able to, and, in embodiments does carry out additional decontaminating processes e.g. disinfection and/or sterilisation. Thus the apparatus is a cleaning apparatus in that it is at least able to perform cleaning of instruments, and may be only able to provide cleaning of instruments, or cleaning and one or more additional decontaminating processes. It will be appreciated that the PCD is adapted to test the effectiveness of automated cleaning by the apparatus. This will enable it to be checked that the cleaning process(es) performed are sufficient to remove contaminants e.g. blood or organic material from instruments before any further sterilisation or disinfection is carried out, which would have the effect of "fixing" any residual contaminants to instruments. Even if the PCD is inspected after further decontamination processes e.g. disinfection or sterilisation are carried out, its state may therefore generally be indicative of the effectiveness of the cleaning operation.

The apparatus may be arranged to carry out a decontaminating cycle comprising cleaning and disinfection and/or sterilisation. Additional decontaminating processes may be carried out at any stage, but preferably after the cleaning process(es). In embodiments the apparatus may carry out disinfection or sterilisation after one or more cleaning processes while the instrument carrier having the PCD mounted thereto, and optionally one or more instruments loaded therein, is disposed in the apparatus. Thus removal of the PCD and carrier from the apparatus may occur after completion of cleaning and any additional decontaminating processes, or directly after completion of cleaning. Disinfection may be carried out by the apparatus in a similar manner to deluge cleaning described above, but using fluid e.g. liquid at an elevated temperature. Of course, the apparatus may only be configured to carry out cleaning, or may only be operated to provide cleaning, with instruments being transferred to another apparatus for other decontamination e.g. disinfection or sterilisation.

In some embodiments no sterilisation process is performed. The cleaning apparatus may be configured such that it cannot provide a sterilising process.

Accordingly, the devices and methods of the present invention are applicable to automated cleaning apparatus that are used to implement any cleaning process or processes for the cleaning of medical instruments. Cleaning may be referred to as "washing". It will be appreciated that the apparatus is for the automated cleaning of medical instruments, and may be arranged to perform an automated cycle for the cleaning of medical instruments. The cleaning performed by the apparatus e.g. cleaning cycle may include any one or ones of the above cleaning processes, and optionally may form part of a decontaminating process e.g. cycle including one or more additional decontamination processes e.g. disinfection and/or sterilisation. The apparatus is arranged to bring a cleaning fluid, i.e. a liquid, into contact with the instruments to be cleaned. The apparatus is preferably arranged to carry out deluge cleaning, although may additionally or alternatively be arranged to carry out ultrasonic cleaning. The apparatus may be configured to carry out additional decontaminating processes such as disinfection and/or sterilisation.

A cleaning cycle which may be performed may, and preferably does comprise any of the above cleaning steps described. The cleaning apparatus may of course be arranged to perform other types of decontamination as part of the or another decontamination cycle.

The cleaning apparatus is preferably an automated washer or a washer- disinfector. However, the apparatus could be of other types. The apparatus may be specific to cleaning a particular type of instrument. For example, the apparatus may be an endoscope cleaning apparatus.

It will be appreciated that the instrument carrier and PCD will be subjected to the same cleaning process as experienced by, or as would be experienced by, instruments with which the carrier is or may be loaded.

The apparatus may be of any type, and may be a cabinet style or chest style apparatus.

The invention is particularly, although not exclusively, applicable to methods and devices for testing the effectiveness of an automated apparatus for the cleaning of surgical instruments, and to methods of providing such devices. However the methods and devices of the invention in its various aspects may also be applied to testing the effectiveness of an automated apparatus for the cleaning of other types of medical instrument. The medical instruments may be for use in any medical field, including dental and veterinary fields. The medical instruments that are loaded or loadable on to the instrument carrier in accordance with the invention in any of its aspects or embodiments may therefore be any type of medical instrument, and may or may not be surgical instruments. The instruments are instruments that are to undergo cleaning e.g. following use of the instruments.

The present invention extends to the PCD of any of the aspects or embodiments of the invention described in a package i.e. for supply to a user. The PCD may be singly packaged, or a plurality of the PCDs may be packaged together. The methods of manufacturing a PCD may comprise the further step of packaging the PCD for supply to a user. The method may comprise a user removing the PCD from a package prior to mounting the PCD to the instrument carrier.

Where not explicitly stated, it will be appreciated that the invention in any of its aspects may include any or all of the features described in respect of other aspects or embodiments of the invention to the extent they are not mutually exclusive.

It will be appreciated that the invention provides a method for or of testing the effectiveness of an automated apparatus for the cleaning of medical instruments, and references to the method may be to a method "for" or "of" so doing.

While the invention in its various aspects has been described by particular reference to the case in which the method is for testing an apparatus for cleaning of medical instruments, and to a PCD for use in such a method, it is contemplated that the invention in any of its aspects may be applied more generally to testing an apparatus which may be used for cleaning other medical equipment or components, e.g. surgical equipment or components. The invention extends to such methods and a PCD for use in such methods. Thus, the invention may be applied to the testing of an automated apparatus for cleaning medical apparatus which may be medical instruments, components or equipment. References to a medical "instrument" herein may be replaced by a reference to medical apparatus. The apparatus may be medical instruments, equipment or components. References to an "instrument carrier" may be replaced by a reference to a "medical apparatus carrier". The method may comprise providing medical equipment in the cleaning apparatus with the PCD.

Some preferred embodiments of the invention will now be described by way of example only, and by reference to the accompanying drawings, of which;

Figure 1 is a top plan view of a process challenge device (PCD) in

accordance with one embodiment of the present invention;

Figure 2 is a schematic view illustrating an instrument basket used in an automated apparatus for cleaning medical instruments having the process challenge device of Figure 1 directly mounted thereto;

Figure 3 is a detailed view illustrating a corner of an instrument basket having a process challenge device in accordance with the embodiment of Figure 1 mounted thereto in one orientation;

Figure 4 is a detailed view illustrating a corner of an instrument basket having a process challenge device in accordance with the embodiment of Figure 1 mounted thereto in an alternative orientation; and

Figure 5 is a schematic vertical cross sectional view of a cleaning apparatus with which the PCD of the present invention may be used.

Figure 1 is a top plan view of a process challenge device (PCD) 10 according to one embodiment of the present invention. The process challenge device 10 includes a main body portion 14. The main body portion 14 is generally rectangular in this embodiment, although other shapes are envisaged.

A test soil material 16 is disposed on the main body of the PCD on one surface thereof. The test soil material 16 is printed onto the main body using a screen printing process. However, it will be appreciated that other techniques may be used. Screen printing has been found to be advantageous in providing reliable and consistent printing of the soil material on to the PCD substrate. Any suitable test soil material known in the art may be used. For example a test soil material including dried blood or a dried blood simulant may be used.

A plurality of attachment formations in the form of tabs 12 extend from the main body portion 14 of the PCD 10. These tabs 12 enable the PCD 10 to be directly mounted to an instrument carrier as described below through cooperation with a mesh structure of the carrier. In the illustrated embodiment the PCD 10 includes six tabs 12; two of the six tabs 12 project from either longitudinal end of the main body 14 between the transverse edges thereof, and the remaining four tabs 12 project from each corner of the main body 14 in a direction generally perpendicular to the two end tabs 12. This tab configuration makes the PCD 10 particularly easy to mount to an instrument carrier through interaction with the mesh thereof. However other configurations and numbers of tabs are envisaged, and attachment formations of different configurations could be used depending upon the type of carrier and part(s) thereof with which the attachment formation(s) are to interact to achieve mounting. In the illustrated embodiment, all the tabs 12 are of equal size and shape although tabs 12 or other attachment formations of different size and shape are envisaged.

The tabs 12 may have an average width or maximum width that is smaller that a mesh size of an instrument carrier e.g. basket with which the PCD 10 is intended to be used. The preferred widths mentioned below have been found to allow the tabs to be inserted into the mesh of certain standard instrument carrier baskets.

The PCD 10 is preferably flat before use. In the illustrated embodiment the main body and tabs all lie flat in the same plane. The PCD 10 is in the form of a plate defining the main body and the tabs, and having the test soil material disposed thereon.

The PCD 10 is a unitary single piece device, provided by a piece of a resiliently flexible substrate defining the main body 14 and tabs 12, and having the test soil material 14 disposed thereon. The main body and tabs are therefore integrally formed. The PCD substrate piece is cut from a sheet of the substrate material.

The substrate is advantageously a metallic substrate. The substrate material may be a stainless steel or aluminium substrate, or may be an aluminiumised polyester material. In one exemplary embodiment the PCD 10 is cut from a sheet of type 316 stainless steel. Type 316 stainless steel is most frequently used for medical applications and particularly surgical instruments and therefore provides a good simulation of typical cleaning conditions.

In one exemplary embodiment the substrate of the PCD 10 is cut from a 0.2 mm thick sheet of stainless steel. A stainless steel sheet of this thickness has been found to have a flexural strength which is low enough that it can be bent using manual force but high enough that it is only elastically deformable, and therefore resilient, under manual force. Of course, other materials may be used for the PCD substrate, which may or may not be resilient, provided that they enable the PCD to be manipulated to allow the PCD to be manually mounted to an instrument carrier in use. Materials which are resiliently deformable are preferred, as the PCD may then recover once mounted to some extent, providing more secure mounting, and may also recover after removal from the carrier after use to facilitate inspection.

In one exemplary embodiment, the main body 14 has a length L_B of about 40 mm and a width W_B of 25 mm. The overall PCD has a length L_P of about 50 mm and a width W_P of about 35 mm. In this embodiment, the tabs 12 have a length L_T of about 5 mm and a width W_T of 3.5 mm. Such sizes allow for easy engagement with the mesh of certain instrument baskets. In another exemplary embodiment the main body 14 has a length L_B of 46 mm and a width W_B of 28.75 mm. The tabs 12 in this embodiment have a length L_T of 5.75 mm and a width W_T of 4.03 mm. The overall PCD length L_P is 57.5 mm and overall width W_P is 40.25 mm. It will be appreciated that the dimensions of the PCD 10 may be selected by reference to the size and type of the instrument carrier to which the PCD 10 is to be mounted, and the configuration of the part of the carrier with which the PCD is to interact to achieve mounting e.g. the mesh structure thereof, or more specifically the openings thereof. Therefore, where a variety of instrument carriers are used, it is envisaged that a variety of PCD 10 sizes may be available. Different ranges of PCDs may be provided by appropriate scaling up or down of these examples. The two exemplary sets of dimensions represent a difference in scale of 15%. However, it will be appreciated that the relative width and length dimensions of the main body and/or tabs may be varied. In general the configuration of the attachment formations e.g. tabs may be more important in facilitating mounting of the PCD to a carrier, and the overall dimensions may be selected to provide ease of handling and inspection of the soil substance, and/or to provide a surface to accommodate a desired area of coverage of the soil substance.

Referring now to Figure 2, the use of the PCD 10 will be described.

Figure 2 shows the PCD 10 of Figure 1 directly mounted to a medical instrument carrier, which, in the illustrated embodiment is an instrument basket 20, although it will be appreciated that the PCD 10 may equally be used with other types of instrument carrier e.g. instrument trays etc. The basket 20 may be a DIN standard basket.

In this embodiment, the instrument basket 20 has a base and sidewalls and is and holds a number of medical instruments 30 in an interior space thereof. The medical instruments are surgical instruments in this example. The basket 20 is, in use, located in a cleaning chamber of a cleaning apparatus loaded with medical instruments to be cleaned, and holds the instruments during the cleaning process. The basket 20 as shown in Figure 2 with the instruments therein, and the PCD 10 mounted directly thereto, is ready to be loaded into a cleaning apparatus.

The base and sidewalls of the basket 20 are formed of a mesh 22 which allows cleaning liquid to enter the basket in use to contact the instruments, but is of a size such that the instruments are retained in the basket. The mesh 22 may be a wire mesh 22.

The instrument basket 20 is rectangular in shape, although it is envisaged that the PCD 10 of the present invention could be used with other basket shapes.

As shown in Figure 2, the PCD 10 is mounted directly to the instrument basket 20 through cooperation between the tabs 12 and the mesh structure of the basket. The PCD is "caught" in the mesh through interaction between the tabs and the mesh structure.

In accordance with the methods of the invention, the PCD 10 is generally flat as shown in Figure 1 before use. In order to directly mount the PCD 10 to the instrument basket 20, the user manually exerts a force on the PCD 10 to deform the PCD 10 such that it bends in one or more directions out of its initial plane to form a convex shape so as to bring tabs 12 closer to each other. The user then inserts the tabs 12 into the mesh 22 of the basket and releases pressure on the PCD 10. The resilient nature of the PCD 10 then causes the tabs 12 to firmly engage with the mesh 22 of the basket 20 as the PCD 10 recovers towards its initial configuration prior to deformation by the user. In this way, the PCD 10 is securely mounted to the instrument basket 20 through direct interaction between the tabs 12 and the basket 20, with the tabs 12 being caught in the mesh 22 of the basket 20. Figure 2 illustrates the case in which the user mounts the PCD 10 to the corner of the instrument basket 20. However, this is merely exemplary.

Figure 3 shows a more detailed view of the PCD 10 of Figure 1 mounted in the corner 24 of an instrument basket 20. As can be seen in greater detail, the tabs 12 are "caught" in the mesh 22 of the basket 20.

Figure 4 shows an alternative mounting arrangement of the PCD 10 of Figure 1 in an instrument basket 20. Again, a number of the tabs 12 are inserted into the mesh 22 of the basket 20 such that the PCD 10 is securely mounted thereto.

It will be appreciated that not all of the tabs 12 need be caught in the mesh 22 to attach the PCD 10 thereto.

As can be seen from Figures 3 and 4, the PCD 10 may remain in a convex shape after mounting to the basket.

It will be appreciated that the PCD may be mounted to the instrument basket before or after it is loaded with instruments.

Once the PCD 10 is mounted into the basket 20, the basket 20 containing the instruments to be cleaned is loaded into a cleaning apparatus e.g. an automatic washer to be tested. The basket is located in a cleaning chamber of the apparatus. The apparatus may be an automatic washer or washer disinfector. The basket 20 may first be placed on a shelf or other carrier, or may be directly mounted in the cleaning chamber of the apparatus.

The apparatus is then operated to perform a cleaning cycle. The PCD 10 is subjected to the same cleaning processes as the instruments in the basket. The cycle may involve cleaning fluid i.e. liquid being brought into contact with the instruments 30, and hence with the PCD located in the instrument basket 20. The PCD 10 remains securely fixed to the instrument carrier through the direct mounting described above throughout the cleaning process. The cleaning process may involve deluge cleaning.

After the cleaning cycle is complete, the PCD 10 is removed from the cleaning apparatus and inspected. This may be achieved by removing the instrument basket from the cleaning chamber, and removing the PCD from the basket. The inspection is advantageously performed visually by the user, and may be carried out in accordance with known techniques. If soil material 16 remains on the PCD 10, then it can be inferred that the cleaning apparatus is not functioning effectively.

It will be appreciated that although the examples relate to its use with an instrument basket, the PCD may be used with other types of instrument carrier. The carrier may comprise a mesh of any type with which the PCD interacts, and a mesh may be provided by a perforated structure, such as a perforated plate, with which the PCD interacts in a similar manner to that described by reference to the mesh in the example above, or by the framework of a carrier. The openings may be of a different scale to those in the illustrated embodiment e.g. being larger openings of a mesh that provides a rack type carrier. For example, the framework may be defined by bent wires in a similar manner to a dishwasher rack. The mesh may form any part or parts of the carrier.

Figure 5 is a vertical cross sectional view of a cleaning apparatus with which the PCD of the present invention may be used. The apparatus shown in Figure 5 is a conventional cabinet style washer, arranged to provide deluge cleaning of medical instruments when located therein. The washer includes a main housing defining a wash chamber 43. A removable carrier 45 is mounted within the wash chamber 43. In use, the instruments to be cleaned are mounted to the carrier. The carrier may be inserted in or removed from the wash chamber for loading or unloading of instruments as known in the art. The carrier 45 includes various shelves upon which instruments to be cleaned may be placed, either directly, or by placing the instruments first in removable instrument carriers e.g. baskets, such as the baskets in relation to which the use of the PCD has been described above. The shelves are not shown in Figure 5 for simplicity.

In the illustrated embodiment , the carrier defines a central column 47 defining a main fluid passageway through which the cleaning fluid may flow in use. A lower end of the column is in fluid communication with an outlet of pump 42. The lower end of the column is fluidly connected to the outlet of the pump when the carrier is inserted in the wash chamber, and is disconnecteable therefrom to permit removal of the carrier from the chamber. The connection is within the region of the dotted lines. The pump 42 is located in the base of the apparatus, and provides a flow of cleaning fluid in use in the direction indicated by the arrow in Figure 1.

A plurality of spray arms 49, 41 extend perpendicular to the column 47 and each define a fluid flow path extending along the length thereof in fluid

communication with the main flow path of column 47. The arms comprise fluid outlets along the lower sides thereof for providing fluid in the form of a spray to the interior of the wash chamber in use. The spray arms include the longer spray arms 9 and shorter spray arms 41 , although it will appreciated that other configurations of spray arms may be used. For example, shorter spray arms 41 may be omitted.

Cleaning fluid i.e. liquid will pass upwards through the fluid path defined by column 47 in use, and will exit the column via fluid paths defined by the plurality of spray arms 49, 41 to be discharged in the form of droplets through the outlets of the spray arms. The spray arms 49, 41 are arranged to be hydraulically actuated to rotate around the central column 47 when fluid is pumped through the fluid path of the central column and from there along the fluid paths spray arms to provide a spray for cleaning the external surfaces of instruments located in the apparatus in use. This is a conventional deluge cleaning type arrangement, similar to that employed in dishwashers.

In some arrangements, the carrier 45 may be inserted into the wash chamber 43 at a first vertical level. The wash chamber may comprise a conveying system, which is not shown in Figure 5, to enable the carrier to then be lowered toward the base of the chamber to enable the central column 47 to be located in fluid

communication with the outlet of the pump 42 to enable fluid to be pumped upward to the column in use.

While the apparatus shown in Figure 5 specifically illustrates a deluge cleaning apparatus, the invention is applicable to cleaning apparatus which additionally or alternatively is arranged to carry out ultrasonic cleaning of instruments. In a combined ultrasonic/deluge cleaning apparatus, the lower part of the wash chamber of the type shown in Figure 5 may be filled with fluid, to cover instruments located at lower levels of the carrier. The apparatus may comprise suitable ultrasonic transducers for applying ultrasonic waves to the instruments which are immersed in the fluid during the relevant part of the cleaning cycle. The lower part of the wash chamber may then be drained so that the same instruments can undergo deluge cleaning. In other arrangements, an instrument carrier might be conveyed towards a lower part of the apparatus for immersion of instruments in a reservoir defined in the base thereof for ultrasonic cleaning, and then raised to remove the instruments from the reservoir as a appropriate in a cleaning cycle.

The cleaning apparatus of Figure 5 is configured to perform an automatic cleaning cycle in use.

In yet other arrangements, the cleaning apparatus may simply be an ultrasonic cleaning apparatus without deluge cleaning means. Such an apparatus might be in the form of an ultrasonic bath into with instruments can be placed e.g. by mounting them first in an instrument carrier e.g. basket. Such an apparatus may be a chest style washer.

It will be appreciated that the PCD may be used in the manner described above, but without medical instruments being located in the instrument carrier. This might be used to test the operation of the cleaning apparatus as part of a set up procedure, before it is used to clean instruments e.g. as part of a daily set up routine.

Claims

1. A method for testing the effectiveness of an automated apparatus for the cleaning of medical instruments, the method comprising:

providing an instrument carrier in the cleaning apparatus together with a

Process Challenge Device (PCD) comprising a test soil material,

wherein the PCD is directly mounted to the instrument carrier.

2. The method of claim 1 wherein the instrument carrier is loaded with one or more medical instruments.

3. The method of claim 2 further comprising loading the instrument carrier with the one or more medical instruments, wherein the method comprises directly mounting the PCD to the instrument carrier before, during or after loading the instrument carrier with the one or more medical instruments, preferably wherein the step of directly mounting the PCD to the instrument carrier is performed after loading the instrument carrier with the one or more medical instruments.

4. The method of any preceding claim wherein the method comprises locating the instrument carrier in the cleaning apparatus, wherein the method comprises directly mounting the PCD to the instrument carrier is carried out before, during or after locating the instrument carrier in the cleaning apparatus, preferably wherein the step of directly mounting the PCD to the instrument carrier is carried out before locating the instrument carrier in the cleaning apparatus.

5. The method of any preceding claim wherein the instrument carrier to which the PCD is directly mounted comprises a mesh, wherein the PCD is directly mounted to the instrument carrier through direct cooperation between the PCD and the mesh.

6. The method of claim 5 wherein the PCD comprises a plurality of attachment portions that cooperate with the mesh to directly mount the PCD thereto.

7. The method of claim 5 or claim 6 wherein the PCD comprises a main body having a plurality of attachment formations projecting therefrom, preferably wherein the attachment formations are in the form of tabs.

8. The method of claim 7 wherein the PCD comprises from 2-8, or from 2-6 attachment formations.

9. The method of claim 7 or 8 wherein the test soil material is disposed on the main body of the PCD.

10. The method of any preceding claim comprising manipulating the PCD to deform the PCD to facilitate mounting of the PCD to the instrument carrier.

1 1. The method of any preceding claim wherein the instrument carrier is an instrument container, preferably wherein the instrument carrier is an instrument tray or an instrument basket.

12. The method of claim 1 1 comprising directly mounting the PCD within the instrument container, preferably in a corner thereof.

13. The method of any preceding claim wherein the PCD is in the form of a plate having the test soil material disposed thereon.

14. The method of any preceding claim wherein the PCD is flexible, and preferably resiliently flexible.

15. The method of any preceding claim wherein the PCD is provided by a substrate having the test soil material disposed thereon, optionally wherein the substrate comprises a metallic material.

16. The method of claim 15 wherein the substrate is cut from a sheet.

17. The method of any preceding claim wherein the step of directly mounting the PCD to the instrument carrier is performed manually by a user.

18. The method of any preceding claim further comprising operating the cleaning apparatus to perform automated cleaning with the instrument carrier having the PCD mounted thereto in the apparatus, optionally wherein the instrument carrier is loaded with one or more medical instruments.

19. The method of claim 18 further comprising removing the PCD from the instrument carrier after completion of automated cleaning by the apparatus.

20. The method of claim 18 or 19 comprising visually inspecting the PCD following completion of automated cleaning in order to assess the efficacy of the cleaning apparatus.

21. The method of any preceding claim wherein the cleaning apparatus is arranged to provide automated cleaning of one or more medical instruments when located therein by bringing a cleaning liquid into contact with the instrument(s).

22. The method of any preceding claim wherein the apparatus is arranged to perform deluge and/or ultrasonic cleaning of medical instruments.

23. The method of any preceding claim wherein the cleaning apparatus is a washer or a washer-disinfector.

24. A method for testing the effectiveness of an automated apparatus for the cleaning of medical instruments, the method comprising:

providing an instrument carrier in the cleaning apparatus together with a unitary Process Challenge Device (PCD) provided by a substrate having a test soil material disposed thereon;

wherein the PCD comprises a main body having a plurality of attachment formations projecting therefrom;

wherein the PCD is directly mounted to the instrument carrier.

25. The method of claim 24 wherein the substrate comprises a metallic material.

26. The method of claim 24 or 25 wherein the substrate is cut from a sheet.

27. A Process Challenge Device (PCD) for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, wherein the PCD has a test soil material disposed thereon, and wherein the PCD is flexible and defines a main body having the test soil material disposed thereon, and a plurality of attachment formations projecting from the main body which may be used to mount the PCD directly to an instrument carrier for an automated cleaning apparatus by cooperation with a mesh of the instrument carrier.

28. The PCD of claim 27 wherein the attachment formations are in the form of tabs.

29. The PCD of claim 27 or claim 28 wherein attachment formations are provided at both ends of the PCD.

30. The PCD of any one of claims 27-29 wherein the PCD comprises from 2-8, or from 2-6 attachment formations.

31. The PCD of any one of claims 27 to 30 wherein the main body is in the shape of a polygon, preferably a quadrilateral.

32. The PCD of any one of claims 27 to 31 wherein the PCD is in the form of a plate.

33. The PCD of any one of claims 27 to 32 wherein the PCD is resiliently flexible.

34. The method or PCD of any preceding claim wherein the PCD is a unitary device.

35. The PCD of any one of claims 27-34 wherein the PCD is provided by a substrate having the test soil material disposed thereon, preferably wherein the substrate is cut from a sheet.

36. The PCD of claim 35 wherein the substrate comprises a metallic material, optionally wherein the substrate consists of or comprises aluminium or stainless steel.

37. A Process Challenge Device (PCD) for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, wherein the PCD has a test soil material disposed thereon, and wherein the PCD defines a main body having the test soil material disposed thereon, and a plurality of attachment formations projecting from the main body which may be used to mount the PCD directly to an instrument carrier for an automated cleaning apparatus by cooperation with a mesh of the instrument carrier, and wherein the PCD is unitary and provided by a substrate having the test soil material disposed thereon.

38. The PCD of claim 37 wherein the substrate comprises a metallic material.

39. The PCD of claim 37 or 38 wherein the substrate is cut from a sheet.

40. A method of using the PCD of any one of claims 27 to 39 comprising providing an instrument carrier in a cleaning apparatus together with the PCD, wherein the method comprises directly mounting the PCD to the instrument carrier, optionally wherein the instrument carrier is loaded with one or more medical instruments.

41. The method of any one of claims 1-26 wherein the PCD is in accordance with any one of claims 27-39.

42. An instrument carrier in combination with the PCD of any one of claims 27 to

39. the PCD being directly mounted or mountable to the instrument carrier.

43. A method of manufacturing a PCD for use in accordance with the method of any one of claims 1 to 26 comprising cutting a piece from a sheet of a substrate having a test soil material applied thereto to provide the PCD, optionally wherein the method comprises applying the test material to the sheet of substrate.

44. A method of manufacturing a PCD in accordance with any one of claims 27 to 39 comprising cutting a piece from a sheet of a substrate having a test soil material applied thereto to provide the PCD, optionally wherein the method comprises applying the test material to the sheet of substrate.

45. A method of manufacturing a unitary Process Challenge Device for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, wherein the PCD comprises a substrate having a test soil material disposed thereon,

the method comprising;

providing a sheet of a substrate having a test soil material applied thereto, and cutting a piece of the substrate having the test soil material applied thereto from the sheet to provide a unitary PCD,

wherein the method optionally comprises the step of applying the test soil material to the sheet of substrate.

46. A method of manufacturing a unitary Process Challenge Device for use in testing the effectiveness of an automated apparatus for the cleaning of medical instruments, wherein the PCD comprises a substrate having a test soil material disposed thereon,

the method comprising;

providing a sheet of a substrate,

cutting a piece of the substrate from the sheet of the substrate,

and applying a test soil material to the cut piece to provide the unitary PCD.

47. The method of manufacturing a PCD of any one of claims 43-46 wherein the device comprises a main body and a plurality of attachment formations projecting therefrom.

48. The method of any one of claims 43-47 wherein the substrate is a flexible substrate, preferably a resiliently flexible substrate.

49. The method of any one of claims 43-48 wherein the substrate is a metallic substrate, optionally wherein the substrate consists of or comprises aluminium or stainless steel.

50. The method of any one of claims 43-49 wherein the step of applying the test soil material to the substrate or piece comprises printing the material onto the substrate or piece, preferably using a contact printing process, such as screen printing.

51. The method or device of any preceding claim wherein the PCD has a length of between 20mm and 100mm, and/or a width of between 10mm and 60mm and/or a thickness of between 0.1 mm and 1 mm.

52. The method or device of any preceding claim wherein the test soil material comprises blood or other organic material, or a blood or other organic material simulant.

53. The method of any one of claims 1-26, 40 or 41 wherein the step of providing the instrument carrier with the PCD mounted thereto in the cleaning apparatus comprises providing the carrier with the PCD mounted thereto in a cleaning chamber of the cleaning apparatus.

54. A method or device substantially as described herein, and with reference to any one of the accompanying drawings.