Software Technology for Apparatus for measuring concentration of disinfectant within a medical device reprocessing systems

Invented by Yan Fang, Nick N. Nguyen, Kaitao Lu, ASP Global Manufacturing GmbH

The ASP Global Manufacturing GmbH invention works as follows

Background for Apparatus for measuring concentration of disinfectant within a medical device reprocessing systems

The discussion below relates to reprocessing, i.e. decontamination, of endoscopes (and other instruments) that are used during medical procedures. The discussion below focuses on an apparatus and method that can be used to reprocess medical devices such as endoscopes after they have been used for a first procedure. This allows the device to be used safely in a second procedure. The discussion below will primarily focus on an endoscope but it is important to note that it can also be applied to other medical devices.

An endoscope can have one or multiple working channels or lumens that extend along at least part of its length. These channels can be designed to allow other medical devices or tubes, etc., to pass through into a particular anatomical area of a patient. Some primitive cleaning or disinfecting methods may make it difficult to clean these channels. The endoscope can be placed into a reprocessing machine that is specifically designed to clean endoscopes and their channels. This endoscope reprocessing device can wash and disinfect endoscopes. A reprocessing endoscope system can include a basin designed to hold the endoscope and a pump which flows cleaning fluids on the outside of the endoscope. The system can also have ports that connect to the working channels on the endoscope, and pumps that circulate cleaning fluids in the working channel. A dedicated endoscope cleaning system can include a detergent wash cycle, a rinse cycle, a disinfection or sterilization cycle and another rinse cycle. In the sterilization cycle, water and disinfection solutions can be used. Alcohol flushing can be included in the process to help remove water. After a rinsing process, an air flush can be used to dry and store the product.

It may be necessary to make sure that the disinfection or sterilization cycle of an endoscope processing system is effective by ensuring the concentration of the disinfection solutions. When disinfection solutions are re-circulated to clean several endoscopes in an endoscope processing system, they may be diluted by residual rinse water. It may be prudent to check the concentration of disinfectant in the disinfection between cycles and to replace it when it is too diluted.

Some conventional systems and techniques provide manual methods to assess the disinfectant solution concentration of an endoscope cleaning system. The system user can expose a strip of test to a sample solution of disinfectant and then observe the color change. This is indicative of a concentration of disinfectant that is below the effective concentration. A subjective test strip method may not be accurate. The test strip method can also increase the risk that the operator will be exposed to the disinfectant. The system operator can also send a sample to a laboratory for high-performance liquid chromatography to determine the disinfectant concentration. This method is not only time-consuming and expensive, but it can also lead to operator exposure.

The concentration of some disinfectants such as aldehydes can be determined by illuminating a sample that contains the disinfectant and measuring its absorbance using an automated system integrated into an endoscope cleaning system. This method is not without its limitations. The aldehyde level in the sample must be low to avoid the aldehyde absorbing all the light that passes through the sample. This would make it impossible to get a meaningful reading of absorbance. This method is susceptible to interference from other substances in the solution such as bio-burden or aging/oxidation products in the sample. It would be ideal to have a method and system that are not sensitive to interference materials that may exist in the disinfectant solutions, and can be used within a wide range of disinfectant concentrations.

The inventors claim that the technology described in this document has never been used or made by anyone else.

The following description of some examples of the technology is not intended to limit its application. The following description will reveal to those with knowledge of the art, other examples, features and aspects of the technology, as well as embodiments and advantages. This is an illustration of one of the most effective ways of implementing the technology. The technology described in this document can be adapted to other obvious and different aspects without deviating from its core. The drawings and descriptions are intended to be indicative and not restrictive.

It is also understood that the examples, teachings, expressions and embodiments described herein may be combined with any other teachings, manifestations, examples or explanations. “It is further understood that any one or more teachings, expressions embodiments examples etc. The following are described. Teachings, expressions and embodiments are described in the following. It is important to not view the teachings, expressions, embodiments, examples etc. in isolation. The teachings in this document will make it obvious to anyone with a basic understanding of the subject matter how the various teachings can be combined. These modifications and variations should be included in the claims.

I. Exemplary medical device reprocessing apparatus

FIGS. The 1-2 illustrate an example of a reprocessing device (2) that can be used to clean endoscopes or other medical devices with lumens or channels. The system (2) in this example includes a station (10), and a station (12). The stations (10, 12), are substantially the same in every respect to allow for decontamination of at least two different medical devices in parallel or series. The contaminated devices are placed in the first and second decontamination sinks (14a, 14b). Each basin (14a, 14b) is sealed selectively by its respective lid (16a, 16b). In the example shown, lids (16a, 16b) work in conjunction with basins 14a,14b to form a microbe-blocking relation to prevent environmental microbes from entering basins 14a,14b during decontamination. As an example, lids (16a, 16b) can include a HEPA or microbe-removal air filter for venting.

A control (20) comprises one or more microcontrollers such as a PLC for controlling decontamination operations and user interface. The control system (20), although shown as controlling the two decontamination stations (10 and 12), can be a separate system for each station (10 and 12). Visual display (22) shows decontamination parameter and machine conditions to an operator. At least one printer (24) prints out a hard copy of the parameters to be attached to or filed with the decontaminated device. Printer (24) should be viewed as an optional feature. In some versions the visual display (22) can be combined with a touchscreen input device. A keypad or other user input device is available to input decontamination process parameter and control the machine. Other visual gauges (26), such as pressure meter and similar devices, provide digital or analogue output of data from decontamination or leak testing for medical device.

FIG. The diagram in Figure 2 shows only one decontamination system (10) but those with knowledge of the subject will know that decontamination stations (12) can be configured and operated just like decontamination stations (10). “It should be noted that the reprocessing systems (2) can be equipped with a single decontamination system (10, 12), or even more than two.

The endoscope (200), shown in FIG. Decontamination of medical devices or endoscopes can be done in the basin (14 a). The flush lines (30) connect any internal channels in the endoscope (202). In this example, each flush line is connected to the outlet of a pump (32), so that in each case a pump (32) is dedicated for a flush line. The pumps (32) in the example are peristaltic pump that can pump liquid or air through the flush line (30) and the internal channels of the endoscope (202). Other suitable types of pumps may also be used. Pumps (32) in the present example can either draw liquid from basin (14) a through a filtered drainage (34) and a Valve (S1), or draw decontaminated Air from an air supply (36) system through a Valve (S2). The air supply system (36) in the present example is comprised of a pump (38), a microbe-removal air filter (41) that removes microbes.

A pressure sensor or switch (42) is fluidly connected to each flush line (30), for the purpose of sensing excessive pressure within the flush line. The excessive pressure or lack in flow may indicate a partial or total blockage of an endoscope channel (200), to which the flush line (30) connected, e.g. by dried bodily liquids or tissue. Each flush line (30), when separated from the others (30), allows for the blocked channel to easily be identified and isolated depending on which sensor (42) detects excessive pressure or lack flow.

Basin (14a)” is in fluid contact with a source of water (50), which could be a tap or utility water connection, including both hot and cold water inlets. A mixing valve (52) then flows into a break-tank (56). A microbe-removal filter (54) such as an absolute pore size of 0.2 m or less is used to decontaminate the water before it enters the break tank (56). A sensor (59), which monitors the liquid level in basin (14a), is used to measure it. If a suitable source of hotwater is not available, an optional water heater (53), can be installed. You can monitor the condition of the filter (54) by either directly monitoring the water flow rate or indirectly monitoring the fill time of the basin using a float or similar device. If the flow rate falls below a certain threshold, it indicates that a filter element is partially clogged and needs to be replaced.

A basin drainage (62) drains the liquid from basin (14a) via an enlarged helical tubular (64) in which endoscope (200), with elongated sections, can be inserted. Drain (62) has fluid communication with both a recirculation (70) pump and drain pump (72). Recirculation pump (71) recirculates fluid from basin drain (62) into a spray assembly (60), spraying the liquid in basin (14a) and on endoscope (202). A coarse screen (71), and a screen with fine mesh (73) are used to filter particles from the fluid. Drain pump (72) pumps the liquid from basin drain (62) into a utility drain 74. A level sensor (76) monitors the flow from pump (72) into utility drain (74). Pumps (70 and 72) can operate simultaneously so that liquid sprays into basin (14a) as basin (14a) drains, encouraging the flow of residue from basin (14a) to endoscope (202). A single pump with a valve assembly can replace the dual pumps (70 and 72).

Some endoscopes (202) include a flexible housing or sheath that surrounds the tubular members, and similar parts which form the interior channels of the endoscope (202). This housing creates a closed, enclosed interior that is kept away from fluids and tissues of the patient during medical procedures. The sheath must be intact and free of any cuts or holes that could allow contamination to the space underneath the sheath. The reprocessing device (2) in the example of this article includes a means of testing the integrity and quality of a sheath. A conduit (112), a valve S5, and an air pump (e.g. pump (38) or another one (110)) pressurize the space defined by sheath (200). In the example shown, a HEPA filter or another microbe-removal filter (113), removes microbes in the air being pumped. A pressure regulator (114), prevents the accidental over-pressurization of sheath. A pressure sensor (116), after valve (S5) has been closed, looks for a decrease in pressure in the conduit (112) which indicates the escape of the air through the endoscope sheath (200). When the testing procedure has been completed, a valve (S6) vents conduit (112) and the sheath endoscope (202) through an optional filter (128). “An air buffer (120), smoothes out the pulsation in pressure from the air pump (110).

In the example shown, each station (10 and 12) contains a spill sensor (132), a drip-basin (130) as well as dripping basins (130). These are designed to alert the operator of potential leaks.

An alcohol source (134), controlled via a valve (S3) can provide alcohol to channel pumps (32), after rinsing, to help remove water from channels (210, 212, 213, 213, 214, 217, 218) of an endoscope (202).