Automated Washer/Sterilizers

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Automating CPD Instrument
Cleaning & Decontamination

By Michael Cain

Despite significant gains in recognition of the value Central Processing Departments (CPDs) have in a hospital's overall success in the delivery of quality healthcare, funds to upgrade or buy new equipment and hire staff are not any easier to come by. The new Millennium has dawned with CPD under more pressure to increase productivity while maintaining or improving quality outcomes at equal or lower cost.

With capital equipment budgets often cut to the bone, directors and managers are looking for technological advancements to provide do-more-for-less solutions. This has manifested itself in renewed interest in automating the cleaning and decontamination processes within CPD, with the overall objective to minimize capital equipment and operating cost per tray or set.

Automated decontamination equipment and systems are not new to Central Processing Departments. However, they have evolved over the course of 30 years, and even today's automation continues to evolve. When considering automating cleaning and decontamination of surgical instruments, keep in mind that there have been two types of advancements in CPD automation. The first, and perhaps most significant, is the advancement made in automating the quality and quantity of processes provided by today's single-chamber washers. Upgrading from manual or semi-manual decontamination to an automatic washer/disinfector alone can help CPD develop a quality decontamination system that will do more for less.

The second advancement has been in automating material handling systems that support automated single-chamber washers, and containing or reducing the amount of staff required to keep them humming.

Automated Washer/Sterilizers

For years, AMP (Automated Material Processing system) have been the dominant products of many CPDs. These two-and four-basket washer/sterilizers use in-line tables to stage, cue, load, wash, rinse, decontaminate and unload 6 to 12 baskets per hour automatically. These products can be equipped with a variety of automation options such as cross-feed tables and return conveyors.

Still in use and marketed by several manufacturers, washer/sterilizers have declined in usage largely because they require manual pre-cleaning and cannot process a significant number of today's more complex instruments and medical devices. Some washer/sterilizers also cause operator back strain when loading and unloading to and from automated stations.

Figure 1: The 7662hi is an automated indexing tunnel washer.

Automated Tunnel Washers

As early as 1983, Indexing Tunnel Washers started to appear in CPDs. These products typically feature four or five inter-connected chambers, each with a specific processing task. The five chamber models include a pre-wash chamber and an ultrasonic cleaning chamber, thus improving upon the AMPS products. An integral two-basket load station feeds baskets to the door of the first chamber automatically.

By placing chambers and processes one behind the other, loads can be sequenced to index to the next treatment process while a new load follows directly behind (Figure 1). The typical treatments are pre-wash for gross debris, ultrasonic wash, detergent wash, clean rinse/final rinse/lubricate, and dry. Once all chambers are loaded, a clean basket will exit from the washer every 3 to 4 minutes, depending on the cycle program. Unloading is also automatic and often includes a combination of power and gravity conveyors to move clean loads away from the machine, to the prep- and pack-area, as well as to transport empty baskets back to the decontamination side.

These products were designed for CPD productivity and they accomplish the job well, turning out 30 or more instrument trays per hour. Because throughput is the primary goal, the indexing tunnel washer is not designed to clean complex instruments with channels or corrugated airways. These must be cleaned manually or in a separate machine. The indexing tunnel washer also has a disadvantage in that if maintenance or service is required on any part of the system, the entire system can be "down" until work is completed. Acquisition of two tunnel washers--or one tunnel washer plus a single chamber washer to process complex instruments and devices--as well as to serve as backup to the tunnel washer--will reduce the impact of such situations.

Automated Single-Chamber Washers

Various designs of US-manufactured single-chamber washers have been in OR workrooms and Central Processing Departments for many years. However, US single-chamber washers began to be replaced by European-designed washer/disinfectors by mid-1980. Designed especially for cleaning and thermal disinfection of surgical instrumentation, they were first sold as point-of-use washers. In time, their cleaning benefits and large-volume loading earned them a place in CPD where they not only replaced manual cleaning sinks, but also replaced routine ultrasonic cleaning.

European washer/disinfectors quickly became fully automated in all their internal processing capabilities. By mid-1990, washer/disinfectors started to feature automated power doors, auto cycle select and auto cycle start. As a direct result of the ability to now bypass manual cleaning and ultrasonic pre-cleaning, these developments immediately led to automated loading and unloading functions.

Automated In-Line Loading and Unloading of Single-Chamber Washers

Initially, Central Processing Departments purchased one or perhaps two automated washer/disinfectors either because this met the hospital needs, because of budget constraints, or because other decontamination equipment such as a washer/sterilizer or an indexing washer were still being used. In the situation of one or two washer/disinfectors, straight in-line loading, in-line unloading or the combinations of both operations are the best choices. This modular approach to washer/disinfector automation also provides options to manage capital budgets by purchasing automation in phases.

Evolving Demands on CS

Either due to mergers or the need to consolidate in-house sterile processing functions through major renovation or new construction, there is an increased demand on CPD to process more with limited budget relief. For all the reasons mentioned, European- type washer/disinfectors have gained wide acceptance as the cleaning and decontamination product of choice.

To meet the increasing demands placed on CPD for throughput and cost control, large hospitals are looking at the acquisition of 3, 4, and sometimes 5 single-chamber washers to replace 3 or 4 washer/sterilizers. For effective returns on investments in capital equipment, floor space, utilities, accessories and FTEs, a Market need was created for a quality automated material handling system to integrate the operations of 3 or more single-chamber washers.

Closed-Loop Automation of Single-Chamber Washers

Recently, several companies have marketed an automated material handling system that can be called "closed-loop" automation for multiple single-chamber washers:

Reduced Floor Space--This system positions multiple washers side-by-side to reduce the floor space required, in lieu of traditional spacing of 18 inches between washers for side service access.

Single-Point Loading--A feed conveyor is positioned at a right angle to the line of washers to serve as a single loading point for racks of soiled material, regardless of the number of washers in the barrier wall.

Cross Feed Conveyor--Another line of conveyor is placed parallel to and directly in front of the washers, to feed soiled loads into position in front of each chamber of the washers in the barrier wall.

Automated Loading--Special devices are used to push the soiled load into the chamber of each available washer.

Single-Point Unloading--The clean side of the washers is fronted with a conveyor line immediately in front of each washer. Once unloaded each rack is moved to the end of the line where it is off-loaded to a right angle conveyor that serves as a single-point unload station. All operations are in reverse order of the load side conveyors.

Automated Return Conveyor--To facilitate return of empty racks to the soiled side, a power return conveyor can be positioned adjacent to the single-point unload and load stations, effectively closing the loop.

Maximize FTE's--Single-point loading and unloading of a system that serves three or more washers, significantly reduces the amount of staff time and effort that would be required to load and unload in-line automation for each individual washer.

Figure 2: The air glide shuttle system loading into the next available washer.

Shuttle Automation of Single Chamber Washers

Reduced floor space, single-point loading and single-point unloading are undisputable benefits for CPD users of multiple automated single chamber washers. However, the "closed loop" automation system also bears several undeniable disadvantages that prospective buyers should consider before making a final decision.

Designed to provide the same key benefits of reduced floor space, single-point loading and single-point unloading, the new patented Air Glide Shuttle (AGS) system from Getinge/Castle, Inc. (Rochester, NY) has eliminated the principle disadvantages of the "closed-loop" system (Figure 2). Washers are similarly installed side-by-side to reduce floor space, and single feed conveyor provides single point loading for up to six washers.The AGS system provides a upper rail-mounted traveling shuttle that picks up soiled loads at the end of the feed conveyor and travels down the line of washers, stopping to load an empty chamber and then returns back to await the next load.

Each time a chamber becomes available, the shuttle will deliver a soiled load to that washer automatically, insert the load and return home. The washer/disinfector automatically closes the door and starts the cycle. Advantages:

  • No floor mounted conveyor line to block the front of the washers.
  • Unobstructed access to the cycle control panel.
  • Unobstructed access to service panels of washers.
  • Option to load washer manually when goods need to be processed quickly.
  • Built-in redundancy allows washers to be loaded manually when AGS needs routine maintenance, maintenance of one washer will not disrupt operation of all other washers.

The AGS System also provides a traveling shuttle for unload operations. When a cycle has been completed, the washer/disinfector opens the chamber door automatically. The shuttle will leave its home position in front of the unload station automatically, travel down the line of washers and remove the clean load from the wash chamber. The shuttle will then return home and position the rack onto the single-point unload station. This action continues automatically as long as material is being processed.

There are some obvious advantages:

  • No floor mounted conveyor line to block the unload side of the washers.
  • Unobstructed access to the chamber and service panels of washers.
  • Option to manually unload washer when goods need to be processed quickly.
  • Built-in redundancy allows washers to be manually unloaded when AGS needs routine maintenance.
  • A similar off-feed conveyor provides the benefits of single-point unloading.
  • An automated power return conveyor is available to close the loop by returning empty racks to the soiled side.

Automated instrument cleaning and decontamination systems will continue to find favor among CPDs as cost containment pressures continue to mount. While automated cleaning systems may appear to be expensive up-front, their potential for cost savings is considerable. They provide superior cleaning which, in the end, provides the most important benefit-protection of employees and patients.

Michael Cain is the Senior Market Manager, Cleaning and Disinfection Systems for Getinge/Castle, Inc. (Rochester, NY). Currently in his thirteenth year with the company, he is responsible for disinfection product development and training.

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