The medical industry is unique in its pneumatic applications. Often times, the system or machine is simply part of a process—such as cleaning instruments or testing samples. Equipment manufactured for the medical industry must meet stringent standards for quality, cleanliness and safety. Not only must pneumatic valves be reliable when lives are on the line, they must be manufactured with utmost attention to cleanliness. By-products of the manufacturing process cannot be left behind to be ingested or infected into a patient.
No greater importance for cleanliness can be found than with equipment designed to clean and sterilize surgical tools and equipment. Although the techniques for the process can vary, the goal is to efficiently destroy microbes existing on chisels and choppers or specula and strippers, which guarantees the surgical process isn’t a contributor to a patient’s ill health.
SMC is a pneumatic product manufacturer, and you wouldn’t be surprised to discover they have product lines suitable for surgical equipment sterilization. Their VQZ valve line has been approved and licensed by both the FDA and Heath Canada for a proprietary sterilization process. Using low temperature sterilization vastly hastens the sterilization process time from five hours down to one hour, using vaporized hydrogen peroxide and ozone to destroy pathogens.
Using various valves, the sterilization chamber is first subjected to a vacuum of 1 Torr before the vaporous hydrogen peroxide is injected at a fixed rate through micro-pulsation of the VQZ valve, which has rapid response time, especially with the metal seals required for this application. The pulsing of the hydrogen peroxide continues until the chamber pressure reaches 19 Torr, and then the reduction cycle begins. Ozone is now injected to react to the hydrogen peroxide to form hydroxyl radicals, further increasing lethality to the microbes. After the process is complete, and using a catalytic converter, the by-products of the process are oxygen and water, making the chamber safe to open and remove the surgical instruments.
It goes without saying, a standard, off-the-shelf valve wouldn’t work well in a high-performance, demanding application such as this. The VQZ valve is available with metal seals, high-powered solenoids, IP65 rating and CE certification. Some valves may be available with some of these options, but it’s the combination of these features that allows it to be used in such a demanding duty.
SMC also makes pneumatic valves and components for blood analyzing equipment. If you’ve been to a medical lab recently to give blood, you know they process patients like concert goers in line at Wembley Stadium. The volume of blood samples, and the number of available tests to those samples, is extraordinary, and would be impossible using the old method of testing individual cartridges by a lab technician.
Modern laboratories use automated machinery to perform biochemical analysis. The process to analyze blood requires cuvettes (sample cups) to be placed into carousels via pneumatic robots. The valves and actuators used are too numerous to describe here, but nearly every function and process uses an SMC component. Even the chilling and handling of reagents is handled via their equipment, and once the process is complete, SMC’s LVM series pneumatic diaphragm valves process the saline and bleach for cleansing.
Using pneumatic components for these applications requires special materials, such as acrylic manifolds for fluidic circuits, similar in concept to those made for compact hydraulic manifolds using cartridge valves. Fluidics are used for the precision logical control of some of the components in the blood analyzer machine, and the special manifolds prevents leaks caused by tubes and fittings. The best way to describe fluidics is to imagine an electronic circuit—but instead of electrons, there are fluid molecules. Jets of fluid can create fluidic amplifiers, triodes and logic elements. This type of unique application of pneumatic valves ensures fluid power has a place in the modern world of technological advancements, and even nanotechnology considers fluidics as an important concept under its umbrella.