Fluid Handling In Medical Device Design: Issues And Challenges

The proliferation of advanced medical devices and diagnostic instruments continues to accelerate. Laboratories, hospitals and physicians are demanding a growing array of increasingly complex yet smaller, faster and more reliable systems. At the same time cost pressures on both original equipment manufacturers (OEM) and end-users continue to grow. To meet these demands, device manufacturers must increasingly find new ways to innovate design and production, while improving efficiency of resource utilization.

Fluids play a role in most medical devices. Wherever a liquid or gas needs to be measured, monitored or controlled, fluid handling is critical. This includes such diverse operations as boiler control on steam sterilizers, reagent dispensing in in-vitro diagnostic equipment, and bulk delivery of gases in hospitals. Fluid handling also plays a role in applications such as cooling of medical lasers and drug delivery in infusion pumps, as well as precise gas delivery in products such as ventilators. Among these devices, there is a range of fluid management needs, such as liquid monitoring, mixing and dispensing, wash systems, and waste control, each with its own unique functional properties.

The field of fluidics may broadly be divided into macro- and micro-applications. The former encompasses situations where moderate or bulk quantities of material must be moved through an instrument, such as tank filling or waste disposal; the latter applies to applications that require delivery of small, precise quantities. Fluidics, especially macrofluidics, often represents a necessary but non-core function in medical device design; that is, it falls outside of a company's proprietary expertise. While internal engineering staff is highly adept at driving an OEM's core technology, they may not have the in-depth knowledge or the time required to develop ancillary systems. Consequently, when an application requires the inclusion of fluid management, OEMs may be best served by engaging an external engineering resource with specialized expertise in this field.