Dealing with challenges of regulations for dialysis equipment suppliers

Luca Raguzzi, business development manager, analytical & medical, Emerson, discusses the challenge of new regulations for dialysis equipment suppliers.

Medical equipment suppliers are meeting the world’s ageing populations need for advanced medical therapies, such as haemodialysis, that offer greater convenience, fewer infections, and improved outcomes. In the case of dialysis, for example, manufacturers are now building hospital-quality haemodialysis machines that have cut clinic-based haemodialysis sessions from 12 hours to 4 hours and have made at-home, peritoneal dialysis a reality and a preferred option for increasing numbers of physicians and patients.  

But dialysis equipment builders and their suppliers face a formidable task. They must not only manage the medical side of the process with precise blood filtration and purification procedures, but also implement the technology through components and products that meet ever-higher regulatory standards while simultaneously improving consistency, reliability, and cost-effectiveness. So, any technological advance to make a treatment like dialysis safer, faster, more portable, and more effective for the patient has been hard-won. 

Europe’s new Medical Device Regulation (MDR), as well as rules by the US Food and Drug Administration (FDA) and other global bodies, require dialysis equipment manufacturers to rely on suppliers of fluid-system automation and control to help them meet regulatory requirements such as strict change controls, while also offering the range of necessary valves and fluid controls.  

The challenges of haemodialysis 

The fluid pathways of haemodialysis machines directly handle human blood and related bodily fluids, so MDR and FDA rules require every wetted surface of these pathways to be made of thoroughly tested biocompatible materials — subject to source-to-end-use change controls to ensure their consistency and purity. In addition, any mechanical flow-control components, such as pumps or valves, must incorporate biocompatible materials while ensuring complete “isolation” — a hermetic separation between their power/control/actuation mechanisms and the fluid path that carries the blood being purified. This isolation prevents the risk of contamination due to metallic particles or external pathogens. 

Of course, device reliability is essential since clinic-based haemodialysis machines are subject to constant use. In this context, improved reliability means flow-control valves that can operate reliably over a life of 5 million to 6 million cycles for a three-to-four-year period. Device configurability is also essential and can take several forms. For example, a large haemodialysis machine can require 20 or 30 valves, enough to run three or four identical dialysis/filtration circuits simultaneously.   

In addition, configurability can also include anything from the ability to modify individual valve bodies to combining multiple valve flow paths — and associated actuators/controls/printed circuit boards (PCBs) — into compact manifolds that meet dimensional requirements. Configurability also encompasses the ability to modify controls, wire leads and connections or a valve’s noise output, since dialysis valves are typically actuated using pneumatics and must operate in a relatively quiet hospital or clinical environment, or even while a patient sleeps at home. 

It is only after a valve complies with all regulatory requirements, materials, isolation, design, manufacturability, and assembly that its actual function comes into play. Within the haemodialysis process, the pressure and flow of fluids must be carefully and consistently managed through a series of dialysing circuits. These circuits expose a volume of blood to physical filtration and a process of diffusion/osmosis where wastes are transferred from blood to a dialysate fluid.   

The task of making better dialysis valves and ensuring their regulatory compliance is ongoing for the team of analytical and medical specialists at Emerson. But in addition to engineering quality and meeting regulatory requirements, these valves must also satisfy customer requirements for performance, configuration, flow rate, reliability, and ease of installation. For example, the ASCO 283/383 Series miniature solenoid valves met requirements for durability and biocompatibility, with valve bodies and fluid paths made of polyetherimide (PEI). However, a prospective customer and dialysis equipment builder asked Emerson to modify the valve to increase flow rates at required pressures (three to four bars) and to provide a special coil with flying leads that would eliminate a manufacturing step and reduce product assembly costs.    

In other situations, customers might ask for a manifold assembly, which links a series of valves such as ASCO Series 188 general-service valves into a single assembly mounted on a printed circuit board along with customer-specified tubing. One such manifold design was produced for a dialysis equipment builder that sought a high-flow/low-leakage solution that would “plug and play” as part of a haemodialysis machine. As the list of regulatory and safety requirements grows, the Emerson team continues to develop new capabilities to meet them in other dialysis-related products such as the ASCO Series 284/384 pinch valves and Series RB general-service valves. 

Peritoneal dialysis applications 

In the case of peritoneal dialysis, the blood is cleaned using the lining of the body’s own peritoneal cavity as both a filtration mechanism and as a container for dialysing fluid. Because the procedure can be done at home — sometimes even while a patient sleeps — the latest ambulatory peritoneal dialysis (APD) machines feature compact design, lightweight componentry, low power consumption and low noise. However, the fluid components in these machines are subject to the same biocompatibility and isolation requirements as haemodialysis equipment since the fluids they carry are in direct contact with the human body. 

To simplify manufacturability of APD equipment, while also meeting the latest MDR and FDA requirements, Emerson often provides equipment builders with modular, multivalve manifolds or assemblies. Like those mentioned earlier, these manifolds or assemblies may be built atop a compact printed circuit board that incorporates valve-mounted pneumatic connections, data links, and multi-pin electrical connectors.   

In one such case, a PCB-based modular assembly built to hold 21 modified 10 mm miniature general-purpose valves offered two key benefits for a maker of APD machines. First, the pneumatically actuated assembly is lightweight and easy to install yet fits within the tight confines of a tabletop APD machine. Second, and more important, the manifold functions reliably for patients by precisely managing the inflow and removal of dialysate within the peritoneal cavity, maintaining the fluid levels and pressures essential for an optimal dialysis process.  

Conclusion 

For decades, medical professionals, dialysis equipment makers and equipment suppliers have collaborated to develop and deliver newer, safer, and more effective dialysis treatments that meet stringent regulatory requirements. With longer lifespans and ageing populations worldwide, the need for and importance of dialysis technology for use in both clinics and in at-home settings will only grow in the years to come, creating new treatment opportunities and technical challenges for the medical device industry.