Watlow’s FLUENT® In-Line Heater Helps Home Hemodialysis Device Marker Meet Multiple Challenges

A new White Paper from internationally renowned industrial technology company manufacturing electric thermal solutions, Watlow® provides a case study in use of the FLUENT® In-Line Heater to help a home hemodialysis device maker meet multiple design challenges. The technical article authored by Watlow Chief Systems Designer Andy Selvy, shows how a system design approach incorporating the innovative FLUENT® heating technology not only helped the manufacturer meet compact size and assured patient safety requirements but also improved overall device  performance.

Design for domestic use

Hemodialysis for cleaning  blood using a dialysis machine with a special filter to at act as an artificial kidney has become an excellent candidate for home care adaptations, raising new design challenges such as the need to assure safety when operated by non-professionals.

It highlights regulations covering home health devices such as IEC 60601-1-11 that outlines safety requirements for medical devices intended for use in home care settings.

The article discusses incorporation of MOPs (Means of Protection) features to guard against electrocution; including reinforced insulation, defined creepage distance, and air gaps between electrically conductive features. It notes that these now need to be accompanied by additional MOPPs (Means of Patient Protection) safeguards for use in non-clinical settings, in effect shifting responsibility for ensuring safe operation to the device manufacturer.

Form factors

At the same time, the design team need to consider functional aspects such as overall device size, weight, portability and user interface. These rule out use of orthodox isolation transformers, for example, to step down input voltage, as too bulky and expensive.

The paper also discusses thermal system considerations in generating the heat needed to keep fluids at body temperature to prevent thermal shock and in disinfection while at the same time mitigating risks of current leakage or overheating.

Systems Approach

All of these factors point to use of highly miniaturized and inherently compliant thermal solutions, including heaters, sensors, temperature controllers, power controllers and supporting software, working together as an integrated system.

The article shows how the ultra-compact Watlow FLUENT® in-line heater, with its ceramic substrate tube construction, can achieve the temperatures required for hemodialysis quickly and efficiently, while meeting space and safety constraints, benefiting the system as a whole.

This requires an overall Systems Approach to Safety and Miniaturization, adopted by Watlow, with various disciplines that are also discussed.