IP (Ingress Protection) determines the device’s ability to stop the intrusion of solid bodies and/or liquid. The way to perform the relative test and the acceptance criteria are subject to the IEC 60529. Relevant product standards can slightly change test procedure and acceptance criteria.
The IP Degree of a product is represented by the letters IP, followed by at least two digits.
The first one indicates the Degree of protection from solid bodies and the scale runs from 0 (no protection) to 6 (complete protection – no ingress of dust).
The second digit specifies the Degree of protection from liquid and the scale runs from 0 (no protection) to 8 (protection for long periods of immersion).
While in the protection for solid bodies each designated degree implies the compliance of the test for all the lower degrees, in the protection against liquid intrusion, this works only for the degrees from 0 to 6.
When To Define The IP Level Of Your Medical Devices?
The IP level of a medical device has to be defined early in the design and development process and it belongs to the product requirements, collected before any designing activity begins.
Among the many features influenced by IP rating, we can list:
- Housings divisions
- Device thickness
- Need of a gasket and consequent need to reduce the internal volume
- Orientation and position of any openings (e.g. holes, holes for connectors, air intakes)
- Electronic components
IP requirements for a medical device can have significant impacts on the device’s design and the medical device development timeline if they are not properly assessed early on. The risks to essential performance and patient safety due to fluid ingress should be discussed and evaluated prior to architecture definition and enclosure design. Once the risks are understood, the methods and design strategies to mitigate them can be explored, if mitigations are needed at all.
Design–based mitigation strategies addressing ingress protection for home healthcare medical devices may take the form of gaskets, adhesives, geometry changes, and meshes. The designers and Medical device engineers should also consider the impacts of these IP strategies on other parts of the system (cables, ventilation, user controls) and how they might negatively affect other design requirements such as mechanical stress, thermal management, manufacturing viability, and product lifetime validation.
One of the best strategies when brainstorming how to design ingress protected enclosures is to study other consumer products that have an IP rating. Some good examples include waterproof bike lights, car key fobs and waterproof headphones.
Following up with a robust testing strategy is crucial to ensure IP mitigations are effective. Using rapid prototyping parts and materials to expedite testing do not always provide an accurate representation of how the final material / process will perform during IP testing. Solely relying on prototyped parts may result in false positives or false negatives due to the differences in tolerances, surface textures, wicking properties and contact angles between materials and manufacturing processes.
What To Consider In The Engineering Of Your IP Rated Device
When you’re approaching medical device engineering, which includes the design and development of your IP-rated medical device you will face three main aspects to take care of.
- Cleanability
If the device needs to be cleaned, having a completely sealed device may not be required. In fact, sealing may actually cause cleaning failures. Sealing the device to IP68 may create small crevices where seals are located which could allow bioburden to build up to unacceptable levels. Sealing through ultrasonic welding or adhesives will require significant validation (both in terms of cleaning, as well as the manufacturing process itself) and add cost to the device which may not be required. - Orientation
If your device is pole-mounted or has its own cart, then the normal orientation of the Medical Device Development would be always considered vertical, and a rating of IP x2 is likely sufficient.
However, handheld or body-worn devices may require a significantly higher rating as the normal operating conditions of the device may be any orientation. - Heat Dissipation
If the device generates heat, achieving high temperature, and air circulation is required, it may be challenging for engineers to meet high IP levels.
The design of the device will have to incorporate any heat dissipation strategies that meet the IP requirements of the device, and that is better done early in the design cycle of the device.
If You Need Help…
If you need expert advice with your next medical device, Creanova drives healthcare companies through the entire medical device development process, from the earlier stages of requirements definition and feasibility study to industrial design, medical device engineering and prototyping, up to contract manufacturing (certified with ISO 13485).
Our medical device engineers are used to develop devices with high IP rating such as for example defibrillators and can bring your project to the market according to your specific requirements.
Contact us and we’ll build with you the suitable plan for your project and we’ll bring your idea to the market, together!
