What to Look for When Purchasing Medical Components
As people become more concerned about their health and wellbeing, there are many new medical-grade products entering the market, for both professional and home use. Due to the fact that most of these devices connect directly to the patient, and a significant proportion are powered from mains voltages, there are stringent safety requirements that must be met before the product can be offered for sale.
IEC60601 is the central standard that defines the regulatory requirements for medical devices, encompassing several standards that relate to the safety of electrical/electronic equipment used in healthcare. The standard was first published around 40 years ago and has progressed significantly to meet the needs of evolving medical technology. The primary aim of the standard is to ensure the safety of both the patient and any medical professional operating the equipment in normal use, and in the event of any failure.
The requirements for products and their components vary depending on their intended use. Clearly, the requirements for a life-support device will be somewhat more stringent than those for, say, a blood glucose meter. For this reason, the fourth edition of the standard (introduced in 2019) defines ‘intended use environments’ along with specific requirements for each environment.
Selecting components that have the requisite approvals is key to all medical purchasing. Alongside the IEC60601 requirements, UL safety approvals are often required, as is CE marking.
By designing-in and procuring components with the relevant safety approvals, significant time and cost can be saved, as the process of achieving safety approvals on the end product is greatly simplified. Many manufacturers have specialist ranges of components that are intended for medical applications, and all of the relevant certifications are listed on their data sheets. However, purchasing professionals should ensure that the components are certified as compliant with the latest version of the standard – in particular IEC60601, which moved from the third to the fourth edition in early 2019.
While electrical safety is incredibly important and is covered by standards, there are other, more subtle requirements for medical devices. It should go without saying that cleanliness and hygiene are critically important, as devices are typically used with one patient, then another. Medical devices are cleaned very regularly, often several times per day, and this can involve liquids which, if they are allowed to get inside the device, can cause failure. Potential areas of liquid ingress include items such as push buttons, switches and connectors. Many of these components are available in waterproof versions, as defined by their ingress protection (IP) rating, which is also mentioned on manufacturers’ data sheets.
Apart from the components themselves, selecting the right supplier is always a key decision. While it is possible to scour manufacturers’ websites to select individual components, it is often a better approach to work with a specialist distributor, such as TTI, which has dedicated teams of technical experts available for support.
Alongside its expertise, TTI stocks a vast array of components and subsystems certified for use in medical applications. One of the most important elements in terms of safety is the power supply, as a failure of this device could cause a patient to be directly connected to the mains supply. TTI carries a wide variety of medically certified power supplies from manufacturers such as Artesyn, Mean Well and Murata, which can be used with complete confidence.
Highly reliable tactile switches from suppliers such as C&K Switches are robust, waterproof and easy to clean, making them ideal for front panel use in medical devices. Connectors are also important in medical applications, as they allow sensors to be changed rapidly, as well as facilitating the use of disposable probes for hygiene reasons. The Eclipta edge card connectors from Smiths Interconnect are widely used in medical applications.
In short, the key to procuring components for medical applications is to know the standards applicable to your application, check for appropriate certification on relevant devices and work with experienced suppliers, such as TTI, who can guide you through the wide range of options available.