Q&A: medical devices, product testing and software

Here are the questions you asked our panel of people who work in the medical devices sector in Ireland.

John Burton (Vitalograph): Software may be embedded within a device with/without a screen and control the device’s medical intended function and associated algorithms and present the resulting medical data to the user.

For example, in Vitalograph, many of the respiratory devices will contain software that interacts with the device’s sensors and electronics to calculate various parameters around the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled by a subject.

The software also includes algorithms for presenting quality related information related to the effort that the subject put in when performing the “blow” with the device. Additional algorithms provide suggested interpretations to aid a clinician in their diagnosis.

However, not all software is embedded in medical devices. These days it’s becoming a lot more common to have software that runs on a PC, on the Web or on a handheld device.

These medical device software applications typically connect to one or many electronic medical devices – and are in their own right considered a “medical device”. Such medical device software offers the power and additional processing and memory capacity of the PC, Web or mobile platform to provide advanced user interfaces, data processing, data storage for the clinician or subject.

They allow the medical device software harness additional features of the platform on which they run e.g. medical device software running on a smart phone may use the phone’s Bluetooth connection to connect to a medical device, and then send that data using the phone’s mobile network connection to a central monitoring station – which in turn may have medical device software for monitoring test results coming in from subject’s around the world.

The scope of how software is being used in a medical device and as a medical device is changing rapidly as the world of mobile technology (smartphones and tablets) continues to evolve.

John Burton: Medical device development is a highly regulated industry with emphasis placed on protecting patient, operator, bystander and environmental safety.

Therefore, focus is placed on overall product quality, with “testing” being just one aspect of quality. Having said that, testing occurs at all stages of a medical device’s development by various disciplines, each with a very different focus. For example, some of the testing that may be involved includes:

• Reviews during the design process via peer/experts and in-depth risk-analysis
• Developer level testing during development e.g. unit/component testing of the medical device software code
• Independent testing during development by a dedicated/independent QA team
• Testing on specialised rigs that can repeatedly simulate physiological tests (‘blows’ in our case) with different characteristics – in accordance with accepted industry standards
• Independent testing using third-party testing specialists
• External EMC testing and other regulatory related tests
• Internal production testing via specific production processes and work instructions
• End-user trials to assess usability
• And finally clinical evaluation to ensure the device is fit for purpose

This is only a sub-set of the overall testing that is performed. The type of testing, standards to be adhered to and the level of testing will be dependent on the device being produced and its overall safety classification.

Sarah Jane Lye (Creganna-Tactx Medical): Creganna-Tactx Medical specialises in minimally invasive delivery and access devices and we work with many of the world’s leading medical device companies.

Our dedicated Design Services department works with many customers from around the world designing and developing finished devices to treat an array of conditions. Within the Design Services department, testing plays a huge part in what we do.

Regulations and industry standards must be followed when developing a product, so testing is completed at every stage of the development of the product. For example, when the first prototype of the product is built, testing will be carried out on it to determine if it does what the customer requires it to do.

This testing can range from measuring the length of the device to testing how the device performs in an environment similar to the part of the body the product will be used in.

As the product is developed further, testing will become more complex with the device being tested under different scenarios such as accelerated aging studies, sterilisation and clinical trials completed on patients.

Every part of the device will be tested including the packaging, to ensure that it is fit for use on patients. All data will be collected and reviewed by the governing body before it can be released onto the market.

Sarah Jane Lye: Thanks to the development of minimally invasive devices, a stent can be fitted in a short procedure (approximately 1- 1.5 hours) and the patient should be able to leave the hospital the following day.

Many patients can go back to work after about a week. The stent remains in the artery permanently, and over time the artery wall heals around the stent. People who have a stent fitted can continue to lead a normal life.

Stents are used in different areas of the body, with the most common area being the heart. Cardiac (heart) stents are used to open narrowed arteries and help reduce symptoms such as chest pain (angina), or to help treat a heart attack.

After a stent has been fitted, blood flow improves and chest pain decreases. In order to maintain good results after the stent has been fitted, the person should try to adopt a heart-healthy lifestyle. Changes in lifestyle can help the person prevent or slow the progression of coronary artery disease.