Testing and test methods in translational biomedical engineering

Besides the use of standard methods, a focus here is on the development of novel test methods. These include above all in-vivo and in-vitro accelerated aging models for active implants, which are necessary to allow the long-term durability of such implants to be determined.

The test systems for medical devices intended for use in aerosol and inhalation therapy follow a risk management approach – the relevant standards such as ISO 20072 do not stipulate the application of particular test methods. Therefore, when it comes to testing novel devices, for example for use in neonates, there is a need to develop new test methods, as there are no suitable test systems available.

Testing of medical inhalers

Development of customized test benches – Testing novel devices with standard methods is often not possible. This is why relevant standards leave scope for action. ISO 20072, for example, does not stipulate the test method to be used for testing of inhalation devices. Quite the contrary, for novel inhalation systems in many cases it is necessary to follow a risk-based approach and adapt existing or develop new test methods.

We use standard methods as well, but our focus is on testing novel devices and especially devices used in inhalation circuits for adults and neonates. This includes not only measurements of device performance, but also investigation of any impact the delivered substance may have on the whole ventilator circuit. This might be, for example, blockage of filters or other air-conducting pathways, such as nasal prongs of neonates.

 

Development of customized test benches

 

  • Enhancement of standard test methods or development of new methods according to a risk-based approach and taking into account specific project requirements
  • Verification of device performance with the above methods during the development phase
  • Identification of potential unwanted effects of medicinal aerosols on the inhalation circuit

Testing of active implants

Modern active devices are designed for early childhood implantation and 100-year periods of use. In order to ensure compliance with these requirements already during development, accelerated testing must be employed. Whilst exposure to higher temperatures has been a working solution for many applications, thin-film polymer devices face reliability limits with a pure temperature increase.

To solve this problem nonetheless, we develop new test methods that make use of a multi-parameter model with elevated pressure and artificial body fluids at high concentrations. By setting up mathematical modeling in parallel, we can provide the desired long-term life span forecasts with acceptable accuracy.