Printed circuit boards in medical applications range from extremely complex to simple builds. Some technologies span from the possibility of remote surgery (not yet FDA approved) to organ tracking devices (RFID), to electroceuticals. As PCB technology becomes smaller and more powerful, medical applications are endless. Here is an overview of PCB function, design, and regulation in the medical industry.
Electroceuticals, Implants, and Devices
Electroceuticals are tiny encased PCB devices. They can be designed to swim in the bloodstream or be implanted to deliver drugs or another signal. Some are designed to facilitate electronic communication between damaged cells. Electroceuticals can be designed to biodegrade over time or remain in the body.
Example of an Electroceutical Implant for Diabetes
Medical models of diabetes show that beta cells, insulin-secreting cells, in the islets of Langerhans stimulate each other through gap junctions to produce insulin. In patients with diabetes, there is a diminished or nonexistent junctional conductance between the cells, inhibiting insulin production upon glucose stimulation.
Researchers have proposed a model in which electroceuticals are implanted to stimulate the islets of Langerhans in the pancreas. The electroceutical will stimulate beta cells to produce insulin by way of electrical current in diabetes patients.
Design Considerations for Electroceuticals and Implants
Both stationary and free-flowing PCB devices can be used as electroceuticals. Each solution comes with its own design problems. When integrating microchips into the human body, the materials used to create the PCB as well as the housing need to be carefully designed so as not to cause immune or wound healing responses to the foreign object. An immune response could destroy the device and be harmful to the patient. A wound healing reaction could cause tissue to grow around an implant, changing how the patient responds to treatment.
PCB Design in Other Medical Devices
Most medical devices are built using flexible circuitry. Flexible circuitry was first adopted to medical devices with implantable pacemakers and defibrillators in the 1970s. A newly developed device using flexible circuitry is a “skin-like material with sensing capability.” This device is something that will be used for burn victims and prosthetics.
3D Printing Pushing the Boundaries in Medical PCB Design
3D printing plays a significant role in the development of increasingly small and complex PCB assemblies. 3D printing allows leeway in component-substrate incorporation, making it easier for flexible substrates to be used in PCB applications. Printing circuit boards gives designers full control over the organization of the board, partially because it lifts the limitations of human ability to populate boards with components.
Regulation & The Future of Medical PCBs
Engineers have reported that regulatory compliance continues to be the most substantial challenge to developing devices for use in medicine. Regulations began to tighten up around the 1960s as people became more aware of unethical medical testing taking place.
This led to major oversight of testing and release of anything given to humans. Medical testing is now a rigorous process, on average it takes 17 years to get a new development from the research stage to the patient.
With the help of 3D printing and great new ideas from engineers and medical professionals, printed circuit boards have an exciting future in the world of medicine. Regulations may ease as the safety and efficacy of devices improve, but until then regulatory oversight will be a necessary hurdle for engineers to overcome.