Medical Device Classification and the Approval Process

The Food and Drug Administration (FDA) has processes for biomedical companies to apply for biomedical device marketing and use.  There are two main processes for medical device approval:  a 510(k) submission and a Premarket Approval Process (PMA) submission.  PMA refers to the scientific and regulatory review necessary to evaluate safety and effectiveness of Class III devices or devices that were found not substantially equivalent to a Class I and II predicate through the 510(k) process.  The PMA process is used to scientifically and reasonably determine if a medical device is effective for its recommended use.  “PMA requires scientific evidence that the possible benefits to health from the intended use of a device outweigh the possible risks and that the device will significantly help a large portion of the target population.”[1] A 510(k) submission indicates that a certain product has an equivalent medical product already approved that serves a similar purpose, and thus since that predicate product is approved by the FDA, the new equivalent product can be approved as well. 

It is important to understand the definitions of Class I, Class II, and Class III devices.  Class I devices are determined to have a low risk or minimal potential for harm; examples of Class I devices are bandages, bedpans, and Glucose meters, among others.  Class II devices are medical devices that have a moderate to high risk to patient or user; examples include MRI machines, infusion pumps, syringes, blood transfusion devices, contact lenses, and ultrasound diagnostic equipment, among others.  Class III devices are classified as such based on their potential risks and benefits to the patient; these devices usually sustain or support life, are implanted, or present an unreasonable risk of illness or injury.  Examples of Class III devices include implantable pacemakers, renal stents, implanted prosthetics, mechanical heart, and implantable middle ear devices, among others.  Essentially, Class III devices can potentially cause harm to the patient, even severe harm, but that risk does not outweigh the benefits they can provide.

Some companies over the years have used the 510(k) submission to bypass the more stringent PMA regulatory processes with the less stringent 510(k) submission.  However, understanding the risks of biomedical device classification is crucial for companies to properly assess if a biomedical device is a Class II or Class III device.  A Biomedical Engineer should be able to analyze not only the potential risk of a device to aid patients, but also the risk that those devices may pose on a patient or care givers.  For example, x-ray machines are useful for understanding fractures and other body ailments.  However, excessive exposure to radiology technicians can be harmful.  Engineers need to assess the safety parameters of these medical devices to the human body.  Some biomedical implantable products have been successfully approved from a 510(k) submission instead of the PMA process, which requires clinical trials.  By definition, any implantable device should be classified as a Class III device and should be approved by the PMA process.  Certain biomedical devices made of polymer-based materials that have been shown to be inert in the body, have been classified as Class II devices through the 510(k) even though they are implantable devices, and even though the location of implantation was physiologically significantly different than the predicate or supposedly equivalent device.  As a result, some medical devices that have gone through the 510(k) process instead of the PMA process have led to significant injury and even death of patients. 

As a forensic expert, the Biomedical Engineer provides a knowledge of engineering principles relating to the safe design, development, and creation of medical or scientific equipment, devices, computer systems, and software that are an aid to medical professionals, and how these devices should be tested and designed to have a safe interaction with patients and medical providers.  These devices include vascular and orthopedic implants, implantable meshes, machines to diagnose medical problems, dental chairs, and surgical instruments, as well as many other devices.  Biomedical Engineers provide safety and efficacy for equipment or instruments, and as such, Biomedical Engineering experts understand how these machines work and operate.  Biomedical Engineers provide a diverse area of expertise in understanding medical products and devices, in particular when the engineer’s undergraduate studies were in mechanical and electrical engineering.  For example, Biomedical Engineers can analyze and design software to run medical equipment, as well as design rehabilitation exercise equipment. Biomedical Engineers also have the knowledge to be reasonably certain devices are safe for their intended use, for the patient those devices serve, and the health care providers that use them.

Consulting Engineers & Scientists, Inc. (CESI) has provided forensic biomedical engineering assistance on matters including pharmacology mixing devices, joint implants, transport chairs, dental equipment, implantable meshes (vascular, bladder, vaginal, etc.), and other medical devices.  At CESI, we can provide assistance in litigation matters where medical devices were used or determine the cause of an injury.  This includes infusion pumps, cardiovascular implants, orthopedic implants, medical equipment, transport chairs, and safety software implementations, among others.  We have a vast knowledge in engineering and science ranging from Mechanical Engineering and controls to Industrial Hygiene that are coordinated with Biomedical Engineering to be able to aid you in the majority of medical device cases.  We also evaluate patient nursing care during and following their medical treatment.  Please do not hesitate to contact us with any questions regarding medical devices or medical products.

[1] https://www.fda.gov/patients/device-development-process/step-3-pathway-approval