Today, medicine has become highly specialised and technology-driven, leading to the widespread use of medical devices as diagnostic and therapeutic healthcare tools. This has led to the rapid growth of the medical device industry. A medical device is different from a drug, as it acts by physical interaction with body/body part and the outcome depends on the skill or experience of the clinician or the technician. Hence, there are separate international and Indian regulations for medical devices.
A medical device is any instrument, apparatus, appliance, software, material or any other article used in human beings for a) diagnosis, prevention, monitoring, treatment or alleviation of disease or alleviation of or compensation for an injury or handicap, b) investigation, replacement or modification of the anatomy or of a physiological process, or c) control of conception.
For regulatory approval purpose, medical devices are classified by risk assessment based on:
• Intended purpose
• Duration of continuous use
• Transient – less than 60 minutes
• Short term – not more than 30 days
• Long-term – more than 30 days
• Critical anatomical locations – central circulatory system, central nervous system
• Active medical devices
As such, medical devices could be 1) non-invasive – stethoscopes, syringes, wound dressings, hemodialyser; 2) invasive – lancets, tracheal tubes, cardiac catheters, coronary stents, contraceptive devices, joint replacement prosthesis; 3) active – hearing aids, MRI, nebulizers dental implants; 4) special category – drug-eluting stents, contraceptive intrauterine devices, biological heart valves, blood bags; 5) In vitro diagnostic medical devices for detecting transmissible agents – HIV , blood grouping or tissue typing, and self-testing – glucometer.
A device which is invasive or for long-term continuous use or used in critical anatomic location or is active carries a higher risk.
The risk categories are:
• Class A Low Risk: e.g. surgical gauze, sterile plasters
• Class B Low-Moderate: e.g. hearing aids, ultrasonic diagnostic equipment
• Class C Moderate-High: e.g. infusion pumps, ventilators, surgical lasers, dental implant
• Class D High: e.g. many implants, replacement heart valves, pacemakers
Classification of the device provides a practical, economic, and feasible approach to decide which category requires rigorous regulatory evaluation. Indian medical devices rule 2017 mandate regulatory approval requirements for all device categories. These requirements describe submission requirements for technical information, quality documentation and clinical evidence. Clinical evidence studies include those that look at 1) Pilot Preliminary Safety and Performance in a few patients; 2) Pivotal Efficacy and Safety/Adverse Effects in a larger number, and 3) Postmarketing long-term safety. The higher the risk category, the greater the regulatory requirement for data and clinical evidence.
The development and marketing of a medical device or a diagnostic medical device require critical attention to technology, quality and the scientific challenges of generating robust clinical evidence.