device
Meaning of device: What separates a device from a drug is mechanism: it acts physically or mechanically rather than through chemical action inside the body.
Definition of device
A device, in health care, is a physical instrument, implant, machine or piece of equipment used to diagnose, monitor, support or treat a condition. Unlike a drug, it achieves its purpose through physical or mechanical means rather than chemical action in the body. The category runs from adhesive bandages and crutches to infusion pumps, artificial joints and implanted heart rhythm devices.
How are devices grouped by risk?
Regulators sort devices by how much harm a failure could cause, not by how complex they look. The lowest group covers items unlikely to injure anyone if they fail: bandages, examination gloves, bedpans, most simple walking aids. A middle group covers equipment needing specific performance controls, such as infusion pumps, powered wheelchairs and many diagnostic instruments. The highest group covers devices that support or sustain life, sit inside the body, or carry a real chance of serious injury, and these face the heaviest evidence requirements before they reach patients.
| Risk level | Typical examples | What oversight focuses on |
|---|---|---|
| Low | Bandages, gloves, bedpans, canes | Basic manufacturing and labeling standards |
| Moderate | Infusion pumps, powered wheelchairs, many monitors | Performance standards and comparison with existing devices |
| High | Implanted pacemaker, heart valves, life support | Clinical evidence before approval and tracking afterward |
Where is the line between a device and a drug?
A medical device works by physical means: cutting, supporting, measuring, delivering, replacing a structure or conducting an electrical signal. A drug works by chemical or metabolic action. The distinction matters because the two are tested and approved through separate routes. Some products sit across the line and are handled as combination products, such as a stent coated with a drug that limits scar tissue, a prefilled auto-injector, or bone cement carrying an antibiotic.
What counts as a device in daily life?
Far more than hospital machinery. An assistive device such as a hearing aid, walker, prosthetic limb or grab rail is a device, and so is a home blood pressure monitor, a thermometer, a contact lens and a glucose meter. Laboratory analyzers and imaging scanners are devices. Software counts too when it interprets data to inform a clinical decision rather than simply displaying it. Because the range is so wide, no single rule about testing, maintenance or replacement applies across the whole category.
Used in a sentence
The patient was fitted with a device to monitor heart rhythm continuously at home.
Good to know
Medical devices are classified by risk rather than treated as one uniform category, since a simple external aid and an implanted device that regulates a body function attract very different levels of oversight.