Which of the following is not considered an active implant?

The mechanical shunt is not considered an active implant because it does not have any electronic components or power source that actively controls its function. Active implants are devices that rely on electricity to perform their intended functions, often involving stimulation, monitoring, or therapeutic mechanisms.

Loop recorders, pacemakers, and bone stimulators all utilize batteries or other power sources to facilitate their operations. Loop recorders continuously monitor the heart rhythm and store data, pacemakers actively regulate heartbeats, and bone stimulators facilitate healing through electrical stimulation. In contrast, a mechanical shunt simply provides a passive route for fluid movement, such as in the case of a cerebrospinal fluid shunt, and operates without the need for electrical power. This distinction is crucial in identifying the classification of these devices in the realm of medical safety and MRI compatibility.