Drugdu.com expert's response:

Passive medical devices refer to those that do not rely on external energy sources (such as electricity or batteries) to perform their intended functions. These devices typically utilize physical principles like mechanics, optics, acoustics, and thermodynamics to achieve their functions, with their energy primarily derived from the human body itself or gravitational forces.

I. Characteristics of Passive Medical Devices

Energy Source: Passive medical devices do not depend on external power sources or other forms of energy. Instead, they operate directly using natural forces such as the human body or gravity.

Function Realization: They achieve their intended medical functions through physical principles like mechanical force, pressure, optical properties, etc.

Safety: Since they do not rely on external power, these devices generally do not generate electromagnetic interference or radiation during use, making them safer for the human body.

II. Classification of Passive Medical Devices

Passive medical devices can be classified based on their mode of contact with the human body and their duration of use:

a. By Mode of Contact

Surface Contact Devices: Devices that come into contact with undamaged skin, mucous membranes, and damaged surfaces, such as medical dressings and contraceptive devices.

Externally Invasive or Access Devices: Devices that enter the human body fully or partially through surgical procedures, such as surgical knives, syringes, and implantable devices.

b. By Duration of Use

Temporary Use: Devices used within 24 hours.

Short-term Use: Devices used from 24 hours to 30 days.

Long-term Use: Devices used for more than 30 days.

III. Common Examples of Passive Medical Devices

Liquid Delivery Devices: Such as syringes and infusion sets.

Blood and Fluid Modification Devices: Though these devices may involve complex mechanisms in their processing, they essentially do not rely on external power for their basic functions, such as hemodialysis machines and blood filters.

Medical Dressings: Including gauze and bandages.

Invasive Devices: Such as surgical knives, forceps, and tweezers.

Implantable Devices: Like cardiac pacemakers (note: while some implantable cardiac pacemakers are active, here it refers to those implantable devices that do not rely on external power, such as certain bioabsorbable implants).

IV. Conclusion:

Passive medical devices play a vital role in the medical field, widely used in surgery, diagnosis, rehabilitation, and other aspects due to their simplicity, safety, and ease of operation. As medical technology continues to advance, passive medical devices are also undergoing continuous innovation and development to meet the growing medical needs.