Medical devices are equipment that are directly related to the lives of patients and medical staff, and must thoroughly comply with various safety standards from the design stage. In particular, for medical devices that operate electrically, insulation is essential to prevent electrical hazards such as electric shock and fire. If insulation is poor, it can lead to serious accidents, which in turn leads to huge cost losses and decreased reliability. This article discusses the necessity of insulation in medical devices and how important insulation design is during development through real-life cases.

Definition and necessity of insulation
Insulation of medical devices is a technology that protects users from electric shock and equipment failure. Medical devices such as cardiac monitors, MRIs, and electrosurgical devices are in direct contact with the patient's skin or are inserted into the body, so insulation design is essential.

The International Electrotechnical Commission (IEC) 60601-1 standard requires two means of protection (MOP) in insulation design to ensure the safety of medical devices. The first is basic insulation, and the second is reinforced insulation, which ensures that the device remains safe to use even if a single insulation failure occurs.

Key elements of insulation technology
The insulation performance of medical devices is evaluated through various factors. The main items are as follows:

- Leakage Current:
Leakage current is a small amount of current that leaks out of a medical device. IEC 60601-1 stipulates that the leakage current of the part that comes into contact with the patient should not exceed 500 μA (microampere).

- Withstand Voltage:
Withstand voltage is a standard for measuring the ability of medical devices to withstand high voltage. Typically, a voltage of between 1500 V and 4000 V is applied to evaluate the insulation status of the device.

- Creepage Distance and Clearance:
Creepage distance is the distance measured along the surface between current-carrying parts, while clearance is the distance measured through air. IEC 60950-1 requires a creepage distance of 3.2 mm for basic insulation and 6.4 mm for double and reinforced insulation.

Real-world examples of medical device insulation

(1) Case of insulation failure in electrosurgical equipment
Electrosurgical equipment uses high-frequency current to cut tissue or stop bleeding. If there is an insulation breakdown, the current will flow incorrectly, which can cause electric shock to patients and medical staff. In a real case, a patient suffered second-degree burns during electrosurgical treatment due to insulation damage. Such accidents can be prevented by proper insulation design and regular equipment inspection.

(2) Utilization case of insulation monitoring device (IMD)
An insulation monitoring device (IMD) is a device that continuously monitors insulation resistance in medical electrical systems. In intensive care units and operating rooms, various medical devices are used, so there is a high possibility of insulation failures. IMD sends an alert when the insulation resistance falls below a set value, allowing action to be taken. This prevents electric shock accidents in advance.

Insulation of medical devices is an important technology that ensures the safety of patients and medical staff. The insulation status must be checked through various factors such as leakage current, withstand voltage, and creepage distance, and it is essential to comply with international standards such as IEC 60601-1. In addition, it is important to introduce an insulation monitoring system and maintain the equipment regularly.

Medical device manufacturers must continue to advance insulation technology and enhance user education to increase the level of protection from electrical hazards.