The 10 meter method and 3 meter method semi anechoic chamber, the electromagnetic shielding room with protruding conical columns on the four walls, several thick steel plates and the immunity test room – this is the first laboratory established in the domestic medical device testing industry.

“Electromagnetic compatibility is a new concept in the field of medical devices and instruments in China. I will give you an example to understand.” Meng Zhiping, director of the electromagnetic compatibility laboratory of Beijing Institute of medical device inspection, said at the open day of the medical device inspection institution on the 26th that a patient was lying on an electric operating table for surgery. During the operation, a high-frequency electric knife was used, and its radiation caused the entire operating table to lift up, causing a medical accident. After research and analysis, it was finally found that “this is caused by electromagnetic incompatibility between medical devices.”

Electromagnetic compatibility refers to the ability of equipment or system to work normally in its electromagnetic environment and not cause unbearable electromagnetic disturbance to anything in the environment.

According to her, at present, with the increasing use of low-power, high-speed and highly integrated circuits in medical electrical equipment, these devices are more vulnerable to the threat of electromagnetic interference than ever before.

“Ah! How dangerous these things are! Is it better not to bring your mobile phone in when we check?” At the open day event, the consumer representatives who visited together shouted that they were incomprehensible and asked questions one after another.

“Of course. The medical equipment in an ambulance stopped working because of electromagnetic interference from the communication equipment in the ambulance. A motorcyclist wearing a bioelectrically controlled prosthetic limb lost control of the prosthetic limb system due to electromagnetic interference when driving under a high-voltage power transmission line, resulting in people leaning over and overturning. When a student with a hearing aid entered the classroom just installed with a new efficient lighting system, his chin began to vibrate.” Meng Zhiping said.

She told reporters that this laboratory can not only detect electromagnetic interference, but also simulate electromagnetic interference to test the ability of medical devices to resist the electromagnetic interference of the surrounding environment. In order to establish high-quality testing ability, the materials and equipment in the laboratory are all imported from abroad, and even the installation is assembled by foreign engineers, so the cost is very high.

On December 17, 2012, the State Food and Drug Administration issued an announcement clearly indicating that the EMC industry standard for medical electrical equipment will be officially implemented from January 1, 2014 to reduce the electromagnetic emission of medical devices, improve their anti-interference ability, and ensure the safety and effectiveness of public use.

The 10 meter method semi anechoic chamber was built at the end of 2012, with radiation protection, large turntable and excellent performance indicators. “These are the most cutting-edge testing equipment and systems in the world at present, with high sensitivity, because many of the medical devices we test are world-class.” Meng Zhiping pointed out.

On the large turntable with a diameter of about 7 meters in the darkroom, there is a dental radiation equipment. There is a screen door on the side of the darkroom. Large medical equipment can be directly driven in and loaded and unloaded on the turntable.

It is reported that the electromagnetic compatibility test requirements of medical equipment include emission and immunity. Emission test includes radiation emission and conduction emission. The former is to test the disturbance radiation field intensity emitted by medical equipment through space, and the latter is to test the disturbance voltage and current emitted by medical equipment through power line or signal line.

“When testing in the darkroom, we can only observe the movement in the darkroom through the camera, and then rely on the computer to analyze the data and draw a conclusion.” Meng Zhiping said.

Liu Yi, director of Beijing medical device inspection institute, pointed out that at present, this laboratory has tested hundreds of medical device products for domestic and foreign enterprises, including high-risk medical devices, physiological monitoring equipment, radiation electromagnetic energy equipment, life support equipment and in vitro diagnostic equipment, helping China’s medical devices break through the technical barrier of electromagnetic compatibility performance and improve their competitiveness in the international market.