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ELECTRICAL SAFETY


Insulation monitoring brings safety and cost-savings


Timo Ohtonen, managing director and owner of Finnish professional electronics specialist, PPO-Elektroniikka, and his colleague, Development manager, Petri Pelkonen, take an in-depth look at the importance of insulation monitoring in protecting both medical staff and patients in operating theatres and other Group II medical facilities.


Any electrical malfunction in an operating theatre could prove fatal, and insulation monitoring is the optimal way to guarantee electrical safety in such an environment and in other Group II medical facilities. A commonly used residual current device reacts too late; the damage will already have happened, potentially posing real danger to both the patient and medical personnel. In addition, connected devices are without an electrical supply, and the operation or other surgical procedure must be suspended. This explains why insulation- level monitoring has been mandatory in all operating rooms in Finland since 1983. The key function of an insulation-level monitoring system it to warn of any malfunction before danger arises. Electrical leakage currents occur in both old and new electrical devices due to malfunction, ageing, and bad design. Common reasons for insulation faults include a poor connection, damaged cable insulant, defective component, or faulty installation. Fast technological development, and the rush to launch new medical equipment, have resulted in new kinds of challenge: new equipment may cause disturbances in the power network and other electrical devices.


An invisible but important part of the theatre


All this requires insulation-level monitoring, which is an invisible but important part of the routine of the operating theatre. Insulation monitoring monitors the ungrounded system between an active phase conductor and earth. The system measures and controls the power supply of IT systems. The units control the insulation level of the IT system, as well as the transformer load and temperature.


European and national standards regulate electrical installations and the operation of devices in medical facilities. Operating rooms are classified as Group II medical facilities. In Europe these facilities have required a specific IT system, as well as monitoring equipment for the


Electrical leakage currents may occur in both old and new electrical devices.


insulation space related to the IT system, since 2015. European countries that have negotiated derogations for electrical installations in medical facilities are an exception to this.


Several risk factors during surgery Risk situations occur frequently in an operating theatre environment. What starts as a minor equipment failure may lead to an electrical fire and electric shock. The breakdown of a medical device may pose an immediate risk of death to the patient or medical team. Because of this, the protective systems in all G2-classified facilities must be more comprehensive than normal. The safety of both the medical staff and the patient must be ensured. Patients are, of course, often entirely dependent on equipment that monitors vital functions/signs. A patient undergoing an operation is typically more infirm than usual, and thus more susceptible to complications, while due to the effects of anaesthesia or strong


medication, he or she is unable to react to dangerous situations caused by electric current. The patient may have damp skin, as well as wounds and subcutaneous device sensors for example, which enhance electrical conductivity. An electrical shock may result from direct contact with a live component or live wire, or a part of a device connected to the patient may become live. Electrosurgical instruments pose a particular risk because their functionality is based on electric voltage.


In a medical IT system with insulation level monitoring system: n The electric power network of the operating theatre is separated from the electrical grid by a medical isolation transformer.


n The insulation-level monitoring system monitors all the electrical devices connected behind this transformer.


n The equipment indicates the faults and problems before dangerous situations arise.


September 2020 Health Estate Journal 69


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