Every day, thousands of people in hospitals are warned against the potential risks involved in forthcoming operations. One risk is often not mentioned: during longer operations, serious reduction in body temperature (hypothermia) can occur in patients. Due to the anaesthetic, metabolism and heat generated by the body is decreased. Patients also lose a lot of body heat in air-conditioned operating theaters.
To solve these problems, the idea of a textile heating system was developed at the Institute for Hygiene and Biotechnology at the Hohenstein Institutes in Bönnigheim, Germany. The heating elements consist of an electrically and thermally conductive yarn which is knitted into a circular knitted fabric. The yarn heats up and heats the surrounding textile. The system consists of six modules in total, one for the chest, one for the stomach and individual modules for each arm and leg.
The newly developed space-saving textile heating system is barely thicker than a surgical drape. The supple nature of the textile and the modular adjustment to the body form also minimizes heat loss to the environment. The system is designed for perioperative treatment, in other words before, during and after surgery. The heating system can be applied to the patient even before the anesthesia; its modular structure makes it possible to remove those parts in the area being operated on for surgery itself. The remaining modules remain in place until after the patient has awoken. The fact that the modules are fitted at an early stage also helps in advance to prevent a rapid drop in temperature due to the redistribution of body heat from the core to the periphery during anesthesia.
The hypothermia prevention system consists of an outer shell and inner textile heating elements. The outer shells are removable and can be reprocessed in a disinfectant washing process. The textile heating elements can also be sterilized and therefore reused. Another advantage of the textile heating elements is the rapid heating; within three minutes, the heating elements reach the maximum temperature of approx. 38°C. After this, the power supply, controlled by a temperature sensor, switches itself off. If the pre-programmed minimum temperature is reached, the elements automatically reheat.