Hohenstein Institute, Bönnigheim, Germany
www.hohenstein.de

Scientists from the Hohenstein Institute in Bönnigheim have developed textile cooling pads to be used to prevent neurological damage after successful resuscitation in cardiac arrest patients. The system does not require electric power, making it ideal for first aid in case of cardiac arrest.

Fig. 1 — Functional principle of zeolite/water adsorption technology. ©Hohenstein Institute

In cardiac arrest, the patient’s chances of survival decrease by 10 percent with every second that passes until reanimation. Defibrillators have now become mandatory in public buildings and public transport. They use electric shock to restart the heartbeat. For most cardiac arrest patients, however, even successful reanimation is merely a partial success — only a few patients survive this lifesaving measure without consequential neurological damage.

To avoid this type of brain damage, scientists from the faculty of Hygiene, Environment & Medicine at the Hohenstein Institute have developed a new therapy method for first aid responders. In the framework of a research project supported by the state of Baden-Württemberg for the competition ‘Biotechnology and Medical Technology,’ the scientists, led by Prof. Dr. Dirk Höfer, developed a prototype of a textile cooling vest. The new type of medical product promises improved acute treatment for cardiac arrest by very quickly cooling down the patient’s body.

Cooling can protect the brain against damage from an oxygen deficit during a lack of blood flow. Targeted lowering of the temperature inside the body to a temperature range of 32° to 34°C has been proven to protect the brain against irreparable neurological damage. This simple but extremely effective therapy principle was used by the Hohenstein scientists. They started by developing waterproof and absolutely airtight textile hollow fabric — so-called cooling pads. These were equipped with appropriate connection options and integrated into a vest. The cooling pads are connected to a metal container under vacuum pressure containing a special mineral (zeolite). When an interposed valve is opened, the water in the pads is instantly cooled down to nearly freezing, which effectively drains body heat from the patient’s body. The cooling system based on zeolite/water adsorption technology has a simple design and allows drastic lowering of the core body temperature after occurrence of a cardiac arrest at any time and in any place — without electric power.

In the future, the self-sufficient cooling pads are intended to complement mobile defibrillators (with automated ECG analysis) for use by those giving first aid without medical knowledge, e.g., in public buildings and public transport. For patients with cardiac arrest, this means a much better chance of sustaining only minor consequential damage.

With this product, the Hohenstein researchers have managed to develop a new noninvasive method for surface cooling of the body. That means no surgical procedure is required and, in contrast to conventional cooling systems, it can be used directly at the place of emergency without any power source.

“The cooling pads harbor enormous potential in the neurological rehabilitation after cardiac arrests,” explained Prof. Dr. Dirk Höfer. “In addition to the benefits for the affected individual, every prevented case of invalidity is also a great financial advantage for the general public.”

Even though the researchers are looking for an industrial partner for production and sales of the cooling pads for the time being, they are already contemplating other innovative applications for textile cooling and heating processes in medicine.