By Ebele Orakpo
FEVER, also known as high fever, high temperature, pyrexia or febrile response, is defined as a body temperature above the normal range due to an increase in the temperature regulatory set-point. Experts agree that a fever in itself, is not an illness but usually a symptom of an underlying condition, often an infection. Fever is a natural bodily defence against infection.
What happens is that the hypothalamus (a part of the brain which controls body temperature) resets the body to a higher temperature in response to an infection, illness or a foreign body in the system.
For instance, high fever can be a sign of a life-threatening infection and it can cause seizures in children. Fevers can indicate the presence of lung, ear, skin, bladder, throat, or kidney infections; cancer, blood clots, autoimmune diseases, hormone disorders, illegal drugs such as cocaine etc. so the earlier it is detected and tackled, the better.
To help in early detection of fever and the underlying condition and subsequent treatment, researchers at the University of Tokyo have developed a fever alarm armband, “a flexible, self-powered wearable device that sounds an alarm in case of high body temperature.”
According to a release by the research groups led by Professor Takayasu Sakurai at the Institute of Industrial Science and Professor Takao Someya at the Graduate School of Engineering, the device which was presented at this year’s IEEE International Solid State Circuits Conference in San Francisco, California, USA, is 30 cm long and 18 cm wide and combines a flexible amorphous silicon solar panel, piezoelectric speaker, temperature sensor and power supply circuit created with organic components in a single flexible, wearable package.
It can be worn either directly on the skin or on top of clothing. The device is designed in such a way that the thermal sensor is located between the arm and the body. “The organic power supply circuit is located under the piezo film speaker to reduce surface area.”
The researchers recognised the fact that “constant monitoring of health indicators such as heart rate and body temperature is the focus of intense interest in the fields of infant, elderly and patient care and sensors for such applications need to be flexible and wireless for patient comfort, maintenance-free and not requiring external energy supply, and cheap enough to permit disposable use to ensure hygiene.”
They developed a flexible solution that incorporates organic components that can be printed by an inkjet printer on a polymeric film as conventional sensors based on rigid components are unable to meet these requirements. The fever alarm armband is the first organic circuit able to produce a sound output,which enables it to provide audible information when the flexible thermal sensor detects a pre-set value within the ranges of 36.5 oC to 38.5 oC.
The device is also the first to incorporate an organic power supply circuit which increases the range of operational illumination by 7.3 times in indoor lighting conditions. “Our fever alarm armband demonstrates that it is possible to produce flexible, disposable devices that can greatly enhance the amount of information available to carers in healthcare settings,” says Prof. Someya. “We have demonstrated the technology with a temperature sensor and fever alarm, but the system could also be adapted to provide audible feedback on body temperature, or combined with other sensors to register wetness, pressure or heart rate.”