Fraunhofer IZM researchers are developing a miniature, low-power wireless microsystem to make hearing aids* so small they can be concealed out of sight within the ear.

The technology is also suitable for implants, pacemakers, and insulin pumps. This all means that the system uses only a fraction of the energy required by conventional devices, keeping cumbersome battery changes to a minimum. “Ideally, patients should not even be feeling of wearing the hearing aid over long periods of time,” says Dr. Dionysios Manessis from Fraunhofer Institute of Reliability and Microintegration IZM in Berlin.

19 components into one micro module



With dimensions of just 4 mm by 4mm by 1 mm, the new microsystem is fifty times smaller than the current models. To achieve this, the project partners first developed especially small components such as innovative miniature antennas, system-on-chip integrated circuitry and high frequency filters, then integrated the 19 discrete components in a single module, using a modular 3D stacking concept that saves extra space.

The development is part of the EU WiserBAN project. Project partners are also looking to optimize energy management.

Hearing aids worn behind the ear are powered by a 180mAh (milliampere hour) battery, which must be either replaced or recharged approximately every two weeks. The aim is to minimize the system’s energy consumption to around one milliwatt (mW) to extend battery life up to 20 weeks.

Could also monitor pulse, blood-pressure, glucose, ECG via wireless, be used in implants

The WiserBAN project partners are also developing special antenna and wireless protocols that can communicate information such as pulse, blood pressure, or glucose levels straight to a physician’s tablet or smartphone. The resulting WiserBAN wireless system makes obsolete the relay station — an extra device that patients have previously been obliged to wear to extend the communication range.

Another advantage is that the wireless protocols developed within the WiserBAN project are based on the reliable IEEE 802.15.4 and 802.15.6 standards. Conventional devices have ordinarily relied on Bluetooth, where there are often issues with interference with other devices.

It is hoped that the new technology will act as the springboard for more comfortable, more reliable healthcare products in the future — from long-term electrocardiography to insulin pumps. Furthermore, there is the potential to use the microsystem in implants and pacemakers.

* According to the World Health Organization (WHO), hearing loss is one of the six most common illnesses in the industrialized world. In Germany, around one in five of those over the age of 14 have to be treated for hearing difficulties. Often a simple hearing aid can restore the lost frequencies and makes it possible for the patient lead a normal life again.