Digitalization provides valuable services in outpatient and inpatient care. It is also the key to a leading self-determined life in one’s own home, including in old age. Smart band-aids for measuring vital data or administering drugs could play an important role here.
Studies indicate that about four million people in Germany will be dependent on care by 2035. And most want to be looked after at home. To give caregivers some relief and keep costs under control, the use of digital helpers is essential. A representative survey conducted by Germany’s digital association, Bitkom, also shows that the majority of respondents expect this to improve the quality of care. For instance, through intelligent sensors on the body for monitoring vital signs.
Ecological disposable band-aids
Researchers from the Belgian research center Imec and the Netherlands Organisation for Applied Scientific Research TNO have transformed the originally passive patch into a convenient measuring instrument for outpatient monitoring. By integrating a whole range of sensor functions into a system on chip (SoC), it can be manufactured as a single-use solution at a fraction of the cost of previous generations. In addition, the high degree of integration ensures a long battery life thanks to significantly increased energy efficiency.
The patch itself consists of a mix of skin-friendly and biocompatible materials. Even the battery is void of toxic substances. Printed electronics provide most of the functionality, while integrated dry electrodes and a silicone adhesive ensure stable “body contact.” The new health patch is completely waterproof and works for up to seven days.
Compared to earlier versions, the current one now also measures blood oxygen saturation (SpO2). This is considered to be an important indicator of health, as a low oxygen content may point to dangerous hypoxemia, for instance. In addition, an acceleration sensor monitors physical activity, an ECG keeps a check on the electrical activity of the heart, and bioelectrical impedance monitoring determines body composition.
Patches that go below the skin
Researchers at the University of California, San Diego are treading a different path when it comes to band-aids. Their recently presented patch uses ultrasound to detect the central blood pressure in the arteries as deep as four centimeters below the skin. This pressure helps the central blood vessels to transport our lifeblood directly from the heart to the organs. In contrast, the peripheral blood pressure, measured with an inflatable cuff, is less significant.
An array of small electronic components connected by spring-shaped copper wires are positioned on the ultrasound patch, which is made of thin silicone elastomer. This allows the electronic functions to remain intact even during stretching and bending.
Piezoelectric transducers in the components produce the ultrasound waves. These are backscattered with modified frequencies according to the Doppler effect on moving objects such as the oscillating arterial wall and detected by a piezo element. Software then transforms this data into a waveform that allows direct conclusions to be drawn about activity or incidents in the heart. This enables predictions of heart failure or assessments about the general blood supply to be made, for example.
In blood pressure tests, the patch was in no way inferior to other clinical methods. In the future, the ultrasound method could also certainly be used to non-invasively track other vital functions and physiological signals from inside the body.
Patches that administer drugs
Scientists at Tufts University in Massachusetts are also turning the age-old band-aid into a state-of-the-art wound healer. Not only does it measure the pH and temperature of a wound, it also immediately administers the necessary drugs, if needed, which start off in gel form and are activated before application by tiny heating elements.
The pH value is an indicator of the healing progress, while the temperature is a sign of the degree of inflammation. Other sensors for specific indications are also conceivable.