Imec/TNO Disposable Patch for the Measurement of Vital Parameters

Wegwerfbares Pflaster zur Messung von drei Vitalparametern.

At CES 2019, the Belgian research center Imec and TNO (Dutch Organization for Applied Research) presented the latest version of a health patch that can measure vital data over a long period of time.

The health patch developed by Imec and TNO is characterized by a high level of comfort and a long battery life. It can also be manufactured at a fraction of the cost of previous generations, making it a user-friendly disposable solution for outpatient monitoring. Bernard Grundlehner, System Architect - Connected Health Solutions at Imec, comments: "A key technological improvement in the new generation of healthcare patches is the integration of many sensor functions into our MUSEIC V3 SoC. As a result, the patch is almost an order of magnitude cheaper, while the high degree of integration makes it even more energy-efficient. Thanks to the significant cost reduction, these patches can now be used as a disposable solution, an important advantage in medical care."

The patch consists of a mixture of skin-friendly and biocompatible materials. The base substrate is a very thin, flexible, and elastic TPU material (thermoplastic urethane). The majority of the electronic functionality is printed electronics, integrated dry electrodes ensure a stable and high-quality electrical connection to the body. A comfortable silicone adhesive is used to ensure long-term adhesion with high comfort. "The new health patch is absolutely waterproof, offers maximum user comfort and can be worn for up to seven days before it needs to be replaced," explains Prof. Jeroen van den Brand, Program Director Printed Electronics at TNO.

In order to limit the ecological footprint of the disposable plaster, Imec researchers have worked with Maxell to develop an environmentally friendly battery that contains no toxic substances. In addition, the MUSEIC V3 SoC improves overall energy efficiency thanks to its energy-saving signal detection. While competing approaches typically achieve a battery life of 3 to 4 days, the imec system achieves over 7 days, in many cases even longer, depending on configuration.

Compared to its predecessor, the new patch now also measures blood oxygen saturation (SpO2). It is regarded as an important vital parameter for assessing the patient's health, as a low oxygen content in the blood can indicate hypoxemia, which - untreated - can impair organ functions and even lead to respiratory or cardiac arrest. The patch also includes an accelerometer to monitor physical activity, an ECG heart activity tracker, and bioelectrical impedance monitoring.

"Traditionally, oxygen saturation in the blood is measured using a separate system attached to the finger. However, this is not very practical for everyday use, which is why we have developed a new technique that uses reflective photoplethysmography to perform this measurement with a breast patch. By adding this sensor function to our portable solution, we are now in a position to measure three essential vital parameters - heart rate, respiratory rate, and oxygen saturation in the blood - with a single, comfortable breast patch," concludes Bernard Grundlehner.