An In-vivo Electrical Property Based Health Monitoring Sensor

This paper introduces a new in-vivo method for continuous monitoring of deep human tissues. Specifically, a technique and an associated sensor is introduced to detect changes in the electrical properties of tissues deep into the human torso as an indicator to detect body irregularities such as lung fluid content. The method uses a set of electrodes that surround the torso. Data is collected from these electrodes at a single low frequency. An expression is also proposed that relates the collected raw signals (port scattering parameters) to the electrical properties of deep biological tissues. Of importance is that the developed relation includes constants that can be adjusted to remove interference from the skin, fat and muscle layers. Further, the constants can be calibrated to account for individual patient outer tissue layers. As such, the proposed lung monitoring sensor provides accurate dielectric constant data to assess the lung's fluid content in a continuous manner.