Low noise subsurface spectrogram with cascaded reference circuit

Abstract

This disclosure provides cascaded reference circuits and low amplitude signal sensing circuits used to perform a Subsurface Spectrogram (SSG). The Subsurface Spectrogram can detect the conductive properties of skin and the underlying tissues. The conductive properties inform what electrolytes and moisture levels are present, which in turn can provide information about the physiological state of the mammal. The Subsurface Spectrogram uses an arbitrary waveform generator to provide a reference signal, the return signals are captured and compared to their original characteristics for changes in amplitude, phase and frequency. From these calculations insight into the amount of skin moisture and electrolyte configuration can be gained. Embodiments of such systems may be especially useful in health and fitness wearable devices where feedback on health and exercise can help mammals achieve an optimal workout, or help them to know when they are experiencing unhealthy stress levels. Methods are provided for using the devices of this disclosure to privately alert wearers to an increase in bad stress in the moment when they can take actions to reduce their physiological stress responses. These devices are useful for measuring and increasing the effectiveness of relaxation techniques. As a result of using methods and devices of this disclosure, people are healthier, they make more responsible decisions, and relationships improve.