Biopotentials are created by electric fields due to ion gradients primarily over muscle cells and neurons. Skin resistance is attenuating the measurable signal requiring electrical amplification.
- Electro Cardio Gram (ECG); heart muscle acticity
- Electro Mio Gram (EMG); any muscle activity
- Electro Occulo Gram (EOG); eye movement
- Electro Encephalo Gram (EEG); brain neural activity
Bioimpedance measures body and tissue impedance by injecting oscillating current through electrodes and measuring the resulting voltage. The frequency response is indicative of electrical tissue composition.
- Whole Body Impedance Analysis (BIA) or Total Body Composition (TBC)
- Segmental Body Impedance (smaller regions of the body).
- Respiratory Rate (RR)
- Lung Composition (LC)
- Pulmonary Edema (PE)
- Galvanic skin response (GSR), Skin Conductance Level (SCL) or Electro dermal activity (EDA)as a result of physiologic arousal
Optical Absorption is measured with light passing through the body and tissue at different optical wavelengths extracting optical absorption properties of tissue constituents such as hemoglobin. Variation in concentration occurs during blood pressure propagation. Background such as melanin and scattering affect these readings and can reduce signal strength. When measuring with more than two wavelenghts, additional Hemoglibin species can be detected, however most common sensor elements support two wavelenghts.
- Pulse Plethysmo Graphy (PPG); detecting the effects of pressure waves passing by the sensor, non contact heart rate and pulse propagation
- Blood Oxygenation
-
$SPO_2$ Pulse Oximetery, oxygen saturation
Temperature is a simple measurement for increased metabolism which can be caused through viral or bacterial load as a defense mechanism to lower viral replication but also due to hyperactivity of cancer or exercise.
- External skin temperature
- Internal temperature
Sound is emitted as a result of mechanical activity such as heart deformation during muscle contraction, closure of valves or blood turbulence causing pressure gradients, abdominal muscle contractions, and airflow resulting in pressure wave propagation through the body.
- Heart sounds (S1, S2)
- Blood vessel sounds induced by blood pressure cuff, als know as Korotkoff sounds
- Lung sounds
- Bowel sounds
Activity expand here..
- Acceleration, Gyration, Mangnetic field
- Barometric Pressure
- GPS
Respiration .. expand here
- Air Flow
- Humidity, Temperature
- Pressure
- Light level
-
$CO_2$ concentration - Particulate matter concentration
- Presence of Volatile Organize Compounts
- Presence of Carbion Monoxide
Cellular Structure microscopy, expand here
Analyte Concentrations expand here