NASA Langley Research Center has developed a novel laser vibrometer sensor for monitoring cardiac activities remotely and non-invasively — specifically, heart functions of valve/chamber opening and closing cycles (cardiac cycles). The device provides precise magnitude and timing information, non-invasively and away from the heart region without interference by patient garments.
Blood circulation carries vibrations due to heartbeats to every part of the body. These vibrations result in minute displacements that are measured by a detector. Defective closures lead to backflow of blood into the chambers, leading to heartbeat slowdown. Displacement strength is indicative of vibration strength, which in turn is indicative of heartbeat. Weak vibrations at the toes, for example, indicate poor circulation of blood as in the case of diabetic issues. Similarly, in other parts of the body, this unit would help in early detection of diabetes and other diseases by non-invasively monitoring blood circulation at various regions of a human body.
The device consists of a laser transmitter, photo-EMF detector, and interferometric architecture that provides motion detection, which aids in measuring displacements. There is also a “speckle-tolerant” property, allowing data to be collected from conformal and rough target surfaces such as garments. Surface preparation is not needed such as in ECG and other cases. The photo-EMF detector is able to measure displacements of less than 1 pm.
This unit would detect precursors for diseases. For astronauts and other operatives, this device could remotely provide the status of their cardiac cycles during physical activities.