Monitoring and diagnostics systems and methods
Embodiments of the present disclosure provide methods, apparatuses, devices and systems for measuring vital signs in human and animals by interrogating electromagnetic signals reflected from tissues in a human or animal subject. Probes may transmit radio frequency electromagnetic waves into a living body and generate signals responsively to the waves that are scattered from within the body. Such embodiments may be suitable for wearable devices as well as for use by medical practitioners.
1. A vital sign measuring apparatus, comprising:
one or more RF sensors configured to be arranged external to a subject and on or adjacent the skin of the subject at a first location proximate to one or more arteries of the subject;
an external dielectrometer probe configured to be arranged external to the subject and on or adjacent the skin of the subject proximate to one or more arteries of the subject;
circuitry for the probe and the one or more RF sensors configured to:
generate one or more first radio-frequency (RF) waves for transmission towards the one or more arteries,
transmit the one or more first radio-frequency (RF) waves towards the one or more arteries of the subject,
receive one or more reflected RF waves therefrom, and
receive one or more dielectrometer probe signals from the external dielectrometer probe;
and
a processor communicably coupled to the circuitry and having computer instructions operating thereon configured to cause the processor to:
receive one or more requests for one or more vital signs of the subject,
determine if the one or more requests comprises a request for heart-rate measurement of the subject, or a request for at least one of blood pressure and respiration rate of the subject,
process at least one of the one or more dielectrometer signals and the one or more reflected RF waves,
determine the heart-rate measurement based on the processed one or more dielectrometer signals upon the one or more requests comprising the request for heart-rate measurement of the subject, and
determine the at least one of blood pressure and respiration rate based on the processed one or more reflected RF waves upon the one or more requests comprising the request for at least one of blood pressure and respiration rate of the subject.
2. The apparatus of claim 1 , wherein the one or more RF sensors comprise a monostatic radar.
3. The apparatus of claim 1 , wherein the one or more RF sensors comprise a bistatic radar.
4. The apparatus of claim 1 , wherein the apparatus is configured with flexibility for conforming the apparatus to the skin of the subject.
5. The apparatus of claim 1 , wherein the one or more RF sensors are configured to be are placed on or adjacent to the skin of the subject via a wearable device, a wearable garment, or an adhesive.
6. The apparatus of claim 5 , wherein the wearable garment comprises one or more of an article of clothing, a collar, a wrist strap, an ear tag, and a skin patch.
7. The apparatus of claim 1 , wherein the dielectrometer probe is configured to be placed on or adjacent to the skin of the subject via a wearable device, a garment, or an adhesive.
8. The apparatus of claim 1 , wherein the transmitted RF waves range from 200 MHz to 3 GHz.
9. The apparatus of claim 1 , wherein the computer instructions are further configured to cause the processor to resolve the received reflected RF waves according to one or more depths into the subject from which one or more of the reflected RF waves occurred.
10. The apparatus of claim 1 , wherein the computer instructions are further configured to cause the processor to condition the received, reflected RF waves using band pass filtering.
11. The apparatus of claim 1 , wherein a frequency range for the one or more reflected RF waves corresponds between 0.5 Hz to 2.5 Hz.
12. The apparatus of claim 1 , wherein the computer instructions are further configured to cause the processor to identify a prominent peak frequency in a frequency range of the received, reflected RF waves corresponding to respirations of the subject from a fast Fourier transform of the one or more received reflected RF waves.
13. The apparatus of claim 12 , wherein the frequency range is between 0.1 Hz to 1 Hz.
14. The apparatus of claim 13 , wherein the computer instructions are further configured to cause the processor to determine the respiration rate of the subject as a function of the peak frequency.
15. The apparatus of claim 1 , wherein the computer instructions are further configured to cause the processor to:
calibrate at least one amplitude of a pulse waveform based on the one or more received reflected RF waves with respect to a reference blood pressure measurement; and
calculate a difference between a maximum of the calibrated amplitude representing systolic blood pressure and a minimum of the calibrated amplitude representing diastolic blood pressure.
16. The apparatus of claim 1 , wherein the computer instructions are further configured to cause the processor to determine a complex permittivity from the one or more dielectrometer probe signals.
17. The apparatus of claim 16 , wherein the computer instructions are further configured to cause the processor to determine one or more changes in radar characteristics of the reflected RF waves.
18. The apparatus of claim 17 , wherein the computer instructions are further configured to cause the processor to determine other vital signs based on the one or more changes in the radar characteristics of the reflected RF waves.