Computation of parameters of a body using an electric field
In some embodiments, an electric field generator includes a differential oscillator that oscillates at a nominal frequency. The electric field generator is connected to a differential antenna that radiates an electric field. A differential detector measures a frequency of the generated electric field as the electric field interacts with a body (such as a human body) in a reactive near-field region of the electric field. For each of one or more internal components of the body, a computation unit determines a respective periodic behavior in the measured frequency indicative of movement of the internal component. The computation unit also computes, for each of the one or more internal components of the body, a respective rate of movement (such as a heart rate or a respiration rate) of the internal component according to the respective periodic behavior in the measured frequency.
1. A system comprising:
an electric field generator comprising a differential oscillator configured to oscillate at a nominal frequency, the electric field generator connected to a differential antenna configured to radiate an electric field;
a differential detector configured to measure a frequency of the generated electric field as it interacts with a body in a reactive near-field region of the electric field; and
a computation unit configured to:
determine, for each of one or more internal components of the body, a respective periodic behavior in the measured frequency indicative of movement of the internal component, and
compute, for each of the one or more internal components of the body, a respective rate of the movement of the internal component according to the respective periodic behavior in the measured frequency.
2. The system of claim 1 , wherein the differential oscillator comprises one of a differential tank oscillator or a differential resonator.
3. The system of claim 1 , wherein the differential detector comprises a differential demodulator.
4. The system of claim 1 , wherein the differential detector comprises one of a differential quadrature demodulator, a differential wideband analog-to-digital converter, or a combination of a differential sample-and-hold circuit and an analog-to-digital converter.
5. The system of claim 1 , wherein the body is a human body.
6. The system of claim 5 , wherein the one or more internal components of the body comprise a heart of the human body.
7. The system of claim 5 , wherein the one or more internal components of the body comprise a femoral artery of the human body.
8. The system of claim 5 , wherein the one or more internal components of the body comprise a heart of the human body and lungs of the human body.
9. The system of claim 5 , wherein one of the respective rates is a heart rate.
10. The system of claim 9 , wherein the heart rate is a nighttime resting heart rate.
11. The system of claim 10 , wherein the computation unit is further configured, in computation of the nighttime resting heart rate, to not use a portion of the measured frequency that is not indicative of movement of a heart of the human body.
12. The system of claim 10 , wherein the computation unit is further configured, in computation of the nighttime resting heart rate, to not use a portion of the measured frequency that corresponds to a non-periodic behavior.
13. The system of claim 12 , wherein the differential detector is further configured to measure an amplitude of the electric field; and
wherein the computation unit is further configured to determine the non-periodic behavior according to the measured amplitude.
14. The system of claim 5 , wherein the respective rates comprise a heart rate and a respiration rate.
15. The system of claim 1 , wherein the measuring of the frequency of the generated electric field does not comprise measuring a reflection of the generated electric field.
16. The system of claim 1 , wherein a first portion of the computation unit is co-located with the differential detector, and a second portion of the computation unit is remotely located from the differential detector and connected to the first portion of the computation unit over a network;
wherein the first portion of the computation unit is configured to determine the respective periodic behavior for each of the one or more internal components of the body; and
wherein the second portion of the computation unit is configured to compute the respective rate of the movement for each of the one or more internal components of the body.
17. A method comprising:
generating an electric field with an electric field generator comprising a differential oscillator oscillating at a nominal frequency;
radiating the electric field through a differential antenna connected to the electric field generator;
measuring, with a differential detector, a frequency of the generated electric field as it interacts with a body in a reactive near-field region of the electric field;
determining, for each of one or more internal components of the body, a respective periodic behavior in the measured frequency indicative of movement of the internal component; and
computing, for each of the one or more internal components of the body, a respective rate of the movement of the internal component according to the respective periodic behavior in the measured frequency.
18. The method of claim 17 , wherein the differential oscillator comprises one of a differential tank oscillator or a differential resonator.
19. The method of claim 17 , wherein the differential detector comprises a differential demodulator.
20. The method of claim 17 , wherein the differential detector comprises one of a differential quadrature demodulator, a differential wideband analog-to-digital converter, or a combination of a differential sample-and-hold circuit and an analog-to-digital converter.
21. The method of claim 17 , wherein the body is a human body.
22. The method of claim 21 , wherein the one or more internal components of the body comprise a heart of the human body.
23. The method of claim 21 , wherein the one or more internal components of the body comprise a femoral artery of the human body.
24. The method of claim 21 , wherein the one or more internal components of the body comprise a heart of the human body and lungs of the human body.
25. The method of claim 21 , wherein one of the respective rates is a heart rate.
26. The method of claim 25 , wherein the heart rate is a nighttime resting heart rate.
27. The method of claim 26 , wherein the computing the nighttime resting heart rate comprises not using a portion of the measured frequency that is not indicative of movement of a heart of the human body.
28. The method of claim 26 , wherein the computing the nighttime resting heart rate comprises not using a portion of the measured frequency that corresponds to a non-periodic behavior.
29. The method of claim 28 , further comprising:
measuring, with the differential detector, an amplitude of the electric field; and
determining the non-periodic behavior according to the measured amplitude.
30. The method of claim 21 , wherein the respective rates comprise a heart rate and a respiration rate.
31. The method of claim 17 , wherein the measuring of the frequency of the generated electric field does not comprise measuring a reflection of the generated electric field.