Abstract:
Various examples are provided for wireless power transfer to implants. In one example, a system includes a radio frequency (RF) power source and a transmitter (TX) array comprising an excitation coil and resonant coils distributed about the excitation coil. The TX array can transfer power from the RF power source to a biomedical implant inserted below a skin surface of a subject when the TX array is positioned on the skin surface adjacent to the biomedical implant. A receiver (RX) coil of the biomedical implant can inductively couple with the TX array for the power transfer. The resonant coils can allow power transfer when the RX coil is not aligned with the excitation coil.
Abstract:
Various examples are provided for accurate heart rate measurement. In one example, a method includes determining a respiratory rate (RR) and respiration displacement from radar-measured cardiorespiratory motion data; adjusting notch depths of a harmonics comb notch digital filter (HCNDF) based upon the respiration displacement; generating filtered cardiorespiratory data by filtering the radar-measured cardiorespiratory motion data with the HCNDF; and identifying a heart rate (HR) from the filtered cardiorespiratory data. In another example, a system includes radar circuitry configured to receive a cardiorespiratory motion signal reflected from a monitored subject; and signal processing circuitry configured to determine a respiration displacement based upon the cardiorespiratory motion signal; adjust notch depths of a HCNDF based upon the respiration displacement; filter the cardiorespiratory motion data with the HCNDF; and identifying a heart rate (HR) from the filtered cardiorespiratory data.
Abstract:
Various examples are provided for accurate heart rate measurement. In one example, a method includes determining a respiratory rate (RR) and respiration displacement from radar-measured cardiorespiratory motion data; adjusting notch depths of a harmonics comb notch digital filter (HCNDF) based upon the respiration displacement; generating filtered cardiorespiratory data by filtering the radar-measured cardiorespiratory motion data with the HCNDF; and identifying a heart rate (HR) from the filtered cardiorespiratory data. In another example, a system includes radar circuitry configured to receive a cardiorespiratory motion signal reflected from a monitored subject; and signal processing circuitry configured to determine a respiration displacement based upon the cardiorespiratory motion signal; adjust notch depths of a HCNDF based upon the respiration displacement; filter the cardiorespiratory motion data with the HCNDF; and identifying a heart rate (HR) from the filtered cardiorespiratory data.
Abstract:
Various examples of methods and systems are provided for vibrational frequency detection (e.g., noncontact vital sign detection) using digitally assisted low intermediate frequency (IF) architectures. In one example, a transceiver system is configured to transmit a modulated signal generated by modulating a local oscillator (LO) signal with an IF carrier; generate an IF signal by down converting a received signal comprising backscatter with the LO signal; and simultaneously sample the IF carrier and the IF signal. A vibration frequency can be determined by demodulating the sampled IF signal with the sampled IF carrier. In another example, a method includes generating and transmitting a modulated signal; receiving backscatter of the modulated signal; generating an IF signal by down converting the received signal with the LO signal; simultaneously sampling the IF carrier and the IF signal; and determining a vibration frequency by demodulating the sampled IF signal with the sampled IF carrier.
Abstract:
Various examples are provided for wireless power charging for versatile receiver positions. In one example, a three dimensional array of transmitter coils is positioned around a charging area. A control circuit causes the array of transmitter coils to generate a magnetic field that charges a device with any position and orientation in the charging area.
Abstract:
A method and system for cancelling body movement effect for non-contact vital sign detection is described. The method begins with sending on a first electromagnetic wave transceiver a first electromagnetic signal with a first frequency to a first side of a body, such as a person or animal. Simultaneously using a second electromagnetic wave transceiver a second electromagnetic signal is sent with a second frequency to a second side of a body, wherein the first frequency and the second frequency are different frequencies. A first reflected electromagnetic signal reflected back in response to the first electromagnetic wave on the first transceiver is received and a first baseband complex signal is extracted. Likewise a second reflected electromagnetic signal reflected back in response to the second electromagnetic wave on the second transceiver is received and a second baseband complex signal is extracted. The first baseband complex signal is mathematically combined with the second baseband complex signal to cancel out a Doppler frequency drift therebetween to yield a periodic Doppler phase effect.
Abstract:
Embodiments of the subject invention are drawn to power supply units and systems for supplying power to loads. Specific embodiments relate to systems incorporating the loads. The power supply units and systems can include a feedback mechanism for monitoring the system and maintaining a parameter of interest at or near a desired value (e.g., for maintaining the frequency of operation at or near resonance). The feedback mechanism is configured such that, if the at least one parameter indicates that the frequency of operation is away from a resonant frequency of the power amplifier, the feedback mechanism adjusts the frequency of operation closer to the resonant frequency of the power amplifier. The at least one load can have a variable impedance, though embodiments are not limited thereto.
Abstract:
Various examples are provided for power amplifiers for coil array systems, which include load-independent Class E power amplifiers. In one example, a wireless charging system includes a three-dimensional (3D) coil array; and control circuitry configured to adjust a magnetic field generated by the 3D coil array, the control circuitry comprising a switching structure coupled to transmitting (TX) coils of the 3D coil array via independent matching networks. The independent matching networks can be LCL-matching networks.
Abstract:
Various examples are provided for accurate heart rate measurement. In one example, a method includes determining a respiratory rate (RR) and respiration displacement from radar-measured cardiorespiratory motion data; adjusting notch depths of a harmonics comb notch digital filter (HCNDF) based upon the respiration displacement; generating filtered cardiorespiratory data by filtering the radar-measured cardiorespiratory motion data with the HCNDF; and identifying a heart rate (HR) from the filtered cardiorespiratory data. In another example, a system includes radar circuitry configured to receive a cardiorespiratory motion signal reflected from a monitored subject; and signal processing circuitry configured to determine a respiration displacement based upon the cardiorespiratory motion signal; adjust notch depths of a HCNDF based upon the respiration displacement; filter the cardiorespiratory motion data with the HCNDF; and identifying a heart rate (HR) from the filtered cardiorespiratory data.
Abstract:
Method and apparatus for detecting a movement, such as two or more periodic vibrations, of a target, by sending a radar signal, e.g., near 60 GHz, at the target and processing the signal reflected by the target. One or more components of the movement can have a predominant frequency, such as a frequency of vibration, and two or more components can have different frequencies and, optionally, different magnitudes. A quadrature receiver processes the received signal to produce a base band output signal having in-phase (I) and quadrature-phase (Q) outputs. The in-phase (I) and quadrature-phase (Q) outputs are cross-referenced and real target movement frequency recovered directly in the time domain. System nonlinearity, which does not occur simultaneously on the I and Q channels, is identified and removed. Radar signals having wavelengths near one or more of the target movement magnitudes can be used.