# US 11,451,366 B2 · Lead-on detection circuitry of biopotential acquisition system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,366 B2 - Document ID: US11451366B2 - Status: Granted - Kind: B2 - Application number: 17/111,474 - Filed: 2020-12-03 - Published: 2021-07-22 - Granted: 2022-09-20 - Earliest claimed: 2020-01-16 - Assignees: Mediatek Inc. - Applicants: Mediatek Inc. - Inventors: Chih-Hsin Chen - Web page: https://patentgrep.com/patent/US11451366B2 ## CPC - H03K 5/249: {using clock signals} - A61B 5/6843: {Monitoring or controlling sensor contact pressure} - H03K 3/017: Adjustment of width or dutycycle of pulses (pulse width modulation H03K7/08 {; to maintain energy constant H03K3/015}) - H03K 5/24: the characteristic being amplitude - H04L 7/0012: {by comparing receiver clock with transmitter clock} - A61B 5/053: Measuring electrical impedance or conductance of a portion of the body - A61B 2560/0209: adapted for power saving - H03D 7/00: Transference of modulation from one carrier to another, e.g. frequency-changing (H03D9/00, H03D11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as a frequency-changers H03F) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H03D: DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER (masers, lasers H01S; circuits capable of acting both as modulator and demodulator H03C; details applicable to both modulators and frequency-changers H03C; demodulating pulses H03K9/00; transforming types of pulse modulation H03K11/00; coding, decoding or code conversion, in general H03M; repeater stations H04B7/14; demodulators adapted for AC systems of digital information transmission H04L27/00; synchronous demodulators adapted for colour television H04N9/66) ## Abstract The present invention provides a lead-on detection circuitry of a biopotential acquisition system. The lead-on detection circuitry includes an input terminal, a duty-cycle controller, a transmitting signal generator and a mixer-based receiver. The duty-cycle controller is configured to generate a first clock signal. The transmitting signal generator is configured to generate a transmitting signal to the input terminal according to the first clock signal. The mixer-based receiver is configured to perform a mixing operation based on the first clock signal and the transmitting signal to generate an output signal, wherein the output signal indicates if an electrode of the biopotential acquisition system is in contact with a human body, and the electrode is coupled to the input terminal. ## Claims ### Claim 1 A lead-on detection circuitry of a biopotential acquisition system, comprising: an input terminal; a duty-cycle controller, configured to generate a first clock signal; a transmitting signal generator, configured to generate a transmitting signal to the input terminal according to the first clock signal; a mixer-based receiver, configured to perform a mixing operation based on the first clock signal and the transmitting signal to generate an output signal, wherein the output signal indicates if an electrode of the biopotential acquisition system is in contact with a human body, and the electrode is coupled to the input terminal; wherein the mixer-based receiver comprises: a mixer, configured to generate a mixed signal according to the transmitting signal and the first clock signal; and a comparator, coupled to the mixer, configured to compare the mixed signal with a reference signal to generate the output signal. ### Claim 2 (depends on 1) The lead-on detection circuitry of claim 1, wherein the mixer is configured to mix the transmitting signal with the first clock signal to generate the mixed signal. ### Claim 3 (depends on 1) The lead-on detection circuitry of claim 1, wherein the mixer-based receiver further comprises: a high-pass filter, configured to perform a high-pass filtering operation on the transmitting signal to generate a filtered signal; wherein the mixer is configured to mix the filtered signal with the first clock signal to generate a mixed signal. ### Claim 4 (depends on 1) The lead-on detection circuitry of claim 1, wherein the mixer-based receiver comprises: a high-pass filter, configured to perform a high-pass filtering operation on the transmitting signal to generate a filtered signal; the mixer, coupled to the high-pass filter, configured to mix the filtered signal with the first clock signal to generate the mixed signal; a low-pass filter, coupled to the mixer, configured to perform a low-pass filtering operation on the mixed signal to generate a filtered mixed signal; and the comparator, configured to compare the filtered mixed signal with the reference signal to generate the output signal. ### Claim 5 (depends on 1) The lead-on detection circuitry of claim 1, wherein the mixer-based receiver comprises: a high-pass filter, configured to perform a high-pass filtering operation on the transmitting signal to generate a filtered signal; the mixer, coupled to the high-pass filter, configured to mix the filtered signal with the first clock signal to generate the mixed signal; a low-pass filter, coupled to the mixer, configured to perform a low-pass filtering operation on the mixed signal to generate a filtered mixed signal; an amplifier, coupled to the low-pass filter, configured to amplify the filtered mixed signal to generate an amplified signal; and the comparator, configured to compare the amplified signal with the reference signal to generate the output signal. ### Claim 6 (depends on 1) The lead-on detection circuitry of claim 1, wherein the mixer-based receiver comprises: the mixer, coupled to the high-pass filter, configured to mix the transmitting signal with the first clock signal to generate the mixed signal; a low-pass filter, coupled to the mixer, configured to perform a low-pass filtering operation on the mixed signal to generate a filtered mixed signal; and the comparator, configured to compare the filtered mixed signal with the reference signal to generate the output signal. ### Claim 7 A lead-on detection circuitry of a biopotential acquisition system, comprising: an input terminal; a duty-cycle controller, configured to generate a first clock signal; a transmitting signal generator, configured to generate a transmitting signal to the input terminal according to the first clock signal; a mixer-based receiver, configured to perform a mixing operation based on the first clock signal and the transmitting signal to generate an output signal, wherein the output signal indicates if an electrode of the biopotential acquisition system is in contact with a human body, and the electrode is coupled to the input terminal; wherein the duty-cycle controller further generates a second clock signal, wherein a frequency of the second clock signal is lower than a frequency of the first clock signal; and the mixer-based receiver is enabled or disabled based on the second clock signal. ### Claim 8 (depends on 7) The lead-on detection circuitry of claim 7, wherein the transmitting signal generator receives the second clock signal, and the transmitting signal generator is enabled or disabled based on the second clock signal. ### Claim 9 A lead-on detection circuitry of a biopotential acquisition system, comprising: an input terminal; a duty-cycle controller, configured to generate a first clock signal; a transmitting signal generator, configured to generate a transmitting signal to the input terminal according to the first clock signal; a mixer-based receiver, configured to perform a mixing operation based on the first clock signal and the transmitting signal to generate an output signal, wherein the output signal indicates if an electrode of the biopotential acquisition system is in contact with a human body, and the electrode is coupled to the input terminal; wherein the duty-cycle controller comprises: an oscillator, wherein the oscillator is configured to generate the first clock signal and a second clock signal, and a frequency of the second clock signal is lower than a frequency of the first clock signal; and a reference signal generator, configured to generate a reference signal to the transmitting signal generator or the mixer-based receiver; wherein the reference signal generator is enabled or disabled based on the second clock signal. ### Claim 10 (depends on 9) The lead-on detection circuitry of claim 9, wherein the mixer-based receiver or the transmitting signal generator is enabled or disabled based on the second clock signal.