An example apparatus includes: an adjustable capacitor having a first terminal coupled to an input terminal, a second terminal coupled to ground, and a control terminal; demodulation circuitry having an input coupled to the first terminal of the adjustable capacitor; calibration circuitry having an input coupled to an output of the demodulation circuitry and an output coupled to the control terminal of the adjustable capacitor; and driver circuitry having an input coupled to the adjustable capacitor and an output coupled to an output terminal.

An example apparatus includes: an adjustable capacitor having a first terminal coupled to an input terminal, a second terminal coupled to ground, and a control terminal; demodulation circuitry having an input coupled to the first terminal of the adjustable capacitor; calibration circuitry having an input coupled to an output of the demodulation circuitry and an output coupled to the control terminal of the adjustable capacitor; and driver circuitry having an input coupled to the adjustable capacitor and an output coupled to an output terminal.

The embodiments of the present disclosure provide a signal processing circuit and a signal processing method. The signal processing circuit may include a control circuit, a switch circuit, an analog circuit, and at least two signal acquisition circuits. The at least two signal acquisition circuits may be configured to acquire at least two-channel target signals. The switch circuit may be configured to control conduction between the at least two signal acquisition circuits and the analog circuit, so that the target signal acquired by a part of the at least two signal acquisition circuits may be transmitted to the analog circuit at the same time. The analog circuit may be configured to process the received target signal. The control circuit may be configured to receive the processed target signal and sample the processed target signal.

An electronic device and method are disclosed herein. The electronic device includes a memory, an electrode module including at least four electrodes respectively connectable to a human body, and at least one processor. The processor implements the method, including: when the at least four electrodes are connected to designated connection points on the human body, obtain contact impedance values from the at least four electrodes, set electrode combination information for respectively connecting the at least four electrodes with the designated connection points, based on the obtained contact impedance values, and store the set electrode combination information in the memory, and measure an electrocardiogram (ECG) based on signals received from the electrode module while the at least four electrodes are respectively reconnected to the designated connection points, based on the stored electrode combination information.

Disclosed herein are devices and methods of using a mobile or wearable device for the acquisition and spatial filtering of ECG signals from an electrode array. One variation of a mobile or wearable device comprises an array of electrodes, one or more reference electrodes, and a controller in communication with the electrodes. In one example, the one or more reference electrodes are located on a wrist-worn device (e.g., a watch), and the electrode array is located on an accessory device that may be contacted with a fingertip. One variation of a spatial filtering method comprises identifying the electrodes that have high levels of noise and excluding the ECG signals from those electrodes from further analyses. In another variation, a method of spatial filtering comprises identifying electrodes with low levels of noise and including only the ECG signals from those electrodes in further analyses.

Disclosed herein are devices and methods of using a mobile or wearable device for the acquisition and spatial filtering of ECG signals from an electrode array. One variation of a mobile or wearable device comprises an array of electrodes, one or more reference electrodes, and a controller in communication with the electrodes. In one example, the one or more reference electrodes are located on a wrist-worn device (e.g., a watch), and the electrode array is located on an accessory device that may be contacted with a fingertip. One variation of a spatial filtering method comprises identifying the electrodes that have high levels of noise and excluding the ECG signals from those electrodes from further analyses. In another variation, a method of spatial filtering comprises identifying electrodes with low levels of noise and including only the ECG signals from those electrodes in further analyses.

Technologies and implementations for determining a respiration rate of a person from heart rate monitoring signal is disclosed.

Technologies and implementations for determining a respiration rate of a person from heart rate monitoring signal is disclosed.

Disclosed herein is a multi-electrode catheter system including an amplifier stage and an amplifier interface. The amplifier stage includes at least a first quantity of amplifier channels. The amplifier interface includes a first interface having at least the first quantity of interface channels. The amplifier channels are respectively electrically coupled to the interface channels The amplifier interface includes a second interface having a second quantity of catheter channels, the second quantity being greater than the first quantity. The catheter channels are configured to be respectively electrically coupled to corresponding electrode leads of a multi-electrode catheter. The amplifier interface includes a switching matrix electrically coupled between the first interface and the second interface. The switching matrix is configured to selectively electrically couple a selected subset of catheter channels to respective interface channels of the first quantity of interface channels.

Disclosed herein is a multi-electrode catheter system including an amplifier stage and an amplifier interface. The amplifier stage includes at least a first quantity of amplifier channels. The amplifier interface includes a first interface having at least the first quantity of interface channels. The amplifier channels are respectively electrically coupled to the interface channels The amplifier interface includes a second interface having a second quantity of catheter channels, the second quantity being greater than the first quantity. The catheter channels are configured to be respectively electrically coupled to corresponding electrode leads of a multi-electrode catheter. The amplifier interface includes a switching matrix electrically coupled between the first interface and the second interface. The switching matrix is configured to selectively electrically couple a selected subset of catheter channels to respective interface channels of the first quantity of interface channels.