Abstract: A light-to-digital converter (2) comprises a light-to-current converter (10); a current integrator (4) with an integrator output (30) resettable to a baseline level; and a counter (18) with a digital output (26), wherein the light-to-current converter (10) is switchably connectable as a positive integration input to the current integrator (4), for, during a light-collecting phase (404-406), integrating a current from the light-to-current converter (10), the integrator output (30) starting from the baseline value and ending at a value to be digitized; a reference current source (14) is switchably connectable as a negative integration input to the current integrator (4), for, during a counting phase (406-408) subsequent to the light-collecting phase (404-406), integrating a reference current from the reference current source (14), the integrator output (30) starting from the value to be digitized and ending at the baseline value, the time spent integrating the reference current corresponding to the value to be

Abstract: An analog-to-digital converter, ADC, circuitry, comprises: an integrator connected to a capacitor, the integrator being configured to switch between integrating an analog input signal for ramping an integrator output and integrating a reference input signal for returning integrator output towards a threshold; a comparator for comparing integrator output to the threshold; and a timer for determining a time duration during which the reference input signal is integrated, the time duration providing a digital representation of an analog input signal value; the ADC circuitry further comprising a feedforward noise shaping loop configured to store a quantization error signal based on digitizing a first sample, the comparator being configured to receive a feedforward noise shaping signal for changing the threshold for digitizing a later sample of the analog input signal following the first sample.

Abstract: The current disclosure relates to methods and devices for measuring concentrations of analytes in the gastrointestinal tract of a subject by orally administering a smart pill to the subject, the smart pill comprising two or more sensors, a reference electrode, a power source, a communication interface and electronic circuits, each sensor being able to measure an analyte in the gastrointestinal tract of said subject, wherein the two or more sensors measure different analytes, measuring a concentration of two or more analytes using the two or more sensors, wherein one of the sensors is a pH sensor for measuring hydrogen ions, and wherein the pH sensor is able to locate the smart pill in the gastrointestinal tract by correlating the measured hydrogen ion concentration to a location in the gastrointestinal tract, and transmitting, using the communication interface, the measured concentrations from the two or more sensors to a base device located outside of the body of the subject.

Abstract: A method of generating a model for generating a synthetic electrocardiography (ECG) signal comprises: receiving subject-specific training data for machine learning, said training data comprising a photoplethysmography (PPG) signal acquired from the subject and an ECG signal acquired from the subject, wherein the ECG signal provides a ground truth of the subject for associating the ECG signal with the PPG signal; using associated pairs of a time-series of the PPG signal and a corresponding time-series of the ECG signal as input to a deep neural network, DNN; and determining, through the DNN, a subject-specific model relating the PPG signal of the subject to the ECG signal of the subject for converting the PPG signal to a synthetic ECG signal using the subject-specific model.

Abstract: A measurement unit for measuring a bio-impedance of a body, the measurement unit comprising a current generator circuit, a readout circuit, and a baseline cancellation current circuit, wherein the current generator circuit is configured to amplify a reference current to form a measurement current to be driven through a body to generate a measurement voltage representing the bio-impedance; wherein the readout circuit comprises a Instrumentation amplifier (IA) which has a transconductance stage and a transimpedance stage, wherein the IA is configured to: produce a first current in the transconductance stage, the first current being proportional to the measurement voltage, receive a second current from the baseline cancellation current circuit, produce an output voltage in the transimpedance stage, the output voltage being proportional to a difference between the first current and the second current and representative of the measured bio-impedance; wherein the baseline cancellation current circuit is confi

Abstract: An analog-to-digital converter, ADC, circuitry, comprises: an integrator connected to a capacitor, the integrator being configured to switch between integrating an analog input signal for ramping an integrator output and integrating a reference input signal for returning integrator output towards a threshold; a comparator for comparing integrator output to the threshold; and a timer for determining a time duration during which the reference input signal is integrated, the time duration providing a digital representation of an analog input signal value; the ADC circuitry further comprising a feedforward noise shaping loop configured to store a quantization error signal based on digitizing a first sample, the comparator being configured to receive a feedforward noise shaping signal for changing the threshold for digitizing a later sample of the analog input signal following the first sample.

Abstract: A device for read-out of a photoplethysmography (PPG) signal comprises: a photodiode, which is configured to detect a PPG signal, the photodiode comprising a first and a second terminal; and a read-out circuitry for reading out the PPG signal, wherein an input stage is connected to receive a first and a second input signal from the terminals and a DC bias voltage, and wherein the input stage is configured for current sensing to provide a fully differential amplification of the input signals to a first and a second current signal, and wherein an output stage is configured to receive the current signals, wherein the current signals comprise an AC and a DC component of the PPG signal, and wherein the output stage is configured to generate a differential output voltage through a gain component.

Abstract: The disclosure includes a biosignal monitoring system for reducing a motion artifact from a biopotential electrical signal input, including a signal processing module, a motion artifact extraction module, and a subtraction module. The motion artifact extraction module and the signal processing module receive the biopotential electrical signal input and the subtraction module receives an extracted signal from an output of the motion artifact extraction module and a biopotential electrical signal from an output of the signal processing module. The subtraction module subtracts the extracted signal from the biopotential electrical signal.

Abstract: A light-to-digital converter (2) comprises a light-to-current converter (10); a current integrator (4) with an integrator output (30) resettable to a baseline level; and a counter (18) with a digital output (26), wherein the light-to-current converter (10) is switchably connectable as a positive integration input to the current integrator (4), for, during a light-collecting phase (404-406), integrating a current from the light-to-current converter (10), the integrator output (30) starting from the baseline value and ending at a value to be digitized; a reference current source (14) is switchably connectable as a negative integration input to the current integrator (4), for, during a counting phase (406-408) subsequent to the light-collecting phase (404-406), integrating a reference current from the reference current source (14), the integrator output (30) starting from the value to be digitized and ending at the baseline value, the time spent integrating the reference current corresponding to the value to be

Abstract: A measurement unit for measuring a bio-impedance of a body, the measurement unit comprising a current generator circuit, a readout circuit, and a baseline cancellation current circuit, wherein the current generator circuit is configured to amplify a reference current to form a measurement current to be driven through a body to generate a measurement voltage representing the bio-impedance; wherein the readout circuit comprises a Instrumentation amplifier (IA) which has a transconductance stage and a transimpedance stage, wherein the IA is configured to: produce a first current in the transconductance stage, the first current being proportional to the measurement voltage, receive a second current from the baseline cancellation current circuit, produce an output voltage in the transimpedance stage, the output voltage being proportional to a difference between the first current and the second current and representative of the measured bio-impedance; wherein the baseline cancellation current circuit is confi

Abstract: A method of generating a model for generating a synthetic electrocardiography (ECG) signal comprises: receiving subject-specific training data for machine learning, said training data comprising a photoplethysmography (PPG) signal acquired from the subject and an ECG signal acquired from the subject, wherein the ECG signal provides a ground truth of the subject for associating the ECG signal with the PPG signal; using associated pairs of a time-series of the PPG signal and a corresponding time-series of the ECG signal as input to a deep neural network, DNN; and determining, through the DNN, a subject-specific model relating the PPG signal of the subject to the ECG signal of the subject for converting the PPG signal to a synthetic ECG signal using the subject-specific model.

Abstract: A device for read-out of a photoplethysmography (PPG) signal comprises: a photodiode, which is configured to detect a PPG signal, the photodiode comprising a first and a second terminal; and a read-out circuitry for reading out the PPG signal, wherein an input stage is connected to receive a first and a second input signal from the terminals and a DC bias voltage, and wherein the input stage is configured for current sensing to provide a fully differential amplification of the input signals to a first and a second current signal, and wherein an output stage is configured to receive the current signals, wherein the current signals comprise an AC and a DC component of the PPG signal, and wherein the output stage is configured to generate a differential output voltage through a gain component.

Abstract: A method of generating a model for heart rate estimation from a photoplethysmography, PPG, signal of a subject comprises: receiving (102) subject-specific training data for machine learning, said training data comprising a PPG signal from the subject and a heart rate indicating signal from the subject, wherein the heart rate indicating signal provides a ground truth of heart rates of the subject for associating a heart rate with a time period of the PPG signal; using (104) associated pairs of a heart rate and a complete dataset of a time-series of a PPG signal over a time period as input to a deep neural network, DNN; and determining (106; 312), through the DNN, a subject-specific model relating the PPG signal of the subject to the heart rate of the subject.

Abstract: A variable capacitor circuit is disclosed. The variable capacitor circuit includes a plurality of MOS capacitors, each MOS capacitor being implemented by a MOS transistor with the gate terminal connected to a first voltage signal and with the drain terminal shorted with the source terminal and connected to a second voltage signal, said MOS capacitors being connected in parallel through the gate terminal connected to the first voltage signal, and being operated in a cut-off region in which the equivalent capacitance of each MOS capacitor remains substantially constant for variations of the first voltage signal.

Abstract: A biopotential signal acquisition system including an analog readout unit configured to receive an analog biopotential signal, which may be acquired from at least one electrode attached to a body; and to extract an analog measured biopotential signal and an analog reference signal. The system also includes an ADC unit configured to provide a digital version of the analog measured biopotential signal and the analog reference signal, a digital filter unit configured to calculate a digital motion artifact estimate based on the digital version of the measured biopotential signal and the reference signal. The system further comprises a reference signal processing unit configured to convert the reference signal into a new reference signal being provided to the digital filter unit based on the correlation between the measured biopotential signal and the reference signal.

Abstract: A biopotential signal acquisition system comprising an analog readout unit configured to receive an analog biopotential signal and to extract an analog measured biopotential signal and an analog reference signal, and an ADC unit configured to provide a digital version of the analog measured biopotential signal and the analog reference signal. The system also includes a first digital filter unit comprising a cascaded integrator-comb filter configured to provide a first digital filtered version of the digital measured biopotential signal and the reference signal, and a second digital filter unit configured to calculate a digital motion artifact estimate based on the first digital filtered version signals.

Abstract: An instrumentation amplifier includes a first amplifier having one input connected to a first input of the instrumentation amplifier, a second amplifier having one input connected to a second input of the instrumentation amplifier, and a feedback network. The feedback network including an active filter having a first low pass filter characteristic with a first cut-off frequency in respect of differential mode signals at the first and second inputs of the instrumentation amplifier, and a second low pass filter characteristic with a second cut-off frequency in respect of common mode signals at the first and second inputs of the instrumentation amplifier. The disclosure also relates to a device for acquiring biopotential signals and a signal amplification method.

Abstract: A biopotential signal acquisition system comprising an analogue readout unit configured to receive an analogue biopotential signal and to extract an analogue measured biopotential signal and an analogue reference signal, and an ADC unit configured to provide a digital version of the analogue measured biopotential signal and the analogue reference signal. The system also includes a first digital filter unit comprising a cascaded integrator-comb filter configured to provide a first digital filtered version of the digital measured biopotential signal and the reference signal, and a second digital filter unit configured to calculate a digital motion artifact estimate based on the first digital filtered version signals.

Abstract: A biopotential signal acquisition system including an analogue readout unit configured to receive an analogue biopotential signal, which may be acquired from at least one electrode attached to a body; and to extract an analogue measured biopotential signal and an analogue reference signal. The system also includes an ADC unit configured to provide a digital version of the analogue measured biopotential signal and the analogue reference signal, a digital filter unit configured to calculate a digital motion artifact estimate based on the digital version of the measured biopotential signal and the reference signal. The system further comprises a reference signal processing unit configured to convert the reference signal into a new reference signal being provided to the digital filter unit based on the correlation between the measured biopotential signal and the reference signal.

Abstract: An instrumentation amplifier includes a first amplifier having one input connected to a first input of the instrumentation amplifier, a second amplifier having one input connected to a second input of the instrumentation amplifier, and a feedback network. The feedback network including an active filter having a first low pass filter characteristic with a first cut-off frequency in respect of differential mode signals at the first and second inputs of the instrumentation amplifier, and a second low pass filter characteristic with a second cut-off frequency in respect of common mode signals at the first and second inputs of the instrumentation amplifier. The disclosure also relates to a device for acquiring biopotential signals and a signal amplification method.