Csem Centre Suisse D'electronique Et De Microtechnique Sa Recherche Et Developpement

Csem Sa

Csem Centre Suisse D'electronique Et De Microtechnique Sa-Recherche At Développement

Csem Centre Suisse D'electronique Et De Microtechnique Sa

Josep Sola I Caros

Josef X Brunner

Andrew Adler

Rolf Vetter

Philippe Renevey

Martin Proença

Hans-Andrea Loeliger

Christophe Verjus

Olivier Chetelat

Marc Correvon

Damien Ferrario

Mathieu Lemay

Andrea Ridolfi

Leopoldo Rossini

Damien Farrario

Stefano Rimoldi

Enrique Muntané Calvo

Leopolodo Rossini

Josef Brunner

Method for determining a blood pressure value including the steps of: providing a pulsatility signal, determining a time-related feature and a normalized amplitude-related feature on the basis of the pulsatility signal; and calculating a blood pressure value on the basis of a blood pressure function depending on the time-related feature, the normalized amplitude-related feature and function parameters.

Method, apparatus and computer program for determining a blood pressure value

A method for estimating blood pressure (BP) values comprises: measuring at a first PTT value, a second PTT value, and further PTTref values using a method comprising measuring a first arterial pressure pulse arrival time (PAT) and measuring a second PAT value; calculating a PTT value from the difference between the first PAT value and the second PAT value; processing a sequence of electrical impedance tomography (EIT) images to identify at least one region of interest (ROI); and estimating at least one of the first and second PAT value from the variation of impedance value determined from the at least one ROI. The method allows for the non-invasive and continuous determination of the PB values by using a calibration factor.

Method and apparatus for the non-invasive measurement of pulse transit times (PTT)

A method for measuring and determining a pulse arrival time (PAT) value of a user using a sensor device having a photoplethysmographic (PPG) multichannel sensor formed from a plurality of PPG sensor channels and being adapted to measure a set of PPG signals, each PPG signal being measured by one of the PPG sensor channels when the multichannel PPG sensor is in contact with the user; having: measuring the set of PPG signals; extracting a plurality of features from each of the measured PPG signals; selecting a subset from the set of PPG signals based on the extracted features; and processing the selected subset of PPG signals to determine the PAT value. The disclosed sensor and method can be embedded into a chest belt and do not need skilled supervision. They can represent a potential candidate for the implantation of PWV measurement campaigns in the ambulatory setting.

Sensor device and method for measuring and determining a pulse arrival time (PAT) value

The present disclosure concerns a method for determining a heart-lung interaction factor of a subject, comprising: measuring a heart activity-related signal comprising heart activity-related information; from the heart activity-related signal, calculating a frequency of cardiac cycle and a frequency of respiratory cycle; from the heart activity-related signal, determining a cardiac cycle energy at the frequency of cardiac cycle, determining a respiratory cycle energy at the frequency of respiratory cycle, and determining a heart-lung interaction energy at an intermodulation frequency corresponding to the difference between the frequency of respiratory cycle and the frequency of cardiac cycle, or the sum of the frequency of respiratory cycle and the frequency of cardiac cycle; and determining a heart-lung interaction factor from the ratio of the heart-lung interaction energy and one of the cardiac cycle energy and the respiratory cycle energy. The heart-lung interaction factor can be determined non-invasively.

Method for determining non-invasively a heart-lung interaction

A method and apparatus for measuring a pulse transit time (PTT) value of a subject, comprise measuring a first arterial pressure pulse arrival time (PAT) and measuring a second PAT value; calculating a PTT value from the difference between the first PAT value and the second PAT value; processing a sequence of electrical impedance tomography (EIT) images to identify at least one region of interest (ROI); and estimating at least one of the first and second PAT value from the variation of impedance value determined from the at least one ROI. The method allows for the non-invasive and continuous measurement of the PTT value and arterial blood pressures.

The present disclosure relates to a method for estimating blood constituent concentration of a user under low perfusion conditions using a spectrophotometry-based monitoring device; the method comprising: measuring a plurality of photoplethysmographic (PPG) signals; measuring a cardio-synchronous (CV) signal; detecting an instantaneous heart rate and determining a heart rate variability from the CV signal; selecting reliable projected PPG signals; estimating a value of said blood constituent concentration from the magnitude of said reliable projected PPG signals. The disclosed method requires diminished computational load compared to conventional methods based on frequency domain approach as FFT or DCT. The disclosure also pertains to a monitoring device for estimating blood constituent concentration in tissue under low perfusion of a user.

Monitoring device and method for estimating blood constituent concentration for tissues with low perfusion

Method and apparatus for estimating an arrival time (PAT) value of a subject in an automatic and unsupervised fashion from a sequence of electrical impedance tomography (EIT) images. The method comprises: providing an EIT imaging device adapted to record impedance signal distribution within a measurement region of the subject; measuring a sequence of temporally discrete EIT images during a predetermined measuring time period in the measurement region using the EIT imaging device, each EIT image comprising one or a plurality of EIT pixel subsets, each of said one or a plurality of EIT pixel subset representing an impedance value; generating one or a plurality of time series, each of said one or a plurality of time series representing a variation of the impedance value of the sequence of EIT images; and estimating the PAT value from each of said one or a plurality of time series.

Method and apparatus for estimating a pulse arrival time value

The invention provides a method and an apparatus for a continuous non-invasive and non-obstrusive monitoring of blood pressure. The method comprises the steps of: a) measuring the value (PW) of a Pulse Wave parameter, equal to or derived from the Pulse Wave Velocity (PWV) parameter of a segment of the arterial tree of a subject, b) measuring the value (CO) of the Cardiac Output parameter, and c) determining the value (BP) of the blood pressure that satisfies where PW is the value measured in step a),(CO, BP) corresponds to a predicted value of the Pulse Wave parameter computed according to a model of the segment of the arterial tree, the value (CO) of the Cardiac Output parameter measured in step b) and an hypothesized value of the blood pressure.

Method and apparatus for a continuous non-invasive and non-obstrusive monitoring of blood pressure

A follower amplifier with power supply biased by a controlled voltage source such that the power supply potentials are, for the frequencies of interest, as close as possible to the potential of the follower output. There is proposed a front-end electronic circuit for biopotential and impedance measurements with outstanding performances (very high input impedance and gain very close to unity). Preferably, the explicit guard electrode and the explicit electronic unit at the belt are no longer necessary; all electronics is embedded in units placed directly at the measurement sites. Moreover, the proposed front-end electronic circuit allows a drastic simplification of the cabling and connectors since all units are connected to only one wire (the theoretical minimum) for potential reference and current return. Preferably, this wire does not even require an electrical isolation and can be easily embedded in the textile of a shirt, in a garment, mesh, belt, etc.

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Neuchâtel, Switzerland

Josep Sola I Caros