Abstract: A biometric measuring device for obtaining biometric measurements on a limb or digit, such as a finger. The biometric measuring device may include a rollable sleeve that is rollable along a longitudinal axis of the limb or digit and multiple biometric sensors attached to the rollable sleeve such that the biometric sensors are positioned on the rollable sleeve to enable the sleeve to be rolled.

Abstract: An optical sensor and a method of using the optical sensor in an optical measuring device that measures cardiovascular properties and compensates for movement artifacts by directing a sheet of light towards an artery. The optical sensor may include one or more light sources, one or more transmit light guides coupled to the one or more light sources and configured to direct light from the one or more light sources as a sheet of light towards an artery, such that the cross-sectional profile of the sheet of light may have a length transverse to a longitudinal direction of the artery that is longer than the diameter of the artery. The optical sensor may include one or more light detectors configured to receive backscattered light and generate an output based on the received backscattered light that is a reflection of the sheet of light from the artery and surrounding tissues.

Abstract: Various embodiments identify valid arterial pulses of a subject. The method may include accessing one or more measured pulses from one or more arterial measurement sensors. The processor may identify one or more valid pulses from the one or more measured pulses based on a comparison of one or more pulse characteristics of the one or more measured pulses to one or more reference pulses. The one or more pulse characteristics are determined based on the one or more measured pulses and a wavelet transform. The wavelet transform is determined based on the one or more reference pulses.

Abstract: One aspect of the subject matter described in this disclosure can be implemented in a device capable of estimating blood pressure. The device includes two or more sensors capable of performing measurements along an artery. The device also includes at least one processing unit coupled with the two or more sensors. The processing unit is capable of accessing one or more parameters including a stress-strain parameter based on a hydrostatic pressure calibration. The processing unit also is capable of determining a pulse transit time (PTT) based on the measurements, and determining a pulse wave velocity (PWV) based on the PTT. The processing unit is further capable of determining a blood pressure based on the PWV and the stress-strain parameter.

Abstract: An system for calculating blood pressure may include a sensor system and a control system. The control system may be capable of controlling one or more sensors of the sensor system to take at least two measurements, the at least two measurements including at least one measurement taken at each of two or more different measurement elevations of a subject's limb. In some examples, the control system may be capable of determining a blood flow difference based on the at least two measurements, of determining a hydrostatic pressure difference based on the two or more different elevations of the at least two measurements and of estimating a blood pressure based on one or more values of blood flow, the hydrostatic pressure difference and the blood flow difference.

Abstract: An ultrasound cardiovascular measuring device may include an ultrasonic sensor system having an ultrasound transmitter layer configured to generate ultrasonic plane waves and a focusing layer that includes one or more lenses. One or more of the lenses may be configured to generate output signals corresponding to detected ultrasonic reflections. The measuring device may include a control system capable of processing the output signals to calculate values corresponding to one or more cardiovascular properties.

Abstract: The present invention relates to a method and a system for carrying out the method of determining at least one cardiovascular quantity of a mammal. The method comprises (i) selecting a measuring site of a vessel; (ii) determining or estimating a mean diameter of the vessel at the measuring site; (iii) determining a pulse wave velocity and/or another elasticity related quantity of the vessel at the measuring site; (iv) determining a distension of the vessel at the measuring site; and (v) calculating the at least one cardiovascular quantity from the determined mean diameter, elasticity related quantity and distension of the vessel at the measuring site.

Abstract: This disclosure provides systems, methods and apparatus for performing signal processing in impedance sensing applications, and more specifically, for recovering data from an amplitude-modulated signal. In one aspect, a device includes a sensing circuit operable to sense an amplitude-modulated signal having a carrier frequency. The device also includes a mixer operable to mix the amplitude-modulated signal with a mixing signal having a mixing frequency to provide a frequency-downshifted signal having an intermediate frequency less than the carrier frequency. The device also includes a filter operable to filter the frequency-downshifted signal to provide a filtered signal. The device further includes a sampler operable to undersample the filtered signal at an undersampling frequency to provide a digital signal, the digital signal being representative of a modulating signal.

Abstract: Systems, methods, and devices of various embodiments enable measurement of blood pressure from an artery. The various embodiments may measure, using a non-interfering arterial measurement sensor, a first change in distension of the artery at a measurement location without interference to an arterial pressure at the measurement location during a series of pulses. A first pulse rate and estimated pulse pressures may be determined from the first change in distension. A coefficient may be determined fitting an exponentially decaying function representing an exponential decay of a portion of a diastolic phase to select ones of the estimated pulse pressures corresponding to the diastolic phase. An absolute blood pressure may be determined by applying the coefficient to a select mathematical model expressing a first relationship between the first change in distension of the artery and the pulse pressure in the artery at the measurement location.

Abstract: Systems, methods, and devices of the various embodiments enable continuous non-invasive monitoring of blood pressure with a minimum of interference. The various embodiments may provide a method for adaptation for the calibration for continuous measurements of blood pressure, wherein the measured quantity may be related to an arterial lumen or arterial cross sectional area comprising calibrating the conversion for incremental variations of arterial properties and absolute value adaptation by exploitation of the exponential decay during the diastole. In various embodiments, continuous calibration of a non-interfering blood pressure measurement device may be initiated based on a change in mean arterial pressure being greater than a threshold value, such as a pressure value associated with an actual measured distension of a patient's artery.

Abstract: Methods, devices, and systems for determining an estimated pulse wave velocity of an artery of a subject. Embodiment methods may include applying a series of counter pressures, measuring a first parameter related to pulse wave velocity, estimating a second parameter in a model, and determining the estimated pulse wave velocity. The counter pressures may be applied at a set location on the subject over the artery with a pressure device. Each of the counter pressures may be different from one another, applied at the set location, and between zero and a diastolic pressure of the subject. The first parameter may be measured when each of the series of counter pressures is applied. The model may establish a relationship of the first parameter measured to each of the series of counter pressures. The estimated pulse wave velocity may be determined based on the second parameter estimated in the model.

Abstract: The present invention relates to a method and a system for carrying out the method of determining at least one cardiovascular quantity of a mammal. The method comprises (i) selecting a measuring site of a vessel; (ii) determining or estimating a mean diameter of the vessel at the measuring site; (iii) determining a pulse wave velocity and/or another elasticity related quantity of the vessel at the measuring site; (iv) determining a distension of the vessel at the measuring site; and (v) calculating the at least one cardiovascular quantity from the determined mean diameter, elasticity related quantity and distension of the vessel at the measuring site.