A fluid circuit of a blood pressure measurement device includes a first cuff connected to a secondary side of a pump that supplies a fluid to a secondary side, a second cuff connected to a secondary side of the first cuff, a first valve provided between the first cuff and the second cuff, the first valve that closes when a differential pressure between the first cuff and the second cuff reaches a predetermined differential pressure, and a fluid resistor provided between the first valve and the second cuff.

A method for estimating blood pressure using a blood flow occlusion system applied to an artery includes receiving from a first sensor a sensed signal; processing at a processor the sensed signal to detect beats in a pulsatile signal; determining validity of the detected beats; storing the detected beats and data associated with the detected beats in the sensed signal as the pressure applied to the artery by the blood flow occlusion system deflates towards a level below a nominal level; determining baseline beat characteristics; evaluating the stored beats and associated data to detect change in beat characteristics as compared to the baseline beat characteristics; selecting a beat before the detected change in the beat characteristic as the last beat indicating the onset of the diastolic blood pressure for the artery; determining a value of the applied pressure at the last beat as the diastolic blood pressure for the artery.

A method for estimating blood pressure using a blood flow occlusion system applied to an artery includes receiving from a first sensor a sensed signal; processing at a processor the sensed signal to detect beats in a pulsatile signal; determining validity of the detected beats; storing the detected beats and data associated with the detected beats in the sensed signal as the pressure applied to the artery by the blood flow occlusion system deflates towards a level below a nominal level; determining baseline beat characteristics; evaluating the stored beats and associated data to detect change in beat characteristics as compared to the baseline beat characteristics; selecting a beat before the detected change in the beat characteristic as the last beat indicating the onset of the diastolic blood pressure for the artery; determining a value of the applied pressure at the last beat as the diastolic blood pressure for the artery.

Systems and methods for detecting data acquisition conditions using color-based penalties can include a computing device obtaining a sequence of images acquired by a photodetector. The computing device can determine, for each pixel position of a plurality of pixel positions associated with the sequence of images, a respective penalty score indicative of a similarity between a color value of a pixel of the pixel position and a desired color value. The desired color value can represent a color property of light emitted from body parts of users when placed opposite to the photodetector. The computing device can determine, using penalty scores of the plurality of pixel positions, a relative position of a body part of a user with respect to a desired position.

Systems and methods for blood pressure estimation using smart offset calibration can include a computing device associating a calibration photoplethysmographic (PPG) signal generated from a first sequence of image frames obtained from a photodetector of the computing device with one or more measurement values generated by a blood pressure measurement device different from the computing device. The computing device can obtain a recording PPG signal generated from a second sequence of image frames obtained from the photodetector, and identify a calibration model from a plurality of blood pressure calibration models based on the calibration PPG signal and the recording PPG signal. The computing device can generate a calibrated blood pressure value using the recording PPG signal, features associated with the calibration PPG signal and the identified calibration model.

A measurement system and method of manufacture can include: a pressure resistant structure; a pressure inducer coupled to the pressure resistant structure, the pressure inducer having an engaged configuration, the engaged configuration of the pressure inducer increasing pressure exerted on a portion of a user in contact with the pressure resistant structure; a light source coupled to the pressure resistant structure; an optical sensor coupled to the pressure resistant structure and configured to detect a signal from the light source; a pressure sensor coupled to the pressure resistant structure, the pressure sensor configured to detect the pressure exerted on the portion of the user in contact with the pressure inducer; and a processor coupled to the optical sensor and the pressure sensor, the processor configured to correlate volumetric data from the optical sensor with pressure data from the pressure sensor and to provide a blood pressure measurement.

A blood pressure measurement method and apparatus, and a wearable device are provided. The blood pressure measurement method includes: detecting a change of a user from a first state to a second state; starting measurement and inflating an airbag (160) to a preset pressure value at a preset rate if determining that the user has changed from the first state to the second state; obtaining first duration of an inflation process; determining a correction value based on the first duration; and after the measurement ends, obtaining a measurement value of a blood pressure, and correcting the measurement value based on the correction value, to obtain a final blood pressure value of the user. The blood pressure measurement method provides an early-morning blood pressure measurement manner in which the early-morning blood pressure can be automatically and accurately measured when the user is insensitive, thereby simplifying user’s operations, and improving user experience.

A blood pressure measurement method and apparatus, and a wearable device are provided. The blood pressure measurement method includes: detecting a change of a user from a first state to a second state; starting measurement and inflating an airbag (160) to a preset pressure value at a preset rate if determining that the user has changed from the first state to the second state; obtaining first duration of an inflation process; determining a correction value based on the first duration; and after the measurement ends, obtaining a measurement value of a blood pressure, and correcting the measurement value based on the correction value, to obtain a final blood pressure value of the user. The blood pressure measurement method provides an early-morning blood pressure measurement manner in which the early-morning blood pressure can be automatically and accurately measured when the user is insensitive, thereby simplifying user’s operations, and improving user experience.

The blood pressure measuring device (1) is designed as a photoplethysmographic measuring system which functions according to the “vascular unloading technique”. Metrological components and a pressure generating and pressure control system are accommodated in the base part (3). The fitted cuff part (2) has an ergonomic palm support (4), two finger supports (6) divided from one another by a web (5), and also a receiving part (7) which comprises two receiving tubes (9) for fingers. The cuff part (2) projects beyond the base part (3), both towards the front and also towards the rear, and covers the base part (3) almost completely, i.e. by more than 90%. The lateral attachment of the cable (8) facing in the direction of the forearm has the advantage that the cable can be guided along the patient's arm, the wrist does not rub against the cable (8), and in particular the carpal tunnel is also protected.

Disclosed herein are in vivo non-invasive methods and devices for the measurement of the hemodynamic parameters, such as blood pressure, cardiac output, stroke volume and vascular tone, of a subject, and the mechanical anelastic in vivo properties of the subject's arterial blood vessels. An exemplary method requires obtaining the peripheral pulse volume waveform (PVW), the peripheral pulse pressure waveform (PPW), and the peripheral pulse velocity waveform (PUW) from the same artery; calculating the time phase shift between the PPW and PVW, and the plot of pulse pressure versus pulse volume; and determining the blood pressures and power law components of the anelastic model from the waveforms PPW and PVW, the cardiac output from the waveforms PPW and PUW, and the quality factor of the artery based upon the calculations. The disclosed methods and devices can be used to diagnose and treat cardiovascular disease in a subject in need thereof.