An example method includes detecting, via a sensor, vibrations originating from a vein of a subject and obtaining an intensity spectrum of the detected vibrations over a range of frequencies. The method further includes using the obtained intensity spectrum to determine a metric selected from a group that includes: a pulmonary capillary wedge pressure (PCWP), a mean pulmonary arterial pressure, a pulmonary artery diastolic pressure, a left ventricular end diastolic pressure, a left ventricular end diastolic volume, a cardiac output, total blood volume, and a volume responsiveness of the subject. An example computing device and an example non-transitory computer readable medium that are related to the method are disclosed as well.

The present application discloses a pulse simulator. The pulse simulator includes a pulse simulation assembly configured to receive a pulse simulation signal and simulate a pulse of a living body based on the pulse simulation signal. The pulse simulation assembly includes a mounting plate; a plurality of retractable bolts on the mounting plate; and a plurality of drivers coupled to the plurality of retractable bolts. Each of the plurality of retractable bolts has a first end attached to the mounting plate and a second end opposite to the first end. Each of the plurality of drivers is configured to drive one of the plurality of retractable bolts to retract and extend between a first position and a second position thereby adjusting a distance between a simulated skin portion and the mounting plate in a region corresponding to the one of the plurality of retractable bolts.

A digital pressure sensor includes a substrate, a pressure sensing structure configured for measuring a pressure of an object to be measured, a signal processing chip configured for receiving a sensing signal of the pressure sensing structure, and a rubber cover having an opening through which the pressure is sensed. The pressure sensing structure and the signal processing chip are mounted on the substrate. The signal processing chip has an analog-digital conversion module that converts the sensing signal output by the pressure sensing structure into a digital signal and outputs the digital signal. The signal processing chip is electrically connected to the substrate. The substrate and the rubber cover are connected to each other and form a mounting cavity for holding the pressure sensing structure and the signal processing chip.

Devices described herein can be used to directly measure left atrial pressure. For example, this document describes multiple embodiments of catheter-based, trans-esophageal tonometry devices that are used to directly measure left atrial pressure in a non-invasive manner.

Some implementations of the disclosure describe a blood pressure measurement apparatus and method that enable continuous, non-invasive blood pressure measurement using sound and ultrasound transducers. In one implementation, a blood pressure measurement device includes: a first transducer configured to emit multiple soundwaves having multiple frequencies, the soundwaves configured to cause a blood vessel of a subject to vibrate; a second transducer configured to capture one or more ultrasound images of the blood vessel; and a processing device configured to: determine, based on the one or more ultrasound images, a wall thickness, a radius, and a resonant frequency of the blood vessel; and calculate, based on the wall thickness, the radius, and the resonant frequency, a blood pressure of the subject.

An arrangement (100) and a device (101) for determining pulse transit time comprise an accelerometer (102) and a pulse wave sensor (103) for sensing a pulse wave. The accelerometer (102) determines a cardiac systole, and the pulse wave sensor (103) determines the pulse wave induced by said cardiac systole ejection. A first trigger signal is determined at the moment of said determined cardiac systole, and a second trigger signal at the moment of said determined pulse wave. The pulse transit time is then determined as a time difference between said first and second trigger signals.

A system for determining a pulse wave velocity comprises a body lumen insertable device with an actuator for providing a pulse in the vicinity of a vessel wall and a sensor for sensing arrival of the pulse. A pulse wave velocity is obtained from the time difference between actuation of the actuator and sensing of the pulse. This system is used to create an artificial pulse which is transmitted along a vessel by a known distance before detection by a sensor.

Provided here are methods of detecting compromised cerebrovascular reactivity in a subject and treating such subject. The method includes acquiring transcranial Doppler signals and cardiac measurements from the subject following a breath-hold maneuver and recording a test set of CBFV measurements. A breath-hold acceleration index is calculated based on a linear regression correlation of temporal variations of the mean velocity across all cardiac cycles during the breath-hold maneuver. The presence of compromised cerebrovascular reactivity in the subject is detected in response to variations in the breath-hold acceleration index of the subject as compared to a healthy individual performing breath-hold maneuver under similar conditions. If the subject has compromised cerebrovascular reactivity, a therapeutically effective compound is administered to the subject along with provision of behavioral modification regimen.

The present invention provides a technique for continuous measurement of blood pressure based on pulse transit time and which does not require any external calibration. This technique, referred to herein as the Composite Method, is carried out with a body-worn monitor that measures blood pressure and other vital signs, and wirelessly transmits them to a remote monitor. A network of body-worn sensors, typically placed on the patient's right arm and chest, connect to the body-worn monitor and measure time-dependent ECG, PPG, accelerometer, and pressure waveforms. The disposable sensors can include a cuff that features an inflatable bladder coupled to a pressure sensor, three or more electrical sensors (e.g. electrodes), three or more accelerometers, a temperature sensor, and an optical sensor (e.g., a light source and photodiode) attached to the patient's thumb.

Examples of portable electronic devices including a piezo actuated vibrator for providing tactile feedback to the user are described. Portable electronic devices according to the present disclosure may include tactile feedback devices, which may be driven by a piezoelectric actuator/vibrator that is operatively coupled to or embedded into the housing of a portable electronic device. In some examples, the housing of the electronic device itself can be made of piezoelectric ceramic material. The piezoelectric element may be coupled to the housing of the product to cause the housing to deflect and/or vibrate. In some examples, the housing of the portable electronic device, which may be a portable media player device, may be configured for placement directly or indirectly in contact with the user's skin such that vibrations of the housing may be felt directly (without audible feedback) by the user.