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.

An intravascular sensor device can be used to guide treatment of a diseased blood vessel in the body of a patient. In some examples, the intravascular sensor device includes a pressure sensor and an ultrasound transducer. The intravascular sensor device is used to measure a pressure within the diseased blood vessel and acquire an ultrasound image of the diseased blood vessel. The pressure may be measured during hyperemic blood flow that is caused by a pharmacologic vasodilator drug. The measured pressure can be used to calculate a fractional flow reserve value. The ultrasound image can be used to determine a physical dimension of the blood vessel, such as cross-sectional area. The fractional flow reserve value and physical dimensions of the blood vessel can be used to optimize patient treatment.

An implantable sensor system using one or more sensor implants comprised of micro-electrical mechanical system (MEMS) sensors for the accurate and continuous measurement of physiological hemodynamic signals such as diastolic and systolic blood pressure. Sensor implants are configured to be subcutaneously injected to a placement site adjacent a blood vessel. In some embodiments, sensors comprise micromachined ultrasonic transducers.

An implantable sensor system using one or more sensor implants comprised of micro-electrical mechanical system (MEMS) sensors for the accurate and continuous measurement of physiological hemodynamic signals such as diastolic and systolic blood pressure. Sensor implants are configured to be subcutaneously injected to a placement site adjacent a blood vessel. In some embodiments, sensors comprise micromachined ultrasonic transducers.

Systems and methods for non-invasively estimating right ventricular pressure are provided. Tricuspid regurgitation echocardiography Doppler signals can be acquired utilizing sonography. Digitization and interpolation of the tricuspid regurgitation Doppler signals can be utilized to estimate tricuspid regurgitation and right ventricular pressure and/or provide a metric for signal quality (quality control) as well as increase confidence in the right ventricular pressure estimates.

Systems and methods for non-invasively estimating right ventricular pressure are provided. Tricuspid regurgitation echocardiography Doppler signals can be acquired utilizing sonography. Digitization and interpolation of the tricuspid regurgitation Doppler signals can be utilized to estimate tricuspid regurgitation and right ventricular pressure and/or provide a metric for signal quality (quality control) as well as increase confidence in the right ventricular pressure estimates.

Embodiments and aspects described herein provide methods and systems for determining pressure difference across a tube arising from fluid flow within the tube, comprising: obtaining three-dimensional time dependent fluid velocity data at a plurality of points along the tube; processing the three-dimensional time dependent fluid velocity data to determine: i) a flow rate (Q) of the fluid through the tube; ii) the kinetic energy (K) of the fluid flow through the tube; iii) an advective energy rate (A) of the fluid flow through the tube; and iv) a viscous dissipation rate (V) pertaining to the fluid flow; and calculating the pressure difference in dependence on all of the flow rate (Q), kinetic energy (K), advective energy rate (A), and viscous dissipation rate (V). Further embodiments are also described.

Embodiments and aspects described herein provide methods and systems for determining pressure difference across a tube arising from fluid flow within the tube, comprising: obtaining three-dimensional time dependent fluid velocity data at a plurality of points along the tube; processing the three-dimensional time dependent fluid velocity data to determine: i) a flow rate (Q) of the fluid through the tube; ii) the kinetic energy (K) of the fluid flow through the tube; iii) an advective energy rate (A) of the fluid flow through the tube; and iv) a viscous dissipation rate (V) pertaining to the fluid flow; and calculating the pressure difference in dependence on all of the flow rate (Q), kinetic energy (K), advective energy rate (A), and viscous dissipation rate (V). Further embodiments are also described.

Embodiments include a system for determining cardiovascular information for a patient. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of the patient's heart, and create a three-dimensional model representing at least a portion of the patient's heart based on the patient-specific data. The at least one computer system may be further configured to create a physics-based model relating to a blood flow characteristic of the patient's heart and determine a fractional flow reserve within the patient's heart based on the three-dimensional model and the physics-based model.