Cardiac Output (CO) has traditionally been difficult, dangerous, and expensive to obtain. Surrogate measures such as pulse rate and blood pressure have therefore been used to permit an estimate of CO. MEMS technology, evolutionary computation, and time-frequency signal analysis techniques provide a technology to non-invasively estimate CO, based on precordial (chest wall) motions. The technology detects a ventricular contraction time point, and stroke volume, from chest wall motion measurements. As CO is the product of heart rate and stroke volume, these algorithms permit continuous, beat to beat CO assessment. Nontraditional Wavelet analysis can be used to extract features from chest acceleration. A learning tool is preferable to define the packets which best correlate to contraction time and stroke volume.

The invention relates to a system for challenging the pericardial space, to provide an indication of the risk of cardiac tamponade in a patient, as well as methods for diagnosis of, and determination of the extent of, a tamponade, and treating a patient in whom there is a detected cardiac tamponade.

Provided herein are methods for in-vivo assessment of intraventricular flow shear stress, risk of hemolysis, also the location and extent of blood flow stasis regions and inside a cardiac chamber or blood vessel. Also provided herein are systems for performing such methods. Also provided herein are methods for assessing hemolysis and/or thrombosis risk in patients implanted with an LVAD. LVAD positioning and/or speed may be adjusted based on the results obtained by using methods described herein, and the risk for hemolysis and/or thrombosis can be minimized.

Aspects of the technology described herein relate to techniques for guiding an operator to use an ultrasound device. Thereby, operators with little or no experience operating ultrasound devices may capture medically relevant ultrasound images and/or interpret the contents of the obtained ultrasound images. For example, some of the techniques disclosed herein may be used to identify a particular anatomical view of a subject to image with an ultrasound device, guide an operator of the ultrasound device to capture an ultrasound image of the subject that contains the particular anatomical view, and/or analyze the captured ultrasound image to identify medical information about the subject.

A system and method are provided for transthoracic echocardiogram imaging using ultrasound transducer arrays. The arrays are distinctly grouped, focused, positioned and directed within a housing comprising a solid yet flexible pad suited for placement on a portion of a patient's body.

Systems and methods are disclosed for to determining a blood supply and blood demand. One method includes receiving a patient-specific model of vessel geometry of at least a portion of a coronary artery, wherein the model is based on patient-specific image data of at least a portion of a patient's heart having myocardium; determining a coronary blood supply based on the patient-specific model; determining at least a portion of the myocardium corresponding to the coronary artery; determining a myocardial blood demand based on either a mass or a volume of the portion of the myocardium, or based on perfusion imaging of the portion of the myocardium; and determining a relationship between the coronary blood supply and the myocardial blood demand.

A method for calculating a heart parameter includes receiving a series of two-dimensional images of a heart, the series covering at least one heart cycle. The method includes calculating a volume of the heart in a first systole image based on an orientation of the heart in the first systole image and a segmentation of the heart in the first systole image, and a volume of the heart in a first diastole image based at least on an orientation of the heart in the first diastole image and a segmentation of the heart in the first diastole image; determining the heart parameter based at least on the volume of the heart in the first systole image and the volume of the heart in the first diastole image; determining a confidence score of the heart parameter; and displaying the heart parameter and the confidence score.

An embodiment of the invention provides a system for automatically deriving a parameter of a human heart from ultrasound results. A first neural network is arranged to receive a plurality of echocardiographic images and to classify the images into one of at least a two-chamber view and a four-chamber view. A second neural network is arranged to receive echocardiographic images comprising a two- or four-chamber view and to identify the endocardial border of the left ventricle (LV) for each view. End-systole and end-diastole images are then identified and a parameter such as LV volume, ejection fraction, global longitudinal strain and regional longitudinal strain is calculated.

Embodiments of the invention provide a method and system for measuring first phase ejection fraction where simultaneous measurement of the systolic pressure during systole of a subject is undertaken at the same time as measurement of the left ventricle volume (LVV). The pressure waveform is then analyzed, for example using automated signal processing techniques, to find a time T1 which corresponds to the point at which the rate of change of systolic pressure during systole begins to reduce. The left ventricle volume at this time T1 is then found from the previous measurements of LVV obtained at the same time as the systolic pressure measurement, and the first phase ejection fraction then calculated in dependence on the LVV at time T1 and the LVV at the start of systole i.e. the end diastolic volume (EDV). In particular embodiments, the first phase ejection fraction is the difference between LVV at EDV and LVV at time T1.

An ultrasound imaging system is for determining stroke volume and/or cardiac output. The imaging system may include a transducer unit for acquiring ultrasound data of a heart of a subject (or an input for receiving the acquired ultrasound data), and a controller. The controller is adapted to implement a two-step procedure, the first step being an initial assessment step, and the second being an imaging step having two possible modes depending upon the outcome of the assessment. In the initial assessment procedure, it is determined whether regurgitant ventricular flow is present. This is performed using Doppler processing techniques applied to an initial ultrasound data set. If regurgitant flow does not exist, stroke volume is determined using segmentation of 3D ultrasound image data to identify and measure the volume of the left or right ventricle at each of end systole and end-diastole, the difference between them giving a measure of stroke volume. If regurgitant flow does exist, stroke volume is determined using Doppler techniques applied to ultrasound data continuously collected throughout a cardiac cycle.