Title :
Computerized system for the assessment of left ventricular function based on ventricular dimensions and intracardiac pressure measurements
Author :
Hnatkova, K. ; Varma, C. ; Waktare, Jep ; Brecker, SJ ; Malik, M.
Author_Institution :
St. George´´s Hospital Med. Sch., London, UK
fDate :
6/21/1905 12:00:00 AM
Abstract :
A computer system to calculate left ventricular (LV) cavity dimension (LVD) from M-mode echocardiography, and LV pressure (LVP) from micromanometer tipped catheter simultaneously was developed. An operator marked the LV posterior wall and septal endocardial borders, the LVP tracing, and reference points on a scanned bitmap image of the echocardiogram and LVP trace. Individual lines were automatically recognized in the bitmap, values at individual points were recalculated and missing data interpolated. The time functions of LVD and LVP were constructed. Signal averaging of cardiac cycles was used to increase the resolution of both functions. Characteristics of LVP and LVD functions were calculated, such as pressure dimension loops, their cycle efficiency, dLVD/dt, dLVP/dt, etc. In total, 25 bitmap echocardiographic images were tested. 8% images required readjustment of operator marking. Of 92% processed images, reliable values and morphologies of cycle efficiency loops were obtained in 83% of tracings. Mean value of 67.7±13.2% of cycle efficiency was noted. Thus, this system offers a possibility to derive the LV cycle efficiency as well as other LV functional parameters precisely and with a restricted manual involvement
Keywords :
blood pressure measurement; echocardiography; medical image processing; spatial variables measurement; M-mode echocardiography; bitmap echocardiographic images; cardiac cycles; computer system; cycle efficiency loops; echocardiogram; individual lines; individual points; intracardiac pressure measurements; left ventricular cavity dimension; left ventricular cycle efficiency; left ventricular function; left ventricular posterior wall; left ventricular pressure trace; micromanometer tipped catheter; missing data; operator marking; pressure dimension loops; processed images; reference points; restricted manual involvement; scanned bitmap image; septal endocardial borders; signal averaging; time functions; Biomedical imaging; Catheters; Color; Echocardiography; Hospitals; Morphology; Motion estimation; Pressure measurement; Signal resolution; Testing;
Conference_Titel :
Computers in Cardiology, 1999
Conference_Location :
Hannover
Print_ISBN :
0-7803-5614-4
DOI :
10.1109/CIC.1999.825988