Y.M. Belozerov, D.A. Prilutski, S.V.Selishchev
Moscow Institute of Electronic Technology
Clinic of Cardiology of Moscow Institute for Pediatry & Surgery
P.O. Box K-498, 103498, Moscow, Russia, E-mail: sersel@redline.ru
Abstract: Computer system for clinical echocardiography, including methods of visualization of the ultrasonic images of heart, measurement of parameters of heart and also enumeration of supported medical techniques of processing echocardiogram.
With progress in the field of personal computers there was an opportunity of creating on their base relatively cheap automated working places for processing of the ultrasonic images of heart, measurement of parameters of heart work and automation of echocardiographic conclusions statement. Such systems permit not only to raise a general qualitative level in diagnostics, but also to supply in the full measure telecommunication opportunities, necessary for an operative consultation on difficult cases of heart diseases and also to be useful at the creation of various archives and atlases of the ultrasonic images. The results of work are oriented for using first of all in clinical and within the limits of the possible in experimental echocardiography.
The videoimage input in a personal computer is executed by means of FrameGraber type device. Videoimage is received from the ultrasonic scanner through the output for a connection of the additional monitor, videorecorder or videoprinter (Figure 1). In addition an electrocardiographic channel with a scanner can be entered in the computer.
Videosequences are inputed with speed from 1 to 35 frames per second and with the sanction 240x206 elements or a separate frame with the sanction 480x412 elements. The image is represented by 256 gradations of grey. All inputed images can be saved without loss of quality on magnetic or optical carriers in a format of multiframe CompuServe GIF89a [1] image with blocks of expansion, describing parameters of synchronization, as well as to be outputed on PCL [2] or PostScript [3] printers.
The computer processing permits to observe simultaneously up to four dynamic videoimages in the real time or at frozen (frame by frame) review [4]. The synchronization of videoimages is semi–automatically provided by mechanical systol and diastol or automatically by the additional ECG channel. It makes possible to hold the research by the method of stress echocardiography on the basis of any of load tests with the evident formation of a research protocol [5,6,7].
A marking out of myocardium moving parts [5] by a colour palette is carried out in a real time. Various thresholds for marking out by a colour of heart moving structures are established, as well as a dynamic range is set up, which colour palette is imposed on.
A reception simultaneously up to 3 arbitrary 1D sections by the time (similar to the M-mode) is stipulated for 2D videosequences (B-mode). The sections are interactively set and can be as linear as nonlinear. The directions of section 1D conformity to the current frame at the 2D image is provided at visualization and, on the contrary, element on the satisfied 2D frame is marked at the directions on the element of section 1D.
The segmental analysis of various image elements, changed from systol to diastol, is carried out. Segmental ejection fractions are calculated with the indication of segments, possessing contractility pathology, for left and right ventricles [5,6].
The measurement of temporary intervals for the M–mode (or –mode sections) and the areas, perimeters, corners and radiuses of curvature for the B–mode is possible directly from the computer screen. The c
onformity between the ultrasonic scanner units of measure system and the computer is automatically supported by the analysis of ultrasonic image sites, containing information about the scale. It permits to receive adequate measurements irrespective of the image scale at the echocardioscope.
According to the conducted measurements, the parameters of intraheart and central hemodynamics are counted, measured significances are compared with the norms, taking into account age, sex, area of the patient's body and the echocardiographical conclusion is automatically formed. The norms for a particular patient are calculated by means of nonlinear mathematical model of the 3–rd order [8]. All data about the research, as well as frames of ultrasonic image, are saved in a database.
The analysis of structural and functional parameters and the forecasting of pathologic conditions of the cardiac–vessel system according to the data of echocardiographic researches is stipulated on the basis of 19–measured linear regressive model [8]. The comparison of the morpho–functional parameters of heart work enables quantitatively and qualitatively to present the level of the functional adaptation of miocardium to the load and depth of heart pathology, as well as the probability of existence and the probability of showings of various diseases (including arrhythmias, arterial hypotonia and hypertension, atherosclerosis, stigmation of heart and etc.) hereafter. The automatic prescription of courses of phytotherapy and homoeopathy for the correction of the condition of the cardiac–vessel system is possible according to the results of the expert valuation.
The computer system COR, intended for realization clinical echocardiography of the adults patients as well as children, is developed. The software is realized in the operating system MS DOS [9] in the protected mode of the processor DPMI [10, 11] and the SVGA/VESA modes of the screen [12, 13].
The atlas–reference of the ultrasonic research of heart is built–in. The atlas contains the images, as well as a text with the comments of the norms and pathologies, the description of echocardiographic (M and B modes), Doppler and differential diagnostic. The hierarchical organization of the atlas permits quickly to find the required information.
The software of the system permits to allocate arbitrary groups from the general quota according to the age, geographical, professional and other attributes. The automatic construction of mathematical models in addition to already existing is possible for the marked groups according to the data, assembled doctor in the period of operation of the system. Use of the system as a tool for processing and the comparisons of the results of the echocardiographic researches is allowed (it is aplicable for the researches in the field of a medicine, statistics, ecology and etc.).
More then 15000 patients were cheked up by means of COR system in various clinics, including 1200 – in Clinic Cardiology Moscow Institute for Pediatry and Surgery of Russia and 3700 – in Republican Children Diagnostic Centre (Moscow).