Multimedia workstation for cardiac image sequences.

Abstract

To diagnose patients with heart disease, cardiologists need to view the co-ordinated movements of various components of the heart, and check for narrowings and blockages in the coronary arteries. Echocardiography and Cardiac Angiography are two imaging modalities which permit visualization of these aspects of the heart. Currently, examinations performed with these modalities are stored on either 35mm cine film or VHS video cassette, making their review tedious and time consuming for the cardiologists. We propose a multimedia workstation to store the examinations and all related textual and graphical information in such a way as to permit convenient access. This information would be supported by a multimedia database which would allow for retrieval based on logical indices, such as patient name and examination date. This thesis details the design, construction and evaluation of such a workstation. To ensure that the workstation is easy to use and that an appropriate set of functions are available to the cardiologist, we employed a user centred design methodology. Our workstation digitized the examinations from S-VHS video tape for storage onto disk. The examinations are displayed at 320 by 240 at 20 frames per second, by selecting the patient and the examination date through a graphical user interface. Usability testing helped to fix both design and implementation errors, and revealed that our user interface was successfully designed. A one week trial in the Coronary Care Unit at the University of Ottawa Heart Institute proved that the workstation is useful for consultations and teaching between the cardiologists and residents on duty.