A workstation for multi-dimensional display and analysis of biomedical images.

The capability to extract objective and quantitatively accurate information from 3-D radiographic biomedical images has not kept pace with the capabilities to produce the images themselves. This is rather an ironic paradox, since on the one hand the new 3-D and 4-D imaging capabilities promise significant potential for providing greater specificity and sensitivity (i.e. precise objective discrimination and accurate quantitative measurement of body tissue characteristics and function) in clinical diagnostic and basic investigative imaging procedures than ever possible before, but on the other hand, the momentous advances in computer and associated electronic imaging technology which have made these 3-D imaging capabilities possible have not been concomitantly developed for full exploitation of these capabilities. Therefore, we have developed a powerful new microcomputer-based system which permits detailed investigations and evaluation of 3-D and 4-D (dynamic 3-D) biomedical images. The system comprises a special workstation to which all the information in a large 3-D image data base is accessible for rapid display, manipulation, and measurement. The system provides important capabilities for simultaneously representing and analyzing both structural and functional data and their relationships in various organs of the body. This paper provides a detailed description of this system, as well as some of the rationale, background, theoretical concepts, and practical considerations related to system implementation.

A new method for shaded surface display of biological and medical images.

Shaded surface display is a useful aid in visualizing and analyzing three-dimensional biological and medical images. However, currently available algorithms have limitations, particularly when applied to clinically important image data requiring fast and flexible interactive analysis. In addition to the problem of computation time is the cost of specialized hardware and the quality of shading. A new algorithm has been designed for use with three-dimensional biological/ medical images which attempts to overcome these limitations. This is accomplished by eliminating less important capabilities and optimizing the essential ones of speed and realistic shading. The algorithm has been successfully employed in planning reconstructive bone surgery, in assessment of both congenital and acquired heart disease, and in studies of normal and pathological lung physiology. Examples which illustrate the versatility and speed of the new algorithm are presented.

Evaluation of a computer simulation program for teaching halothane uptake and distribution.

A pilot evaluation of a simulation program used during a tutorial for the teaching of uptake and distribution of the inhalational anaesthetic halothane shows a highly significant improvement in the students' answers after the tutorial using a 'before and after' questionnaire. The students showed an understanding of the program's display and model limitations. This encourages the further use of the program.

Teaching the uptake and distribution of halothane. A computer simulation program.

A computer aided learning program for teaching the kinetics of uptake and distribution of the inhalational anaesthetic halothane is described. The program is based on a seven-compartment model which simulates the action of halothane on ventilation and on the cardiovascular system. The program is available to the student in four forms: one with no changes in circulation or respiration, one with the cardiovascular effects of halothane included, one with respiratory effects only, and one with both of these effects combined. The student can study the importance of the influence of halothane on respiration and blood circulation by comparing results from simulations on different models. The simulation is presented as graphs which are continuously displayed on an alphanumeric visual display terminal. Interaction with the program is possible at all times to change the simulation speed, the variables being graphed, the inspired halothane fraction, and the fresh gas flow.