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Biomedical subjects

J W Sundsten

Publications and source records attributed to J W Sundsten.

15 recordsLinked to original sources
PubMed1995

The cerebral ventricles: a computer-based interactive tutorial.

The computer-based tutorial, "The Cerebral Ventricles," enables the user to review the anatomy, imaging, and common pathologic conditions of the human cerebral ventricular system. The program runs on a workstation that includes a laser videodisk player and a videodisk with 21,000 still images plus motion sequences. By using a mouse to select specific portions of the anatomic diagram depicting the ventricles, the user can review different planes of normal gross anatomy, corresponding computed tomographic and magnetic resonance images of normal anatomy, images of gross specimens of different pathologic entities, and corresponding radiologic images. The motion sequences portion of the program shows reconstructed three-dimensional images of ventricular anatomy and helps the user gain a greater understanding of the complex anatomy as seen from all angles. Subprograms provide more detailed information about anatomic relationships, disease entities, and bibliographic references. "The Cerebral Ventricles" assists radiologists in gaining a greater understanding of the ventricles so that an appropriate differential diagnosis of an intraventricular lesion can be offered when such masses are encountered in clinical practice.

Cerebral Ventricles↗
PubMed1991

A multimedia Anatomy Browser incorporating a knowledge base and 3D images.

We describe a multimedia program for teaching anatomy. The program, called the Anatomy Browser, displays cross-sectional and topographical images, with outlines around structures and regions of interest. The user may point to these structures and retrieve text descriptions, view symbolic relationships between structures, or view spatial relationships by accessing 3-D graphics animations from videodiscs produced specifically for this program. The software also helps students exercise what they have learned by asking them to identify structures by name and location. The program is implemented in a client-server architecture, with the user interface residing on a Macintosh, while images, data, and a growing symbolic knowledge base of anatomy are stored on a fileserver. This architecture allows us to develop practical tutorial modules that are in current use, while at the same time developing the knowledge base that will lead to more intelligent tutorial systems.

Anatomy↗
PubMed1991

Videodisc animation of 3D computer reconstructions of the human brain.

Our group is creating a database of x-, y-, z- coordinates of central nervous system structures from serial cross-sections. We produce 3D computer images of the brain and its components and record them on videodisc. Useful animations include combining objects from different databases to correct anatomical scale, rendering a surface translucent to reveal underlying components, slicing and paging brain slabs with and without protruding individual objects, and dissecting functional pathways. We are beginning to use videodisc animations of the nervous system in computer-based interactive tutorials.

Brain↗
PubMed1985

A new method of measuring brain atrophy: the effect of aging in its application for diagnosing dementia.

A new method of measuring cerebral atrophy using a ratio of brain parenchyma to ventricular and subarachnoid space is described. It uses digitized brain CT. This ratio was measured prospectively on 117 consecutive elderly patients referred for evaluation of cognitive dysfunction. Diagnosis was determined by preestablished criteria and confirmed by follow-up. Despite the improved accuracy and reproducibility of this method, its ability to differentiate persons with senile dementia of the Alzheimer's type (SDAT) from those suffering from pseudodementia was confounded by age, and was hence of limited utility. We conclude that even with sophisticated measures of cerebral atrophy, CT is unable to discriminate among common causes of cognitive dysfunction in the elderly.

Aged↗
PubMed1984

Folding of the cerebral cortex in mammals. A scaling model.

A model of cortical folding in mammals is presented. The model consists of a cube, superimposed on which are straight close-packed gyri, running the length of the cube. The cortex is represented by a thin layer of constant thickness. It proves possible, by adjusting the length, height, and width of the 'gyri' and the thickness of the 'cortex', to obtain a reasonable fit to the available empirical data (which extend over three to four orders of magnitude in brain weight). The model directs attention to possible features of the macroscopic organization of the mammalian brain which are novel and hitherto unremarked.

Animals↗
PubMed1983

Three-dimensional reconstruction from serial sections: II. A microcomputer-based facility for rapid data collection.

A microcomputer-based facility is described that permits the data required for three-dimensional reconstructions to be collected quickly and inexpensively from serial sections. The facility consists of a microcomputer, a digitizer tablet, a graphics terminal, a printer, a plotter, and telephone coupler. Images of serial sections are superimposed on the digitizer tablet. Contours of interest on each section are digitized and the coordinates are stored on "floppy" disks. The problems of putting successive sections in correct register and of taking into account magnification factors are discussed briefly. Use of the facility for high-resolution applications is also considered.

Animals↗
PubMed1976

The maximum aerobic power of the Temiars.

A settlement of Temiars, an aboriginal tribe residing in the north-eastern jungles of the Malay Peninsula, was selected for a study of their cardiorespiratory fitness. A step-test was used to elicit the Vo2max, V E max and HR max in a group of 19 boys aged 12 to 18 years and 6 men aged 19 - 40 years. The mean VO2max of the boys was found to be 45.9 +/- 6.9 ml-kg-1-min-1 compared with 45.6 +/- 5.4 ml-kg-1-min-1 for the men. The mean V E max, HR max and blood lactate levels were found to be 65.5 +/- 11.31/min and 69.2 +/- 23.71/min; 194 +/- 8 beats/min and 186 +/- 10 beats/min; and 79.8 +/- 13.4 mg% and 97.7 +/- 33.4 mg% respectively. These results are comparable to those obtained in urban populations as well as those found in other primitive communities. Telemetric monitoring of the routine daily physical activity of the men revealed that these jungle dwellers rarely tax their oxygen transport systems in their daily living and their cardiorespiratory functions were similar to communities who do not specifically train for physical fitness.

Adolescent↗