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Biomedical subjects

K G Vosburgh

Publications and source records attributed to K G Vosburgh.

11 recordsLinked to original sources
PubMed1998

Experience with MR-guided therapy.

The use of magnetic resonance imaging (MRI) for the real time guidance of surgical procedures is now undergoing clinical trials. Among the many procedures explored, open craniotomy neurosurgery appears to be among the most promising. Over 50 such cases have been done at the Brigham and Women's Hospital (BWH) in Boston. We review the technical approach used in these and related procedures. We consider the way in which imaging is used to augment and improve the procedures. As well, the implications of these protocols for remote diagnosis and telesurgery are explored. Finally, the implications of this experience for the insertion of new technology into medicine are discussed.

Biopsy↗
PubMed1997

Image guided surgery and its potential.

The use of higher technology in medicine promises improved outcomes and enhanced productivity. That is, successful techniques will lead to lower cost, higher quality care for a larger population. In surgery, these changes range from the more efficient use of skilled medical practitioners, through improvements to conventional practice (a recent example is the shift to endoscopic surgery in the abdomen), to the creation of new procedures which capitalize on the availability of information in new forms._Image Guided Surgery may be defined as the use of advanced technology to help the surgeon see with 1) Better resolution 2) Orientation and context setting 3) Higher contrast, and 4) Vision inside "solid objects", including the elimination of occlusion by the surgeon's tools or other external items. We describe here the current imaging processes and their limitations with regard to direct guidance of therapy. The physical properties of real time image acquisition systems are described along with the mechanisms for inherent and enhanced contrast. Examples of the use with surgical instruments or other interventional devices for image-monitored and guided procedures are then discussed, and future prospects elucidated.

Humans↗
PubMed1977

Storage and retrieval of radiographic images.

Storage and retrieval of radiographic images was studied to quantify existing procedures and determine the applicability of new technology. Storage practices were found to be consistent among different types of hospitals. About one third of American hospitals have serious problems, particularly lack of space. Most hospitals save radiographs 4-7 years after the latest examination, but one third fall outside this range. It does not appear that there is near-term technological solution for radiographic storage problems.

Economics, Medical↗
PubMed1973

Cellular effects of heavy charged particles.

The human cell is rendered reproductively inactive by the passage of a single heavy ion through its nucleus when the heavy ion deposits energy at a rate greater than about 3500 MeV cm-1. This is demonstrated by the correlation of inactivation probability with nuclear area when cells having nuclei of different sizes are compared. This single-hit inactivation is irreversible and unmodifiable. The ion path length over which cells will be inactivated in this way is calculable from stopping power theory. Laboratory experiments in which three-dimensional human cell cultures were irradiated with high-energy nitrogen ions (3.9 GeV) at the Princeton Particle Accelerator confirm that cells are inactivated with maximum probability over the last 0.5 cm of the ion trajectory. This means that groups of adjacent cells in the ion path will be inactivated by a single ion with high probability. Organized systems of multiplying cells would be expected to amplify this spatially correlated effect of heavy ion irradiation. Abnormalities induced in Zea seedlings by heavy ion irradiation of seeds are consistent with the inactivation of embryonic cells in groups.

Animals↗
PubMed1972

Visual sensations induced by relativistic nitrogen nuclei.

The ability of the human eye to detect nitrogen nuclei that enter the retina at speeds just above the Cerenkov threshold has been confirmed in an experiment at the Princeton Particle Accelerator. A system for beam transport and subject alignment delivered individual nitrogen nuclei onto a spot 3 millimeters in diameter on the retina at a visual angle of 7 degrees on the temporal side of the fovea. The beam particles entered the retina within 25 degrees of normal and induced visual sensations that had the appearance of streaks for three out of four subjects.

Dark Adaptation↗
PubMed1971

Prediction of the spatial distribution of cell survival in heavy ion beams.

The possible use of heavy ion beams for biomedical applications was examined through calculations of the physical beam properties and the spatial distribution of cell survival. Range straggling, creation of secondary particles, electron pickup, and the effects of inhomogeneous absorbers were analyzed in terms of cell survival. Depth-survival plots for typical irradiations provide substantial encouragement for the investigation of these beams for biomedical applications in which localized tissue destruction is desired.

Cell Survival↗
PubMed1971

Spatial distribution of biological effect n a 3.9-Gev nitrogen ion beam.

A beam of nitrogen ions obtained with the Princeton Particle Accelerator was used for the irradiation of Chinese hamster (M3-1) cells in monolayer culture. The 3.9-billion-electron-volt (Gev) beam passed along the monolayer, so that ions were stopped in the culture. A sharply defined zone of extensive cell destruction occurred in the last centimeter of the beam path.

Animals↗