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Biomedical subjects

S Bohrer

Publications and source records attributed to S Bohrer.

5 recordsLinked to original sources
PubMed1991

Inverse perspective mapping simplifies optical flow computation and obstacle detection.

We present a scheme for obstacle detection from optical flow which is based on strategies of biological information processing. Optical flow is established by a local "voting" (non-maximum suppression) over the outputs of correlation-type motion detectors similar to those found in the fly visual system. The computational theory of obstacle detection is discussed in terms of space-variances of the motion field. An efficient mechanism for the detection of disturbances in the expected motion field is based on "inverse perspective mapping", i.e., a coordinate transform or retinotopic mapping applied to the image. It turns out that besides obstacle detection, inverse perspective mapping has additional advantages for regularizing optical flow algorithms. Psychophysical evidence for body-scaled obstacle detection and related neurophysiological results are discussed.

Algorithms↗
PubMed1987

Indium 111 labeled white blood cell scintigraphy for the diagnosis of upper abdominal abscesses in a child with Wiscott-Aldrich syndrome.

We report on a case of multiple hepatic abscesses in an immunodeficient patient where initial radiologic evaluation by ultrasonography and computed tomography confused early management by failing to demonstrate the abscesses and by suggesting other diagnoses. Indium 111 (In-111) white blood cell (WBC) scanning with Tc-99 liver-spleen scan subtraction accurately demonstrated subcapsular hepatic abscesses in four out of four sequential studies, and later confirmed resolution of the abscesses. We suggest that In-111 WBC scanning may be used as a highly specific method of diagnosing suspected upper abdominal abscesses in children.

Child↗
PubMed1987

The efficacy of computed tomography in evaluating abdominal injuries in children with major head trauma.

Physical examination may be unreliable in the evaluation of children with blunt abdominal trauma particularly in those with associated major head injuries. In the absence of obvious clinical signs or physical findings of intraabdominal injury, the usefulness of abdominal computed tomography in children is controversial. To test the efficacy of CT scans, a 12-month prospective study of computed tomography for the initial assessment of children with blunt abdominal trauma and major head injuries was carried out. Of 320 pediatric trauma admissions to our regional trauma center, 65 consecutive patients with Glasgow Coma Scores less than ten were managed with sequential head and abdominal computed tomography in the emergency room for (1) closed head injury and (2) suspected abdominal trauma. Fifteen patients (23%) were found to have significant intraabdominal injury. Only two required operative intervention. No patients died as a result of the abdominal injuries. In children with significant head trauma and suspected abdominal trauma, combined head and abdominal CT proved to be reliable.

Abdominal Injuries↗