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Biomedical subjects

W Bickel

Publications and source records attributed to W Bickel.

5 recordsLinked to original sources
PubMed1991

Use of computer graphics simulation for teaching of flexible sigmoidoscopy.

The concept of simulation training in endoscopy is now well-established. The systems currently under development employ either computer graphics simulation or interactive video technology; each has its strengths and weaknesses. A flexible sigmoidoscopy training device has been designed which uses graphic routines--such as object oriented programming and double buffering--in entirely new ways. These programming techniques compensate for the limitations of currently available desk-top microcomputers. By boosting existing computer 'horsepower' with next generation coprocessors and sophisticated graphics tools such as intensity interpolation (Gouraud shading), the realism of computer simulation of flexible sigmoidoscopy is being greatly enhanced. The computer program has teaching and scoring capabilities, making it a truly interactive system. Use has been made of this ability to record, grade and store each trainee encounter in computer memory as part of a multi-center, prospective trial of simulation training being conducted currently in the USA. A new input device, a dummy endoscope, has been designed that allows application of variable resistance to the insertion tube. This greatly enhances tactile feedback, such as resistance during looping. If carefully designed trials show that computer simulation is an attractive and effective training tool, it is expected that this technology will evolve rapidly and be made widely available to trainee endoscopists.

Computer Graphics↗
PubMed1990

[Myelolipoma of the adrenals--a chance sonographic finding].

A markedly echogenic and sharply marginated suprarenal mass was found incidentally during an abdominal sonography in the case of three patients. One female patient died due to a mesenterial infarct, in the other cases the tumors were removed surgically. In two cases the histological diagnosis indicated a myelolipoma of the adrenal gland, in one case an angiolipoma attached directly to the adrenal. Myelolipoma is a benign and hormone-inactive tumorous lesion, which most commonly occurs in the adrenal gland. Knowledge of the clinical and sonomorphologic characteristics along with computed tomography helps to distinguish other tumors of the retroperitoneum. Thus, unnecessary surgical intervention can be avoided.

Adrenal Gland Neoplasms↗
PubMed1987

Three-choice drug discrimination in opioid-dependent humans: hydromorphone, naloxone and saline.

Opioid-dependent volunteers were trained in a three-choice drug discrimination procedure to discriminate between the effects of i.m. administered saline (0.5 ml), hydromorphone hydrochloride (10 mg) and naloxone hydrochloride (0.15 mg). Subjects earned monetary reinforcement by correctly identifying the training drugs by letter code. Subjects received a single drug administration in each daily experimental session. During each session, subjective and physiological effects and three behavioral measures of discrimination (including an operant response, a qualitative response and a quantitative response) were collected. The study was done in three phases: a training phase in which training drugs were identified to subjects by letter code before the session, a test of acquisition phase in which the subject's ability to identify the training drug by letter code was tested and a generalization phase in which dose-response curves for the two active training drugs were tested. Results of acquisition testing of the training drug doses were similar in all three discrimination measures. The two active drugs produced contrasting effects on the various subjective report measures (opioid agonist-like effects vs. opioid withdrawal-like effects). In generalization testing, hydromorphone produced dose-related hydromorphone-appropriate responding, and naloxone produced dose-related naloxone-appropriate responding. Lowest doses of each drug produced saline-appropriate responding; there was no cross-generalization between either active drug. Similarly, hydromorphone and naloxone produced orderly dose-dependent effects on subjective effect scales similar to those produced by the training doses.

Adult↗