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Biomedical subjects

R N Tremewan

Publications and source records attributed to R N Tremewan.

10 recordsLinked to original sources
PubMed1994

Total-body irradiation on an isocentric linear accelerator: a radiation output compensation technique.

A treatment technique for total-body irradiation (TBI) is proposed that combines arc therapy with dynamic output control to achieve high-grade dose uniformity. The patient lies on a low couch and receives exposure in the prone and supine positions from a modulated arcing beam. The technique has been validated using a personal computer to control the linear accelerator and we demonstrate that only minor alterations to current dynamic therapy systems would be required. We have examined the practical application of this treatment with emphasis on methods of conformal therapy where an optimized dose distribution is prepared from a matrix of caliper measurements taken from the patient. This technique provides a means for regular TBI treatment on a computer-controlled linear accelerator that is easy to set up, requires short exposure times and is comfortable for the patient.

Equipment Failure Analysis↗
PubMed1980

The mid-trimester low lying placenta: a prospective study.

Thirteen women who were found to have a low lying placenta on ultrasound scan during the mid-trimester were followed prospectively with repeated ultrasound examinations in older to observe changes in placental position and to determine the prognostic significance of low-lying placentae found during the mid-trimester. Two women aborted spontaneously and in the remainder the placenta ceased to be previa by 30 to 32 weeks gestation ie about the time of the formation of the lower uterine segment.

Abortion, Spontaneous↗
PubMed1979

Fetal respiratory movements observed by ultrasound during abnormal pregnancies.

Observations of fetal respiratory movements were carried out during 35 pregnancies with complications likely to indicate increased fetal risk. Fetal breathing was demonstrated in 25 of 35 patients studied, and in 29 of 47 separate examinations. Of 17 patients delivering after 36 weeks gestation in whom observations were made with two weeks of delivery, three did not demonstrate fetal breathing. Infants born from these pregnancies were severely growth retarded in two instances and light for dates in the other. Although absent fetal breathing is likely to detect increased fetal hazard near term, the time and expense needed for accurate recording of fetal breathing will restrict application of the technique in the meantime.

Female↗
PubMed1976

Ultrasonic monitoring of fetal respiratory movement.

Ultrasonic monitoring of fetal respiratory movement including velocity measurements is described. Both proximal and distal walls of the fetal chest are imaged simultaneously. The time-position mode clearly defines fetal respiratory movement and rejects artefacts.

Female↗
PubMed1976

Diagnosis of gross vesico-ureteric reflux using ultrasonography.

A simple non-invasive ultrasonic technique which identifies gross vesico-ureteric reflux (VUR) in adults is described. It is based on the time position (TP)-mode (or M-mode) of ultrasound imaging. This method warrants assessment as a possible screening procedure for gross VUR in newborn children.

Dilatation, Pathologic↗