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Biomedical subjects

R J Voots

Publications and source records attributed to R J Voots.

7 recordsLinked to original sources
PubMed1991

Monothermal differential caloric testing in patients with Menière's disease.

The monothermal differential caloric test allows determination of vestibular recruitment and decruitment, variables which may help discriminate peripheral from central vestibular lesions. Previous reports indicated a strong association between vestibular recruitment and Menière's disease. This study examined patients having unilateral Menière's disease. Nystagmus beat frequency (NBF) and slow-component velocity (SCV) responses were recorded by electronystagmography (ENG). Electronystagmographic findings showing unilateral dysfunction were present in 54% of patients by slow-component velocity and in 31% by nystagmus beat frequency. Unilateral hypofunction was the most frequent lateralizing ENG finding. Absolute vestibular recruitment occurred in less than 10% of patients but relative recruitment was found in nearly 20% of patients. Slow-component velocity had higher sensitivity than nystagmus beat frequency, with excellent clinical concordance. Monothermal caloric testing as described in this study best detects peripheral vestibular disease in Meniere's patients using slow-component velocity to determine unilateral hypofunction and relative vestibular recruitment.

Adolescent↗
PubMed1977

Influence of succinylcholine on middle component auditory evoked potentials.

Auditory evoked potentials in the middle component time domain (post-stimulus, 8 to 50 msec) were recorded in response to 1,000-Hz tone pips in a normal-hearing adult subject. Electromyographic (EMG) responses in response to ulnar nerve shocks were recorded from the ipsilateral hypothenar muscles. With the assistance of an anesthesiologist, data were collected during a normal resting state, a state of light sedation, and a state of complete skeletal muscle paralysis from succinylcholine administration. During the paralyzed state, there was abolition of the normal EMG responses seen in the resting and sedated states. The auditory evoked potentials, however, appeared unchanged during the paralyzed state, indicating that they were not of myogenic origin.

Acoustic Stimulation↗
PubMedDate not supplied

The role of photoplethysmography in the prediction of the experimental flap survival.

A standard photoplethysmography, modified to differentiate between arterial and venous vasculature in skin tissue, has been used to measure arterial supply in 100 unipedicle skin flap in 25 pigs. A datum transform from a light intensity scale to a relative arterial blood density scale has been introduced and empirically labeled the vascular coefficient (VC). Statistical analysis of the VC data shows a significant difference between necrotic and surviving flap group mean data as early as 24 hours. Additional analysis in which a normal ogive was fitted to the sample VC data distributions suggests that statistically significant predictions of the probability of eventral flap necrosis can be made using VC measurements obtained immediately postoperatively. It is concluded that the modified photoplethysmograph, in conjunction with the VC data transform constitutes a usable measuring technique for skin flap viability prediction in the experimental animal.

Animals↗
PubMedDate not supplied

Photoplethysmography in the prediction of experimental flap survival.

A standard photoplethysmograph, modified to differentiate between arterial and venous vasculature in skin tissue, has been used to measure arterial supply in 100 unipedicle skin flaps in 25 pigs. A datum transform from a light intensity scale to a relative arterial blood density scale has been introduced and empirically labelled the vascular coefficient (VC). Statistical analysis of the VC data shows a significant difference between necrotic and surviving flap group mean data as early as 24 hours. Additional analysis in which a normal ogive was fitted to the sample VC data distributions suggests that statistically significant predictions of the probability of eventual flap necrosis can be made using VC measurements obtained immediately postoperatively. It is concluded that the modified photoplethysmograph in conjunction with the VC data transform, constitutes a usable measuring technique for skin flap viability prediction in the experimental animal.

Animals↗