W. E. Schoenlein

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The authors describe a novel system for sensing and displaying the distribution of contact pressure caused by a patient's lying on a hospital bed. The system includes a flexible, pressure-sensitive mat, electronics to activate the mat, a small computer to process data, and a color video display. The present prototypes can sense pressure at 1,536 discrete(More)
This study was undertaken to determine the effect of interposed abdominal compressions (IAC) during cardiopulmonary resuscitation (CPR) on gastric insufflation when the airway is not secured with an endotracheal tube. A canine model was used in which a common ventilation pressure was applied to separate cuffed esophageal and tracheal tubes. Gas entering the(More)
In this paper a technique for predicting thoracic impedance to defibrillator pulses is described. The impedance to low-current (1.0 mA) high-frequency (10-500kHz) sinusoidal current is used as an indicator of the impedance of the thorax to high-current, damped sinusoidal waveform pulses. Results from 71 dogs to which defibrillator shocks of 4 to 220 A peak(More)
Atrial fibrillation (AF) was induced electrically and the duration of AF was measured in six isoflurane-anesthetized sheep (weight range 54.5-72.7 kg), and in five unanesthetized sheep (weight range 60-75 kg). In the anesthetized sheep, AF was induced by direct electrical stimulation of the right atrium with a catheter electrode and the duration of AF was(More)
A new type of disposable external defibrillation electrode has been developed to reduce the skin irritation commonly associated with defibrillation and synchronised cardioversion. This design employs an impedance gradient to reduce the proportion of current delivered to the electrode periphery. The temperature distribution under the new electrode was(More)
We investigated in sheep, non-thoracotomy extraction of leads which had been chronically implanted in the right atrium (RA), coronary sinus/great cardiac vein (CS/GCV) and right ventricle (RV) for atrial implantable defibrillation. Clinical success of extraction as well as gross and histologic findings in the heart are reported. Six of nine sheep had(More)
To illustrate the abilities of several physiologic events to indicate a change in metabolic status, dinitrophenol was used to induce hyperthermia. Ten dogs were divided into two groups, one being mechanically ventilated and the other allowed to breathe spontaneously. End-tidal CO2 (ETCO2) and CO2 production, O2 consumption, mean blood pressure, and rectal(More)
The dynamic effect of left vagal stimulation on atrioventricular conduction was studied in six isofluorane-anesthetized dogs ranging in weight from 22 to 29 kg. The cervical vagus nerve trunks were left intact and no beta-adrenergic blockade was produced so that any influences of the sympathetic nervous system and autonomic reflex activity could be(More)
Thirteen anesthetized canine subjects (17-29 kg) were used to demonstrate that mild cervical left vagal stimulation could control ventricular rate effectively during atrial fibrillation (AF). Two studies are presented. The first study used six subjects to demonstrate the inverse relationship between (manually applied) left vagal stimulation and ventricular(More)
The human femoral artery can bleed dangerously following the removal of a catheter uring cardiac catheterization. In this study, a modified technique of needle insertion, simply inserting the needle bevel-down instead of the standard bevel-up approach, was tested as a means to reduce bleeding after catheter removal. Large bore needle punctures were made in(More)