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Noninvasive Device (noninvasive + device)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Validation of a New Noninvasive Device for the Monitoring of Peak Endocardial Acceleration in Pigs: Implications for Optimization of Pacing Site and Configuration

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2008
PIERRE BORDACHAR M.D.
Introduction: The peak of endocardial acceleration (PEA) is an index of myocardial contractility. We aimed to (1) demonstrate that the PEA measured by the noninvasive cutaneous precordial application of an accelerometer sensor is related to left ventricular (LV) dP/dt max and (2) assess the usefulness of PEA monitoring during graded ischemia and during different configurations of sequential biventricular pacing. Methods and Results: Measurements of invasive LV dP/dt max were compared with measurements of transcutaneous PEA in seven pigs at baseline and during acute drug infusions; increased heart rate; right, left, biventricular and sequential biventricular pacing before and after graded ischemia induced by the constriction of the left anterior descending coronary artery. A consistent PEA signal was obtained in all animals. PEA changes were highly related to LV dP/dt max changes (r= 0.93; P < 0.001). The changes of LV contractility induced by the different pacing configurations were detected by PEA analysis in the absence of ischemia (r= 0.94; P < 0.001) and in the presence of ischemic LV dysfunction (r= 0.91; P < 0.001). Conclusion: Noninvasive PEA measurement allows monitoring of left ventricular contractility and may be a useful tool to detect global effect of ventricular ischemia and to optimize the choice of both pacing site and pacing configuration. [source]

The reliability of endtidal CO2 in spontaneously breathing children during anaesthesia with Laryngeal Mask AirwayTM, low flow, sevoflurane and caudal epidural

PEDIATRIC ANESTHESIA, Issue 5 2002
Per AASHEIM MD
Background: Noninvasive devices for monitoring endtidal CO2 (PECO2) are in common use in paediatric anaesthesia. Questions have been raised concerning the reliability of these devices in spontaneous breathing children during surgery. Our anaesthetic technique for elective infraumbilical surgery consists of spontaneous breathing through a Laryngeal Mask Airway (LMATM), low fresh gas flow, sevoflurane and a caudal epidural. We wanted to compare PECO2 and arterial CO2 (PaCO2) during surgery. Methods: Twenty children, aged 1,6 years, scheduled for infraumbilical surgery, were studied and one arterial sample was taken 45 min after induction of anaesthesia. PECO2, inspiratory PCO2, oxygen saturation, heart rate, respiratory rate, mean arterial blood pressure and expiratory sevoflurane concentration were measured every 5 min. The respiratory and circulatory parameters were stable during surgery. Results: The mean PaCO2 , PECO2 difference was 0.15 (0.16) kPa [1.1 (1.2 mmHg)]. Conclusions: PECO2 is a good indicator of PaCO2 in our anaesthetic setting. [source]

Direct fluorescence visualization of clinically occult high-risk oral premalignant disease using a simple hand-held device

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2007
Catherine F. Poh DDS
Abstract Background A considerable proportion of oral cancer and precancer is not clinically apparent and could contribute significantly to the late diagnosis and high mortality of oral cancer. A simple method to identify such occult change is needed. Methods Patients in the Oral Dysplasia Clinics at British Columbia are currently being examined with a simple hand-held device that permits the direct visualization of alterations to autofluorescence in the oral cavity. Tissue showing loss of autofluorescence is biopsied. Results We present 3 representative cases in which occult lesions were identified with fluorescence visualization during longitudinal follow-up, resulting in the diagnosis of a primary dysplasia in case 1, a second primary cancer in case 2, and cancer recurrence in case 3. Conclusions This is the first report of the diagnosis of occult oral disease using a simple noninvasive device. These early examples indicate the potential value of this technology to guide the management of patients with oral lesions, facilitating the detection of high-risk changes not apparent with white-light visualization. © 2006 Wiley Periodicals, Inc. Head Neck, 2006 [source]

Assessment of autonomic cardiovascular changes associated with recovery from anaesthesia in children: a study using spectral analysis of blood pressure and heart rate variability

PEDIATRIC ANESTHESIA, Issue 6 2000
ISABELLE CONSTANT MD PhD
Recovery from anaesthesia is associated with large changes in cardiovascular autonomic activity, which are poorly documented in children. This study was undertaken to investigate the cardiovascular autonomic activity in anaesthetized and recovering children, using a noninvasive approach based on spectral analysis of heart rate (HR) and blood pressure (BP) variability. Ten children (aged 5,13 years) undergoing major surgery were studied. Continuous HR and BP were recorded using a noninvasive device during deep anaesthesia and recovery. Spectral analysis was used to determine the main oscillatory components of HR and BP signals. For each power spectrum, the frequency components were identified as follows (i): the low frequency (LF) component (0.04,0.14 Hz) both parasympathetically and sympathetically mediated for HR and corresponding to vasomotor sympathetic modulation for BP; and (ii) the high frequency (HF) component (0.2,0.6 Hz) parasympathetically mediated for HR, and reflecting mechanical influence of ventilation on cardiac output for BP. In addition, the LF : HF ratio for HR, reflecting the cardiac sympathovagal balance, was calculated. Under deep anaesthesia, HR variability and BP variability were very low and mainly due to mechanical influence of intermittent positive pressure ventilation. Conversely, the recovery period was associated with a marked increase of HR and BP overall variability. Compared to anaesthesia, spectral analysis of HR and BP revealed that the LF component of BP and HR spectra increased 40-fold during recovery; the LF : HF ratio of HR was also increased during recovery (0.1 ± 0.1 versus 1.3 ± 1.2, P=0.008). The results of this study demonstrate that the recovery period is associated with an increase of cardiovascular sympathetic drive in children after major surgery. [source]