Purpose: To compare the performance of a forehead probe to a conventional finger pulse oximetry probe in anesthetized patients.
Methods: Eighteen patients participated in the study. Each probe was connected to a Nellcor N-550 pulse oximeter. Anesthesia was induced and maintained with propofol. After intubation, the patients received air to achieve a steady-state of peripheral arterial oxygen saturation (SpO(2)). Ventilation was interrupted to induce a hypoxic state. As soon as one of the two SpO(2)'s decreased to 90%, the patients' lungs were ventilated with 100% oxygen. To evaluate the performance of the two pulse oximeters, time to the lowest (TL), time of recovery (TR) and lag times to beginning of SpO(2) decrease (Lag) were measured.
Results: There were no significant differences in TL and TR between forehead and finger pulse oximetry under normal perfusion conditions during general anesthesia. When the axillary artery was compressed to mimic reduced peripheral perfusion, SpO(2) in the forehead decreased sooner than in the finger during hypoxia. The forehead and finger TLs were similar, however, TR was significantly longer in the finger.
Conclusion: The forehead SpO(2) sensor can be used as an alternative to the conventional finger sensor during general anesthesia.
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http://dx.doi.org/10.1007/BF03018304 | DOI Listing |
Physiol Meas
December 2024
University of Glasgow James Watt School of Engineering, James Watt School of Engineering, Glasgow, Glasgow, G12 8QQ, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
Objective: We study the changes in morphology of the photoplethysmography (PPG) signals-acquired from a select group of South Asian origin-through a low-cost PPG sensor, and correlate it with healthy aging which allows us to reliably estimate the vascular age and chronological age of a healthy person as well as the age group he/she belongs to.
Methods: Raw infrared PPG data is collected from the finger-tip of 173 appar- ently healthy subjects, aged 3-61 years, via a non-invasive low- cost MAX30102 PPG sensor. In addition, the following metadata is recorded for each subject: age, gender, height, weight, family history of cardiac disease, smoking history, vitals (heart rate and SpO2).
Comput Methods Biomech Biomed Engin
December 2024
School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing, China.
This study proposes a rapid method for determining pregnancy status based on fingertip pulse signals. A finger pulse sensor collects data, which is processed into unified multimodal signals. The Bamboo-Net model, combining ResNet, LSTM, and 1D-CNN, extracts key features from time, frequency, and time-frequency domains.
View Article and Find Full Text PDFFront Neurosci
November 2024
Department of Medical Biology, Section Systems Physiology, Amsterdam University Medical Centers, Amsterdam, Netherlands.
During an ECG-training course, a case of extreme respiratory sinus arrhythmia (RSA) was found in a 19-year-old slender, female student who was not active in sports. The heart rate (HR) fluctuated from above 100 to below 60 beats per minute (bpm), often from one beat to the next. The pattern was repetitive and appeared to be linked to respiration, representing an extreme form of RSA.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklay Str., 117997 Moscow, Russia. Electronic address:
Non-conventional snake venom toxins, such as WTX from the cobra Naja kaouthia, are three-finger proteins containing a fifth disulfide bond in the N-terminal polypeptide loop I and inhibiting α7 and muscle-type nicotinic acetylcholine receptors (nAChRs). Because the central polypeptide loop II of non-conventional toxins plays an important role in their biological activity, we synthesized several WTX loop II fragments with two cysteine residues added at the N- and C-termini and oxidized to form a disulfide bond. The inhibition by peptides of several nAChRs subtypes was investigated using different methods and the effects of peptides on the rat arterial pressure and heart rate were analyzed.
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