View clinical trials related to NIRS.
Filter by:NIRS estimates tissue saturation of oxygenation in tissue beds. Animals studies suggested that transscrotal NIRS measurements can quantify testicular hypoxia and differentiate between torsed and non torsed testicles. The results of human studies are not conclusive. The hypothesis is that the difference in NIRS values between torsed and healthy testicles would not be zero and that this difference would be zero in control group and that NIRS could help to detect rapidly a TT Testicular torsion (TT) is a functional emergency. The diagnosis is sometimes difficult to make. No paraclinical examination can eliminate it with certainty. The investigators aimed to evaluate the interest of transscrotal near-infrared spectroscopy (NIRS) for the diagnosis of TT of child
The experiment will consist of 3 consecutive trials performed in a sound-insulated climate chamber (20°C and 40% RH) at the VUB. Participants will be asked to return 3 successive weeks. Trained staff (pre-doctoral researchers and trained master students) will be present during the experimental trials. The first visit will be a familiarization trial in which they will complete all procedures as if it was an experimental trial, except for the interventional 60min Stroop task. Instead of the 60-min Stroop task the participants' maximal cognitive capacity will be determined. The participant wil come in, perform a cognitive performance test, will then perform the intervention/control procedure, which will be followed by an additional conduction of the same cognitive performance test as before the intervention/control, as well as a physical performance test (time to exhaustion cycling test). The intervention will consist of a 60 min Stroop task, while the control trial will consist of watching a documentary of the same duration. Multiple different questionnaires (e.g. to assess the mentally fatigued state of participants) will be assessed throughout the experimental/control trial. The aim of this study will be to research if mental fatigue influences prefrontal cortex oxygenation during a time to exhaustion cycling test. Marcora et al. (2009) already showed a decrease in cycling performance during the exact same protocol.
Introduction Both Mental Fatigue (MF) and hypoxia impair multiple aspects of cognitive functioning. The decline in cognitive functioning in hypoxic conditions is associated with alterations in brain oxygenation and hemodynamic responses. These hemodynamic responses are preferably measured at the prefrontal cortex, an area of the brain that is known for its executive function and role in decision making, planning, attention and (short-term) memory. This study will investigate the role of prefrontal cortex oxygenation during the development of mental fatigue and during cognitive performances by altering the ambient oxygen availability through normobaric hypoxia (3800m; 12,9% O2) and normoxia. Methods Subjects will perform four trials in a sound-insulated climate chamber (20°C and 40% RH). Upon entry in the climatic chamber participants will adapt to the environment for 30 minutes. Next, they will perform a modified cognitive test battery "cognition", a fine motor task "Motor Performance Series" and a visuomotor-fitlight task before and after a 60-minute individualized Stroop task or control task (randomized. blinded, placebo controlled, counter-balanced, cross-over design). Nearinfrared spectroscopy (NIRS) will be used to assess hemodynamic changes (oxygenated hemoglobin (O2Hb), deoxygenated-hemoglobin (HHb) and total hemoglobin (tHb)) at the PFC. Hypotheses 1) MF will lead to earlier changes in the prefrontal NIRS-parameters (O2Hb, HHb, tHb) with lower oxygen availability. 2) The effects of MF on cognitive performance manifest itself to a greater extent with lower oxygen availability.3) Visuomotor performance declines to a greater extent due to MF with lower oxygen availability.
Bronchofiberoscopy is a widespread invasive intervention in clinical practice with a number of diagnostic and therapeutic indications. The Clinic of Pulmonary Medicine in Debrecen carries out nearly 2000 examinations a year. The intervention is guided by the recommendation of the Vocational College for Pulmonary Medicine in 2005, but it does not contain a clear recommendation on the oxygen therapy used during the intervention. The Hungarian recommendation states that pulsoximetry is mandatory in bronchoscopy, but it does not contain information on the indications and the implementation of oxygen suplementation. The British Thoracic Society Guideline 2013 deals with the issue and makes the following statements: - patients should be monitored for oxygen saturation under bronchofiberoscopy - oxygen supplementation during the test is recommended if the patient's desaturation is significant (greater than 4% or less than 90%) and is over 1 minute - during the bronchoscopy, the occurrence of oxygen saturation decreases depending on the level of initial oxygen saturation, respiratory function, co-morbidity, sedation and the course of intervention. The aim of our study is to investigate the frequency with which systemic hypoxia occurs during bronchoscopy, what factors may contribute to its development and how the level of cerebral oxygen saturation changes with systemic desaturation (in the case of NIRS, a 20% reduction from baseline is considered significant).
During open surgery of a thoraco-abdominal aortic aneurysma (TAAA), diminished blood flow to the myelum can result in hypoxia, compromising proper function of the spinal cord. Intraoperatively, motor evoked potentials (MEP) are elicited to measure the functional integrity of the spinal cord. MEPs have proven to be a reliable marker of spinal cord ischemia. Moreover, these potentials react within minutes, which facilitates interventions to restore the blood flow. Monitoring intraoperatively with this ancillary test has reduced the rate of paraparesis to < 5%. Unfortunately, in the early postoperative period, spinal cord vulnerability is high. Therefore, some patients develop paraparesis, not during the surgical procedure, but after the surgical procedure. Postoperatively, suboptimal blood flow may lead to critical loss of function. This inadequate perfusion results in "delayed paraparesis". In the postoperative patient, it is not possible to measure MEPs when sedation is decreased, due to the high intensity of the electrical stimulus, which is unacceptably painful in the unanesthetized or partially anesthetized patient. Therefore ancillary tests are needed which can detect spinal cord ischemia postoperatively early, thus preceding the phase with clinically overt paraparesis. The test should be reliable and easy to perform for an extended period of time (up to several days). The purpose of this study is to explore the usefulness of various neurophysiological tests regarding accuracy and feasibility for the detection of spinal cord ischemia. In particular, to find a diagnostic test which is acceptable for the unanesthetized or partially anesthetized patient and therefore can also be performed postoperatively. These tests will be examined in fully sedated as well as partially sedated patients. The following candidate tests will be examined: 1. Long loop reflexes (LLR) consisting of F-waves. 2. Oxygenation measurements of the paraspinal muscles using Near-infrared spectroscopy (NIRS).
Aim oft he study is to compare two different devices for cerebral oximetry (FORE-SIGHTTM Monitor (CAS Medical Systems, Branford, Connecticut, USA and INVOSTM Somanetics, Troy, Michigan, USA) in patients undergoing surgical carotid thrombendarterectomy (cTEA) with crossclamped internal carotid artery (ACI). All procedures will be performed in regional anesthesia, therefore the patients will be awake and direct neurological examination during the procedure will be possible, giving information how the drop in cerebral saturation (measured with INVOS and FORESIGHT both on the same patient) correlates with any clinical symptoms. We expect to see a difference in the total drop and in the delay of the drop of cerebral oxygen saturation, making it possible to detect varieties in specificity and sensitivity of both devices compared to neurologic examination in the awake patient.