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Tag Archives: Clinical Applications
Su-007-Exploring Motor Network Connectivity in Parkinson’s Disease Using fNIRS
Seed-based bilateral motor functional connectivity during a motor task was investigated in patients with Parkinson's disease (PD) and healthy controls using CW fNIRS. Functional activation analysis was used to localize active channels to use as seeds for functional connectivity (FC). Results show that PD patients exhibit lower functional connectivity than control participants during the task with the dominant hand, suggesting a neural basis for motor deficits in PD patients. Continue reading
Sa-009-Assisting Diagnostic Applications of Functional Near-Infrared Spectroscopy for Depression and Bipolar disorder
Distinguishing between major depressive disorder (MDD), bipolar disorder (BP), and healthy individuals poses challenges due to overlapping symptoms and limited neuromonitoring tools. This study explores the potential of fNIRS technology to address this issue. Participants diagnosed with MDD, BP, and healthy controls underwent cognitive stimulation while hemodynamic responses were measured using fNIRS. Significant differences were observed in age, education, and task performance among groups. Hemodynamic features showed promise in distinguishing individuals with mood disorders from healthy controls. Continue reading
Sa-002-Physiological response to partial and full body submerged, end-inspiratory, and end-tidal apnea
Physiological responses to apnea involve complex mechanisms to manage the distribution of oxygen, theorized to increase in magnitude with facial submersion in water. The different effects of apnea in wet conditions have been closely studied in experienced free divers, but the responses of untrained individuals to apnea under similar conditions are not well understood. Our study, using near-infrared and diffuse correlation spectroscopy, found that oxygen levels and blood flow increased significantly in cerebral regions but decreased in peripheral regions during apnea. Submersion intensified these effects in the brain, but not in other regions. These findings help specify how the body adapts to oxygen deprivation, relevant for conditions like sleep apnea. Continue reading
Fr-108-Near-Infrared Spectroscopy Based Cerebral Oximetry Monitoring in Extremely Preterm Infants: Discussion of Two Recent Controversial Clinical Trials (SafeBoosC-II, SafeBoosC-III)
There were two studies on the usefulness of near-infrared spectroscopy based cerebral oximetry (NIRSCO) in extremely preterm infants to prevent death or severe brain injury. The first smaller study showed a borderline significant but large effect. However, the second larger study showed no differences between the NIRSCO and control groups. Our statistical analysis showed that the results of the two studies are significantly different. Possible reasons for this discrepancy are discussed. Continue reading
Fr-105-Finite Element Modelling of Abdominal Near Infrared Spectroscopy for Infant Intestinal Oximetry
Necrotizing enterocolitis (NEC), an inflammatory injury of the intestines, is a major complication affecting newborns with congenital heart disease. Abdominal near-infrared spectroscopy (NIRS) holds promise for the early diagnosis of intestinal ischemia associated with NEC, but the optimal NIRS sensor design for intestinal oximetry is not well defined. Using finite element modeling to simulate abdominal NIRS signals from infants, we computed contrast-to-noise ratio (CNR) as a function of source-detector distance for intestinal oximetry. Intestine CNR was maximal at source-detector distances between 4-5 cm. Sensitivity to intestine tissue also exceeded sensitivity to superficial adipose tissue in the 4-5 cm range. Continue reading
Sa-014-Developing a novel brain-based biomarker of depression treatment response using time-domain functional near-infrared spectroscopy
Despite the heavy burden of major depressive disorder, quantitative tools to guide clinicians in making treatment decisions are lacking. In this study, we measured depression patients longitudinally using Time-Domain functional Near-Infrared Spectroscopy (TD-fNIRS) brain recordings at rest and during a cognitive task. Patients were measured before they started treatment, after the first treatment, and at the end of treatment, and additional clinical and self-report data was collected. We found metrics that differentiated treatment responders from remitters, including neural responses during a verbal fluency task. Future work will include building a classification model for predicting depression treatment response. Continue reading
Sa-045-A digital instrument simulator to optimize the development of hyperspectral systems for intraoperative brain mapping
In this study, we developed a digital instrument simulator based on Monte Carlo simulations to obtain realistic images of exposed brain cortex. In addition, we developed an optimization procedure for identifying the optimal wavelength for resolving Haemoglobins and Cytochorme-C-Oxidase concentrations accross the visible and NIR range. Continue reading
Sa-042-A diffuse optical tomography system to scan acute traumatic brain injury patients in the intensive care unit: a prospective study on healthy volunteers
Diffuse optical tomography (DOT) is untested on traumatic brain injury (TBI) in the intensive care unit (ICU). We developed a system for this data acquisition and analysis. Probe displacements and monitoring of the intracranial (ICT) and extracranial tissues (ECT) were tested in 23 healthy volunteers during 5 Valsalva maneuvers, using DOT. Probe displacement of 5.5 mm, and a sufficient capacity to isolate oxyhemoglobin (O2Hb) (p=6.4·10-6) and total hemoglobin (HbT) (p=2.8·10-5) in the ICT from the ECT, and to monitor O2Hb (p=9.2·10-4) and HbT (p=1.0·10-3) in the ICT. The developed approach is suitable for TBI in the ICU. Continue reading
Sa-039-Contrast-enhanced diffuse optical tomography in acute, moderate and severe traumatic brain injury: a prospective observational study
Contrast-enhanced diffuse optical tomography (DOT) could monitor the heterogenous cerebral perfusion in traumatic brain injury (TBI) (1, 2). We present the first contrast-enhanced DOT study in acute, moderate and severe TBI in the intensive care unit. Changes of absorption coefficient in the intracranial (ICT) and extracranial tissues (ECT) following two injections of indocyanine green (ICG) were scanned using DOT on 10 TBI patients. The ICG kinetic and brain lesions were compared. The width parameter (seconds) and lesion locations agreed in the ICT (p=3.5·10-3), but not in the ECT (p=1.8·10-1). Pathological cerebral perfusion were retrieved using DOT. Continue reading
Sa-094-Assessing the Reproducibility of a Hybrid Time-Resolved NIRS/DCS System for Daily Hemodynamic ICU Monitoring
Bedside cerebral oxygenation and blood flow monitoring in the intensive care unit (ICU) has the potential to improve early detection of cerebral ischemia. To assess the feasibility of daily optical monitoring, the reproducibility of oxygenation and blood flow measurements using an in-house built time-resolved NIRS/DCS system was assessed. Data were collected on three days (1,2, and 7); each consisted of three acquisition sessions where the probes were removed and re-secured between sessions. Oxygenation varied by <6% within and between sessions, while blood flow varied by 15% within sessions and 26% between sessions. Continue reading