[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100658600":3},{"organization":4,"outcomesModule":7,"designInfo":18,"detailedDescription":21,"studyPopulation":22,"armGroups":23,"interventions":17,"overallOfficials":30,"centralContacts":35,"locations":44,"responsibleParty":66,"collaborators":17,"id":68,"slug":69,"hasResults":70,"nctId":71,"briefTitle":72,"officialTitle":73,"acronym":17,"eligibilityCriteria":74,"healthyVolunteers":75,"sex":76,"minAge":77,"maxAge":78,"enrollmentInfo":79,"targetDuration":17,"studyType":82,"phases":17,"briefSummary":83,"conditions":84,"keywords":17,"overallStatus":47,"whyStopped":17,"lastUpdateSubmitDate":97,"lastUpdatePostDateStruct":98,"startDateStruct":101,"completionDateStruct":103,"leadSponsor":105,"locationsCount":106},{"fullName":5,"class":6},"Heinrich-Heine University, Duesseldorf","OTHER",{"primaryOutcomes":8,"secondaryOutcomes":13,"otherOutcomes":17},[9],{"measure":10,"description":11,"timeFrame":12},"microvascular tissue oxygenation","StO₂, expressed as a percentage","within 20 Minutes of ischemia\u002Freprefusion protocol measurement",[14],{"measure":15,"description":16,"timeFrame":12},"Retinal funduscopy parameters","measured by NIRS",null,{"allocation":17,"interventionModel":17,"interventionModelDescription":17,"primaryPurpose":17,"observationalModel":19,"timePerspective":20,"maskingInfo":17},"COHORT","PROSPECTIVE","The study is a prospective, monocentric, controlled experimental study in healthy volunteers. It examines how external conditions, physiological states, and everyday behaviors influence measurements obtained with two-dimensional near-infrared spectroscopy (2D-NIRS). The imaging method is intended to assess local tissue oxygenation and microvascular perfusion non-invasively.\n\nDetailed study description\n\n1. General purpose\n\n   The CHECK-NIRS2D study is a prospective, monocentric, controlled experimental study conducted at the University Hospital Düsseldorf. It investigates how external conditions, physiological states, and behavioral factors influence measurements of local tissue oxygenation obtained using two-dimensional near-infrared spectroscopy (2D-NIRS).\n\n   The study uses the SnapshotNIR camera system (KD203, Kent Imaging Inc., Calgary, Canada). This non-invasive method produces spatially resolved images of tissue oxygenation, allowing the investigators to examine not only the overall oxygenation of a tissue region but also possible differences in perfusion between individual areas.\n\n   The study is intended as physiological and methodological research. It does not evaluate the therapeutic efficacy or safety of the device and does not provide a direct medical benefit to participants. Its longer-term objective is to develop a standardized protocol for future studies involving patients with acute or chronic diseases, particularly in emergency and intensive-care medicine.\n2. Participants\n\n   The study plans to include healthy adults:\n   * Age: 20-40 years\n   * Male and female participants\n   * Voluntary written informed consent after detailed explanation\n   * No acute illness at the time of examination\n   * No relevant cardiovascular, pulmonary, renal, vascular, or neurological history\n   * No relevant disease, previous surgery, or acute pathology affecting the examined upper limb\n   * Resting oxygen saturation of at least 95%\n   * No relevant resting hypotension or hypertension\n\n   Participants who regularly use medication affecting the cardiovascular system or blood coagulation, as well as pregnant or breastfeeding participants, are excluded.\n\n   Five substudies, designated A-E, are planned. Approximately 20 participants per experimental group are intended. Participants may take part in more than one substudy, but this is voluntary. The order of experimental protocols is randomized, and a recovery period of at least 60 minutes is planned between measurements of the same extremity, except where the caffeine- and nicotine-specific protocols require a different arrangement.\n3. General examination procedure\n\nThe examinations generally take place with the participant sitting upright. The arm to be examined is positioned beside the body, with the palm facing upwards and the elbow approximately at the level of the lower end of the sternum.\n\nThe following measurements are generally performed:\n\n* 2D-NIRS imaging of the hand or upper extremity\n* Measurement of regional and microvascular tissue oxygenation.\n* Repeated imaging during baseline, temporary ischemia, and reperfusion.\n* Vascular occlusion test (VOT)\n* A pneumatic blood-pressure cuff is inflated to 200 mmHg.\n* The radial pulse is checked at one-minute intervals to confirm interruption of arterial blood flow.\n* Depending on the protocol, the occlusion lasts three, five, or six minutes.\n* The cuff is then deflated, allowing reperfusion of the extremity.\n* Blood-pressure measurement\n* Systolic blood pressure\n* Diastolic blood pressure\n* Mean arterial pressure\n* Pulse oximetry\n* Measurement of peripheral oxygen saturation, or SpO₂.\n* Heart-rate measuremen\n* Capillary reperfusion time\n* Assessment of the time required for capillary perfusion to return.\n* Subjective pain assessment\n* Pain or discomfort during the vascular occlusion test is recorded using a Numeric Rating Scale (NRS).\n* Confocal retinal funduscopy\n* In specified experimental groups, the retinal microcirculation is examined using fully automated, confocal funduscopy.\n\nDepending on the substudy, this is performed at baseline and at the end of the experiment or repeatedly during control measurements.\n\nDuring the standard VOT protocols, heart rate, blood pressure, SpO₂, and pain are generally recorded at one-minute intervals. NIRS imaging and capillary reperfusion measurements are performed at shorter intervals during ischemia and early reperfusion, including every 30 seconds during ischemia and during the first five minutes after reperfusion begins.\n\nThe protocol includes:\n\n* Smokers and non-smokers\n* VOT and control conditions\n* Measurements after abstinence\n* A specific acute nicotine-exposure condition in smokers\n* NIRS imaging, VOT-related measurements, blood pressure, heart rate, SpO₂, pain assessment, and capillary reperfusion measurements are performed. In selected groups, retinal funduscopy is conducted at the beginning and end of the experiment.","healthy volunteers",[24,27],{"label":25,"type":17,"description":26,"interventionNames":17},"Intervention","predefined measurements",{"label":28,"type":17,"description":29,"interventionNames":17},"Control Group","Standardized 2D-NIRS imaging at rest under predefined reference conditions, including the protocol-defined VOT.",[31],{"name":32,"affiliation":33,"role":34},"Malte Kelm, MD","Division of Cardiology, Pulmonary Disease and Vascular Medicine at University Hospital Duesseldorf","STUDY_CHAIR",[36,41],{"name":37,"role":38,"phone":39,"phoneExt":17,"email":40},"Patricia Wischmann, MD","CONTACT","+49211 18000","patricia.wischmann@med.uni-duesseldorf.de",{"name":42,"role":38,"phone":17,"phoneExt":17,"email":43},"Stefan Hof, MD","Stefan.hof@med.uni-duesseldorf.de",[45],{"facility":46,"status":47,"city":48,"state":17,"zip":49,"country":50,"countryCode":51,"cosmosGeoPoint":52,"geoPoint":57,"contacts":58},"University Hospital Duesseldorf","RECRUITING","Düsseldorf","40225","Germany","DE",{"type":53,"coordinates":54},"Point",[55,56],6.77927,51.22319,{"lat":56,"lon":55},[59,60,62,64],{"name":37,"role":38,"phone":39,"phoneExt":17,"email":40},{"name":42,"role":38,"phone":61,"phoneExt":17,"email":43},"+ 49211 81 18800",{"name":37,"role":63,"phone":17,"phoneExt":17,"email":17},"PRINCIPAL_INVESTIGATOR",{"name":42,"role":65,"phone":17,"phoneExt":17,"email":17},"SUB_INVESTIGATOR",{"type":67,"investigatorFullName":17,"investigatorTitle":17,"investigatorAffiliation":17,"oldNameTitle":17,"oldOrganization":17},"SPONSOR","100658600","check-nirs2d-study-100658600",false,"NCT07854431","CHECK-NIRS2D-Study","Influence of External Physiological and Behavioral Factors on Two-Dimensional Near-Infrared Spectroscopy-Based Imaging in Healthy Volunteers: A Controlled Experimental Study","Inclusion Criteria:\n\n* Healthy volunteers aged 20-40 years\n* Written informed consent\n* Ability to understand and comply with the study procedures\n\nExclusion Criteria:\n\n* Age below 20 years or above 40 years\n* Cardiovascular disease or other relevant medical conditions\n* current medication, where relevant to the study procedures\n* contraindication to or inability to undergo the planned examinations\n* Any condition that may interfere with the study procedures or outcome measurements",true,"ALL","20 Years","40 Years",{"count":80,"type":81},20,"ESTIMATED","OBSERVATIONAL","The study investigates how external, physiological, and behavioral factors influence the measurement of regional tissue oxygenation using two-dimensional near-infrared spectroscopy (NIRS) imaging in healthy volunteers. It aims to improve the standardization and reliability of this non-invasive method for assessing microvascular perfusion and tissue oxygenation.\n\nThe study also examines the effects of temporary vascular occlusion, ambient temperature, physical activity, caffeine consumption, and nicotine consumption on NIRS-based tissue oxygenation measurements. The findings are intended to establish a standardized measurement protocol for future clinical research and the assessment of microvascular perfusion in critically ill patients.",[85,86,87,88,89,90,91,92,93,94,95,96],"NIRS","Tissue Oxygenation","Microvascular Perfusion","Vascular Occlusion Test","Ischemia-reperfusion","Healty Volunteers","Physiological and Behavioral Factors","Temperature","Caffeine","Nicotine","Microcirculation","Protocol Standardization","2026-09-28",{"date":99,"type":100},"2026-10-02","ACTUAL",{"date":102,"type":100},"2026-07-28",{"date":104,"type":81},"2027-03-01",{"name":5,"class":6},1]