Evaluating the State of Microvessels by Minimum Rise Time (MRT01)

NCT02527070 | Completed

• 1 other identifier: 2080-15-SMC
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 1

Brief Summary

Photoplethysmography (PPG) is a simple uncalibrated optical method of monitoring variations in skin blood volume. The objective of the current study is to investigate a potential relationship between MRT (minimum rise time, in time units) a measure derived from PPG and the state of microvessels. This study includes a 1-2 hour single session per subject during which PPG and other microvascular and systemic variables will be monitored in response to non-invasive interventions that are known to elicit microvascular responses.

Conditions

Healthy

Outcome Measures

Primary Outcomes (3)

• MRT as measured from finger Photoplethysmography in response to changes in breathing rate

  Change from baseline to up to 1 minute after termination of 2 minutes of constant breathing rate (15, 10, and 6 breath/min)

• MRT as measured from finger Photoplethysmography in response to light source

  Change from immediately before exposure to light source to up to 10 minutes after exposure to light source

• MRT as measured from finger Photoplethysmography in response to temperature changes

  Change from immediately before exposure to temperature provocations to up to 2 minutes after exposure to warm water, and up to 2 minutes after exposure to cold water

Secondary Outcomes (2)

• Capillary blood flow (red blood cell velocity or flux in 'perfusion units') as measured by laser doppler

  At baseline, 1 minute after each changes in breathing rate, 5 and 10 minutes after exposure to light source, 1 minutes after each exposure to temperature changes

• Transcutaneous oxygen pressure (tcpO2 in mmHg)

  At baseline, 1 minute after each changes in breathing rate, 5 and 10 minutes after exposure to light source, 1 minutes after each exposure to temperature changes

Study Arms (2)

Red LED

EXPERIMENTAL

Light emitting diodes, 670 nm, 50 mW/cm2, Quantum Warp10 (Quantum Devices Inc, Barneveld, WI, USA); RESPeRATE; Heat/cold provocation

Device: RESPeRATE (Paced Breathing); Device: Quantum Warp10 (Red LED); Other: Heat/cold provocation

Near Infrared LED

ACTIVE COMPARATOR

Light emitting diodes, 830 nm, 55 mW/cm2, Omnilux new-U (Photomedex, Horsham, PA, USA); RESPeRATE; Heat/cold provocation

Device: RESPeRATE (Paced Breathing); Device: Omnilux new-U (Near Infrared LED); Other: Heat/cold provocation

Interventions

RESPeRATE (Paced Breathing) DEVICE

The subjects will be guided by a digital metronome to breath at 15, 10, and 6 breaths/min for 2 minutes each using the metronome function of the device RESPeRATE (InterCure, Israel) that guides breathing using musical tones played at selectable rhythm.

Near Infrared LED; Red LED

Quantum Warp10 (Red LED) DEVICE

Red LED

Omnilux new-U (Near Infrared LED) DEVICE

Near Infrared LED

Heat/cold provocation OTHER

Immersion of one foot in a warm water bath ( 43-45 degrees C) for few seconds and then immersion of the same foot in cold water bath (5-7 degrees C) for 1 min.

Near Infrared LED; Red LED

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy males and females, between 18 and 65 years of age.
• Willing to sign informed consent.

You may not qualify if:

• Currently smoking
• Any abnormal skin condition in the area of light irradiation.
• Pregnant having given birth less than 3 months ago, and/or breastfeeding.
• Having a history of diseases stimulated by heat, such as recurrent Herpes Simplex in the treated area, unless treatment is conducted following a prophylactic regimen.
• Having any illness that might affect the vasculature, such as diabetes (type I or II)
• Suffering from significant concurrent illness, such as cardiac disorders, , or pertinent neurological disorders.
• As per the Investigator's discretion, any physical or mental condition which might make it unsafe for the subject to participate in this study.

Sponsors & Collaborators

• Afeka, The Tel-Aviv Academic College of Engineering: lead
• Sheba Medical Center: collaborator

Study Sites (1)

Afeka, Tel-Aviv Academic College of Engineering

Tel Aviv, Israel

Location

Related Publications (1)

• Gavish B. Plethysmographic characterization of vascular wall by a new parameter--minimum rise-time: age dependence in health. Microcirc Endothelium Lymphatics. 1986-1987;3(3-4):281-96.

  PMID: 3431526 RESULT

Study Officials

• Moshe Halak, MD

  Sheba Medical Center

  PRINCIPAL INVESTIGATOR

• Zehava Blechman, PhD

  Afeka, Tel-Aviv Academic College of Engineering

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 28, 2015
• First Posted: August 18, 2015
• Study Start: September 1, 2015
• Primary Completion: June 1, 2016
• Study Completion: October 1, 2016
• Last Updated: October 17, 2016

Record last verified: 2016-10

Locations

IL (1)