Thermographic Analysis of Hemodynamics Changes Through & Following Wingate Test
Condition: Health, Subjective
Study type: Observational

Summary: 
      Remote sensing and measurements of hemodynamic changes in blood flow for Wingate Anaerobic
      test using a novel image processing algorithm. The algorithm calculates the heat distribution
      from the thermal images and assesses the changes in blood flow and temperatures in the torso
      and legs for each individual participant.
    

Detailed description: 
      Remote sensing and measurements of hemodynamic changes in blood flow during and following the
      Wingate Anaerobic test using Infra-Red (IR) cameras with novel image processing algorithms.
      The algorithm calculates the heat distribution from the thermal images and computes the
      changes in temperatures measured in the torso and that measured in the lower limbs before the
      test, immediately after, and during 10 minutes recovery period.

      Background Thermal imaging The human body is self-generating and regulates the essential
      levels of temperature for survival. The body core is relatively stable in temperature, but
      the shell of the body (the surface tissues, which are mainly the skin) forms part of the
      regulatory process. Body temperature has been used to study many diseases where skin
      temperature can depict the presence of inﬂamation in underlying tissues, or where blood ﬂow
      is increased or decreased because of a clinical abnormality. Thermal imaging has been
      investigated for numerous medical applications. Several studies reviewed medical thermography
      [1-3]. Thermal imaging has been investigated for bowel ischemia [4], fever screening [5],
      diabetic foot, vascular disorder [6], thermoregulation study [7], and breast cancer [8].

      Wingate Test In the last 50 years, the Wingate Test is considered to be a common standard for
      the assessment of the anaerobic capability of athletes. The test is usually performed on
      computerized stationary bikes, while the participant has to pedal as hard as possible for
      only 30 seconds at resistance equivalent to 0.075 of their body weights (3).

      A previous study (4) has shown a high correlation between the effective power generated and
      the hemodynamic changes between the leg muscles and the thoracic area of the participant.

      Acute hemodynamic changes are the result of intensive vasodilation of metarterioles
      surrounding the main leg muscles and heavy blood perfusion. The massive blood flow in these
      areas causes congestion and slows the venous return to the heart.

      During this phase, we expect to see significant temperature change between the warm legs, and
      relatively cooler heart (torso). As the recovery phase progress, we expect to see the legs
      cool down and the torso warms up until homeostasis is reached.

      Thermal imaging and analysis The thermal imaging analysis will be performed using MATLAB
      software to extract two main features: mean temperature and the entropy, in a selected
      region-of-interest (ROI). First, the thermal image parameters will be stored in an EXCEL file
      as a two-dimensional matrix of temperature values. Then, the image (CSV file) is read to the
      program and the entire matrix is divided into the maximal temperature in the image. This
      yields a set of normalized temperatures in which the maximal value is 1 and which will be
      measured at rest, before the Wingate test has been performed. (This normalization is required
      to obtain correct entropy values using the MATLAB command.) The image is then resized
      fourfold in each axis and the result is displayed to the user. The user manually selects from
      this image a rectangular region, and the program extracts the mean value and the entropy of
      this region. The obtained mean value is multiplied by the maximal temperature in the original
      image (before normalization) to get the actual mean temperature (rather than the normalized
      temperature) in the selected ROI.

      The main study goal suggests a correlation between the power generated during the 30 seconds
      of the Wingate Test and the temperature difference between the hot legs and relatively cold
      torso.

      Method: 16 - 20 participants (10 men + 10 Women) healthy, age: 18-38, with some sports
      experience.

      Candidates will be screened by questionnaire + verbal interview, and then they'll sign the
      Voluntary Informed Consent form (copy attached). Each participant will do his test alone for
      about one hour.

      Test procedure: 5 minutes of warm-up, 2 minutes rest, ½ minute test, 10-15 minutes staying
      relaxed on the bike while the IR cameras are taking photographs synchronously every minute.

      Data gathering: 3 IR cameras (ONE Pro) will be fixed on 3 tripods, one for each leg, and one
      for the torso photographing. A Voice recorder will record every individual test completely.

      Data analysis The picture analysis will provide us with average (right & left) legs and torso
      temperatures every minute from test start and 15 minutes later.

      The SRM® bike computer will produce a power graph over 30 seconds of the test + Heart Rate
      recording of the participant for 15 minutes.

      Assuming a positive correlation between the average output power, and the temperature
      difference (legs vs torso), we'll draw a graph of all participants.

      Additional outcome results: Time required to full recovery - homeostasis, Heart Rate (HR)
      changes during recovery time. We may compare these additional results to the main correlation
      graph.
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Israeli volunteers