The Affect of a Ventilated Helmet on Physiological Load

Study Overview
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Brief Summary
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The use of infantry helmets under heavy heat stress conditions, during physical exertion, may hinder the body's ability to effectively dissipate heat from the head area, thereby damaging the soldier's function. Therefore head cooling may potentially enable a longer duration of activity until reaching fatigue. An improvement in function may also be possible.The purpose of this research is to determine the extent of the cognitive and physiological strain caused by wearing a helmet under exertional conditions while exposed to heavy heat stress and to evaluate the effect of a unique ventilation system connected to the helmet on strain reduction.

Detailed Description
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12 young, healthy civilian volunteers, aged 21-28 will participate in the study. Following a day of examinations and 6 days of acclimatization in a climatic chamber in accordance with a well accepted protocol, the subjects will undergo 3 days of experiment that will include exposure to hot environmental conditions with different helmet-wearing scenarios, while wearing uniform and a combat vest: (a) without a helmet (b) with a helmet (c) with a helmet connected to a ventilation system. All 3 scenarios will include a two hour effort (walking on a treadmill) in heavy heat stress in the climatic chamber at our institute (the Heller institute of medical research).

Official Title
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The Affect of a Ventilated Helmet System on Human Physiological Load

Conditions
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Physiological Strain

Intervention / Treatment
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* Procedure: Ventilated Helmet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy civilian volunteers aged 21-28 without known medical illnesses or medication use Exclusion Criteria: the existence of or suspicion of existing cardiac or respiratory disease hypertension diabetes any hormonal disease or any other chronic illness that may inhibit participation in the experiment infectious disease 3 days prior to the experiment.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 28 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: The experiment subjects<br>The subjects will undergo: 6 acclimatization days carried out by a standard protocol including a daily 2 hour effort performed in a climatic chamber, during which the subjects walk on a treadmill at 5km/h on a 2% incline under heat conditions (40 deg. centigrade & 40% RH). Core (rectal) and skin temperatures and heart rate will be monitored continuously. Three consecutive days including 3 scenarios: Without a helmet b.With a helmet c.With a ventilated helmet During the experiment days the subjects will be exposed to the following protocol : A 5 minute sitting, performing cognitive tests on a computer for 15 min, 120 min walking on a treadmill at 5km/h on a 2% incline, at the end of the effort the same cognitive tests will be repeated for extra 15 min, 155 min in total. | Procedure: Ventilated Helmet<br>* The ventilation system is installed on the inner part of the helmet and connected to a bellows and an energy source placed on the vest worn by the soldier. The system's working principal is based on air perfusion with a small ventilator.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Physiological strain | The physiological strain will be determined by body core temperature and heart rate of the subjects during a heat tolerance test(HTT). | 9 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rectal temperature | The Rectal temperature will be mesured by a rectal thermistore during each HTT | 9 days | 
| Skin temperature | The Skin temperature will be mesured by skin thermistores on 4 sites (chest, leg and arm and head). | 9 days | 
| Heart Rate | Heart rate will be monitored using a polar watch. | 9 days | 
| Sweat Rate | Sweat rate will be calculated from the patient's weight and his water balance | 9 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Helmet, Heat Tolerance Test, ventilation System