Development of Helmet-Patient Interface for Non-Invasive Ventilation (Oxygen Helmet)

Need for Non-Invasive Ventilation in COVID-19 in India

  • Unprecedented health crisis in India
  • Graph still exponential with 12.4 lakhs cases and 29,861 deaths (8 am July 23 )
  • COVID-19 causes respiratory distress
  • ~5% of the infected patients need oxygenation and ~2% need ventilator support
  • High-flow Nasal Canula is conventionally used for oxygenation
  • A helmet patient interface (HPI) which delivers oxygen-rich air at a constant positive airway pressure (CPAP) is very effective way of oxygenation for COVID-19 Hypoxia patients
  • The effectiveness of this NIV helmet with COVID-19 patients has been reported from Europe

Strong Case for Helmet Patient Interface

  • Clinical review of 152 studies establishes efficacy of helmet-based NIV
  • NIV with helmet reduces CO2 rebreathing and ventilator asynchrony
  • Review concludes “NIV delivered by helmet could be safe alternative to the face mask in patients with acute respiratory failure”
  • Suggested key points
    • – Long duration NIV
    • – Skin lesions
    • – Air leaks in masks/Mask intolerance
    • – Avoid CPAP via Mechanical Ventilator
    • – 50% higher PEEP with helmets as compared to masks

Helmet Patient Interface (HPI) Non-invasive Ventilation (NIV) for Hypoxia

HPI SPECIFICATIONS
• Continuous Air/O2 delivery
• Adjustable flowrate: 15 – 60 LPM
• FiO2 between 21% (Air) to 100% (Pure O2)
• Adjustable expiratory pressure : 5 – 20 cm H2O
• HPI works with CPAP device, wall oxygen-air supply, or any
commercial ventilator

Studies have found non-invasive ventilation to be extremely effective
based on objective parameters of pulmonary mechanics, biochemistry
and final treatment outcomes

Key Features and Benefits

• Benefits for the Patient
– Ventilation asynchrony is not present, minimizes claustrophobia, avoids pain and sense of suffocation
– No nasal cannula or intubation, no headgear to tighten, no irritation → Comfort for a longer period
– Spacious with a clear view all around
– Patient can speak, listen, drink, wear glasses while being treated
• Patient Management
– Due to completely sealed and “zero leakage”, protects associated health workers
– As patient is more comfortable, treatment is continued without breaks associated with intubation, mask
pressures, nebulized drug therapy etc.
– LARGE ACCESS PORT: For easy care – drink, facial cleaning, expectorate
– SEALED CATHETER PORT: Provides access for drug delivery, sensors, liquid intakes
– The upper portion is easily removable
• Safety Features and Alarms
– Anti-asphyxia valve and pressure relief valves
– The HEPA filter ensures patient exhales pathogen-free air for safety of health workers
– AUDIO-VISUAL ALARMS: Low Pressure/High Pressure/Battery Fault/Low Battery/Battery Charge Indicator
– Separate flow meters for oxygen and total flow/FiO2 calculator (On CPAP device)

Computational Fluid Dynamics (CFD)

• CFD analysis provides a streamlined flow of air/oxygen under different flow rate conditions.
• Inlet/Outlet locations optimized for minimum CO2 rebreathing and maximum oxygenation

System Verification and Validation

Test protocols designed to verify the functioning of the device
• Integrity, leakage and pressure hold test (up to 30 cm H2O pressure)
• Flow and pressure drop test (up to 40 LPM flow)
• PEEP pressure hold test (up to 40 LPM flow, 20 cm H2O pressure)
• High flow mode test (up to 60 LPM)
• Helmet fitment, fogging, and noise level test (on mannequin)
• Safety interlock check

Technical Matter & Images copyright https://www.ircc.iitb.ac.in/IRCC-Webpage/rnd/Prof_RameshSingh.pdf

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Dr Satish Deopujari

Dr Satish Deopujari is on a mission to keep on innovating, much like a perpetual innovation machine, which works across boundaries of disciplines, geographies, you name it. He has worked with innumerable causes and people from rural India to the top experts globally. He is hungry for contributing more innovations to humanity and if you're looking to collaborate with him, reach out to him right away!