Research Article
Volume 8 Issue 5 - February 2020
DOI: 10.19080/AJPN.2020.08.555808
Acad J Ped Neonatol
Copyright © All rights are reserved by Anuj Bellare
A Low-Cost Venturi Ambient Air-Oxygen
Blender for Neonatal Oxygen Therapy
Kamyar Mollazadeh-Moghaddam
1,2,3
, Thomas Friedrich Burke
1,3,4,5,6,ǂ
, Michelle Dundek
1,3,ǂ
, Shu Ho Yeung
2
, Rupam
Sharma
1,3
, Revathi Ravi
1,6
and Anuj Bellare
2,3
*
1
Division of Global Health Innovation, Department of Emergency Medicine, Massachusetts General Hospital, Boston, USA
2
Orthopedic Nanotechnology Laboratory, Department of Orthopedic Surgery, Brigham and Women’s Hospital, Boston, USA
3
Vayu Foundation, Boston, USA
4
Harvard Medical School, Boston, USA
5
Harvard TH Chan School of Public Health, Boston, USA
6
Department of Pediatrics, Massachusetts General Hospital for Children, Boston, USA
Submission: January 09, 2020; Published: February 04, 2020
*Corresponding author: Anuj Bellare, Orthopedic Nanotechnology Laboratory, Department of Orthopedic Surgery, Brigham and Women’s Hospital,
Boston, Massachusetts, USA
ǂCo-second authors: Thomas Friedrich Burke, Division of Global Health Innovation, Department of Emergency Medicine, Massachusetts General
Hospital, Boston, Massachusetts, USA
Michelle Dundek, Division of Global Health Innovation, Department of Emergency Medicine, Massachusetts General Hospital, Boston, Massachusetts,
USA
Acad J Ped Neonatol 8(5): AJPN.MS.ID.555808 (2020)
Introduction
Supplemental oxygen is often necessary for preterm newborns
in respiratory distress [1]. Nasal cannulas (with low flow or high
flow gas), different types of continuous positive airway pressure
(CPAP), nasal intermittent positive pressure ventilation, hoods,
and facemasks are common noninvasive devices used to deliver
supplemental oxygen to neonates [2-7]. While supplemental
oxygen is often important for these patients, high concentrations
(hyperoxia) may be harmful [8]. Bronchopulmonary dysplasia
and retinopathy of prematurity are two major adverse effects of
administering high concentrations of inspired oxygen to preterm
Academic Journal of
Pediatrics & Neonatology
ISSN 2474-7521
0069
Abstract
The concentration of oxygen delivered to neonates in respiratory distress should be controlled to prevent hyperoxia. Current available
oxygen blending devices have limited use in resource-limited settings due to their reliance on electricity, compressed air, skilled maintenance,
and high cost. This study evaluated the ability of a novel blending device that addresses these limitations to deliver inspired concentrations
of oxygen over a range of 30-100%. Our blending device was designed based on the Venturi principle. The blender consists of a nozzle, air
entrainment window, and orifice. Oxygen exits the nozzle at high velocity into an air-entrainment chamber, where the low pressure surrounding
the jet draws in ambient air. The mixture of air and oxygen is then transported into the orifice and thereafter further downstream via tubing. We
investigated the effect of geometric factors and process variables on the delivered oxygen concentrations. The diameter of the Venturi nozzle and
outlet orifice, the cross-sectional area of the air-entrainment window, the distance between the Venturi nozzle and the outlet orifice, flow rate,
and temperature were each analyzed as independent variables. Understanding the geometric relationships between Venturi nozzle diameters,
air-entrainment window cross-sectional areas, and Venturi nozzle to outlet orifice distances provided guidance on the design of an ultra-low-
cost Venturi ambient air-oxygen blender. This study demonstrates the feasibility of manufacturing an air-oxygen blender that is low cost, does
not require electricity or compressed air, and can provide accurate concentrations of oxygen for optimal delivery to neonates with respiratory
distress.
Keywords: Global health; Affordability; Accessibility of health services; Healthcare quality; Oxygenation; Hyperoxia; Neonatal diseases; Medical
device design; Biomedical engineering; Respiratory distress and failure
Abbreviations: CPAP: Continuous Positive Airway Pressure; FiO
2
: Fractional Oxygen Concentration