SCOPE OF STUDY: The objective of the study to evaluate the Breathable Crib Mattress for its potential to create a hazardous condition for carbon dioxide rebreathing.
CARBON DIOXIDE (CO2) REBREATHING HAZARD ASSESSMENT: Carbon dioxide rebreathing increases respiratory effort. Rebreathing of exhaled air is one proposed mechanism for the increased risk for Sudden Infant Death Syndrome (SIDS) among prone sleeping infants. An increased risk for SIDS has been noted for infants at the age of 13 to 24 weeks.
EXPERIMENT DESIGN: The capability of the crib mattress sample provided by Secure Beginnings to act as a carbon dioxide reservoir was compared with the capability of products with known levels of hazard. Sheepskins and fabric covered polystyrene bean filled cushions have been implicated in a significant number of SIDS fatalities, and therefore have been selected to represent products with a high level of hazard. A firm crib mattress covered by a cotton sheet has been selected to represent a low level of hazard consistent with the policy statement of the American Academy of Pediatrics task force on SIDS. The mattress brand used in this assessment is a Sealy ‘Cozy Rest’ crib mattress.
For the comparator items, the presence of carbon dioxide was evaluated in an area at close proximity to the oral and nasal openings within the product itself, to determine the potential of the product to act as a reservoir for carbon dioxide. Because the Secure Beginnings Crib Mattress is hollow, the presence of carbon dioxide was evaluated in an area just underneath the sleep surface.
A mannequin representing a six month old infant was used as the interface to evaluate the product. The mannequin was placed with its oral opening against the sample. This position is implicated in SIDS incidents.
BREATHING CONTROL AND DATA ACQUISITION:
The mechanical breathing hardware consists of a four channel USB controlled relay module, four 120VAC pneumatic solenoids, two diaphragm style pumps and a tank of CO2/Air mixed gas. The solenoid valves, compressed gas, and diaphragm pumps were plumbed such that by controlling the opening and closing of the valves a simulated breathing pattern could be achieved. Each breath of the breathing pattern consisted of three parts, an inhale portion, an exhale portion, and a rest portion. The inhale portion was 45% of the cycle, the exhale portion was 45% of the cycle, and the rest portion was 10% of the cycle.
The respiration rate is in breaths per minute and can be increased or decreased by changing parameters in the control software while the flow rate is controlled by rotameters.
The data acquisition hardware used in this experiment was a TreyMed OEM Compact CO2 Waveform Analyzer. The OEM Compact CO2 Waveform Analyzer (CO2WFA) is a complete data collection and analysis system for monitoring respiratory carbon dioxide concentration. The CO2WFA module includes a miniature CO2 sensor, barometric pressure transducer, sampling flow control and a miniature low-power vacuum pump. A microprocessor collects the sensor data and calculates various real-time parameters: instantaneous CO2 concentration, respiration rate, end-tidal CO2, inspired CO2, inspiration and expiration times.
The pump provided with the CO2WFA module is capable of sampling patient gas at a regulated 50-250 cc/min, and can provide some protection from occlusions in the sample line. The module automatically performs calibrations to correct for changes in temperature, altitude and electronic component drift by switching a solenoid valve from the sample line to ambient air for a few seconds in order to collect a reference point used in the CO2 calculation. All communications between the host computer and the module i.e. sent commands; received waveforms, breath parameters and command responses are via 3.3V asynchronous serial data lines.
Human exhaled air is composed of nitrogen, oxygen, carbon dioxide and water. The sensors used in this study can be negatively affected by the presence of water; therefore, dry air was used for this study. Except for the absence of water, the composition is similar to that of human expiration; 76% N, 17% O, 5% CO2, 2% Argon.
THE MANNEQUIN for this setup was designed to be the interface between the evaluation hardware and the product sample to be tested. It was constructed of bio-simulating materials and was plumbed with tubing simulating air passages in order to introduce and draw off the evaluation gasses into and out of a sample. Along with simulated air passages, the mannequin was constructed to be the appropriate size and weight of a child approximately 6 months of age. This is to provide a realistic physical interaction between the mannequin and the sample material.
As the mannequin and the accompanying hardware breathe into the sample, the mixture of gasses that are expelled are representative of those gasses present in the exhaled air of an at-rest human. As the mannequin inhales from the sample, the gasses that it breathes back in are a mixture of the previous exhaled gasses and the ambient room air.
This carbon dioxide rebreathing evaluation was conducted on the Secure Beginnings Crib Mattress sample and compared to items with a known hazard level, including a firm inner spring crib mattress with cotton sheet, sheepskin, and fabric covered polystyrene bean bag cushion.
For all experiments, the head of the mannequin was placed with its face pressed into the samples (in a position prone to CO2 rebreathing hazard).
The results from the carbon dioxide rebreathing assessment of the Secure Beginnings Crib Mattress showed very low risk compared to the known lower level hazard comparator item of a firm mattress. Carbon dioxide retention for the Secure Beginnings Crib Mattress (6.55 %CO2seconds)
The testing data/results along with visual images were sent to Dr. William W. Fox, Division of Neonatology, Children’s Hospital of Philadelphia, and Dr. Thomas H. Shaffer, Department of Biomedical Research, Alfred I. duPont Hospital for Children for expert medical opinion to confirm the level of hazard for carbon dioxide rebreathing. They confirmed that the Secure Beginnings Crib Mattress has a very low risk for carbon dioxide rebreathing.
Given the results of the carbon dioxide evaluation and the expert medical consultation, the Secure Beginnings Crib Mattress poses a significantly lower hazard for carbon dioxide rebreathing than the tested firm crib mattress. While the firm crib mattress represents a known low hazard item and is recommended by the American Academy of Pediatrics to reduce the risk of SIDS, SIDS cases have occurred on firm crib mattresses. The Secure Beginnings Mattress demonstrates a significant decrease in carbon dioxide retention compared to the firm crib mattress and presents a significantly lower hazard level than the firm crib mattress.
See full test results at http://www.securebeginnings.com/
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Secure Beginnings, Manufacturers of Safe Sleep Products for infants and toddlers. Located in Detroit, Michigan. Company founders experienced loss of loved one to SIDS (Sudden Infant Death Syndrome), and have developed revolutionary Breathable Mattresses and bedding to address ALL the risk factors associated with SIDS and safe sleep.