Transcript Temperature Monitor and Control

Temperature Monitor and
Control for Infant Incubators
Team Members: Kristin Donato and Qingwen Kawaji
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Who Needs Incubators?
• Temperature regulation is one of the most important factors affecting
survival in newborn infants.
• Premature infants are at an even greater disadvantage because of the
larger skin surface area to body mass ratio, decreased subcutaneous fat, and
low supplies of brown fat. Also, the normal surge in metabolic rate that
occurs after birth is reduced in preterm infants, resulting in limited heat
production.
[Antonucci, R., et al. The infant incubator in the neonatal intensive care unit: unresolved issues and future developments. Journal of
Perinatal Medicine. 37(6): 587-98.]
• In developing countries, neonatal complications including
prematurity and low-birth weight are common, and thus the use of
infant incubators may considerably contribute to reducing infant morbidity
and mortality. Unfortunately, the limited access to modern, high-tech
incubators along with the lack of infrastructure and replacement parts
render such devices worthless in these regions.
[Antonucci, R., et al. The infant incubator in the neonatal intensive care unit: unresolved issues and future developments. Journal of
Perinatal Medicine. 37(6): 587-98.]
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Why Incubators?
• Infants typically lose heat to their environment in four different
ways: through conduction, convection, radiation, and evaporation.
• Premature brain cannot provide adequate temperature regulation.
[Dr. Van Hemel. HEBI-incubator.org]
• Studies have shown that creating an environment of ideal
temperature for infants increases the survival rate.
[Day, Richard L., et al. Body Temperature and Survival of Premature Infants. Pediatrics 34.2 (1964): 171-81. ]
• One of the very first incubators, invented by Stéphane Tarnier in the
late 19th century, reportedly reduced mortality among infants with
birth weights between 1200 and 2000 g from 66% to 38%.
[Auvard, A. De La Couveuse Pour Enfants. Archives de Tocologie des Maladies des Femmes et des Enfants Nouveau-nés.
10:577-609, October 1883.]
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Giraffe Incubator
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Most recent product of GE Health Care
Advantages:
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Precise temperature control
Minimizes external stress such as light, sound
and touch.
Built in scale
X-ray can be taken from the canopy
Built in rotating mattress & for pressure point
release (Patented Baby Susan)
Humidifier tested to avoid the spread of
pseudomonas aeruginosa. (common pathogen
linked to use of ambient relative humidity)
Disadvantages:
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Needs professional personnel: Need to take a
class provided by GE in order to be qualified to
use the incubator. (cost: $3185)
Very expensive: $30,000-40,000
Vendor’s Site:
https://www2.gehealthcare.com/portal/site/usen/menuitem.e8b305b80b84c1b4d6354a1074c84130/?vgnextoid=470117398714
0210VgnVCM10000024dd1403RCRD&productid=3701173987140210VgnVCM10000024dd1403
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
“Car Part” Incubator
• Advantages:
▫ Made from readily available parts
▫ Moderately cheap ($1,000)
▫ Glass is more “baby safe”
• Disadvantages
▫ Difficult to assemble
▫ New design with no study on
infection rates
▫ No sleeves for contact with the
infant
▫ No fine temperature control
Center for Integration of Medicine &
Innovative Technology (CIMIT)
Global Health Initiative and Design
that Matters project from 2008
Vendor’s Site: http://www.cimit.org/images/programs/GHI_Incubator_Handout.pdf
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
“Car Part” Incubator
• Made from:
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Exterior metal and windows
Heater and fan system
Battery
Lights and alarm system
• How it works:
▫ Automotive parts are capable of being repurposed to produce
heat, light, air convection, a power reservoir, as well as auditory
and visual alarms.
Vendor’s Site: http://www.cimit.org/images/programs/GHI_Incubator_Handout.pdf
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
HEBI (Hemel Baby Incubator)
• Advantages:
First built in Uganda in 1968.
About 25 new incubators are
supplied each year, and the basic
model comes as a construction
kit. They are manufactured with
aid from many sponsors.
▫ Relatively Cheap (about $600 USD)
▫ Reliable (oldest incubators are still operational
w/o any serious maintenance)
▫ Includes hygrometer for humidity control
▫ Excellent infection control
▫ Sleeves for unlimited contact
▫ Assembly takes only about an hour for an
untrained person
• Disadvantages:
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Does not have a motor
No fine temperature control
Consumes 150 Watt/hr
Must be shipped by plane from the Amsterdam
airport
Vendor’s Site: http://www.hebi-incubator.org/templates/heb/global/index.php?lngid=2&sqlmode=1&fid=395
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
HEBI (Hemel Baby Incubator)
• Made from:
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Light bulbs
Container to hold water (for humidity)
Thermostat
Perspex and Wood
• How it works:
▫ Light bulbs heat air in the bottom part of the incubator. The air passes over a
container with evaporating water, so that its humidity increases. The warm, humid
air then flows upwards (chimney effect) into the baby compartment. A thermostat in
an exit hole compares the air temperature with the desired temperature. If it is too
high, the light bulbs will be switched off; if it is too low, the bulbs will be switched
on. The baby can be viewed through Perspex and it can be handled via two armholes
with sleeves. The Perspex front and top can be hinged back for full access.
Vendor’s Site: http://www.hebi-incubator.org/templates/heb/global/index.php?lngid=2&sqlmode=1&fid=395
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Kangaroo Mother Care
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Started in Bogota, Columbia.
Advantages:
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Allows interact with mother.
Allow early and exclusive breastfeeding
Psychological and mental support between
mother and baby.
Babies stabilize faster on skin to skin care
Easy to assemble
Free
Disadvantages:
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Increase risk of infectious disease due to
mother infant contact.
Cumbersome for the mother
Cannot get a full naked view of the baby
Site: http://www.kangaroomothercare.com/index.htm
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Comparison of Incubators
Specifications
Giraffe
Car Part
Incubator
HEBI
Kangaroo
Our
Project
Cheap
X
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Preventing infections
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X
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X
TBD
Easy to use
X
X
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Infant visibility
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X
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Accuracy of temperature
control
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X
X
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Low maintenance
X
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Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Incubator Basics
• What does it do:
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Keep an infant’s core temperature stable at 37˚C
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Additional features:
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Humidify
Increase oxygen supply
Provide a sterile environment
• How does is work:
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The mattress is usually enclosed by a clear plastic canopy
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Temperature in the incubator is increased by a heater element below the mattress
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Motor driven fan draws in fresh air through a filter and blows it past the heater, warming the air.
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Air is directed up through slots in to the area above the mattress and circulated around.
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Air temperature is monitored by temperature sensor and adjusted by controlling the current to
the heater.
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Humidity is increased by water baths (passive) or dripping water on a heated element (active).
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The baby is cared for through special access doors called arm ports.
Flinders University School of Medicine, Department of Biomedical Engineering. http://www.fbe.org.au/Clin/BasicEquipment/InfantIncubator.htm
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Design Specifications for Consideration
• Low-cost
• Low power consumption
• Well-insulated
• Sterile
• Humid
• Allows for infant visibility
• Allows for infant accessibility
• Easy monitoring and control of temperature
• Easy to build and use
• Accessibility of materials in third world countries
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Project Goal
• Design an incubator with the given specifications using previous case studies of
incubators, the EWH temperature control alarm legacy project, and current research as
examples.
• Depending on
time, research
and modify this
to make it more
cost and energy
efficient.
• If completed,
work to deploy
the incubator
to needed areas
for use.
Top that will open for
easy access
Main compartment for
infant with front and
top panels of sterile,
insulating film
24”
24”
6”
36”
Humidifying Compartment
with Circulator Fans
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Material
Details
Unit Price
Plywood
(0.5“ or thicker)
1- 36”x30” panel (back)
2- 30”x18” panels (sides)
1- 34.5”x18” panel (main comp. bottom)
1-36”x6” panel (front bottom)
1- 36” x 18” panel (humidity comp. bottom)
2-36” length (front and back top- for access frame)
4- 15” length (top sides for access frame and main frame)
2-35” length (front and back top- for main frame)
1-31.5” length (front bottom- for main frame)
4-22.5” length (up-and-down corner supports for main frame)
2-5.5” length (front bottom for humidifying compartment)
For access frame
In place of plexiglass. 0.004” thickness, clear polysheeting.
0.006” thickness used to further insulate walls.
12 V/ 16.7 A
Car Heater – 12 V, 150 W
12 V/ 0.13A
MX052 digital temperature controller
Baking pan from any local store
Available in Clark 223
Available in Clark 223 or readily available from personal supply
FREE! (< $30)
Support Wood
(1.5” x 1.5” in width)
Hinges (2 sets)
ULINE Polyethylene Window
Insulator
Power Supply
Heater
PC Fans (2)
Temperature Control System
Water Pan to Maintain Humidity
Electrical Supplies (wire, electrical tape, etc)
Misc (screws, double-sided tape, etc)
Total
$6.10 (Home Depot)
$5.96 (Home Depot)
FREE! (< $10)
$100
$9
FREE!
$39.99
< $2
< $5
< $5
< $215
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Results of the Project
• An working infant incubator made of common or readily available
parts
• Less than $215
• Very easy to construct
• Easy to use
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Future Improvements (for commercial incubators)
Factor
Unresolved Issues
Possible Solutions
Temperature control
Heat loss from the newborn
To develop advanced temperature control systems
To use double-walled incubators
Appropriate air temperature (22–26˚C) in the NICU
To develop advanced air circulation systems
Eddies around the newborn
Noise environment
High noise levels inside the incubator
(external and internal sources)
To attenuate environmental sound
(acoustical foam, sound absorbing panels)
To reduce the noise generated within the incubator
(motor)
To reduce human-related sources (NICU staff) of noise
Light environment
Continuous lighting and bright light
(NICU environment)
To promote circadian lighting
To reduce the amount of light within the incubator
(covers)
Electromagnetic Fields
Relevant EMF levels within the
incubator
To redesign the position of various incubator components
To implement ferromagnetic panels
To increase the distance between incubator and
electronic equipment
[Antonucci, R., et al. The infant incubator in the neonatal intensive care unit: unresolved issues and future developments.
Journal of Perinatal Medicine. 37(6): 587-98.]
Problem
Available Solutions
Project Design
Parts Needed
Project Results
Future Work
K. Donato - Infant Incubator Project
Future Improvements (for our incubator)
• low internal noise level (below the 60 dBA limit during normal
operation)
• attenuation of environmental noise and noisy incubator
reverberating effects
• low level of EMFs at extremely low frequencies within the incubator
baby compartment
• oxygen connector which allows delivering supplemental oxygen to
the baby, if necessary