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 • • Most recent product of GE Health Care Advantages: ▫ ▫ ▫ ▫ ▫ ▫ • 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: ▫ ▫ 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: ▫ ▫ ▫ ▫ 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: ▫ ▫ ▫ ▫ 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: ▫ ▫ ▫ ▫ 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 • • Started in Bogota, Columbia. Advantages: ▫ ▫ ▫ ▫ ▫ ▫ • 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: ▫ ▫ ▫ 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 Preventing infections X X TBD Easy to use X X Infant visibility X Accuracy of temperature control X X Low maintenance X Problem Available Solutions Project Design Parts Needed Project Results Future Work K. Donato - Infant Incubator Project Incubator Basics • What does it do: ▫ Keep an infant’s core temperature stable at 37˚C ▫ Additional features: Humidify Increase oxygen supply Provide a sterile environment • How does is work: ▫ The mattress is usually enclosed by a clear plastic canopy ▫ Temperature in the incubator is increased by a heater element below the mattress ▫ Motor driven fan draws in fresh air through a filter and blows it past the heater, warming the air. ▫ Air is directed up through slots in to the area above the mattress and circulated around. ▫ Air temperature is monitored by temperature sensor and adjusted by controlling the current to the heater. ▫ Humidity is increased by water baths (passive) or dripping water on a heated element (active). ▫ 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