by Jamie Lawson Reeves

The Vanderbilt Register, Jan 19-25, 1998, page 4

Two Vanderbilt biomedical engineering graduates want to improve infant care in neonatal intensive care units with a mattress that simulates the comforting warmth, heartbeat and breathing of a mother cradling a newborn infant.

"The Infant Sleep Mate," designed by Anne Morgan and Elizabeth Kuhls, was recognized in an international competition this fall in Chicago. Morgan and Kuhls are pursuing a patent for their mattress design. Although untested at this point, the mattress is scheduled to undergo clinical trials next summer at Vanderbilt’s NICU.

Professor of Biomedical Engineering Paul King encouraged his students to enter their senior design project in the 19th annual International Conference of the Institute of Electrical and Electronics Engineers/ Engineering in Medicine and Biology Society, Oct. 30-Nov. 2. The Vanderbilt engineering students' entry placed first among 100 entries in the student paper competition against students from Yale, Mercer and Texas A & M. They designed the prototype with assistance from Dr. Bill Walsh, a neonatologist who directs Vanderbilt's NICU, and Vanderbilt NICU nurse Claire Cooper.

The competition was sponsored by the Whitaker Foundation, a private nonprofit foundation that primarily supports research and education in biomedical engineering.

A visit to the neonatal intensive care unit at Vanderbilt Hospital during their sophomore year inspired Morgan and Kuhls to design a device that would simulate the mother’s presence and comfort outside the womb, thereby enhancing sleep conditions and improving the growth and development of NICU infants during this critical time in their development. These tiny patients are often bombarded with harsh but life-sustaining conditions -- loud sounds from ventilators, continuous bright lighting and uncomfortable touch during medical procedures.

The students’ mattress is unique because it combines motion, heat, surface and sound.

"I think the idea behind the mattress is very intriguing," said Walsh, who has been director of the hospital’s nursery since 1992. "Keeping the baby warm and the gentle motion of the mattress should decrease the apnea spells they have."

The first criterion for the design was to provide a soft support for intensive care infants. The Infant Sleep Mate uses a gel mattress, which is soft and reduces pressure points on the infant. After researching several options, the Vanderbilt team chose a gel mattress provided by Children's Medical Ventures, a company that manufactures devices for babies, especially those under critical care.

The gentle, up-and-down motion of the mattress simulates the breathing of the mother, which in turn helps the infants breathe better, possibly reducing the number of apnea spells. "In future studies we would like to measure the reduced number of apnea spells, monitor weight gain, head shape, length of hospital stay and duration of sleep cycles among infants using the mattress," Morgan said. The motion system was constructed using an air sac that is inflated by an adjustable ventilator.

The water heating device of the mattress heats the infant from below, rather than from bed warmers located above the infant. Currently, most infants in a NICU are placed on beds heated from an overhead heating source. Convective heat loss is a problem with this type of heating unit, Morgan said.

The Infant Sleep Mate utilizes heartbeat sounds. The heartbeat and sounds were recorded on a microcassette with the help of Dr. Drew Gaffney in the Department of Cardiology.

"The NICU is one of the loudest environments in a hospital, with 50 to 90 decibels of sound," Morgan said. "We wanted to add soothing sounds to compensate for the loud environment."