Although it’s normal for infants to have some disruptions in their breathing while sleeping, prolonged periods of sleep apnea can cause their blood oxygen levels to fall dangerously low, sometimes even resulting in death – this is a particular risk for babies born prematurely. Usually, when an infant does stop breathing while asleep, all that’s required to get them started again is a gentle nudge or some other kind of disturbance. Unfortunately, however, neonatal wards in developing nations are often understaffed, so nurses might not notice a non-breathing infant until it’s too late. That’s why a group of five bioengineering students from Houston’s Rice University invented the Babalung Apnea Monitor.
The Babalung consists of a chest strap that is wired to a small control box, which is in turn wired to a bicycle tail light. The strap is worn by the infant, and contains an elastic sensor. That sensor expands and contracts as the baby breathes, sending electrical signals to the box. As long as breathing continues relatively normally, the system’s electronics register the signals as an unbroken sine wave.
If the baby stops breathing for at least 20 seconds, however, a vibrating motor in the strap will be activated. Hopefully, this will be sufficient to rouse the infant, and get them breathing again. If they’re still not breathing within an additional five seconds, then the bike light will start flashing. This should alert the nurse, so they can take action. An audible alarm was considered, although the team worried that it might not be heard unless it was loud enough to damage the baby’s hearing.
The students have performed 50 tests of the Babalung (mostly on themselves), and found that it detected every instance of their breath-holding for 20 seconds or more. It also gave no false alarms, which is a common complaint of commercial SIDS and apnea monitors.
Currently it costs about US$25 to put one of the devices together, although the students hope that the price will decrease as the system is developed further. They’re planning on sending three prototypes for testing in developing countries in coming months, although they wonder if it might also end up seeing use in America.
The team – Rachel Alexander, Rachel Gilbert, Jordan Schermerhorn, Bridget Ugoh and Andrea Ulrich – created the Babalung as part of Rice’s Beyond Traditional Borders program, in which students design low-cost health technologies for use in Third World nations. Past examples of other devices made for the program have included a centrifuge made from a salad spinner, a respirator based around a water bottle, and a $240 battery-powered fluorescence microscope.
More information on the Babalung is available in the video below.
Source: Rice University