An inexpensive portable device could make it easy to monitor fetal health in remote locations, and it might also provide an alternative to more expensive machines currently used in doctors’ offices in the developed world.
The device, a cardiotocography machine dubbed Sense4Baby, was designed by engineers at the nonprofit West Wireless Health Institute, a medical research organization whose mission is to use wireless technology to reduce the cost of health care.
“We designed Sense4Baby from the ground up to be low-cost,” says Joe Smith, West Wireless’s chief medical officer. “It takes every advantage of consumer-scale microelectronics and ubiquitous low-cost communication infrastructure.” The institute is now planning field tests of the device in Mexico and is in talks to organize tests at major health-care systems in the United States. The device has not yet been approved by the U.S. Food and Drug Administration.
Cardiotocography machines are currently used by obstetricians, typically during the third trimester and in high-risk pregnancies, to measure fetal heart rate and uterine contractions as an indicator of fetal distress. The heart rate of a healthy fetus drops during a contraction and then rapidly comes back to normal. “If the doctor sees a lack of change or early or late changes in heart rate, it could be a sign of trouble,” says Steven Garverick, an engineer at West Wireless who has been leading the project.
Sense4Baby uses the same basic sensors as existing devices: Doppler ultrasound to measure fetal heart rate and a pressure sensor called a tocodynamometer (or toco) to measure the force of the contraction via the tension of the maternal abdominal wall. But it eliminates the large bedside machine used to process these measurements in standard cardiotocography, replacing it with a Bluetooth transmitter and a smart phone or tablet running custom software.