Nine months ago, on what I had expected to be one of the happiest days of my life, my baby aspirated on amniotic fluid during delivery. He was rushed to the neonatal intensive care unit (NICU) and put on oxygen support; his tiny new body was completely covered with sensors and wires and he was placed in a little plastic box. Over the next several days, his condition worsened as his lung collapsed due to barotrauma. I was not allowed to carry or even touch him. Never in my entire life have I felt so utterly helpless, frustrated and sad.
For days, my husband and I sat in solemn vigil, hours upon hours, transfixed on his vital sign monitor. The doctors told us that when his breathing patterns improved (his breathing was way too fast and shallow to be sustainable), it would imply his lung was healing and we could eventually start weaning him from oxygen support -- and maybe even get to carry him.
So we sat entranced, struggling to decipher his breathing patterns from the continuous photoplethysmogram and electrocardiogram. After days staring at the sine waves and sporadically getting excited when he seemed to take deeper and more sustainable breaths, we sought confirmation from the doctors. Unfortunately, they informed us that while it accurately reported his breathing rate, its amplitude did not reflect respiratory volume. Further, the doctors agreed that such information would constitute an important medical advance.
Thankfully, our story has a happy ending as my son eventually recovered. Yet, the discontent over the status quo persisted. How could no device exist to continuously and comprehensively monitor a patient’s breathing? Spirometry was invented in 1846, and respiratory inductance plethysmography (RIP) in 1967. Surprisingly, little in the way of technology has evolved since.
My team at UC Irvine has developed small Band-Aid© like sensors that can continuously monitor both respiration rate and volume. We made these disposable sensors with an inexpensive children’s toy, Shrinky-Dinks. My PhD student and lead author Michael Chu demonstrated that we achieve significant correlations between the response of our sensors and the gold standard, medical grade spirometry, in healthy subjects. Spirometry requires a face-mask and the patient to ‘breathe maximally’ to determine respiratory dynamics. In contrast, our little Band-aid© like sensor can be worn continuously and breathing patterns can be wirelessly transmitted to a smart phone. Unlike with RIP, which is cumbersome and prone to slippage, we show ours can be worn during physical activities. I’m hoping we can develop this into a solution not just for the ICU, but for parents who worry about the respiration of their children which chronic diseases, such as cystic fibrosis and asthma. It is our hope that such an advance just might help everyone breathe a little easier.