First-of-their-kind wearables have been developed to capture body sounds. This is part of medical devices that continuously monitor health. In terms of real-life applications, such devices can be used with any human, from premature babies to the elderly.
This is a natural extension of what happens during many routine medical visits, where physicians listen to sounds inside their patients’ bodies. This includes air moving in and out of the lungs, heart beats and even digested food progressing through the long gastrointestinal tract. These sounds provide valuable information about a person’s health.
Pilot studies undertaken by Northwestern University researchers have shown how these devices can accurately track the sounds associated with cardiorespiratory function, gastrointestinal activity, swallowing and respiration. The data comparison showed how the devices performed with clinical-grade accuracy.
A key advantage of the devices is the ability to simultaneously listen and compare different regions of the lungs. For example, by spatially mapping how air flows into, through and out of the lungs as well as how cardiac rhythm changes in varied resting and active states, and how food, gas and fluids move through the intestines.
These new wireless devices are designed sit softly onto the skin to continuously capture sounds (tracking all required sounds simultaneously and wirelessly), then stream data to smartphones or tablets in real time. The software that controls the devices can separate sounds within the body from ambient noise outside the body.
In terms of what the devices are composed of, each one contains miniaturised pairs of high-performance, digital microphones and accelerometers encapsulated within soft silicone. Each device also contains a flash memory drive, tiny battery, electronic components, Bluetooth capabilities and two tiny microphones — one facing inward toward the body and another facing outward toward the exterior. By capturing sounds in both directions, an algorithm can separate external (ambient or neighbouring organ) sounds and internal body sounds.
In one of the supporting studies, researchers tested the devices on adult patients, which included 35 adults with chronic lung diseases and 20 healthy controls. In all subjects, the devices captured the distribution of lung sounds and body motions at various locations simultaneously, enabling researchers to analyse a single breath across a range of regions throughout the lungs.
Where more than one device is used, the devices will interact to create a comprehensive non-invasive sensing network.
Outlining the potential importance of these devices, Northwestern’s John A. Rogers said: “Currently, there are no existing methods for continuously monitoring and spatially mapping body sounds at home or in hospital settings. Physicians have to put a conventional, or a digital, stethoscope on different parts of the chest and back to listen to the lungs in a point-by-point fashion. In close collaborations with our clinical teams, we set out to develop a new strategy for monitoring patients in real-time on a continuous basis and without encumbrances associated with rigid, wired, bulky technology.”
The research appears in the journal Nature Medicine, titled “Wireless broadband acousto-mechanical sensors as body area networks for continuous physiological monitoring.”
