Image: The visual representation shows different lung areas and their ventilation situation (Photo courtesy of Fraunhofer IKTS)
Patients with severe respiratory or lung diseases require intensive treatment and their lung function should be continuously monitored. For more than 200 years, the stethoscope has been a standard tool for doctors who use it to listen very precisely to heartbeats and lungs and, therefore, to diagnose diseases. Now the stethoscope gets help. A team of researchers has developed a technology to record sounds in the lungs using a textile vest with built-in acoustic sensors. The signals are then converted and displayed visually using software. This way, patients can be discharged from the intensive care unit (ICU) sooner but can still be continuously monitored. Technology increases diagnostic options and improves the patient’s quality of life.
As part of the Pneumo.Vest project, researchers from Fraunhofer IKTS (Dresden, Germany) have developed a textile vest with integrated acoustic sensors, presenting a high-performance complement to the traditional stethoscope. Piezoceramic acoustic sensors have been incorporated into the front and back of the vest to record any noise produced by the lungs in the thorax, no matter how small. Software records the signals and amplifies them electronically, while the lungs are visually represented on a screen. Since the software knows the position of each individual sensor, it can assign the data to its precise location. This produces a detailed acoustic and optical picture of the ventilation situation of all parts of the lungs. But what is particularly special with the system is that it collects and stores data permanently, examinations can take place at any time and in the absence of hospital staff.
Pneumo.Vest also shows the condition of the lungs over a period of time, for example over the past 24 hours. Needless to say, traditional auscultation can also be performed directly on patients. However, instead of performing the auscultation manually at different points with a stethoscope, several sensors are used simultaneously. In addition to the acoustic sensors, the software is at the heart of the vest. It is responsible for the storage, representation and analysis of data. It can be used by the physician to visualize acoustic events in specific individual areas of the lungs on the screen. The use of algorithms in digital signal processing enables targeted evaluation of acoustic signals. This means that it is possible, for example, to filter out heartbeats or to amplify characteristic frequency ranges, which makes lung sounds, such as rustling or wheezing, much easier to hear.
In addition to this, researchers are now developing machine learning algorithms. In the future, these will be able to structure and classify complex ambient noises in the thorax. Then the pulmonologist will make the final evaluation and diagnosis. Patients can also benefit from the digital sensor alternative. While wearing the vest, they can recover without the constant observation of medical personnel. They can be transferred to the common ward and possibly be sent home and move around more or less freely. Despite this, the lungs are constantly monitored and any sudden deterioration can be immediately reported to medical personnel. The technology was originally designed for respiratory patients, but it also works well for people in healthcare settings and for use in sleep labs. It can also be used to train young doctors in auscultation. The first tests showed that the concept succeeds in practice.
Pneumo.Vest is a product tailored to the increasingly tense situation in hospitals. Millions of patients with respiratory or lung diseases require hospital treatment every year, most of them being connected to a ventilator for more than 24 hours. This does not take into account the current increase in respiratory patients due to the COVID-19 pandemic. Due to the increase in life expectancy, the medical industry also expects the number of elderly patients with respiratory problems to increase. With the help of new technology, the burden on hospitals and especially expensive intensive care units can be eased as their beds will not be occupied for as long.
“Pneumo.Vest does not seek to make the stethoscope superfluous and does not replace the skills of experienced pulmonologists,” explained Ralf Schallert, project manager at Fraunhofer IKTS. “However, auscultation or even CT scans of the lungs only ever present a snapshot at the time of examination. term, even if the patient is not attached to the ICU machines but has instead been admitted to the general ward.