Q&A: Smart devices measuring respiratory sounds show promise in pulmonary medicine

Key takeaways:

• Devices that monitor wheeze, snoring, coughing or crackles remotely can allow for faster treatment.
• For children, these devices have the potential to catch lung diseases/conditions early on in life.

With advancements in artificial intelligence and patient-monitoring technology, properly diagnosing individuals who report wheezing, snoring, coughing or crackles is expected to get easier, according to a review published in CHEST.

As Healio previously reported, artificial intelligence (AI) has the ability to determine whether someone has pneumonia through cough recordings and a smart mask has been developed to detect differences in breathing, coughing and speaking for diagnoses of respiratory diseases.

These technologies, as well as several others, can positively impact patients though remote tracking of respiratory sounds that allow for a quicker diagnosis and treatment. According to the review, long-term recording of respiratory sounds can also evaluate treatment adequacy, and this is particularly beneficial for patients with a cough or those who snore and use CPAP.

To learn more about smart devices that measure respiratory sounds and the impact they will have on care provided by pulmonologists, Healio spoke with review authors Steve S. Kraman, MD, FCCP, professor emeritus in the department of internal medicine at the University of Kentucky, Hans Pasterkamp, MD, FRCPC, professor emeritus in the department of pediatrics and child health at the University of Manitoba, and George R. Wodicka, PhD, Vincent P. Reilly Professor of biomedical engineering at Purdue University’s Weldon School of Biomedical Engineering.

Healio: Why has it only recently become possible to monitor/manage respiratory sounds via smart devices?

Steve S. Kraman

Kraman, Pasterkamp and Wodicka: This technology has been around for decades, and the potential usefulness has been recognized as well. For instance, cough counters and wheeze detectors have been presented in meetings such as the International Lung Sounds Association. What was missing from these devices was that they weren’t “smart” in the sense that a clinician could use them without extensive training. They were also big, heavy and often composed of various parts connected by cables. They looked like someone’s hobby rather than a commercially attractive medical device. Recently, the advent of cheap, subminiature, efficient electronic devices has made it possible to build acoustic recorders and analyzers into packages as small as a patch that can be affixed to the chest wall and send data wirelessly to a smart phone for storage and processing for (perhaps) transmission via Wi-Fi and internet to a server in a hospital of doctor’s office. All this capability and more is already present in the cell phones carried by most of the world’s people. All that is left is for engineers to use current technology to design and commercialize these gadgets, which is already happening.

Healio: You wrote that four sounds — wheeze, snoring, cough and crackles — offer the most promise in this technology. To which diseases/conditions can each of these sounds be linked?

George R. Wodicka

Kraman, Pasterkamp and Wodicka: Wheeze, linked to COPD and asthma, is easily heard using a stethoscope in the clinic. But is asthma controlled during sleep? Adults can report that they wake up coughing and wheezing but a young child cannot. A stick-on wheeze detector or even an app running on a smart phone next to the bed could detect and measure the length and number of episodes and send the report directly to the physician’s office. The patient’s medications could then be modified to assure better nighttime coverage.

Snoring is linked to obstructive sleep apnea. Detection of loudness, pattern and rate of snoring as well as background breathing noises can give important hints about the possibility of obstructive sleep apnea. This could be done with an app on a smartphone at virtually no cost.

Cough is linked to asthma, rhinitis, gastric reflux, viral and post-viral coughs. The Hyfe company has designed a smart phone app that counts coughs and is working with Merck to distribute it for free. It can be downloaded and used by anyone. It is not FDA-approved yet, but the aim of the app is for a patient to track the rate and pattern of coughing day-to-day to document changes over time and whether a specific treatment is working. Chronic cough is one of the most frequent problems encountered by pulmonologists in the clinic and this or similar devices could become useful in objectively determining the cough pattern and whether a cough is improving or worsening.

Crackles are linked to COPD, bronchiectasis, heart failure and pulmonary fibrosis. Crackles are quite faint but can be detected by a stick-on microphone and would likely be of most use in detecting nocturnal heart failure.

Healio: How could these devices specifically help children with wheeze, snoring, cough or crackles? Could these devices possibly prevent the development of lung diseases/conditions in children?

Pasterkamp: The ability to remotely monitor children and babies with respiratory illnesses may be the most crucial use of these smart devices. Children often have most of these abnormal respiratory sounds at some point, particularly during their early years of life. Separating wheezing as an early indicator of asthma from similar sounds that are simply reflecting “snotty lungs” is a challenge that smart devices are more likely to manage than reports by parents or a brief auscultation at the doctor’s office. Coughing is common during childhood due to the frequency of respiratory viral infections. Most of these coughs disappear within a couple of weeks. However, young children may have respiratory infections so frequently that reporting by parents may not clarify what is recurrent vs. persistent or even chronic. Again, recording by smart devices, perhaps even with characterization of the type of cough that could point to underlying causes, is promising an advancement in the management of young patients.

Additionally, snoring during sleep when they have obstructed noses is common in young kids. However, documentation of regular snoring, particularly with acoustic patterns that suggest obstructive apneas, will be valuable to direct further investigations and treatments that could prevent cardiovascular and neurodevelopmental consequences of sleep apnea/hypopnea.

Healio: You mention that studies on these devices do not appear in medical journals. Why is that, and what can be done so that more pulmonologists and primary care practitioners hear about advancements in smart devices/AI for respiratory monitoring?

Kraman, Pasterkamp and Wodicka: Most of these machines and apps using AI are coming from engineering labs in academia and companies hoping to commercialize their products. They tend to publish in engineering journals unlikely to be seen by physicians. Private companies may not publish at all to protect their proprietary designs. They can advertise widely but that is expensive. We published our review paper in a widely read and highly regarded medical journal to make chest physicians aware of these developments.

Healio: Are there any challenges that remain to be overcome before these devices can be used widely?

Kraman, Pasterkamp and Wodicka: Certainly. For a medical device to be widely adopted and financially profitable, there must be clinical trials that support its safety and efficacy, hopefully leading to FDA clearance. Such studies are expensive, especially for a start-up. Physicians and hospital administrators must be persuaded that the newly marketed devices will provide meaningful advantages in patient care at reasonable cost and that insurers will see the benefits of covering the use of these devices.

Healio: When can pulmonologists expect to see these devices in routine clinical practice?

Kraman, Pasterkamp and Wodicka: It has already started. Electronic stethoscopes are now beginning to be paired with AI to help analyze abnormal heart sounds and at least one company, Eko, offers a 3-lead ECG built into the stethoscope head.

The Hyfe cough counter app is already being offered free to anyone and is being used in ongoing and planned clinical studies. The Leicester Cough Monitor (Sennheiser), available in the U.K., and VitaloJAK (Vitalograph), available in the U.S. and U.K., are also commercially available for cough counting.

StethoMe (StethoMe sp. z o.o.) for detection of wheeze in the European Union and Feelix (Sonavi Labs) in the U.S. for detection of crackles and wheeze have recently become commercially available. Many more are mentioned in our paper.

Reference:

• Kraman SS, et al. CHEST. 2023;doi:10.1016/j.chest.2023.01.024.

For more information:

Steve S. Kraman, MD, FCCP, can be reached at sskram01@uky.edu.