In the United States alone, there are an estimated 18.7 million people with asthma, accounting for 17 million ambulatory care visits and nearly 500,000 hospitalizations. In general, it is a clinical diagnosis based on history and exam; objective data like spirometery is hard to obtain and interpret.
iSonea applies a novel approach to get some objective data on asthma – in essence, it “listens” to patients breath and analyzes the sounds for signs of wheezing, rhonchi, and other abnormalities. The Wheezometer, shown here, is a noninvasive device that measures the “wheeze rate” simply by analyzing the sounds of a patient breathing. And while its a separate device now, the company plans to change that – they recently discussed plans to shift to a smartphone-based platform.
They have recently announced the launch of a study – the Wheezometer Correlation Study – that aims to directly correlate the wheeze rate measured by the device with spirometry data, exam findings, and symptom severity. This study represents one of the critical steps a novel device must take before entering widespread use.
In the acute management of asthma and other pulmonary diseases with a reactive airways component, history and exam are crucial. As subjective measures, they are prone to issues like inter-observer variability, unclear histories, and so on. Additionally, children often won’t even be able to provide a history.
Objective data is limited at best. Spirometry, which is often sited in iSonea-related pieces, is hard to get for a number of reasons. Peak flows are, however, quite easy – done at the bedside, cheap, and are useful to follow with therapy. Even peak flows, however, require some patient cooperation which may not be possible in very young children and other patient groups.
iSonea’s WheezoMeter analyzes 30 seconds of breath sounds using a variety signal processing algorithms to detect, quantify and objectively document the presence of wheeze and its extent. The wheeze rate is the proportion of the respiratory cycle duration occupied by wheezing. They demonstrated the device at HIMSS this year, as seen in the video below.
iSonea has a fair amount of publications listed on the healthcare professionals information page. That, plus the now launching study, are encouraging in that it suggests that at the very least iSonea is intent on proving that we should all care.
Prior data, according to the company, has shown a correlation between clinical wheezing and spirometry measurements; there does not appear to be correlation of the wheeze rate, as measured by the Wheezometer, with spirometry data. In some small studies, the Pulmotrack, another iSonea device that measures wheezing using acoustic inputs, appears to be comparable to and at times better than clinical assessment for detecting wheezing. The Pulmotrack also has some data in use for treatment of nocturnal asthma symptoms, which therapy correlating to both clinical improvement and reduced wheeze rate.
This study appears to now seek to demonstrate a direct link between the Wheezometer and spirometer data, exam findings, and symptoms. That would be critical in going to the next step – a trial showing how that use of the Wheezometer in asthma management is, in fact, better than traditional management in some way.
The Wheezometer is likely to offer a number of potential benefits. First, it requires nothing of the patient other than breathing – if they aren’t doing that, they have bigger problems. That gives it an advantage over even peak flows.
Its also very portable. With their recent Qualcomm partnership, they can use the 2Net platform to remotely collect data – making it a potential tool for care of patients in facilities and remote care. It also creates options for home care programs for difficult to treat patients, analogous to the programs we have for heart failure.
If iSonea is able to shift to utilization of a smartphone-based platform, where the smartphone microphone or an inexpensive peripheral can be used, then these possibilities will only grow.
I do wonder about some of the other claims around the device, such as in-hospital use. Will it really be beneficial to detect wheezing 30 minutes earlier than we would otherwise pick it up by exam? Maybe, but I’m skeptical.
More data doesn’t always mean better care. However, one only need spend a night in the pediatric ER to see that we could be doing a better job (or for that matter, an adult ER). While measuring the wheeze rate won’t get us all the way there, it may end up being be a critical tool – that’s certainly what iSonea is out to prove.
I’m certainly not an asthma expert – but some of our readers are. We’d love to hear your thoughts on the wheeze rate as a clinically useful metric, these devices, and the future of asthma management – leave a comment!
Source: Press Release