Devices & Diagnostics, Startups, Diagnostics

Can a sound-based smartphone app replace X-rays to identify bone fractures?

Dr. Todd O’Brien is trying to develop and commercialize a smartphone app that can be used at the point of care to identify fractures on the athletic field, combat field or any other site of traumatic injury.


Source: ScanDx

Todd O’Brien, ScanDx founder, is trying to develop and commercialize a smartphone app that can be used at the point of care to identify fractures on the athletic field, combat field or any other site of traumatic injury. The so-called FractureDx technology must displace the trusty X-ray in order to succeed.

In a phone interview, O’Brien said the technology was inspired by the historical use of tuning forks to determine whether a patient suffered from a trauma, as fractured bone transmits less sound. “What if we could take that concept, and use technology to really improve the accuracy so you could have a really accurate screening method for identifying fractures, versus everyone having an X-ray?” O’Brien asked.

Having already invented a commercially available electronic tuning fork to diagnose diabetic peripheral neuropathy, the Orono, Maine-based podiatrist adapted the technique for the smartphone with the aim of identifying fractures. FractureDx is an early-stage device that consists of a smartphone attached to a high-sensitivity microphone and stethoscope for picking up the resulting sound. A smartphone app interprets the soundwaves and automatically returns a diagnosis of fracture or no fracture.

“Can it quantify the extent of the fracture?” asked Decision Resources Group analyst John Rizzo, after viewing the FractureDx website and a proof-of-concept study about the technology.

“Not yet. That would be a next-generation idea,” O’Brien told me. “There’s a lot of data in there that we haven’t done the signal processing on. We probably will be able to figure out, ‘OK, that fracture point is 3.5 centimeters from such and such a point, and there’s multiple fragments there’ and what not.”

The entrepreneur believes FractureDx’s current, limited utility is sufficient because it could serve as a “screening test” that eliminates unnecessary X-rays among patients without a fracture, saving the healthcare system money and reducing exposure to harmful radiation, which slightly increases one’s risk of developing cancer.

O’Brien is right that the use of inexpensive screening tests to determine the need for more invasive, costly tests and procedures is a trend to watch in the new era of cost-conscious medicine.

But Rizzo questioned whether the X-ray market is amenable to such an approach, saying the well-established imaging method is already cheap and accurate. “The challenge the app faces is you have to convince a doctor to adopt it,” he said.

Besides potentially improving resource utilization, another selling point of the app is mobility. GE Healthcare and others already provide mobile-X-ray systems within the hospital setting, but taking a point-of-care device to the athletic field or other non-traditional setting could constitute a novel solution.

Here, usability and regulatory issues rise to the forefront.

O’Brien and Rizzo agree that average consumers are not likely to download the app or keep the accessories on hand, even if the FDA were to approve it for general use. O’Brien said potential users of FractureDx include school nurses, athletic trainers, first responders and combat medics.

O’Brien said he’s looking for at least $250,000 out of a desired $1.5 million to develop the next prototype of FractureDx. Rizzo said potential backers of FractureDx would want to know more about the level of training necessary to utilize the app.

While the app itself is fairly easy to use and gives a diagnosis automatically, it does require a certain level of prior knowledge. “The more skill intensive thing is making sure that the microphone and the speaker are on the correct anatomic landmarks. That’s more of a clinical thing, where users need to know where that bony prominence is,” O’Brien said.

Will doctors trust the performance of an athletic trainer enough to forgo an X-ray? What sorts of medical malpractice issues does that raise? These are the sort of questions that must be carefully addressed for FractureDx (and other new medical technologies) to succeed.

Meanwhile, O’Brien’s team needs to carry out formal clinical trials for FDA approval. In order to receive approval through the less stringent 510(k) pathway, an approved “predicate device” must be identified, but that could prove challenging due to the device’s deployment of a smartphone app and novel use of acoustic soundwaves for diagnostic purposes.

The FDA will require a lot more data prior to granting approval than the six patients assessed in the proof-of-concept study that was presented at this year’s World Podiatry Conference in Montreal.

Commercialization is a few years away, assuming FDA clearance. O’Brien plans on charging about $50 for the smartphone accessories (the attachable microphone and stethoscope), and said downloading the app will probably be free.

Improving the algorithm and analyzing the data to broaden its utility is a key part of the company’s business plan. “What we envision this becoming is a subscription service to get that higher level of data,” O’Brien said. Then, subscribers will receive an interpretation of the soundwave data that could include information such as the size and precise location of the fracture.

(Mobile ECG company AliveCor is the company to watch to determine the potential of such a service-based model. Its device has already proven successful, setting the stage for the transition to a data-based monetization strategy.)

“There are going to be some other applications for this, such as bone density assessment (in the consumer healthcare space), looking at orthopedic hardware failure, joint assessment, and things like that we’ve just touched the tip of the iceberg on,” O’Brien added.

Philip’s mobile ultrasound device Lumify is an example of a portable diagnostic device that is selling quickly, according to Rizzo.

One crucial difference FractureDx’s is that greatest utility is likely to be felt outside the hospital setting. Moreover, Lumify is another iteration of pre-existing imaging technology, while FractureDx is intended to reduce the entrenched use of X-rays, and alter the dominant care paradigm by adding a screening test.

“How disruptive can this be in the industry?” Rizzo asked. “That’s kind of the underyling question.”