The Scanadu Scout "medical tricorder" is kaput

The Scanadu Scout sparked significant buzz with its self-portrayal as a type of "medical tricorder." As a reminder, the medical tricorder was a fictitious futuristic device from the T.V. show Star Trek that possessed a hand-held high-resolution scanner that could diagnose diseases, collect valuable health information, and even administer life-saving treatments to a patient, all within a matter of seconds. To make this science fiction future a reality today, the chip company Qualcomm sponsored the Tricorder X contest to "build a device that will allow consumers to perform their own tests for up to 24 different ailments and deliver a diagnosis on the spot, as well as send the data to a cloud-based software platform for further analysis by physicians."

Scanadu's entry garnered a lot of attention because of its superficial physical resemblance to the Star Trek tricorder (Figure 1). The Scout, is placed "in contact with the patient’s temple and detects a range of vital signs, including heart and respiration rate, blood oxygenation, pulse transit time and temperature." There were also "electrodes to measure the electrical signals of the heart and an infra-red temperature sensor, among other things" (The Economist). The tricorder sensor being placed against the patient's temple was a signature move by Dr. McCoy in Star Trek.

The other contestants in the Qualcomm challenge were more pragmatic, putting function ahead of form. Among the 7 finalists, there was an interesting diversity of approaches which employed a variety of off-the-shelf technologies including activity tracking, non-invasive spectroscopy of blood flow and content, sound measurements, visual measurements, urine measurements, lab-on-a-chip analysis of bodily fluids, electrical measurements (EKG), ballistocardiograms, blood tests using strips, questionnaires, etc.

Unfortunately, Scanadu was not one of the finalist, and instead it chose a different route toward commercialization. They embarked on a crowdfunding campaign (STAT):

"So it was no surprise that “Scout,” a device marketed as a real-life version of the “Star Trek” tricorder, made history in 2013 when its manufacturer, the startup Scanadu, raised a record $1.5 million on the crowdfunding website Indiegogo in a matter of weeks to bring it to consumers."

Scanadu has gone on to raise an additional $45 million from venture capital. The Scout product has been renamed Vitals with some features (e.g. electrodes) removed from the original model (Scanadu):

"Scanadu Vitals is an electronic device being designed for people to measure the following physiological parameters: blood pressure, temperature, heart rate, and pulse oxymetry—all cuffless, wireless and in seconds. The vital signs are obtained from a gentle touch with the left hand on the Scanadu Vitals device touching the left side of the forehead. All measurements are sent via Bluetooth LE to the user’s smartphone. The information is designed to be displayed, stored and shared via the Scanadu app."

It is possible to make an educated guess about the inner workings of the Scanadu device. They are most likely using conventional technology rather than anything exotic or super-sophisticated.  For example, the heart rate and pulse oximetry (blood oxygen levels) are likely measured using photoplethysmography ("which illuminates the skin and measures changes in light absorption"), the same technique employed by the Apple Watch, but the illuminated skin region is at the finger tip (similar to the Samsung Galaxy heart rate monitor) rather than the wrist. The blood pressure is probably measured in a similar fashion to the Wello device in which the pressure of the finger on a solid surface alters the amplitude of the finger pulse (by constricting blood vessels) which depends on both how much pressure the finger is applying (pressure sensor) and your blood pressure. Finally an infrared temperature sensor (measuring the thermal radiation from the skin) can estimate body temperature when placed near the forehead.

One important decision was whether or not to seek FDA approval. As I mentioned before, FDA approval is important because it vouches for the device/test efficacy (accuracy) and safety, and is widely viewed as the gold standard for test validation. On the other hand, it is not necessary, with many medical lab tests lacking FDA approval, although they typically possess some type of alternative accreditation. Indeed, the vast majority of the diagnostic tests of the troubled company Theranos were never approved by the FDA.

Consumer-oriented healthtech devices such as the Apple Watch reside in the gray area between consumer and medical devices. How should the FDA regulate this intermediate region (Bloomberg)?

"The FDA's guidelines on regulating mobile applications, released in February, leave fitness-tracking and other wellness-related products largely free from scrutiny, while technology used for diagnosis, treatment and prevention will get a closer look. A lot depends on how the device is marketed, Patel said. If a company is promoting a product to assist doctors in making medical decisions, it will require more oversight, he said. In January, the FDA approved a glucose-monitoring iPhone app for the first time."

In other words, if the app or device is encouraging healthful behaviors like walking, then that is more consumer-oriented and the FDA will not intervene. On the other hand, if it is "trying to mimic the function of a medical device", then the FDA is more likely to intervene. A medical device needs to make an accurate measurement for a medically important condition.

Given that Scanadu is touting its product as a medical tricorder, then aiming for FDA approval was a sensible approach. However, their strategy backfired when the FDA did not grant its approval. As a result, Scanadu is planning to discontinue the device, which includes "bricking" (deactivating) any existing devices (STAT):

"The company’s email to customers on Tuesday, first reported by TechCrunch, said that “FDA regulations require that we deactivate” the devices at the formal conclusion of the Scripps study this coming May. At that point, the device “will cease to function,” Scanadu wrote."

Needless to say, many customers are irate at having paid between $149 to $199 for a device that will be completely useless in five months. However, there is not much that they can do (STAT): "Customers who pre-order devices on a site like Indiegogo have little recourse if the company fails to deliver it — or if it doesn’t measure up to the marketing pitch." The moral of the story is not to be misled by claims of being a "medical tricorder." On a more upbeat note, the Qualcomm Tricorder X contest is set to announce its winners in early 2017. I am eager to find out about the performance and accuracy of the top contenders.

Figure 1. The Scanadu Scout (Vitals) "scanning" a patient for information about heart rate, blood pressure, blood oxygen, and temperature.