December 2, 2019 -- Smartphones are evolving into new point-of-care (POC) diagnostic tools, changing the way many common health conditions are initially diagnosed.
The technical capabilities of these phones have become so advanced that they can compete with technology once thought to be only the domain of physicians' offices and hospitals. Research groups and startup companies are developing apps and technology that turn smartphones into tools that can diagnose eye disease, perform home-based urinalysis, diagnose ear infections and respiratory disease, and help women learn about their reproductive health.
Reproductive health monitoring
For example, engineering scientists at Simon Fraser University in Burnaby, British Columbia, Canada, developed a way to use a smartphone's camera to help women with family planning and reproductive health monitoring. Researcher Zhendong Cao took advantage of how the camera can distinguish up to 16 million colors and perform the same kind of diagnostic testing as a microplate reader.
One indicator of a woman's reproductive health that could be tested was estrogen. Cao changed the camera software so that it analyzed the colored pixels and ultraviolet light in an image of a biological sample. The colors in the photo's pixels correspond to a signature produced by a substance under examination. Scientists can determine the concentration of the sample by the way light is absorbed or emitted.
The results from the smartphone testing kit could inform female patients about their daily reproductive status in real-time so they can make better-informed health-related decisions.
"I designed a system that excited a sample with light and measured its concentration by taking a picture with a smartphone," Cao commented by email. "We built a simple and working prototype that proved the concept."
Diabetic eye disease
Meanwhile, Remidio Innovative Solutions in Glen Allen, VA, is selling a portable, iPhone-based fundus camera for diagnosing diabetic eye disease. The Non-Mydriatic Fundus on Phone (NM-FOP) is an infrared-enabled disease detection and triaging device for eye care screening. It is designed to capture reflex-free, high-quality images of the retina for diagnosis.
The product has been approved by the U.S. Food and Drug Administration (FDA), and it includes a patented lens and lighting system, a Remidio app for capturing and communicating the medical grade images, and an iPhone.
The app also offers cloud storage, review, and report generation. In addition, images can be sent securely and wirelessly, in DICOM format, to a doctor's PACS or electronic medical record system.
Outside of the U.S., for a separate charge, NM-FOP also comes with artificial intelligence (AI) screening and diagnostic software. Remidio has begun the process of obtaining approval for the software in the U.S.
"The company is in the FDA review process for the AI-based software app for the screening and diagnosis of diabetic retinopathy, the No. 1 cause of preventable blindness worldwide, all right on the iPhone," noted Erik Hafkey, chief commercial officer.
Remidio sees the device being used as both a mydriatic and nonmydriatic fundus camera. Its mobile design and handheld use are suited for telehealth, screenings, health fairs, and mission work, Hafkey said. Future developments will be in the area of AI for the early detection of glaucoma, cataracts, and age-related macular degeneration. The device could be used in the offices of ophthalmologists, optometrists, and primary care providers.
Tracking the urinary tract
On another front, Tel Aviv-based Healthy.io has developed a smartphone-based, 10-parameter urinalysis test kit called Dip.io that can be used to test for urinary tract infections (UTIs) or in prenatal care.
The company received FDA clearance for the kit last year. Then in September, Healthy.io received an additional 510(k) clearance for its test to be used to diagnose chronic kidney disease. It also closed a $60 million series C funding round, which will be used to accelerate Healthy.io's global expansion and product development, the company said.
Healthy.io's smartphone-based test is cleared for use by healthcare professionals at any point of care, such as in a pharmacy, urgent care center, or health clinic.
The system uses a standard smartphone camera and a dipstick. After downloading the company's app, a user tests a sample of urine with the dipstick and places it in a proprietary color board. After the user takes a photo of the color board, the app uses AI and colorimetric analysis to extract the true color of each reagent reaction to deliver patient results in less than a minute.
The company claims that the kit is as accurate as the standard lab-based urinalysis analyzer. It is CE and ISO 13485 certified for sale in the European Union, and it is cleared by the FDA as a class II medical device. The company recently announced a partnership with the Boots U.K. chain involving placement of its Dip UTI test kits in pharmacies.
Hearing ear infections
Scientists at the University of Washington in Seattle have developed a smartphone app that can detect fluid behind the eardrum using a piece of paper and a smartphone's microphone and speaker. The smartphone makes a series of soft chirps into the ear through a small paper funnel; depending on the way the chirps are reflected back to the phone, the app determines the likelihood of fluid being present with an 85% probability of detection, according to the researchers.
"The smartphone system outperformed a commercial acoustic reflectometry system in detecting middle ear fluid in 98 pediatric patient ears, and the system could be easily operated by patient parents without formal medical training," wrote Justin Chan, of the Paul G. Allen School of Computer Science and Engineering, and colleagues in Science Translational Medicine (May 15, 2019, Vol. 11:492).
Meanwhile, in Australia, ResApp Health of Brisbane has developed technology that uses sound to diagnose respiratory disease. The company is using machine learning to develop algorithms that diagnose disease from cough and respiratory sounds, according to the ResApp website.
Researchers have generated a unique set of signatures and classifier technology that accurately characterize the respiratory tract. The diagnosis can be made using a high-quality microphone integrated into a smartphone, which can be useful in telehealth applications, for example.
In September, ResApp Health received the CE Mark for ResAppDx-EU version 2, the latest version of its smartphone diagnostic that now addresses both adults and children. This CE Mark approval adds the ability to test adults for lower respiratory tract disease, pneumonia, asthma exacerbation, and chronic obstructive pulmonary disease exacerbation. The first version tested for acute pediatric respiratory disease.