Smartphones and tablet computers have an emerging role as mobile medical monitoring devices, and may help to extend the use of pulse oximetry for monitoring blood oxygen levels to developing countries around the world, according to an article in Anesthesia & Analgesia by Dr J. Mark Ansermino of University of British Columbia, Vancouver. He writes, “The widespread adoption of mobile devices, even in low-resource settings, promises to make vital signs monitoring available anywhere and at low cost.”
Pulse oximetry
Today’s mobile devices “have the computing capability, display, and battery power to become powerful medical devices that measure vital signs and provide intelligent interpretation or immediate transmission of information,” according to Dr Ansermino. He notes that of the nearly six billion mobile phone users worldwide, two-thirds live in developing countries and remote areas.
In particular, mobile devices could increase access to pulse oximetry: the familiar ‘finger clip’ device used to monitor arterial oxygen saturation during anaesthesia and surgery, alongside other procedures. In developed countries, pulse oximetry has become so widely used that it has been called the ‘fifth vital sign’, added to body temperature, pulse rate, blood pressure and respiratory rate.
But pulse oximetry is still not routinely available in many areas, because of the costs of purchasing, using, and maintaining the monitoring equipment. In those places, mobile phones or tablet computers as monitors could provide an effective and economical approach to increasing the availability of blood oxygen measurement.
“The inherent computing power of these devices and their everyday availability offer the opportunity to create a stand-alone piece of equipment that can be used in the home by patients, yet which can also communicate with clinicians in real time,” Dr Ansermino writes, adding that previously owned smartphones and tablets could be “repurposed” for use in medical monitoring in developing countries.
Some mobile monitoring apps available now
Some technologies for mobile pulse oximetry are already in use; commercial modules that can communicate with mobile devices are now in clinical trials. An app that allows the iPhone to monitor pulse oximetry and other vital signs is also available, though not approved for medical use. While the technology still needs to be refined, these types of applications “deliver the promise of pulse oximetry combined with supportive diagnostic and treatment applications into every medical setting and every home,” writes Dr Ansermino.
For example, mobile monitoring could be an important tool in reducing deaths from pneumonia in children – still a common event in many resource-poor countries. Declining blood oxygen levels could be detected more promptly, thus allowing faster intervention. This technology could also identify women at risk of developing pre-eclampsia.
In addition, modern smartphones and tablets also have the computing power to perform sophisticated analyses of the photophlethysmographic (PPG) data produced by pulse oximeters. They could also be used to improve contact with healthcare providers, as an information resource to guide care, and as an educational tool for patients and healthcare providers.
