Smartphones may soon convert patients’ homes into hybrid doctors’ offices, making access easier, especially for elderly and disabled patients. The cost savings may be considerable.

With each new product release, smartphones take sharper pictures and deliver better sound quality. Savvy medical device manufacturers and software engineers have figured out that those great cameras and microphones can be adapted to produce diagnostic tools that patients and caregivers can use in the home. Some of these products are so effective that doctors are starting to use them in their offices.

Smartphone-based medical devices fall broadly into two categories: those that require additional equipment to attach to the smartphone, and those that rely only on the smartphone’s camera and microphone.

Alexander Graham Bell’s gift to the world that keeps on giving

A wise doctor once said that the most powerful instrument in medicine was the telephone. This was before smartphones. The telephone is an even more powerful instrument today. Smartphone technology provides doctors with the type of remote access to patients that had previously only been imagined in science fiction. The technology has improved so much that doctors and patients can hear and see one another with quality that rivals the face-to-face visit. Many devices previously found only in doctors’ offices are now available as smartphone adaptations that patients and caregivers can use anywhere.

A stethoscope in every pocket

The stethoscope has become a symbol of the physician. Prior to its invention, physicians would simply place their ear against a patient’s chest. The stethoscope allows amplification of breath and heart sounds that provides insights into lung and heart function without having to look inside the patient. Today, smartphones have enhanced the power of the stethoscope. Patients and many doctors use smartphone-based amplifying devices to replace the ear-pieces from the traditional stethoscope. Now both patient and provider can hear breath or heart sounds and discuss their meaning in real time.

An even more exciting development is an application that can interpret breath sounds and coughs in combination with other symptoms that the patient enters. The app can indicate the likelihood that a person has various respiratory conditions. The application, ResApp, uses the smartphone’s microphone, and is particularly effective at diagnosing croup, asthma and pneumonia.

Electrocardiogram (ECG)

Most ECG machines are consoles about the size of a laptop computer, attached to as many as 12 wires that are then attached to a patient’s body. Today, crude ECG recordings can be taken by smart watches; even better ECG recordings can be taken with smartphone apps connected to as few as four leads that most anyone can be taught to attach. Other new systems include devices the size of business cards that the user can touch with his/her fingers to get an ECG reading that connects wirelessly to a smartphone.

Electroencephalogram (EEG)

EEGs are devices that measure the electrical activity of the brain. They are used to diagnose and monitor patients with epilepsy. Epilepsy patients must travel to EEG centers, where they are fitted with several leads that are glued to their scalp. Smartphone technology makes it possible for patients to monitor themselves at home and transmit the data to their neurologist. A proof-of-concept study in Nature.com determined that this innovation could soon make EEG technology available to the millions of epilepsy sufferers with limited access to EEG centers.

The otoscope (also known as the “ear thing”)

Every pediatrician has an otoscope for looking in children’s ears, generally used to diagnose ear infections. Pneumatic otoscopy, as it is officially called, requires some skill to learn. However, the most significant limitation of the technique is the otoscope itself, which very often provides the practitioner with only the most fleeting glimpse of a tiny eardrum attached to a wriggly child. Fortunately, the cameras on smartphones have gotten so good that a simple attachment allows high-resolution magnified views, providing doctors — and now parents — the ability to capture images of the ear drum, which they may send to a doctor.

The ophthalmoscope (also known as the “eye thing”)

Specialized attachments and associated applications have turned smartphones into devices that produce images almost as good as those available in eye doctors’ offices. The technology may not become available to the general public, however, because these examinations often require the use of pupil-dilating eye drops, which are used only in office settings. Simpler devices, however, are able to perform visual acuity exams, alerting patients when their eyeglass prescriptions become outdated.

The age of the hybrid doctor’s office

Some physicians have voiced concerns about diagnostic devices being used in patients’ homes. Expertise and judgment are indeed required when interpreting any medical test. Nevertheless, no one expects smartphone-based devices to completely replace the physician. Only trained cardiologists can read ECGs, and only trained neurologists can read EEGs. For other devices, physicians can and should actively participate in guiding the patient through the diagnostic and therapeutic process. Finally, skilled nurses can help patients use these devices in ways that can greatly increase their accuracy.

As the most powerful instrument in medicine, the smartphone, grows more powerful every year, physicians and home caregivers can harness that power for the benefit of their patients.