A new hand-held device can quickly measure blood pressure and other vital signs from a patient’s lips and fingertip.
Researchers say the battery-powered MouthLab, now in prototype form, could replace bulky, restrictive monitors currently used to display patients’ vital signs in hospitals. It could also collect more kinds of data than are typically available in an ambulance, emergency room, doctor’s office, or patient’s home.
“We see it as a ‘check-engine’ light for humans,” says Gene Fridman, assistant professor of biomedical engineering at Johns Hopkins University School of Medicine.
No training needed
MouthLab’s measurements of heart rate, blood pressure, temperature, breathing rate, and blood oxygen compare well with patient vital signs measured by standard hospital monitors, according to the study that is published in the Annals of Biomedical Engineering. The device also does electrocardiograms to measure electrical activity in the heart.
“It can be used by people without special training at home or in the field,” Fridman says. The device may be able to detect early signs of medical emergencies, such as heart attacks, or avoid unnecessary ambulance trips and emergency room visits when a patient’s vital signs are good.
Because the device monitors vital signs in the mouth, future versions of the device may be able to detect chemical cues in blood, saliva, and breath that act as markers for serious health conditions.
“We envision the detection of a wide range of disorders,” Fridman says, “from blood glucose levels for diabetics, to kidney failure, to oral, lung and breast cancers.”
The prototype consists of a small, flexible mouthpiece like those that scuba divers use, connected to a hand-held unit about the size of a telephone receiver. The mouthpiece holds a temperature sensor and a blood volume sensor.
The thumb pad on the hand-held unit has a miniaturized pulse oximeter—a smaller version of the finger-gripping device used in hospitals, which uses beams of light to measure blood oxygen levels. Other sensors measure breathing from the nose and mouth.
MouthLab also has three electrodes for electrocardiograms—one on the thumb pad, one on the upper lip of the mouthpiece, and one on the lower lip—that work about as well as the chest and ankle electrodes used on basic ECG equipment in many ambulances or clinics.
That ECG signal is the basis for MouthLab’s new way of recording blood pressure. When the signal shows the heart is contracting, the device optically measures changes in the volume of blood reaching the thumb and upper lip. Unique software converts the blood flow data into systolic and diastolic pressure readings. MouthLab blood pressure readings effectively match those taken with the familiar arm-squeezing cuffs.
The hand unit relays data by Wi-Fi to a nearby laptop or smart device, where graphs display real-time results. The next generation of MouthLab will display its own data readouts with no need for a laptop, Fridman says. Ultimately, patients will be able to send results to their doctors via cellphone, and an app will let physicians add them to patients’ electronic medical records.
A 3D printer made the parts for the prototype, “which looks a lot like a hand-held taser,” Fridman says. “Our final version will be smaller, more ergonomic, more user-friendly, and faster. Our goal is to obtain all vital signs in under 10 seconds.”
Maryland Technology Development Corp. funded the work. Fridman is founder and sole owner of Multisensor Diagnostics LLC, which has an option from Johns Hopkins on the MouthLab technology. The arrangement has been reviewed and approved by the university in accordance with its conflict of interest policies.
Source: Johns Hopkins University