How will the baby-boomers shape the future of medical technology? Well, shirts embedded with live electrocardiograms and pulse oximeters that wirelessly communicate data to your “digital nurse” or [real] doctor may be an example.
Six Fraunhofer Institutes in Germany have spent two years working on a system that can record the main cardiovascular functions 24 hours a day over a long period of time, even away from the doctor’s office, and enables communication with qualified medical staff.
The key components of the mobile health assistant were developed in a joint Fraunhofer project entitled senSAVE® (Sensor Assistance for Vital Events). Along with comfortable, easy-to-wear sensors that constantly measure all the necessary data and transmit them by radio to a PDA, the assistant has the necessary software to collect and analyze the flood of information and send it via Internet or mobile network to a telemedical support center, where trained staff can assess how critical the situation is, advise patients over the phone, and call a doctor if necessary.
It was a challenging task to find suitable electrodes for channeling the ECG readings, as they would need to be in permanent contact with the patient’s skin for days at a time. The Fraunhofer researchers developed a highly flexible dry electrode that can be woven into the elastic fibers of a sensor shirt. Potential wearers are fitted with their own tailor-made sensor shirt. The sheer pressure of the garment is sufficient to establish contact between the skin and the adhesive electrodes. A second layer of fabric covers the sensor wiring and the electronic circuit board.
The oxygen saturation of the blood and the pulse wave curve are determined by a pulse oximeter. Until now the pulse oximeter has been pushed over the index or middle finger with a commercially available finger clip. In future it will be integrated in a strap to be worn on the person’s wrist. From there, the readings will be radioed to a miniature computer, such as a smart phone or a PDA, which at the same time receives the ECG readings. The time difference between these two sets of readings yields the pulse wave transit time, from which it is possible in turn to deduce the blood pressure transit time — non-stop, 24 hours a day.
The PDA is the platform for the ‘mobile health assistant’. As well as recording the objective medical readings, it registers the user’s subjective feelings and experiences — ranging from wellbeing or weight, through drugs taken and meals eaten, to sporting activities and exciting events. Such additional information makes it easier for the doctor to interpret and respond to irregularities and changes in the patient’s cardiovascular readings. The patient is also advised and monitored on health issues. Rather like a personal organizer, the ‘digital nurse’ can manage health plans, motivate the patient to stick to them, and suggest alternatives where appropriate.
Many senior citizens are unaccustomed to using a cell phone or a PDA. To meet this need, the Fraunhofer researchers have developed interface prototypes that take into account the particular abilities or limitations of their future users. One version is very simple, displaying only the most important facts in large type which can be read even by patients who have misplaced their spectacles. The other version is rather more complex, and so configured that it can be combined with other services on a PDA. The ergonomic design of this user interface can be viewed at CeBIT in a live demonstration of the ‘mobile health assistant’.