Health monitoring is among the most attractive application fields for wearable electronics, and has been studied by many research groups. A variety of wearable devices for monitoring physiological parameters are commercially available today (e.g POLAR
http://www.polarusa.com/) with many others in research and development stage. However the majority of such devices are aimed at the recreational market (e.g joggers) and are not suitable for medical monitoring of high risk patients. Those devices that have been qualified for medical use are usually fairly simple, often measuring just one or two parameters and providing little or no online analysis. Many are also quite bulky.
The system developed by the AMON project is a next generation, fully wearable, medical monitoring computer aimed at high risk patients. The key innovations of AMON are:
· Multi-parameter monitoring and logging. The system continuously monitors and logs pulse, blood oxygen saturation and temperature of a patient. It also has an acceleration sensor to indicate the level of physical activity. Additional readings of blood pressure and single-lead ECG can be taken whenever necessary.
· Online health state analysis. Using the continuously monitored parameters and user activity information the system performs an online analysis of the user's health status. Should the system decide that the user's state deviates from a predefined user specific range, additional measurements including ECG and blood pressure are performed.
· Automatic and manual alerts. Should analysis of the additional measurements confirm such deviations, the system can automatically alert a doctor at a remote Medical Center using a built-in mobile phone link. A key advantage of AMON lies in the complexity of the analysis which minimizes the number of false alarms. Of course the system also has a manual alert function that can be user triggered whenever he or she feels that they need help. In either case an alert is triggered. All data logged during the hours preceeding an alert is sent to the medical center providing doctors with a basis for more accurate diagnosis.
· Interactive communication. The system allows medical center personnel to communicate with the patient using simple on-screen text messages. In addition the medical center personnel can control the AMON device and instruct it to make new measurements.
· Watch-like fully wearable form. All the parts of AMON, the electronics, sensors, and a battery sufficient for 24h, are contained in a watch-like housing mounted on a wrist worn blood pressure cuff.
The AMON wearable is comprised of several components: the sensor/analog subsystem, a user interface subsystem, a communication subsystem, a digital data processing unit, and a power supply and management subsystem. The ETH group has been responsible for the data processing unit (including system software), the power management and the user interface. Building upon our expertise in low power and wearable system design our group has made sure that despite complex functionality, the goal of having a truly wearable, unobtrusive system has been reached.
