Considering the User in Device Design
As medical systems move from hospitals to homes and onto human bodies, designers need to realize their users are not professionals anymore. These new at-home users do not understand conditions that could impact measurements and the validity of measurements. When a number shows up on a display, the user would assume the measurement has been done properly. Designers must now develop medical products that deliver timely and accurate results for an untrained user.
Some at-home medical devices have evolved to reduce user-error. For example, in the past, blood glucose meters required users to enter a date code before measurement because the chemistry on the strip varies with time. Many new meters eliminate this step by using auto-detection. Likewise, future generations of blood pressure monitors and oximeters can employ accelerometers with high-performance microcontrollers to detect body movement during measurement for more accurate results. Remote trend monitoring, for example, via cell phones, could also allow physicians and nurses to detect abnormal patterns.
On-body medical devices, on the other hand, have a different use model. Patients who need on-body medical devices, such as continuous blood glucose meters or ECG monitors, have medical conditions that require 24/7 monitoring. In these systems, it is best to have no display because showing the data could lead to the users trying to interpret it. These systems could use Bluetooth Low Energy to send data to a cell phone that relays the information to the doctor’s office for in-time monitoring. Performing these functions while constrained by a small coin cell battery would require an energy efficient microcontroller and low power radio technology.