Hermie J. Hermens

Ambulatory Estimation of Relative Foot Positions by Fusing Ultrasound and Inertial Sensor Data

Relative foot position estimation is important for rehabilitation, sports training and functional diagnostics. In this paper an extended Kalman filter fusing ultrasound range estimates and inertial sensors is described. With this filter several gait parameters can be estimated ambulatory. Step lengths and stride widths from 54 walking trials of three healthy subjects were estimated and compared to an optical reference. Mean ( ± standard deviation) of absolute difference was 1.7 cm ( ±1.8 cm) and 1.2 cm ( ±1.2 cm) for step length and stride width respectively. Walking with a turn and walking around in a square area were also investigated and resulted in mean absolute differences of 1.7 cm ( ±2.0 cm) and 1.5 cm ( ±1.5 cm) for step lengths and stride widths. In addition to these relative positions, velocities, orientations and stance and swing times can also be estimated. We conclude that the presented system is low-cost and provides a complete description of footstep kinematics and timing.

Putting the patient at the centre making telemedicine services personal again

In aging societies, healthcare innovations are becoming increasingly important. ICT is a key factor in many of these innovations, as it possesses great potential for increasing efficiency in the healthcare domain. We stress the importance of both attention for the complete patient health status, and framework adoption for telemedicine applications. This is achieved through the adoption of a holistic health model such as the ICF (International Classification of Functioning, Health and Disabilities) and the provision of care support wherever and whenever possible to assist patients in their social context. In the U-Care project, which we describe as our use case, we adopt these ideas. In this paper, we elaborate a holistic view on telemedicine application design, involving the context of the end-users, to develop evolvable and tailorable care services.

Coaching of Body Awareness Through an App-Guide: The HealthNavigator

The article describes the process of the development of an app to support people in lifelong secondary prevention, e.g. after a heart attack or with chronic diseases. The goal of this app-guide, called the HealthNavigator, is to coach people walking on leisure paths through guidance, motivation, and better understanding of physical abilities (body awareness). There were three development cycles, each one followed by a demonstrator test with health professionals and patients. The outcomes of these tests were taken into account for the following development cycle. Focus was placed on how to motivate people to exercise regularly and in a healthy manner. The evaluations showed that HealthNavigator was found to be usable tool for teaching body awareness and making users feel safe, while motivating them to take walks in the open air.

Recent Developments in Implantable and Surface Based Dropped Foot Functional Electrical Stimulators

One approach to improving the gait of patients with foot drop is the use of functional electrical stimulation (FES) as a neural prosthesis. However, there remain limitations with the current clinically used technology and the paper describes some recent developments addressing some of these problems. The paper describes initial work on an alternative surface-based solution and recent developments of an implantable two channel stimulator.