Band 59, Heft 10 -

The drainage of cerebrospinal fluid by an external ventricular drainage is an indispensable therapy for acute brain pressure rise which at present is realized commonly with purely mechanical devices. The new drainage concept presented in this work uses a mechatronic device with automatic pressure control to enable a more reliable and automated therapy for the patient and a comprehensive examination of the disease for the doctor by the monitoring of the important parameters brain pressure, drained cerebrospinal fluid and compliance. To control the ventricular drainage, a partial static compensation of the process nonlinearity was combined with a proportional integral controller. This controller was tested in simulations and in a human-like test rig. The controlled ventricular drainage was able to achieve all brain pressure control targets.

Recent forms of therapy for spinal cord injury and stroke patients, especially for therapy of orthostatic hypotension, suggest among others verticalisation and passive leg movement by use of automatic tilt tables with robotic actuators. This article suggests the enhancement of such a device with the goal of enabling the patient´s active participation by allowing him to control his own work rate, based on visual biofeedback. At the same time the amount of the patient´s physiological stress is digitally controlled by adjustment of the visualised target work rate. As a result the patient´s cardio-pulmonary performance may be systematically increased. This enhancement has been realised as a prototype by integration of appropriate sensors and peripherical devices for digital control, operation and visualisation. Tests in line with a strictly technical validation study with several able-bodied male test persons yielded positive results, regarding the volitional work rate control by the individuals as well as the control behavior of the digital stress controllers.

This contribution presents a new approach to human arm position control under electrical stimulation that employs an acceleration feedback. During stimulation of antagonistic muscle pairs, this approach can noticeably reduce negative effects that are caused by an uncertain dead-zone within the muscular activation. The acceleration controller, realised using a disturbance observer, represents the lowest level of a cascaded control scheme. On higher levels the angle and the velocity are controlled. The overall control design is based on a highly simplified neuro-muscular model, which can be easily adapted to different subjects.

Traditional surgical procedures involving the implantation of artificial hearing devices in the inner ear are challenging due to the size and complexity of anatomical structures within the temporal bone. To date, no stereotactic instrument guidance technology providing the necessary levels of accuracy is available. This work presents an approach to robot assisted implantation of hearing devices. Specifically, the robot system was used to mill a cavity to for a direct acoustical stimulation implant. As the precision of such cavities increases, so also can future implant generations improve in terms of size, complexity and cost effectiveness. Additionally, patients themselves would profit from shorter procedure times and less painful interventions.

“HumanLib” is an object-oriented model library with components of the human cardiovascular system and physiological control mechanisms. In this paper, after specifying structure and modeling methods, simulated data is compared to measured data of an experimental calf model and to physiological textbook data.