Thomas Schlebusch

On the Road to a Textile Integrated Bioimpedance Early Warning System for Lung Edema

Early detection of lung edema for patients suffering from chronic heart disease improves the medical treatment and can avoid committal of the patient to an intensive care unit. Therefore, an early warning system monitoring the amount of fluid in the lungs by measuring trans-thoracic bioimpedance outside the body has been developed. The proposed system(TiBIS) consists of a textile integrated measurement module and a Personal Digital Assistant for signal processing and user interaction.

Bladder volume estimation from electrical impedance tomography

Non-invasive estimation of bladder volume is required to progress from scheduled voiding to a demand-driven emptying scheme for patients with impaired bladder volume sensation. Electrical impedance tomography (EIT) is a promising candidate for the non-invasive monitoring of bladder volume. This article focuses on four estimation algorithms used to map recorded EIT data to a volume estimate. Two different approaches are presented: the tomographic algorithms (one based on global impedance, the other on equivalent circular diameter) rely on the reconstruction of a tomographic image and then extract a volume estimate, whereas the parametric algorithms (one based on neural networks, the other on the singular value difference method) directly map the raw data to a volume estimate. The four algorithms presented here are evaluated for volume estimation error, noise tolerance and suppression of varying urine conductivity based on finite element simulation data.

An RFID Communication System for Medical Applications

During the last years the significance of RFID systems has increased rapidly. In fact, its use is expected to increase by a factor of twenty until 2016. Medical applications are expected to be a main cause of this development. Currently, RFID systems are primary identification systems, based on the transmission of a key number or little further information. Using new technical developements and higher integration levels, it may be possible to extend these systems to measure and transmit data. Such RFID systems can be used in different areas of medical technology, because of the combination of application flexibility with the possibility of identification and data collection. For example, they can be used to identify patients or pharmaceuticals, monitor blood preservations or for medical implant communication.

Simulation of a current source with a cole-cole load for multi-frequency electrical impedance tomography

An accurate current source is one of the keys in the hardware of Electrical impedance Tomography systems. Limitations appear mainly at higher frequencies and for non-simple resistive loads. In this paper, we simulate an improved Howland current source with a Cole-Cole load. Simulations comparing two different op-amps (THS4021 and OPA843) were performed at 1 kHz to 1 MHz. Results show that the THS4021 performed better than the OPA843. The current source with THS4021 reaches an output impedance of 20 MΩ at 1 kHz and above 320 kΩ at 1 MHz, it provides a constant and stable output current up to 4 mA, in the complete range of frequencies, and for Cole-Cole (resistive and capacitive) load.

Effect of electrode arrangements on bladder volume estimation by electrical impedance tomography

The estimation of bladder volume by electrical impedance tomography is a promising technology to provide continuous volume estimates to patients who suffer from impaired bladder volume sensory. To find an optimized electrode arrangement for electrical impedance tomography of the human bladder, seven different electrode arrangements have been analysed using a finite element model. The arrangements under consideration can be assigned to three general groups: ring arrangements, linear arrangements and matrix arrangements. For each arrangement in these three groups, the condition of the Jacobian matrix and the global impedance for several bladder volumes has been calculated and compared using the EIDORS toolkit.

Unobtrusive and comprehensive health screening using an intelligent toilet system

Abstract Home monitoring is a promising technology to deal with the increasing amount of chronically ill patients while ensuring quality of medical care. Most systems available today depend on a high degree of interaction between the user and the device. Especially for people relying on advanced levels of care, this scheme is impracticable. In this paper, we are presenting an “intelligent toilet” performing an extensive health check while being as simple to use as a conventional toilet. The main focus of the system is to support the treatment of diabetes and chronic heart failure, but additional applications are possible.