Bandwidth and Common Mode Optimization for Current and Voltage Sources in Bioimpedance Spectroscopy.

Bioimpedance measurements use current or voltage sources to inject an excitation signal into the body. These sources require a high bandwidth, typically from 1 kHz to 1 MHz. Besides a low common mode, current limitation is necessary for patient safety.

Pulmonary Effects of Sustained Periods of High-G Acceleration Relevant to Suborbital Spaceflight.

Members of the public will soon be taking commercial suborbital spaceflights with significant G (chest-to-back) acceleration potentially reaching up to 6 G. Pulmonary physiology is gravity-dependent and is likely to be affected, which may have clinical implications for medically susceptible individuals. During 2-min centrifuge exposures ranging up to 6 G, 11 healthy subjects were studied using advanced respiratory techniques.

Dynamic lung behavior under high G acceleration monitored with electrical impedance tomography.

. During launch and atmospheric re-entry in suborbital space flights, astronauts are exposed to high G-acceleration. These acceleration levels influence gas exchange inside the lung and can potentially lead to hypoxaemia.

Multi-channel bioimpedance spectroscopy based on orthogonal baseband shifting.

. Multi-channel bioimpedance spectroscopy (BIS) systems typically sample each channel's impedance sequentially using multiplexers and a single analog-to-digital converter. These systems may lose their real-time capability with an increasing number of channels, especially for low excitation frequencies.

Reconstruction algorithm for frequency-differential EIT using absolute values.

Objective: Tissues in the body differ by their frequency-dependent conductivity. Frequency-differential electrical impedance tomography (fdEIT) is a promising technique to reconstruct the distribution of tissue inside the body by injecting current at two frequencies and measuring the resulting surface-potential.

Approach: The Gauss-Newton method is one way to map the surface measurements to a conductivity image.

Three-dimensional Pulmonary Monitoring Using Focused Electrical Impedance Measurements.

Lung pathologies such as edema, atelectasis or pneumonia are potentially life threatening conditions. Especially in critically ill and mechanically ventilated patients, an early diagnosis and treatment is crucial to prevent an Acute Respiratory Distress Syndrome [1]. Thus, continuous monitoring tool for the lung condition available at the bedside would be highly appreciated.

Development of a wearable multi-frequency impedance cardiography device.

Cardiovascular diseases as well as pulmonary oedema can be early diagnosed using vital signs and thoracic bio-impedance. By recording the electrocardiogram (ECG) and the impedance cardiogram (ICG), vital parameters are captured continuously. The aim of this study is the continuous monitoring of ECG and multi-frequency ICG by a mobile system.