Fractional Fourier Transform-Based Signal Separation for Ultrasonic Guided Wave Inspection of Plates.

Detecting defects in plates is crucial across various industries due to safety risks. While ultrasonic bulk waves offer point-by-point inspections, they are time-consuming and limited in coverage. In contrast, guided waves enable the rapid inspection of larger areas.

Sensor-Location-Specific Joint Acquisition of Peripheral Artery Bioimpedance and Photoplethysmogram for Wearable Applications.

Background: Cardiovascular diseases (CVDs), being the culprit for one-third of deaths globally, constitute a challenge for biomedical instrumentation development, especially for early disease detection. Pulsating arterial blood flow, providing access to cardiac-related parameters, involves the whole body. Unobtrusive and continuous acquisition of electrical bioimpedance (EBI) and photoplethysmography (PPG) constitute important techniques for monitoring the peripheral arteries, requiring novel approaches and clever means.

Electrical Bioimpedance Analysis for Evaluating the Effect of Pelotherapy on the Human Skin: Methodology and Experiments.

Background: Pelotherapy is the traditional procedure of applying curative muds on the skin's surface-shown to have a positive effect on the human body and cure illnesses. The effect of pelotherapy is complex, functioning through several mechanisms, and depends on the skin's functional condition. The current research objective was to develop a methodology and electrodes to assess the passage of the chemical and biologically active compounds of curative mud through human skin by performing electrical bioimpedance (EBI) analysis.

Non-Standard Electrode Placement Strategies for ECG Signal Acquisition.

Background: Wearable technologies for monitoring cardiovascular parameters, including electrocardiography (ECG) and impedance cardiography (ICG), propose a challenging research subject. The expectancy for wearable devices to be unobtrusive and miniaturized sets a goal to develop smarter devices and better methods for signal acquisition, processing, and decision-making.

Methods: In this work, non-standard electrode placement configurations (EPC) on the thoracic area and single arm were experimented for ECG signal acquisition.

Study of Electrode Locations for Joint Acquisition of Impedance- and Electro-cardiography Signals.

ICG (impedance cardiography) and ECG (electrocardiography) provide important indications about functioning of the heart and of overall cardiovascular system. Measuring ICG along with ECG using wearable devices will improve the quality of health monitoring, as ICG points to important hemodynamic parameters (such as time intervals, stroke volume, cardiac output, and their variability). In this work, various electrode locations (12 different setups) have been tested for possible joint ECG & ICG data acquisition (using the same electrodes) and signal quality has been evaluated for every setup.

Methods for Detection of Bioimpedance Variations in Resource Constrained Environments.

Changes in a certain parameter are often a few magnitudes smaller than the base value of the parameter, specifying significant requirements for the dynamic range and noise levels of the measurement system. In case of electrical bioimpedance acquisition, the variations can be 1000 times smaller than the entire measured value. Synchronous or lock-in measurement of these variations is discussed in the current paper, and novel measurement solutions are presented.

Adaptive LINE-P: An Adaptive Linear Energy Prediction Model for Wireless Sensor Network Nodes.

In the context of wireless sensor networks, energy prediction models are increasingly useful tools that can facilitate the power management of the wireless sensor network (WSN) nodes. However, most of the existing models suffer from the so-called fixed weighting parameter, which limits their applicability when it comes to, e.g.

Dual-Source Linear Energy Prediction (LINE-P) Model in the Context of WSNs.

Energy harvesting technologies such as miniature power solar panels and micro wind turbines are increasingly used to help power wireless sensor network nodes. However, a major drawback of energy harvesting is its varying and intermittent characteristic, which can negatively affect the quality of service. This calls for careful design and operation of the nodes, possibly by means of, e.

Crest factor optimization of the multisine waveform for bioimpedance spectroscopy.

The multisine excitation is widely used in impedance measurements to retain the advantages of the sine wave, while reducing the measurement time. Adding up sine waves increases the amplitude of the excitation signal, but, for the linearity assumption to be valid, the overall amplitude of the signal needs to be kept low. Thus, the crest factor (CF) of the excitation signal must be minimized.

Wearable data acquisition system of multimodal physiological signals for personal health care.

The paper proposes a wearable multimodal data acquisition system for biological signals. The system enables logging of electrical bioimpedance signals from multiple electrodes, electrocardiographic signals (ECG), acceleration signals from multiple locations, and spirometric data from a moving object. Later it will be used to conduct field measurements for characterizing health of the object under investigation.

Wearable system for non-invasive and continuous monitoring central aortic pressure curve and augmentation index.

The paper presents a non-invasive method and system for a long-term and continuous monitoring of the central aortic pressure (CAP) waveform and the augmentation index (AI). The CAP curve is estimated from the measured radial electrical bio-impedance (EBI) using spectral domain transfer functions (TF), which are established on the basis of data analysis during clinical experiments. Experiments were carried out on 3 volunteers by now.

Binary signals in impedance spectroscopy.

Using of binary waveforms in the fast impedance spectroscopy of biological objects is discussed in the paper. There is shown that the energy of binary waveforms can be concentrated onto selected separate frequencies. We can optimize the binary excitation waveform depending on the shape of frequency response of the impedance under study to maximize the levels of signal components with certain selected frequencies.

Improvements in design of spectra of multisine and binary excitation signals for multi-frequency bioimpedance measurement.

The paper discusses the usability of multi-frequency binary waveforms for broadband excitation in fast measurements of impedance spectrum of biological objects. It is shown that up to 70% of the energy of the amplitude spectrum of such two-level binary signals can be concentrated into the selected separate frequencies. The levels of selected frequency components are controllable in tens and hundreds of times.