Volume 9, Issue 2 - Proceedings of the 2023 Annual Meeting of the Austrian Society for Biomedical Engineering (ÖGBMT)

Locked-in Syndrome (LIS) severely restricts the communication abilities of individuals due to extensive paralysis. The Intracranial Neuro Telemetry to Restore communication (INTRECOM) project aims to aid patients in overcoming these limitations by developing a fully implantable brain computer interface (BCI) system based on state-of-the-art technology holding great promise in revolutionizing the lives of LIS patients. In this project, the Graz BCI group, with its expertise in understanding brain dynamics associated with movement, focuses on the algorithmic development of advanced decoders that enable the user to execute specific commands by simply attempting corresponding movements. Our preliminary findings using electrocorticography (ECoG) data obtained from one individual with LIS that underwent implantation of a BCI communication system demonstrate the applicability of a ‘brain switch’ function that detects brain signals associated with attempted movements. This switch can then be used to translate the intention of the user into a click/select function on a screen.

The cochlear implant was the first effective and is still the most common neuroprosthetic device which is employed for people with severe to profound hearing loss. To restore auditory perception, an array of micro-electrodes that deliver electrical pulses to the auditory nerve is surgically implanted into the lower cochlea duct, the scala tympani (ST). However, implantation into the upper cavity, the scala vestibuli (SV) has been tested due to severe anatomical obstruction or ossification of the ST. Clinical results revealed similar performance and thresholds for SV and ST cochlear implant users. We present a simulation study of auditory nerve fibre response to monophasic stimulation of both polarities. Excitation profiles are compared for microelectrodes placed in the SV and equivalent positions in the ST. In total, 7 different electrode positions for 4 different fibres have been investigated in a homogenous 2D model. Results for the intact fibres predict generally higher anodic thresholds in comparison to cathodic stimulation at the same electrode position and mostly lower thresholds for the SV electrodes in comparison to their ST counterparts. In contrast, anodic thresholds are mostly lower than cathodic thresholds for the degenerated fibres. Furthermore, due to the increased electrode-fibre distance for degenerate fibres which have completely lost the dendrite, SV stimulation is less beneficial. However, for basal fibres and the clinically relevant mid scala placement of the electrode the typically high thresholds remain similar for ST and SV positions.

The project "Barrierfree dEsign foR Teaching and Learning" (BERTL) aims to identify and reduce barriers in teaching, with a focus on Universal Design or Design for All. BERTL includes an analysis of the situation at the University, to identify barriers faced by people with disabilities, chronic diseases, and in different life situations The BERTL Simulation Lab and Toolbox will be developed based on the analysis to help identify and eliminate barriers in their courses, and the continuing education program. In the different phases of the project, pilot courses with different didactic concepts are analyzed, checked for barriers in teaching materials and course procedures also peer feedbacks are conducted. These results will be used to improve and expand the courses of the University Applied Science and the used didactic principles. Establishing a handbook and a training series at the University is also aim of this project as practice collection and sample courses to support lecturers. The project results will be used in teaching and made publicly available.

In this study, we employed calcium imaging to investigate the dynamics of intracellular calcium levels in embryonic chicken cardiomyocytes upon extracellular, optoelectronic stimulation. A photovoltaic layer of donoracceptor pigments on a flexible PET substrate was used as a wireless stimulation electrode. Our findings revealed a distinct change in their spontaneous activity pattern in cardiac cells following asynchronous light stimulation. A short pause in cellular activity, indicative of overdrive suppression, was observed in recordings from several different cells. The pause in activity signifies a transient refractory period induced by stimulation of the photovoltaic device with red light. These findings suggest that photovoltaic electrodes can be used to effectively modulate the electrical activity of cardiac cells in a wireless, non-pharmacological manner. This opens new avenues for non-invasive and precise light-modulated control of cellular electrophysiology as well as potential therapeutic applications for cardiac rhythm disorders.

Detecting cells on substrates time-continuously without the need of optical microscopy is broad interest in biotechnological applications. We demonstrate the stability and repeatability of a method to detect cancer cells using cell adhesion noise spectroscopy across different CMOS-based microelectrode arrays. We analyze the recordings in terms of spectral power density.

Fluid flow in the human body can be modeled using a water-level tank, a commonly used mechanistic approach in mechanical engineering for fluid transport processes. Postoperative fluid data from patients undergoing cardiac surgery is used to estimate fluid flow dynamics and total body water in the human body. This simplified model provide a basic understanding of the dynamics of fluid flow processes in the human body and could aid in modeling distribution of fluids in compartments.

The Electro Cardio Gram (ECG) is a very valuable clinical tool to access the electric function of the heart. It provides insight into the different phases of the heart beat and various kinds of disorders which may affect them. In literature the impact of linear dependency between feature signals upon the classification outcome and how to reduce it have been largely investigated and discussed. This study puts a focus upon linear dependency between samples of imbalanced data sets, its relation to the observed over fitting with respect to majority classes and hot to reduce it. A set of 58 feature signals is used to train a several LDA classifier either discriminating 3 classes (Normal, Artefact, Arrhythmic) or 5 Classes (Normal, Artefact, Atrial and ventricular premature contractions and bundle branch blocks). The training data set is preprocessed using four sample reduction approaches and a nearest neighbour clustering method. In the case of 5 classes accuracies of 96.82% in the imbalanced case and 97.44% for the data preprocessed with the QR or SVD methods were obtained. For 3 classes curacies of 97.68% and 98.12% were achieved. With the nearest neighbour clustering method only accuracies of 96.00% for 5 classes and 97.37% for 3 classes could be achieved. The results clearly show that imbalanced ECG data does contain linear dependent samples. These cause a bias towards majority class which will be over fitted by the classifier. Sample reduction methods and algorithms which are not aware of the presence linear dependent samples like the nearest neighbour clustering approach even further increase this bias ore even worse destroy relevant information by merging samples which encode distinct aspects of the beat class, destroying relevant information.

Simulation is essential for healthcare professionals, students, and researchers, providing a safe environment for skill development and improved patient care. This paper presents enhancements to the xPULM TM electro-mechanical lung simulator, enabling simulation of adult and neonatal breathing patterns. Hardware improvements include interchangeable flow sensors and additional temperature, humidity, volatile organic compounds (VOCs), and pressure sensors. The software redesign separates control and processing elements, enhancing performance. Measured parameters demonstrate expanded capabilities, such as increased airflow range and higher sampling frequency. Airtightness measurements show improved chamber sealing. Future developments aim to simulate neonatal breathing patterns and optimise software for high-frequency measurements. The enhanced xPULM TM simulator provides a realistic platform for simulating lung mechanics, benefiting respiratory medicine research and education.

This paper discusses possibilities to explain which Kv channels can be considered as first-order systems. This means that the dynamic behavior of these channels can be described with a first-order differential equation and are the most straightforward dynamical systems. For example, a typical first-order system is an RC circuit, and analogously, Kv channels can be considered with the dynamic behavior of first-order systems following RC circuits. This work represents a family of KV channels that can be described as first-order systems, providing an efficient method of ion channel modeling in computational electrophysiology.

This paper introduces CloveBiotech, an extension and optimization of CLOVE, which is designed to accurately classify complex structural variants (SVs) resulting from genetic modifications in the genomes of microbial strains. While CLOVE covers various complex SV types, it lacks support for large insertions, targeted vector integrations and substitutions of genes with a marker cassette. CloveBiotech addresses these limitations by modifying the algorithm to handle more diverse SV scenarios, including new fusion patterns. However, covering these scenarios demanded a major rewrite of multiple classes and functions. Performance evaluations on simulated data demonstrate its improved precision and recall rates of up to 0.92 and 0.96 respectively, across different sequencing parameters. With these enhancemanets, CloveBiotech provides a valuable tool for scientists working with genetically modified microorganisms, facilitating accurate SV detection and classification.