Search

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.

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.

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.

Due to globalization and the quick development of technology, each government aims to ensure the safety and performance of products brought to their markets to protect its population. The peoples’ health state is of great significance and influenced easily by the quality of medical products. Therefore governments enact laws, directives and regulations to assure that quality. Nevertheless, these regulations can impede innovation and create trade barriers which result in an adverse effect on national economies. Where in some states no regulatory system is installed, others have highly sophisticated registration requirements that must be met. These diversities result in a challenge especially for small and medium sized companies, whose resources are often limited. [1] Manufacturers must control these diverse regulatory requirements by analyzing each market. Therefore an efficient procedure of registration should be defined that streamlines different registration requirements and ensures regulatory compliance. Next to regulatory authorities describing these requirements also harmonization groups play an important role in the design of the global regulatory landscape. Therefore also the most important harmonization groups and their current activities were investigated. The analysis showed that the impact of harmonization groups can be identified easily since new defined or updated regulatory requirements are oriented on their guideline. Still the harmonization of regulatory requirements in the medical device sector is not sufficiently enhanced. Thus the confrontation with each national regulatory system is inevitable.

Along with increasing enthusiasm for sports comes an increase of sport related injuries. One of the most common injuries in the human knee is the tear of the anterior cruciate ligament (ACL). The selection of a graft fixation device is an important factor that determines the outcome of an anterior cruciate ligament reconstruction. Before the healing process is completed, the graft is dependent on tibial and femoral fixation devices to maintain normal ACL graft tension. Among various devices, the use of an adjustable loop suspensory fixation device (ALD) in soft-tissue graft reconstruction attracts current interest. An advantage of the ALD is the ability to draw the graft to the depth of the bone tunnel to achieve adequate graft tension while minimizing the empty space in the tunnel. In this study a comprehensive controlled laboratory investigation is performed to examine the biomechanical properties of commonly used cortical fixation devices, with the aim of implementing a standard testing procedure for adjustable loop devices. The procedure consists of three test series, a loop shortening test and two different stability test series (singe device and tendon device test). Those test series are used to compare the performance of a new ALD from Arthrex (Naples, USA) with five competitor devices already on the market. In order to obtain representative results eight samples of each device are tested. In comparison to the previously performed studies, a complete unloading is applied in the stability tests, which allows for a detailed examination of the ALDs locking mechanisms in dynamically loaded test situations. Furthermore, the performed loop shortening tests reveal important aspects, such as the shortening accuracy and settling effects of the loops, that are not found in previous studies. Therefore, the used test protocol can be recommended for further testing.

The aim of this work was to analyse the medication process and the potential for errors during the process steps. For this purpose, a literature review was conducted and a questionnaire was developed to compare the results from the literature with the current medication process in Styrian hospitals. The questionnaire was divided into four different parts with a total of 29 questions. For the survey all 37 Styrian hospitals were contacted whereas 11 filled out the questionnaire. The survey showed that there is no standardized medication process defined and that the rate of medication errors is generally underestimated. In addition, technical solutions may help to reduce errors but are expected to be hardly used in clinical practice.

Usability of medical devices is one of the main determining factors in preventing use errors in treatment and strongly correlates to patient safety and quality of treatment. This thesis demonstrates the usability testing and evaluation of a prototype for locomotor therapy of infants. Therefore, based on the normative requirements of the EN 62366, a concept combined of evaluation procedures and assessing methods was created to enable extensive testing and analysis of the different aspects of usability. On the basis of gathered information weak points were identified and appropriate measures were presented to increase the usability and operating safety of the locomotor prototype. The overall outcome showed an usability value of 77.4% and an evaluation score of 6.99, which can be interpreted as “satisfactory”.