17 research outputs found

    A Surface-Integrated Sensor Network for Personalized Multifunctional Catheters*

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    Augmenting the sensing/actuating capabilities of multifunctional catheters used for minimally invasive interventions has been fostered by the reduction of transducers’ sizes. However, increasing the number of transducers to benefit from the entire catheter surface is challenging due to the number of connections and/or the required integrated circuits dedicated for multiplexing the transducer signals. Modular concepts enabling personalized catheters are lacking, at all. In this work, we investigated the feasibility of a simple and daisy-chainable transducer node network for active catheters, which overcomes these limitations. Sequentially accessible nodes enabling analog interaction (including signal buffering) with transducers were designed and fabricated using miniature components suited for catheter integration. The effective sampling rate (ESR) per node for acquiring bio-signals from 10 nodes was examined for various signal-to-noise ratios. Thanks to the low circuit complexity, an ESR up to 20 kHz was achieved, which is high enough for many bio-signals.Clinical relevance— Typical daisy-chaining features, namely theoretically indefinite node extension and simple reconfiguration facilitates modularization of the catheter design. The proposed network consequently ensures application and patient-specific requirements while incorporating transducer functions over the entire catheter surface, both may improve minimally invasive interventions

    Modulation Scheme Analysis for Low-Power Leadless Pacemaker Synchronization Based on Conductive Intracardiac Communication

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    Conductive intracardiac communication (CIC) has been demonstrated as a promising concept for the synchronization of multi-chamber leadless cardiac pacemakers (LLPMs). To meet the 2–5 μ W power budget of a LLPM, highly specialized CIC-transceivers, which make optimal use of the cardiac communication channel, need to be developed. However, a detailed investigation of the optimal communication parameters for CIC-based LLPM synchronization is missing so far. This work analyzes the intracardiac communication performance of two low-power modulation techniques, namely On-Off-Keying (OOK) and Manchester-encoded baseband transmission (BB-MAN), as a function of the transmitted bit-energy. The bit error rate (BER) of a prototype dual-chamber LLPM was determined both in simulation and in-vitro experiments on porcine hearts. A BER of 1e − 4 was achieved with a median bit-energy in the range of 3-16 pJ (interquartile range: 4-15 pJ) for data rates from 75-500 kbps and a receiver input noise density of 7 nV/ √Hz . Both modulation schemes showed comparable performance, with BB-MAN having a slight bit-energy advantage (1-2 dB at 150-500 kbps) under equalized transceiver characteristics. This study demonstrates that reliable CIC-based LLPM synchronization is feasible at transmitted power levels < 10 nW under realistic channel conditions and receiver noise performance. Therefore, modulation techniques such, as BB-MAN or OOK, are preferable over recently proposed alternatives, such as pulse position modulation or conductive impulse signaling, since they can be realized with fewer hardware resources and smaller bandwidth requirements. Ultimately, a baseband communication approach might be favored over OOK, due to the more efficient cardiac signal transmission and reduced transceiver complexity

    Therapie der Psoriasisarthritis unter Berücksichtigung neuer Behandlungsoptionen

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    Therapy of Psoriasis Arthritis Taking into Account New Treatment Options Abstract. Psoriatic arthritis occurs in about 20-30 % of patients with psoriasis. The disease is heterogeneous and can involve a variety of the distinct anatomical sites. The choice of medication depends on the type and the severity of clinical features. The recommendations of EULAR and GRAPPA serve as a guide for the choice of medication, which is used in sequential treatment steps. This is presented in our review in usable, simplified terms. Potential comorbidities leading to contraindication for certain treatments are considered. We present new and highly effective treatments, based on the pathogenesis of psoriasis and psoriatic arthritis, targeting the IL-23/IL-17 pathway. = Die Psoriasisarthritis wird bei ca. 20–30 % der Patienten mit Psoriasis vulgaris diagnostiziert und weist ein heterogenes Erscheinungsbild auf. Die Therapie richtet sich nach den Manifestationsarten der Arthritis, wobei auch das Ausmass des Hautbefalls in die Therapieentscheidungen miteinfliessen soll. Es existieren verschiedene Klassen von Therapeutika, die gemäss einem Stufenschema eingesetzt werden, das in dieser Arbeit vereinfacht nach den Richtlinien der EULAR und der GRAPPA dargestellt wird. Eventuelle Kontraindikationen ausgehend von Komorbiditäten sollen mitberücksichtigt werden. Neuerdings sind Therapeutika zugelassen, die sich eng an der Pathogenese der Psoriasis und Psoriasisarthritis via IL-23/IL-17-Achse orientieren

    Identifying maintenance hosts for infection with Dichelobacter nodosus in free-ranging wild ruminants in Switzerland: A prevalence study.

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    Footrot is a worldwide economically important, painful, contagious bacterial foot disease of domestic and wild ungulates caused by Dichelobacter nodosus. Benign and virulent strains have been identified in sheep presenting with mild and severe lesions, respectively. However, in Alpine ibex (Capra ibex ibex), both strains have been associated with severe lesions. Because the disease is widespread throughout sheep flocks in Switzerland, a nationwide footrot control program for sheep focusing on virulent strains shall soon be implemented. The aim of this cross-sectional study was to estimate the nationwide prevalence of both strain groups of D. nodosus in four wild indigenous ruminant species and to identify potential susceptible wildlife maintenance hosts that could be a reinfection source for domestic sheep. During two years (2017-2018), interdigital swabs of 1,821 wild indigenous ruminant species (Alpine ibex, Alpine chamois (Rupicapra rupicapra), roe deer (Capreolus capreolus), red deer (Cervus elaphus)) were analysed by Real-Time PCR. Furthermore, observed interspecies interactions were documented for each sample. Overall, we report a low prevalence of D. nodosus in all four indigenous wild ruminants, for both benign (1.97%, N = 36, of which 31 red deer) and virulent (0.05%, N = 1 ibex) strains. Footrot lesions were documented in one ibex with virulent strains, and in one ibex with benign strains. Interspecific interactions involving domestic livestock occurred mainly with cattle and sheep. In conclusion, the data suggest that wild ungulates are likely irrelevant for the maintenance and spread of D. nodosus. Furthermore, we add evidence that both D. nodosus strain types can be associated with severe disease in Alpine ibex. These data are crucial for the upcoming nationwide control program and reveal that wild ruminants should not be considered as a threat to footrot control in sheep in this context

    Leadless atrio-ventricular synchronous pacing in an outpatient setting - early lessons learned on factors affecting atrio-ventricular synchrony.

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    BACKGROUND Leadless pacemakers (PMs) capable of atrio-ventricular (AV) synchronous pacing have recently been introduced. Initial feasibility studies were promising, but limited to just a few minutes of AV synchronous pacing. Real-world long-term data on AV synchrony and programming adjustments affecting AV synchrony in outpatients are lacking. OBJECTIVE To investigate AV synchrony and influences of PM programming adjustments in outpatients with leadless VDD PMs. METHODS All patients who received a leadless VDD PM (Micra™ AV, Medtronic, US) between 07/2020 and 05/2021 at our center were included in this observational study. AV synchrony was assessed repeatedly postoperatively and during follow-up using Holter ECG recordings. AV synchrony was defined as a QRS complex preceded by a p-wave within 300ms. The impact of programming changes during follow-up on AV synchrony was studied. RESULTS 816 hours of Holter ECG from 20 outpatients were analyzed. During predominantly paced episodes (≥80% ventricular pacing), median AV synchrony was 91% (IQR 34-100%) when patients had sinus rates 50-80/min. Median AV synchrony was lower when patients had sinus rates >80/min (33%, IQR 29-46%, p<0.001). During a stepwise optimization protocol, AV synchrony could be improved (p<0.038). Multivariate analysis showed that a shorter maximum A3 window end (p<0.001), a lower A3 threshold (p=0.046), and minimum A4 threshold (p<0.001) improved AV synchrony. CONCLUSION Successful VDD pacing in the outpatient setting during higher sinus rates is more difficult to achieve than can be presumed based on the initial feasibility studies. The devices often require multiple reprogramming to maximize AV sequential pacing

    Analysis of a European general wildlife health surveillance program: Chances, challenges and recommendations.

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    In a One Health perspective general wildlife health surveillance (GWHS) gains importance worldwide, as pathogen transmission among wildlife, domestic animals and humans raises health, conservation and economic concerns. However, GWHS programs operate in the face of legal, geographical, financial, or administrative challenges. The present study uses a multi-tiered approach to understand the current characteristics, strengths and gaps of a European GWHS that operates in a fragmented legislative and multi-stakeholder environment. The aim is to support the implementation or improvement of other GWHS systems by managers, surveillance experts, and administrations. To assess the current state of wildlife health investigations and trends within the GWHS, we retrospectively analyzed 20 years of wildlife diagnostic data to explore alterations in annual case numbers, diagnosed diseases, and submitter types, conducted an online survey and phone interviews with official field partners (hunting administrators, game wardens and hunters) to assess their case submission criteria as well as their needs for post-mortem investigations, and performed in-house time estimations of post-mortem investigations to conduct a time-per-task analysis. Firstly, we found that infectious disease dynamics, the level of public awareness for specific diseases, research activities and increasing population sizes of in depth-monitored protected species, together with biogeographical and political boundaries all impacted case numbers and can present unexpected challenges to a GWHS. Secondly, we found that even a seemingly comprehensive GWHS can feature pronounced information gaps, with underrepresentation of common or easily recognizable diseases, blind spots in non-hunted species and only a fraction of discovered carcasses being submitted. Thirdly, we found that substantial amounts of wildlife health data may be available at local hunting administrations or disease specialist centers, but outside the reach of the GWHS and its processes. In conclusion, we recommend that fragmented and federalist GWHS programs like the one addressed require a central, consistent and accessible collection of wildlife health data. Also, considering the growing role of citizen observers in environmental research, we recommend using online reporting systems to harness decentrally available information and fill wildlife health information gaps

    Dichelobacter nodosus in sheep, cattle, goats and South American camelids in Switzerland-Assessing prevalence in potential hosts in order to design targeted disease control measures.

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    Footrot is a contagious foot disease caused by the bacterium Dichelobacter nodosus (D. nodosus) that affects sheep worldwide. Due to substantial economic and welfare impact, various countries have developed control programs against footrot. The aim of this cross-sectional study was to estimate the national prevalence of virulent and benign D. nodosus in Switzerland in the four domestic ruminant species sheep, cattle, goats and South American camelids (SAC) to detect potential host populations and to propose targeted disease control measures. Risk factors for infection with the virulent strain of D. nodosus, based on a survey carried out among farmers, were investigated on animal and herd level. Overall, 613 farms and 2920 animals were investigated during 2017-18 applying a two-stage cluster sampling strategy. A Real-Time PCR method for simultaneous detection of virulent and benign strains of D. nodosus was used for the first time in such a large study. On animal level, the true prevalence (TP) of virulent D. nodosus in sheep was estimated at 16.9% (95% confidence interval (CI%): 9.5-24.3%). In cattle and goats no virulent D. nodosus was detected and in SAC an apparent prevalence (AP) of 0.2% (CI%: 0.0-0.4%) was observed. On farm level, a TP of virulent D. nodosus of 16.2% (CI%: 8.4-25.2%) for sheep and an AP of 1.5% (CI%: 0.3-5.2%) for SAC herds was estimated. Since the Swiss control program only targets the virulent strains of D. nodosus, it was concluded that cattle, goats and SAC do not play a role in footrot epidemiology in Switzerland. Adult sheep were at higher risk of infection for virulent D. nodosus compared to lambs and yearlings. On herd level, risk factors for infection with virulent D. nodosus in sheep were earlier occurence of footrot, winter compared to summer and autumn, and goat contact on pasture. Liming pastures had a protective effect on D. nodosus infection. For benign D. nodosus, the TP in sheep was 6.3% (CI%: 1.6-11.0%) and in cattle 88.4% (CI%: 83.8-93.0%). The TP for benign D. nodosus in sheep farms was 2.8% (CI%: 0.0-10.5%) and in cattle farms 95.9% (CI%: 91.7-98.1%). In goat and SAC farms, the AP was 6.6% (CI%: 3.4-11.5%) and 7.4% (CI%: 3.8-13.1%), respectively. These findings could be relevant for wild ruminants such as Alpine ibex (Capra ibex ibex), which can develop clinical footrot after infection with benign D. nodosus. The findings of this study are crucial for assessing targeted disease control measures in Switzerland

    Conduction System Pacing Today and Tomorrow

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    Conduction system pacing (CSP) encompassing His bundle (HBP) and left bundle branch area pacing (LBBAP) is gaining increasing attention in the electrophysiology community. These relatively novel physiological pacing modalities have the potential to outperform conventional pacing approaches with respect to clinical endpoints, although data are currently still limited. While HBP represents the most physiological form of cardiac stimulation, success rates, bundle branch correction, and electrical lead performance over time remain a concern. LBBAP systems may overcome these limitations. In this review article, we provide a comprehensive overview of the current evidence, implantation technique, device programming, and follow-up considerations concerning CSP systems. Moreover, we discuss ongoing technical developments and future perspectives of CSP
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