bluuebunny/crossref_metadata_2025_split huggingface dataset:
Training students to use syringe pumps: an experimental comparison of e-learning and classroom training
Authors: Grundgeiger Tobias , Kolb Lorenz , Korb Maximilian O. , Mengelkamp Christoph , Held Volker 
Published: September 2015

AbstractThe inadequate use of syringe pumps can jeopardize patient safety, and syringe pump trainings are conducted to manage this risk. A critical step in this risk management process is the learning success of trainees. In the present paper, we compared an e-learning approach with standard classroom training in learning success effectives, trainees’ opinion on the trainings, and investigated the relation between technological affinity and learning success. The results showed that e-learning was as effective as classroom training but nursing students’ confidence in using the pump and satisfaction with the training was decreased for e-learning compared with classroom training. We discuss the results in context of the nursing e-learning literature. Finally, we discuss the literature for risk identification, risk analysis, risk treatment, and risk monitoring and control in the context of syringe pump training and add the lessons learned from the evaluated e-learning program.
The development of an experimental setup to measure acousto-electric interaction signal
Authors: Kristín Inga Gunnlaugsdóttir 
Published: September 2015

Abstract
A new method is desirable for secure efficiency of FES treatment of degenerated denervated muscles. Degeneration of denervaed muscles as a consequence of spinal injuries are treated with functional electrical stimulation (FES). So far, no effective method to monitor the effectiveness of the treatment over the whole treated muscle is available. The most common method is placing finger on appropriate tendons and sense the movement. We suggest new approach. As pressure wave changes locally electrical conductivity in its propagation direction of the medium, a change in voltage is detected when electrical field is applied simultaneously at that location. This change in voltage is called acousto-electric interaction (AEI) signal. By recording AEI signal a distribution of electrical activity can be mapped, known as ultrasound current source density imaging (UCSDI). In this paper, an experimental setup to investigate the AEI signal is developed. The signal is measured and compared to calculated values. Debye effect and AEI signal is detected.
Field mapping of ballistic pressure pulse sources
Authors: Rad Abtin Jamshidi , Ueberle Friedrich 
Published: September 2015

Abstract
Ballistic pressure pulse sources are used since late 1990s for the extracorporeal treatment of chronic Enthesitis. Newly indications are found in trigger-point-therapy for the treatment of musculoskeletal disorders. In both applications excellent results without relevant side effects were found in clinical trials. The technical principle of pressure pulse source is based on the same techniques used in air guns. A projectile is accelerated by pressurized air and hits the applicator with high kinetic energy. By this a compression wave travels through the material and induces a fast (4..5μs), almost singular pressure pulse of 2..10 MPa, which is followed by an equally short rarefaction phase of about the same amplitude. It is assumed that the pressure pulse accounts for the biomedical effects of the device. The slower inertial motion of the waveguide is damped by elastic stoppers, but still can be measured several micro seconds after the initial pressure pulse. In order to characterize the pressure pulse devices, field mapping is performed on several radial pressure pulse sources using the fiber optic hydrophone and a polyvinylidenfluorid (PVDF) piezoelectric hydrophone. It could be shown that the current standard (IEC 61846) is not appropriate for characterization of ballistic pressure pulse sources.
Spike sorting: the overlapping spikes challenge
Authors: Sauer Inga , Doerr Christopher , Schanze Thomas 
Published: September 2015

Abstract
When recording action potentials (spikes) from many neurons simultaneously via multichannel micro-electrodes the overlapping of spikes from different neurons is a demanding problem for detection and classifi-cation of spikes (spike sorting). Since multichannel electrodes provide better possibilities to separate the superimposed waveforms, we refined an algorithm for separation of overlapping spikes for the use on multichannel recordings and tested it on simulated data with different numbers of signal channels and with several signal parameters. We show that the larger the number of signal channels the better the separation that may be achieved, especially under demanding recording conditions.
Compressed sensing of multi-lead ECG signals by compressive multiplexing
Authors: Tigges Timo , Sarikas Janis , Klum Michael , Orglmeister Reinhold 
Published: September 2015

Abstract
Compressed Sensing has recently been proposed for efficient data compression of multi-lead electrocardiogram recordings within ambulatory patient monitoring applications, e.g. wireless body sensor networks. However, current approaches only focus on signal reconstruction and do not consider the efficient compression of signal ensembles. In this work, we propose the utilization of a compressive multiplexing architecture that facilitates an efficient implementation of hardware compressed sensing for multi-lead ECG signals. For the reconstruction of ECG signal ensembles, we employ an greedy algorithm that exploits their joint sparsity structure. Our simulative study shows promising results which motivate further research in the field of compressive multiplexing for the acquisition multi-lead ECG signals.
Synchronization in wireless biomedical-sensor networks with Bluetooth Low Energy
Authors: Bideaux André , Zimmermann Bernd , Hey Stefan , Stork Wilhelm 
Published: September 2015

Abstract
Bluetooth Low Energy (BLE) has reduced the energy consumption for sensor nodes drastically. One major reason for this improvement is a non-continuous connection between the nodes. But this causes also a nondeterministic data transmission time. Most synchronization protocols are influenced by this characteristic, with the result of less accuracy. In wireless body sensor networks this accuracy is often of vital importance. Therefore this paper evaluates different synchronization principles customized for BLE.
For the evaluation measurements we used two BLE modules connected to one micro controller. This setup allowed us to calculate the error directly for the different principles. First we measured the send-receive time as a reference which influences most synchronization protocols. This time is directly affected by random transmission delays of BLE. Second we used the time difference between receiving and acknowledging a message as principle (A). The last principle (B) can only be used between nodes that use BLE that don’t require a constant connection, because it needs to connect and disconnect the nodes. After a new connection the “connected” events occur in the BLE nodes almost at the same time and can be used for synchronization. The reference measurement showed the worst results. The average delay was 4.76 ms with a standard deviation of 2.32 ms. Principle (A) showed average delays of 7.51 ms, which was almost exactly 1 connection interval in our setup. The standard deviation was 0.41 ms. Principle (B) showed the best results with an average time difference of 39.92 μs and a standard deviation of 14.19 μs
The results showed that with the principles (A) and (B) the synchronization of nodes can be highly improved compared to the reference. In future we will test the principles with synchronization protocols in real sensor nodes also with respect to the processor load.
Effects of sampling rate on automated fatigue recognition in surface EMG signals
Authors: Kahl Lorenz , Eger Marcus , Hofmann Ulrich G. 
Published: September 2015

Abstract
This study investigated the effects different sampling rates may produce on the quality of muscle fatigue detection algorithms. sEMG signals were obtained from isometric contractions of the arm. Subsampled signals resulting in technically relevant sampling rates were computationally deduced from the original recordings. The spectral based fatigue recognition methods mean and median frequency as well as spectral moment ratio were included in this investigation, as well as the sample and the fuzzy approximate entropy. The resulting fatigue indices were evaluated with respect to noise and separability of different load levels. We concluded that the spectral moment ratio provides the best results in fatigue detection over a wide range of sampling rates.
Metal artifact reduction by projection replacements and non-local prior image integration
Authors: Stille Maik , Thorsten Buzug M. 
Published: September 2015

Abstract
The presence of high-density objects remains an open problem in medical CT imaging. Data of projections that passing through such objects are dominated by noise. Reconstructed images become less diagnostically conclusive because of pronounced artifacts that manifest as dark and bright streaks. A new reconstruction algorithm is proposed, which incorporates information gained from a prior image. Based on a non-local regularization, these information are used to reduce streaking artifacts. In an iterative scheme, the prior image is transformed in order to match intermediate results of the reconstruction by solving a registration problem. During iterations, temporally appearing artifacts are reduced with a bilateral filter and projection values passing through high-density objects are replaced by new calculated values, which are used further on for the reconstruction. Results show that the proposed algorithm significantly reduces streaking artifacts.
Inkjet printing of viable human dental follicle stem cells
Authors: Mau Robert , Kriebel Katja , Lang Hermann , Seitz Hermann 
Published: September 2015

Abstract
Inkjet printing technology has the potential to be used for seeding of viable cells for tissue engineering approaches. For this reason, a piezoelectrically actuated, drop-on-demand inkjet printing system was applied to deliver viable human dental follicle stem cells (hDFSC) of sizes of about 15 μm up to 20 μm in diameter. The purpose of these investigations was to verify the stability of the printing process and to evaluate cell viability post printing. Using a Nanoplotter 2.1 (Gesim, Germany) equipped with the piezoelectric printhead NanoTip HV (Gesim, Germany), a concentration of 6.6 ×106 cells ml−1 in DMEM with 10% fetal calf serum (FCS) could be dispensed. The piezoelectric printhead has a nominal droplet volume of ~ 400 pl and was set to a voltage of 75 V and a pulse of 50 μs while dosing 50 000 droplets over a time of 100 seconds. The volume and trajectory of the droplet were checked by a stroboscope test right before and after the printing process. It was found that the droplet volume decreases significantly by 35% during printing process, while the trajectory of the droplets remains stable with only an insignificant number of degrees deviation from the vertical line. It is highly probable that some cell sedimentations or agglomerations affect the printing performance. The cell viability post printing was assessed by using the Trypan Blue dye exclusion test. The printing process was found to have no significant influence on cell survival. In conclusion, drop-on-demand inkjet printing can be a potent tool for the seeding of viable cells.
The use of an icebindingprotein out of the snowflea Hypogastrura harveyi as a cryoprotectant in the cryopreservation of mesenchymal stem cells
Authors: Vierthaler M. , Reinard T. , Glasmacher B. , Hofmann N. 
Published: September 2015

Abstract
Today researchers look for a possibility to keep cells for a long time without losing their viability. For that cryopreservation is often used. In this process it is necessary that the cells are not destroyed so cryoprotective agents (CPA) are needed. At the moment 5 to 10 % dimethylsulfoxide (DMSO) is mostly used, but this chemical is cytotoxic to the cells. So an alternative is needed. In this work experiments are made with an icebindingprotein (IBP) of Hypogastrura harveyi, as an alternative to DMSO. It was shown in previous studies that this protein isn’t cytotoxic for the cells, with crude extract and purified inclusion bodies it even seems that the mixtures have a positive effect on growth and proliferation. As a first step the protein was produced heterologous in E. coli and then the crude extract and the purified inclusion bodies were used for experiments on the influence of the IBP on the cryopreservation of mesenchymal stem cells from the common marmoset monkey Callithrix jacchus. In the process it was found that the protein could not replace DMSO completely. But it was possible to show that the DMSO-concentration can be reduced by adding the IBP.
QRS and QT ventricular conduction times and permanent pacemaker therapy after transcatheter aortic valve implantation
Authors: Takam P.C. , Höfflin D. , Heinke M. 
Published: September 2015

Abstract
Transcatheter aortic valve implantation is a therapy for patients with reduced left ventricular ejection fraction and symptomatic aortic stenosis. The aim of the study was to compare the pre-and post- transcatheter aortic valve implantation procedures to determine the QRS and QT ventricular conduction times as a potential predictor of permanent pacemaker therapy requirement after transcatheter aortic valve implantation. QRS and QT ventricular conduction times were prolonged after transcatheter aortic valve implantation in heart failure patients with permanent dual chamber pacemaker therapy after transcatheter aortic valve implantation. QRS and QT ventricular conduction times may be useful parameters to evaluate the risk of post-procedural ventricular conduction block and permanent pacemaker therapy in transcatheter aortic valve implantation.
Improving tactile sensation in laparoscopic surgery by overcoming size restrictions
Authors: Wiederer C. , Fröhlich M. , Strohmayr M.W. 
Published: September 2015

Abstract
Hepatic tumors appear as stiff inclusions within the surrounding soft, healthy tissue. In open surgery they are searched for by manual palpation with the gloved fingertip. However, to exploit the benefits of MIS it is mandatory to implement a substitution for the human sense of touch. Therefore, a tactile instrument has been developed with the aim of enlarging the sensing area at the tool tip once it enters the abdominal cavity through the trocar. The provision of a large sensitive surface enables the detection of nearly all sizes of tumors and decreases the time needed for the performance of this task. A prototype was manufactured by laser sintering in PA serving as a carrier for an existing flexible silicone sensor. Automated as well as manual subject palpation tests have shown that a prototypical instrument with a laterally opening lid would be a suitable device for tumor detection in laparoscopic liver surgery.
Evaluation of endourological tools to improve the diagnosis and therapy of ureteral tumors – from model development to clinical application
Authors: Wagner D. , Porsch M. , Detert M. , Bartel F. , Siedentopf S. , Schindele D. , Wendler JJ. , Lux A. , Schmidt B. , Schostak M. , Liehr UB. 
Published: September 2015

Abstract
Adequate diagnosis of upper urinary tract (UUT) tumors is essential for successful local treatment. Organsparing approaches are technically difficult and require consistent further development. Appropriate models for investigating new diagnostic and therapeutic methods are not yet available. This study demonstrates the incorporation of a fresh sample model into five different test levels (I-V) for improving the diagnosis and therapy of ureteral tumors. In these test levels, new diagnostic and ablation techniques are evaluated for feasibility, application safety, efficacy and accuracy. An assessment of their suitability for broad preclinical and clinical application also took economic aspects into account.
Frequency based assessment of surgical activities
Authors: Maktabi Marianne , Vinz Sascha T. , Neumuth Thomas 
Published: September 2015

Abstract
In hospitals the duration of surgeries plays a decisive role in many areas, such as patient safety or financial aspects. By utilizing accurate automated online prediction efficient surgical patient care and effective resource management can be attained. In this work several surgical activities during an intervention were examined for their potential to forecast the remaining intervention time. The method used was based on analysing in the frequency domain of time series which represented the status of surgical activities during an intervention. A nonparametric estimation of power spectral density was calculated for single surgical tasks during an intervention. The power spectral densities (PSD) of different surgical activities were compared in a leave-one-out cross validation of forty surgical workflow recordings of lumbar discectomies. The results showed that the activity irrigate with a mean prediction error of 26 min 23 s is best-suited for determining the remainder of the intervention. To construct a scheduling support for a wider range of surgery types the actions conducted by the surgeon’s right and left hand would eminently be more suitable; the error of the action right hand was 41 min 39 s, yet. In conclusion sophistication into the presented frequency based method might support time and resource management in a general manner.
Pseudo-haptic feedback in medical teleoperation
Authors: Neupert Carsten , Matich Sebastian , Pott Peter P. , Hatzfeld Christian , Werthschützky Roland 
Published: September 2015

Abstract
Pseudo-haptic feedback is a haptic illusion based on a mismatch of haptic and visual perception. It is well known from applications in virtual environments. In this work, we discuss the usabiliy of the principle of pseudo-haptic feedback for teleoperation. Using pseudo-haptic feedback can ease the design of haptic medical tele-operation systems.
Thereby a user’s grasping force at an isometric user interface is used to control the closing angle of an end effector of a surgical robot. To provide a realistic haptic feedback, the coupling characteristic of grasping force and end effector closing angle is changed depending on acting end effector interaction forces.
With an experiment, we show the usability of pseudo-haptic feedback for discriminating compliances, comparable to the mechanical characteristic of muscles relaxed and contracted. The provided results base upon the data of 10 subjects, and 300 trails.
Feasibility of interactive gesture control of a robotic microscope
Authors: Antoni Sven-Thomas , Sonnenburg Christian , Saathoff Thore , Schlaefer Alexander 
Published: September 2015

Abstract
Robotic devices become increasingly available in the clinics. One example are motorized surgical microscopes. While there are different scenarios on how to use the devices for autonomous tasks, simple and reliable interaction with the device is a key for acceptance by surgeons. We study, how gesture tracking can be integrated within the setup of a robotic microscope. In our setup, a Leap Motion Controller is used to track hand motion and adjust the field of view accordingly. We demonstrate with a survey that moving the field of view over a specified course is possible even for untrained subjects. Our results indicate that touch-less interaction with robots carrying small, near field gesture sensors is feasible and can be of use in clinical scenarios, where robotic devices are used in direct proximity of patient and physicians.
Integrating multimodal information for intraoperative assistance in neurosurgery
Authors: Eisenmann U. , Metzner R. , Wirtz C.R. , Dickhaus H. 
Published: September 2015

Abstract
Computer-assisted planning of complex neurosurgical interventions benefits from a variety of specific functions and tools. However, commercial planning- and neuronavigation systems are rather restrictive concerning the availability of innovative methods such as novel imaging modalities, fiber tracking algorithms or electrical dipole mapping. In this respect there is a demand for modular neurosurgical planning systems offering flexible interfaces for easy enhancement. Furthermore all relevant planning information should be available within neuron-avigation. In this work we present a planning system providing these capabilities and its suitability and application in a clinical setting. Our Multimodal Planning System (MOPS 3D) offers a variety of tools such as definition of trajectories for minimally invasive surgery, segmentation of ROIs, integration of functional information from atlas maps or magnetoencephalography. It also supplies plugin interfaces for future extensions. For intraoperative application MOPS is coupled with the neuronavigation system Brainlab Vector Vision Cranial/ENT (VVC). We evaluated MOPS in the Department of Neurosurgery at the University Hospital Heidelberg. Surgical planning and navigation was performed in 5 frequently occurring clinical cases. The time necessary for planning was between 5 and 15 minutes including data import, segmentation and planning tasks. The additional information intraoperatively provided by MOPS 3D was highly appreciated by the neurosurgeons and the performance was satisfactory.
Respiratory motion tracking using Microsoft’s Kinect v2 camera
Authors: Ernst Floris , Saß Philipp 
Published: September 2015

Abstract
In image-guided radiotherapy, monitoring and compensating for respiratory motion is of high importance. We have analysed the possibility to use Microsoft’s Kinect v2 sensor as a low-cost tracking camera. In our experiment, eleven circular markers were printed onto a Lycra shirt and were tracked in the camera’s color image using cross correlation-based template matching. The 3D position of the marker was determined using this information and the mean distance of all template pixels from the sensor. In an experiment with four volunteers (male and female) we could demonstrate that real time position tracking is possible in 3D. By averaging over the depth values inside the template, it was possible to increase the Kinect’s depth resolution from 1 mm to 0.1 mm. The noise level was reduced to a standard deviation of 0.4 mm. Temperature sensitivity of the measured depth values was observed for about 10-15 minutes after system start.
Experimental evaluation of different weighting schemes in magnetic particle imaging reconstruction
Authors: Szwargulski Patryk , Rahmer Jürgen , Ahlborg Mandy , Kaethner Christian , Buzug Thorsten M. 
Published: September 2015

Abstract
Magnetic Particle Imaging (MPI) is a new imaging technique with an outstanding sensitivity, a high temporal and spatial resolution. MPI is based on the excitation and detection of magnetic tracer material by using magnetic fields. The spatial resolution strongly depends on the reconstruction parameters and on the selection and weighting of the system function frequency components. Currently, no fundamental strategy to weight the system function for the reconstruction is given. In this contribution, the influence on the spatial resolution of different selection and weighting methods is analyzed. Thereby, a new strategy is proposed to select and weight the components with respect to their mixing order. As a result, it is confirmed that a weighted system function provides better results of image reconstruction than a non-weighted one. In addition to this, it is shown that the usage of the mixing order in combination with established weightings improves the resolution.