bluuebunny/crossref_metadata_2025_split huggingface dataset:
Criteria for Implant Fit Assessment in Total Knee Arthroplasty – A Review
Authors: Grothues Sonja , Radermacher Klaus 
Published: September 2022

Abstract
Patient satisfaction in total knee arthroplasty is still limited and lower compared to patient satisfaction in total hip arthroplasty. While there are multiple influence factors for patient satisfaction, implant design is one aspect to consider. In clinical practice, the patient-specific assessment of implant fit is limited to a matching of the anteroposterior and mediolateral size, based on X-rays. Hence, the goal of this review was to identify other potential criteria for a patientspecific implant fit evaluation. A literature review was performed in PubMed. Inclusion criteria were a patientspecific assessment of knee implant components, a comprehensible motivation or a statistically proven relationship with an outcome measure, and a clear method description. Implant fit was considered not only as a matching of size, shape and interface, but also to include the implant’s (rotational) alignment, as proposed by Dai et al. (2014). Several studies reported a statistically significant relationship of implant fit criteria with outcome measures. Many more studies proposed fit criteria, motivated by a potential relationship with outcome measures. Most criteria assessed the bone-implant interface, second the morphology of the articulating surfaces and third the component and resulting bony alignment. Obstacles for the assessment of the criteria identified is the limited availability of 3D surface models in TKA. However, with new imaging technologies this availability is likely to increase. The decision process regarding the implant in TKA could be supported by a comprehensive automated fit analysis of several designs and/or sizes. An adequate matching of the implant to the respective patient may improve patient satisfaction.
Towards Test Bench for Aspiration Catheters in Realistic Evaluation Scenarios
Authors: Paulsen Benjamin Alexander , Schwenke Hannes , Seemann Jakob , Schramm Peter , Männel Georg , Rostalski Philipp 
Published: September 2022

Abstract
Aspiration catheters play an important role in mechanical thrombectomy in interventional neuroradiology as they provide support for stent retrievers or are increasingly used separately for contact aspiration. To evaluate the performance of different aspiration catheters in terms of suction force, most current studies rely on manual measurement methods or the suction force is not measured close to the aspiration catheter tip. Moreover, there is currently no standardized method that records measurements digitally and with high temporal resolution. To overcome these challenges, we propose a new test bench that simulates a dedicated aspiration scenario and takes measurements close to the aspiration catheter tip. To meet the requirements, a simplified vascular phantom, a pressure sensor and a simplified clot model were implemented in the prototype. To demonstrate the applicability of the prototype, two commonly used aspiration catheters were evaluated. The obtained measurements show that it is possible to perform standardized comparisons between aspiration catheters from different manufacturers as well as different aspiration pumps and aspiration tubings and their combinations. The developed prototype overcomes the still widely used manual and semimanual and thus error prone measurement methods for the evaluation of vacuum based thrombectomy systems.
Muscle fatigue detection using near-infrared spectroscopy and electromyography
Authors: Badoni Abhinav , Agarwal Kshitij , Pinkoski Adam , Samant Rahul , DeLorey Darren , Vette Albert 
Published: September 2022

Abstract
Introduction: Muscle fatigue is often experienced by athletes and in work settings. Excessive fatigue can lead to injury and musculoskeletal disorders. Surface electromyography (EMG) is typically used to detect and ultimately prevent fatigue during isometric movement. The application of EMG to fatigue detection in dynamic movement requires, however, a secondary confirmation of fatigue based on physiological measures. Our objective was to determine if muscle oxygenation derived via near-infrared spectroscopy (NIRS) was correlated with relevant EMG indicators of neuromuscular fatigue and whether observed correlations were related to the fatigue process. Methods: Bilateral electromyograms from three upper leg muscles and the tissue oxygenation index (TOI) of the vastus lateralis muscle were recorded in sixteen non-disabled individuals during cycle ergometry to volitional exhaustion. Six EMG activity features were extracted and the Pearson correlation coefficient between each feature and TOI was determined. Results: The EMG root mean square, spectral standard deviation, second spectral moment, and zero-crossing rate (ZC) were strongly correlated with TOI. The time course of ZC and the correlation of this feature with TOI suggest that there could be a relation between muscle oxygenation and fatigue. Conclusion: Future work should use the knowledge gained in this study to investigate whether NIRS can be used to verify the onset of fatigue as detected by EMG.
Augmented Reality for 6-DoF Motion Recording, Preview, and Execution to Enable Intuitive Surgical Robot Control
Authors: Karnam Murali , Zelechowski Marek , Cattin Philippe C. , Rauter Georg , Gerig Nicolas 
Published: September 2022

Abstract
In robot-assisted surgeries, the surgeon focuses on the surgical tool and its pose, and not on the complete robot’s shape. However, the joints of redundant robots (robots that have more degrees of freedom (DoF) than needed for the positioning of surgical tools) might move in unexpected/undesired ways. Joint motions that lead to patient or collisions are safety critical. We assume that the medical personnel in the operating room can best decide if a planned robot motions come too close to the patient or not. Therefore, we propose an augmented reality-based solution to interact with the robot during surgery planning, and intervention. The tool can be used to command a robot by drawing a trajectory in augmented reality (AR), visualizing the robot movement to check if it is safe before execution. The proposed solution allows surgeons to plan safe robot motion paths before-hand and adapt them when necessary in situ. As a proof-of-concept, we implemented and demonstrated the proposed solution on a 7-DoF redundant robot by commanding different trajectories. The control architecture to plan and execute motion for a surgical robot using AR is a key result of this work.
LA-TT-EALR / PromCERA: Comparison of preoperatively performed electrically evoked auditory potentials at the brainstem and cortical level during local anesthesia
Authors: Polterauer Daniel , Mandruzzato Giacomo , Neuling Maike , Polak Marek , Müller Joachim , Hempel John-Martin 
Published: September 2022

Abstract
Introduction: In the past years, some groups established methods to use promontory stimulation and subjective responses as a tool for preoperative stimulation of the cochlea before cochlear implant (CI) surgery by a temporary transtympanic needle placed on the middle ear. Our research group tested CI candidates when the presence of the auditory nerve could not be confirmed by other pre-operative tests and analyzed objective results of electrical auditory brainstem response recorded with trans-tympanic promontory stimulation in local anesthesia (LA-TT-EABR) with a “golfclub” electrode placed on the round window niche (Polterauer et al. 2018). However, EABR recording suffers from an electrical artifact from the stimulation and focuses on the excitability of the solely auditory nerve. We hypothesize that late evoked potential response (EALR) can be used for the assessment of the auditory pathway up to the cortical area with less electrical artifact interference. Methods: The trans-tympanic electrically evoked auditory late response in local anesthesia (LA-TT-EALR) was added to our protocol right after the LA-TT-EABR in a unique recording session. In this study, we investigated the feasibility of LA-TT-EALR using MED-EL hardware and software. These two pre-operative trans-tympanic measurements, LATT- EABR and LA-TT-EALR, were compared. Results: In a total n=18 tested subjects, it could be possible to record LA-TT-EABR in 10 and LA-TT-EALR in 13. In contrast to the fact that acoustically evoked auditory late responses are often hard to detect, and an electrical artifact heavily affects LA-TT-EABR, we did not experience these problems on LA-TT-EALR recordings. The matching between two measurements was present in 67% of the cases. Conclusion: LA-TT-EALR may be a complement to the existing state-of-the-art LA-TT-EABR for pre-operative assessment before cochlear implantation offering information about auditory pathways in the auditory brainstem and cortex with a small increase of recording time. The equivalency of these two methods is encouraging.
360° Laparoscopic Imaging System to Facilitate Camera Control and Orientation in Minimally Invasive Surgery
Authors: Schäfer Max B. , Eggstein Selina , Stewart Kent W. , Pott Peter P. 
Published: September 2022

Abstract
During laparoscopic procedures, the surgeon's view of the situs, and thus her or his performance, is dependent on the skills of the camera assistant. The surgeon lacks control over his own field of view and there is a high potential for reducing mental load and workflow issues. In this paper, a research setup of a 360° laparoscopic imaging system is presented and evaluated. The system consists of a 360° camera and a head-mounted display, through which the surgeon can inspect the situs. In a user test, the system showed advantages over a conventional laparoscope regarding orientation in the situs, intuitiveness of operation, and faster task completion.
Investigation of an Acceleration Pipeline for Single Fiber Action Potential Simulation
Authors: Oltmann Andra , Petersen Eike , Kusche Roman , Rostalski Philipp 
Published: September 2022

Abstract
Surface electromyography (sEMG) records the electrical potentials on the skin surface generated by the electrical activity of muscle fibers. To better understand physiology and to assess signal processing algorithms, sEMG models have been developed in the past. However, numerical models required for modeling accurate geometries very often have a high computational complexity rendering realistic simulations challenging. In order to cope with this challenge, a pipeline is investigated to accelerate the calculation of the single fiber action potential (SFAP) based on the principle of reciprocity. To enable a comparison to an analytical solution, the investigation is carried out in a highly simplified muscle model. The results show that the pipeline is suitable for calculating SFAP with a low mean absolute error sufficient for application in sEMG models. In addition, there is a significant reduction of the calculation time allowing the simulation of even highly complex geometries and a large number of muscle fibers.
Feedback Linearization of a Blower in an Anesthesia Workstation
Authors: Prüßmann Jannik , Männel Georg , Brendle Christian , Rostalski Philipp 
Published: September 2022

Abstract
Radial compressors, Blowers, which are often used in modern devices for medical ventilation, are known to have non-linear dynamics regarding the generated pressure. To make them accessible for the large field of linear control theory their model needs to be linearized. This paper uses a gray box model of a blower driven by a brushless direct current (BLDC) motor to design a controller based on feedback linearization. The controller is designed to achieve approximate linear closed loop behavior of the system. The controller is then evaluated concerning reference tracking and disturbance rejection in simulation and on a demonstrator system. The evaluation showed that an approximate linear closed loop behavior was achieved.
Prediction of Fluorescent Ki67 Staining in 3D Tumor Spheroids
Authors: Bruch Roman , Vitacolonna Mario , Rudolf Rüdiger , Reischl Markus 
Published: September 2022

Abstract
3D cell culture models are important tools for the development and testing of new therapeutics. In combination with immunoassays and 3D confocal microscopy, crucial information like morphological or metabolic changes can be examined during drug testing. However, a common limitation of immunostainings is the number of dyes that can be imaged simultaneously, as overlaps in the spectral profiles of the different dyes may result in cross talk. We therefore present a 3D deep learning method, able to predict fluorescent stainings of specific antigens on the basis of a nuclei staining. Using the proliferation marker Ki67, we showed that the presented model was able to predict the Ki67 staining with a strong correlation to the real signal. Additional analysis showed, that the model was not relying on signal cross talk. This approach, based on staining of the cell nuclei and subsequent prediction of the target antigen, could reduce the number of parallel antigen stains to a minimum and incompatible staining panels could be circumvented in the future.
Automatic detection of subviral particles in fluorescence microscopy images of Marburg virus infected cells using a convolutional neural network
Authors: Naber Sarah , Busch Nils , Rausch Andreas , Schanze Thomas 
Published: September 2022

Abstract
In collaboration with the Institute of Virology at the University of Marburg, a tracking algorithm has been developed in recent years. Thereby, for the tracking of subviral particles and their intracellular transport through the cell, the detection of these particles is the first major step. In this work a deep-learning based approach for automatic processing of fluorescence video sequences of virus infected cells is presented. The focus of this work was to generate synthetic data for training neuronal networks and to represent a particle using only a single delta peak. It was shown that a simple convolutional network is able to predict the particle positions with an almost identical accuracy as the algorithm developed by Kienzle, Rausch and colleagues [1-3], and that even a small dataset is sufficient for that purpose.
Analysis of Dielectric Properties of Gelatin-based Tissue Phantoms
Authors: Hess Andreas , Liu Jan , Pott Peter P. 
Published: September 2022

Abstract
In this work, an electrode was developed to determine the dielectric properties of tissue phantoms using impedance measurements. For this purpose, a coaxial electrode design was selected as the most suitable electrode design. Three tissue phantoms (blood, fat, muscle) were prepared from distilled water, sodium chloride, 1,2-propanediol, agar, and gelatine, and then characterized. Measurements were performed using an impedance analyzer in a range between 1 kHz and 1 MHz. A comparison with literature values showed good correspondance of the permittivity values determined, thus proving the applicability of the electrode design. However, the conductivity values measured were different from literature values. In the future, alteration and minimization of the electrode can be done to further improve the characterization.
KneTex – Improvements to classification methods for a sensor system for rehabilitation after ACL surgery
Authors: Cramer Lukas , Yavuz Sinan , Schlage Nana , Mühlen Andreas , Kitzig Andreas , Naroska Edwin , Stockmanns Gudrun 
Published: September 2022

Abstract
Injuries and the associated surgery to the anterior cruciate ligament (ACL) can often trigger unpredictable effects, such as the so-called giving way effect, which is an uncontrolled buckling of the knee joint. For this purpose, the KneTex project has developed a smart textile-integrated sensor and actuator bandage system to record the movement of such patients and to monitor and support the rehabilitation process. Long-term monitoring and analysis of the movement data will identify patterns or gait types that can lead to a giving way effect. This paper describes the recent developments of the random forest model-based motion classification system developed within the project. Improvements have been achieved by reducing the number of features needed by 25% using feature importance analysis, speeding up the computation time by 14%, and increasing the classification efficiency. Feature elimination is a useful tool to improve classification systems in settings where feature count is high and feature importance analysis contributed by improving our understanding which sensor of our system are important for the motion classification task.
Automated human temporal-bone experiments
Authors: Kempa Stepan , Martin Michael , Dalhoff Ernst 
Published: September 2022

Abstract
Temporal-bone (TB) experiments are useful for the investigation of middle-ear and inner-ear transfer properties, and the analysis and development of active or passive middleear prostheses or related devices. To acquire the mechanical middle-ear (ME) response, the Laser-Doppler vibrometry (LDV) is utilized as a preferred method. In most setups, the exact measurement point chosen on the biological structure of interest as well as the direction of the corresponding vibration measurement is not precisely defined and of unknown reproducibility. Hence, an automated setup controlling coordinates of TB and measurement direction is developed and tested. To test the reproducibility, TBs were measured with ER7C and ER10C probe microphones employing a small industrial robot to position the TB to the ME points of interest and align it to the laser beam. The position and vibration data acquired at the same locations at different points of time were processed and compared. Measured transfer functions indicate noticeable differences at some frequency ranges. Nonetheless, the reproducibility of positioning to repeatedly measured points proved itself relatively accurate, if no manipulations in the setup are made. In conclusion, the current study shows that automated LDV TB measurement system is in principle capable to adapt to the changes in setup during intermediate preparation steps. With more acquired data, the setup stability and reproducibility can be more precisely verified, and additional improvements can be made.
Camera-based Pain Assessment during Surgical Interventions
Authors: Reichard Bianca , Schrumpf Fabian , Anders Franz , Bode Kerstin , Fuchs Mirco 
Published: September 2022

Abstract
Pain assessment in clinical settings can be a challenging task for clinic staff and patients. An automatic and contactless pain estimation system via facial expression is a decisive advantage. In the following article we present a method for pain classification based on mimic descriptors. To automatically process facial expressions from video data we applied the Facial Action Coding System (FACS). First, we employed a logistic regression model to predict pain using a publicly available database. Second, we utilized this procedure to predict pain in individual intraprocedural patient data. We reached a mean accuracy of 80.94% for the publicly available data and 73.14% for our individual patient data by classifying data as pain and non-pain.
Apnea detection from photoplethysmography signal using dicrotic notch
Authors: Rafl-Huttova Veronika , Cizek Dominik , Rafl Jakub , Rozanek Martin 
Published: September 2022

Abstract
Photoplethysmography signal (PPG) provides information about the cardiovascular, respiratory, or nervous system activity. Recent studies proposed methods of apnea identification from PPG using amplitude or baseline modulation, or area under the curve. We hypothesized that analysis of the dicrotic notch could improve the sensitivity and specificity of apnea detection. We applied four methods to detect apnea from PPG records experimentally obtained from 10 volunteers, where each volunteer simulated three apneic pauses. We adopted the Area under the PPG and Pulse wave amplitude parameters, and we proposed the Dicrotic notch area parameter. For the methods, we determined the delay in apnea detection and the sensitivity and specificity of apnea detection. The average delay in detecting an apneic pause from the PPG using the Dicrotic notch area was 6.1 s. Combining the parameters of the Area under the PPG with the Dicrotic notch area increased the specificity of apnea detection from 73.8% to 80.0%, although sensitivity decreased from 91.1% to 85.6%. The newly proposed parameter Dicrotic notch area showed its potential for automatic apnea detection.
Long Term Evaluation of the Barrier Properties of Polymer/Metal Oxide Hybrid Layers for Use in Medical Implants
Authors: Simon Nicolai , Schmid Marvin , Blendinger Felix , Bucher Volker 
Published: September 2022

Abstract
Encapsulation is essential for mechanically flexible and electrically active implants as it protects them from the harsh environment inside the body. Since the performance and longevity of implants depends on the quality of encapsulation, research continues into new and better encapsulation strategies. Chemical vapour deposition can be used to deposit Parylene-C, a biocompatible polymer, at room temperature. Plasma enhanced atomic layer deposition can be used to deposit ultra-thin, conformal, and hermetic metal oxide layers. These strategies are both used for the encapsulation of implants. In this work, these two methods are combined to create a polymer/metal oxide hybrid system in which a layer system of metal oxides is sandwiched between two Parylene- C layers. DC leakage-current measurement and elevated temperature are used to qualify the barrier property of the layer-system. After more than one year, the barrier properties still show no significant decrease.
A Concept for 6D Motion Sensing with Magnetoelectric Sensors
Authors: Hoffmann Johannes , Hansen Clint , Maetzler Walter , Schmidt Gerhard 
Published: September 2022

Abstract
Active magnetic motion sensing relies on a combination of magnetic sensors and actuators to indirectly sense a time-varying change in position and orientation. Based on our previous work on a 1D setup with magnetoelectric (ME) sensors, we introduce a concept for a full 6D sensing system, which is positioned as a modular setup for human movement pattern capture with regard to neurodegenerative diseases. In this paper, we implemented an inverse model based on ideal triaxial sensors and coils. We then included results from the previous experiments to estimate the prospective performance in a physical setup. We obtained a spatial error of a few cm and approx. 10° with focus on superimposed sinusoidal movements of 1, 5, and 10 Hz.
A systematic review of recorded technical settings used in bipolar and monopolar transurethral resection of bladder tumors
Authors: Kiefer Ann-Kathrin , Espig Kevin , Moeller Knut 
Published: September 2022

Abstract
High-frequency (HF) surgery has been established in medicine for decades and is very popular in transurethral (minimally invasive) surgery. However, the technical settings of generators are almost exclusively based on empirical data. So far, making a well-founded statement about a possible impact of technical parameters in HF surgery is nearly impossible. Therefore, the aim of this research was to systematically review the published data for transurethral resection of bladder tumor (TURBT) to find out, whether the publications consider both sufficiently, technical parameters and physical parameters. It is shown that although technical parameters are reported, they have been insufficiently considered in analyses so far. Further analyses must be performed.