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1.	Johansson, Martin L, et al. (författare) Non-invasive sampling procedure revealing the molecular events at different abutments of bone-anchored hearing systems–A prospective clinical pilot study 2022 Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 16 Tidskriftsartikel (refereegranskat)abstract Purpose: To investigate the molecular activities in different compartments around the bone-anchored hearing system (BAHS) with either electropolished or machined abutments and to correlate these activities with clinical and microbiological findings. Materials and methods: Twelve patients received machined or electropolished abutments after implant installation of BAHS. Peri-abutment fluid and tissue were collected from baseline to 12 months. Gene expression of cytokines and factors related to tissue healing and inflammation, regeneration and remodelling, as well as bacterial recognition were determined using quantitative-polymerase chain reaction (qPCR). The clinical status was evaluated using the Holgers scoring system, and bacterial colonisation was investigated by culturing. Results: The gene expression of inflammatory cytokines (IL-8, IL-1β, and IL-10) and bacteria-related Toll-like receptors (2 and 4) was higher in the peri-abutment fluid than at baseline and in the peri-abutment tissue at 3 and 12 months. Conversely, the expression of genes related to tissue regeneration (Coll1a1 and FOXO1) was higher in the tissue samples than in the peri-abutment fluid at 3 and 12 months. Electropolished abutments triggered higher expression of inflammatory cytokines (IL-8 and IL-1β) (in peri-abutment fluid) and regeneration factor FOXO1 (in peri-abutment tissue) than machined abutments. Several cytokine genes in the peri-abutment fluid correlated positively with the detection of aerobes, anaerobes and Staphylococcus species, as well as with high Holger scores. Conclusion: This study provides unprecedented molecular information on the biological processes of BAHS. Despite being apparently healed, the peri-abutment fluid harbours prolonged inflammatory activity in conjunction with the presence of different bacterial species. An electropolished abutment surface appears to be associated with stronger proinflammatory activity than that with a machined surface. The analysis of the peri-abutment fluid deserves further verification as a non-invasive sampling and diagnostic procedure of BAHS.
2.	Abbaspour, S., et al. (författare) Real-Time and Offline Evaluation of Myoelectric Pattern Recognition for the Decoding of Hand Movements 2021 Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 21:16 Tidskriftsartikel (refereegranskat)abstract Pattern recognition algorithms have been widely used to map surface electromyographic signals to target movements as a source for prosthetic control. However, most investigations have been conducted offline by performing the analysis on pre-recorded datasets. While real-time data analysis (i.e., classification when new data becomes available, with limits on latency under 200-300 milliseconds) plays an important role in the control of prosthetics, less knowledge has been gained with respect to real-time performance. Recent literature has underscored the differences between offline classification accuracy, the most common performance metric, and the usability of upper limb prostheses. Therefore, a comparative offline and real-time performance analysis between common algorithms had yet to be performed. In this study, we investigated the offline and real-time performance of nine different classification algorithms, decoding ten individual hand and wrist movements. Surface myoelectric signals were recorded from fifteen able-bodied subjects while performing the ten movements. The offline decoding demonstrated that linear discriminant analysis (LDA) and maximum likelihood estimation (MLE) significantly (p < 0.05) outperformed other classifiers, with an average classification accuracy of above 97%. On the other hand, the real-time investigation revealed that, in addition to the LDA and MLE, multilayer perceptron also outperformed the other algorithms and achieved a classification accuracy and completion rate of above 68% and 69%, respectively.
3.	Brown, Shannon, et al. (författare) Intarsia-sensorized band and textrodes for real-time myoelectric pattern recognition 2016 Ingår i: Engineering in Medicine and Biology Society (EMBC), 2016 IEEE 38th Annual International Conference of the. - : Institute of Electrical and Electronics Engineers (IEEE). - 1557-170X. - 9781457702204 ; , s. 6074-6077 Konferensbidrag (refereegranskat)abstract Surface Electromyography (sEMG) has applications in prosthetics, diagnostics and neuromuscular rehabilitation. Self-adhesive Ag/AgCl are the electrodes preferentially used to capture sEMG in short-term studies, however their long-term application is limited. In this study we designed and evaluated a fully integrated smart textile band with electrical connecting tracks knitted with intarsia techniques and knitted textile electrodes. Real-time myoelectric pattern recognition for motor volition and signal-to-noise ratio (SNR) were used to compare its sensing performance versus the conventional Ag-AgCl electrodes. After a comprehending measurement and performance comparison of the sEMG recordings, no significant differences were found between the textile and the Ag-AgCl electrodes in SNR and prediction accuracy obtained from pattern recognition classifiers.
4.	Hafid, Abdelakram, et al. (författare) Full Impedance Cardiography Measurement Device Using Raspberry PI3 and System-on-Chip Biomedical Instrumentation Solutions 2018 Ingår i: IEEE journal of biomedical and health informatics. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2168-2194 .- 2168-2208. ; 22:6, s. 1883-1894 Tidskriftsartikel (refereegranskat)abstract Impedance cardiography (ICG) is a noninvasive method for monitoring cardiac dynamics using electrical bioimpedance (EBI) measurements. Since its appearance more than 40 years ago, ICG has been used for assessing hemodynamic parameters. This paper presents a measurement system based on two System on Chip (SoC) solutions and Raspberry PI, implementing both a full three-lead ECG recorder and an impedance cardiographer, for educational and research development purposes. Raspberry PI is a platform supporting Do-I t-Yourself project and education applications across the world. The development is part of Biosignal PI, an open hardware platform focusing in quick prototyping of physiological measurement instrumentation. The SoC used for sensing cardiac biopotential is the ADAS1000, and for the EBI measurement is the AD5933. The recordings were wirelessly transmitted through Bluetooth to a PC, where the waveforms were displayed, and hemodynamic parameters such as heart rate, stroke volume, ejection time and cardiac output were extracted from the ICG and ECG recordings. These results show how Raspberry PI can be used for quick prototyping using relatively widely available and affordable components, for supporting developers in research and engineering education. The design and development documents will be available on www.BiosignalPl.com, for open access under a Non Commercial-Share A like 4.0 International License.
5.	Seoane, Fernando, 1976-, et al. (författare) Textile-Friendly Interconnection between Wearable Measurement Instrumentation and Sensorized Garments-Initial Performance Evaluation for Electrocardiogram Recordings. 2019 Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 19:20 Tidskriftsartikel (refereegranskat)abstract The interconnection between hard electronics and soft textiles remains a noteworthy challenge in regard to the mass production of textile-electronic integrated products such as sensorized garments. The current solutions for this challenge usually have problems with size, flexibility, cost, or complexity of assembly. In this paper, we present a solution with a stretchable and conductive carbon nanotube (CNT)-based paste for screen printing on a textile substrate to produce interconnectors between electronic instrumentation and a sensorized garment. The prototype connectors were evaluated via electrocardiogram (ECG) recordings using a sensorized textile with integrated textile electrodes. The ECG recordings obtained using the connectors were evaluated for signal quality and heart rate detection performance in comparison to ECG recordings obtained with standard pre-gelled Ag/AgCl electrodes and direct cable connection to the ECG amplifier. The results suggest that the ECG recordings obtained with the CNT paste connector are of equivalent quality to those recorded using a silver paste connector or a direct cable and are suitable for the purpose of heart rate detection.
6.	Ortiz Catalan, Max Jair, 1982, et al. (författare) Patterned Stimulation of Peripheral Nerves Produces Natural Sensations With Regards to Location but Not Quality 2019 Ingår i: IEEE Transactions on Medical Robotics and Bionics. - 2576-3202. ; 1:3, s. 199-203 Tidskriftsartikel (refereegranskat)abstract Sensory feedback is crucial for dexterous manipulation and sense of ownership. Electrical stimulation of severed afferent fibers due to an amputation elicits referred sensations in the missing limb. However, these sensations are commonly reported with a concurrent “electric” or “tingling” character (paresthesia). In this paper, we examined the effect of modulating different pulse parameters on the quality of perceived sensations. Three subjects with above-elbow amputation were implanted with cuff electrodes and stimulated with a train of pulses modulated in either amplitude, width, or frequency (“patterned stimulation”). Pulses were shaped using a slower carrier wave or via quasi-random generation. Subjects were asked to evaluate the natural quality of the resulting sensations using a numeric rating scale. We found that the location of the percepts was distally referred and somatotopically congruent, but their quality remained largely perceived as artificial despite employing patterned modulation. Sensations perceived as arising from the missing limb are intuitive and natural with respect to their location and, therefore, useful for functional restoration. However, our results indicate that sensory transformation from paresthesia to natural qualia seems to require more than patterned stimulation.
7.	Capece, Sabrina, et al. (författare) A general strategy for obtaining biodegradable polymer shelled microbubbles as theranostic devices 2013 Ingår i: Chemical Communications. - 1359-7345 .- 1364-548X. ; 49:51, s. 5763-5765 Tidskriftsartikel (refereegranskat)abstract Fabrication of multifunctional ultrasound contrast agents (UCAs) has been recently addressed by several research groups. A versatile strategy for the synthesis of UCA precursors in the form of biodegradable vesicles with a biocompatible crosslinked polymer shell is described. Upon ultrasound irradiation, acoustic droplet vaporization transforms such particles into microbubbles behaving as UCAs. This proof of concept entails the features of a potential theranostic microdevice.
8.	Bondesson, Johan, 1991, et al. (författare) Definition of Tubular Anatomic Structures from Arbitrary Stereo Lithographic Surface 2017 Ingår i: Initiative Seminar Engineering Health, 8-9 November 2017, Chalmers. Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract An accurate description of anatomies and dynamics of vessels is crucial to understand their characteristics and improve surgical techniques, thus it is the basis, in addition to surgeon experience, on which stent design and operation procedures rely. The process of producing this description is user intensive, and recent improvement in image processing of medical3D imaging allows for a more automated workflow. However, there is a need to bridge the gap from a processed geometry to a robust mathematical computational grid. By sequentially segmenting a tubular anatomic structure, here defined by a stereo lithographic (STL) surface, an initial centerline is formed by connecting centroids of orthogonal cross-sectional contours along the length of the structure. Relying on the initial centerline, a set of non-overlapping 2D cross sectional contours are defined along the centerline, a centerline which is updated after the 2D contours are produced. After a second iteration of producing 2D contours and updating the centerline, a full description of the structure is created. Our method for describing vessel geometry shows good coherence to existing method. The main advantages of our method include the possibility of having arbitrary triangulated STL surface input, automated centerline definition, safety against intersecting cross-sectional contours and automatic clean-up of local kinks and wrinkles.
9.	Lui, Hoi-Shun, et al. (författare) On the matching medium for microwave stroke diagnosis 2019 Ingår i: Biomedical Physics and Engineering Express. - : IOP Publishing. - 2057-1976. ; 5:4 Tidskriftsartikel (refereegranskat)abstract The choice of matching medium can directly affect the amount of power transmitted into and through human bodies, which impacts on the quality of the reconstructed images in microwave-based medical imaging, and thus the diagnosis accuracies. In this paper, the amount of the transmitted and reflected power of multi-layer planar healthy and hemorrhagic stroke brain models under different choices of matching medium are determined. These multi-layer planar brain tissue models are made up of at least 17 tissue layers with realistic dielectric properties. A layer of blood with different thickness is introduced to model the case of hemorrhagic stroke. Our results show that matching medium with low relative permittivity provides better intrinsic contrast between healthy brain and hemorrhagic brain. Analysis on how the reflection coefficient and transmittance vary under different matching medium are included to provide better insights to the findings.
10.	Rezaei Aghdam, Sina, 1989, et al. (författare) Reducing Motion Artifacts in Microwave-Based Hemorrhagic Stroke Detection 2019 Ingår i: 13th European Conference on Antennas and Propagation, EuCAP 2019. Konferensbidrag (refereegranskat)abstract The use of microwave technology for brain stroke detection opens up the opportunity for developing low-cost transportable devices which can be employed for rapid and prehospital detection of bleeding in patients with traumatic brain injury. Since the detection relies on changes in the scattering parameters of the tissues during pathological conditions, the movements in head or the antennas can deteriorate the detection accuracy. As a countermeasure to this problem, we introduce a technique for reducing the sensitivity of the detection system to motion artifacts. Via analyzing the scattering from an anatomically accurate model of human brain, we evidence that the channels between different pairs of antennas exhibit significantly different levels of sensitivity to the movement. Using this as a ground truth, we develop a generalized singular value decomposition (GSVD)-based approach for assigning appropriate weights to the channels between different antennas such that the probability of correct bleeding detection is maximized.
11.	Rowa, Per, et al. (författare) Automated Malaria Parasite Detection 1977 Rapport (övrigt vetenskapligt/konstnärligt)abstract A system for malaria parasite detection in thin blood-smears is presented. Sample slides prepared with standard methods are accepted. A low-cost TV-camera mounted on an ordinary microscope with a computer controlled stage is used as a picture sensor. Frames, digitized in windows of 64 x 64 pixels are fed into a special purpose picture processor at normal frame rate (25 frames/sec). In the picture processor measurements are made on the images at high speed. The classification problem is split into different levels each having different characteristics such as different sampling density. Four classes, three of which are different types of malaria parasites, are recognized. As a whole the classification is best labelled as a sequential pattern recognition procedure.In its preliminary version the system has been run at a speed comparable to that of a human operator, that is l 500 cells per minute. A test on 80 000 cells gave 25 false negatives out of 283 parasites (9%) and 41 false positives (0.05%).
12.	Tomasic, Ivan, et al. (författare) Comparison of publicly available beat detection algorithms performances on the ECGs obtained by a patch ECG device 2019 Ingår i: 2019 42nd International Convention on Information and Communication Technology, Electronics and Microelectronics, MIPRO 2019 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9789532330984 ; , s. 275-278 Konferensbidrag (refereegranskat)abstract Eight ECG beat detection algorithms, from the PhysioNet's WFDB and Cardiovascular Signal toolboxes, were tested on twenty measurements, obtained by the Savvy patch ECG device, for their accuracy in beat detection. On each subject, one measurement is obtained while sitting and one while running. Each measurement lasted from thirty seconds to one minute. The measurements obtained while running were more challenging for all the algorithms, as most of them almost perfectly detected all the beats on the measurements obtained in sitting position. However, when applied on the measurements obtained while running, all the algorithms have performed with decreased accuracy. Considering overall percentage of the faulty detected peaks, the four best algorithms were jqrs, from the Cardiovascular Signal Toolbox, and ecgpuwave, gqrs, and wqrs, from the WFDB Toolbox, with percentages of faulty detected beats 1.7, 2.3, 2.9, and 3, respectively.
13.	Zanoli, Massimiliano, 1989 (författare) Ultra wideband microwave hyperthermia for brain cancer treatment 2022 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Despite numerous clinical trials demonstrating that microwave hyperthermia is a powerful adjuvant modality in the treatment of cancers, there have been few instances where this method has been applied to brain tumors. The reason is a combination of anatomical and physiological factors in this site that require an extra degree of accuracy and precision in the thermal dose delivery. Current clinical applicators are not able to provide such control, partly because they are designed to operate at a single fixed frequency. In terms of treatment planning, the use of a single frequency is limiting as the size of the focal spot cannot be modified to accommodate the specific tumor volume and location. The introduction of ultra wide-band (UWB) systems opens up an opportunity to overcome these limitations, as they convey the possibility of adapting the focal spot and obtaining different power deposition patterns to reduce the heating of healthy tissues. In this thesis, we explore whether the current SAR-based treatment planning methods can be meaningfully translated to the UWB setting and propose new solutions for deep UWB microwave hyperthermia. We analyze the most commonly used cost functions for treatment planning optimization and discuss their suitability for use with UWB systems. Then, we propose a novel SAR-based cost function (HCQ) for UWB optimization that exhibits a high correlation with the resulting tumor temperature. To solve for the HCQ, we describe a novel, time-reversal-based, iterative scheme for a rapid and efficient optimization of UWB treatment plans. Next, we investigate the design possibilities of UWB brain applicators and introduce a fast E-field approximation scheme to quickly explore a large number of array configurations. The method determines the best antenna arrangement around the head with respect to the multiple objectives and requirements of clinical hyperthermia. Together, the proposed solutions manage to achieve the level of tumor coverage and hot-spot suppression that is necessary for a successful treatment. Finally, we investigate the benefit of integrating hyperthermia delivered by an optimized UWB applicator into the radiation therapy plan for a pediatric medulloblastoma patient. The results suggest that UWB microwave hyperthermia for brain cancer treatment is feasible and motivate efforts for further development of UWB applicators and systems.
14.	Zeng, Xuezhi, 1980, et al. (författare) Investigation of an ultra wideband noise sensor for health monitoring 2020 Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 20:4 Tidskriftsartikel (refereegranskat)abstract Quick on-scene assessment and early intervention is the key to reduce the mortality of stroke and trauma patients, and it is highly desirable to develop ambulance-based diagnostic and monitoring devices in order to provide additional support to the medical personnel. We developed a compact and low cost ultra wideband noise sensor for medical diagnostics and vital sign monitoring in pre-hospital settings. In this work, we demonstrated the functionality of the sensor for respiration and heartbeat monitoring. In the test, metronome was used to manipulate the breathing pattern and the heartbeat rate reference was obtained with a commercial electrocardiogram (ECG) device. With seventeen tests performed for respiration rate detection, sixteen of them were successfully detected. The results also show that it is possible to detect the heartbeat rate accurately with the developed sensor.
15.	Eklund, Anders, 1965-, et al. (författare) A catheter tactile sensor for measuring hardness of soft tissue : measurement in a silicone model and in an in vitro human prostate model 1999 Ingår i: Medical and Biological Engineering and Computing. - 0140-0118 .- 1741-0444. ; 37:5, s. 618-624 Tidskriftsartikel (refereegranskat)abstract Tissue hardness is related to tissue composition, and this is often changed by disease. It is therefore of interest to measure the hardness in an objective and non-invasive way. A tactile sensor based on a vibrating piezoelectric ceramic element in a feedback loop is described. When the sensor touches an object it produces a frequency shift related to the hardness of the object. The aim of this study was to develop an in vitro hardness measurement method using a catheter type version of the sensor. The method was evaluated in an established silicone tissue model and on human prostate tissue in vitro. A linear relationship was found with a high degree of explanation (R2 = 0.98) between a cone penetration hardness standard (DIN ISO 2137) applied to the silicone model and the corresponding frequency shift. The results from measurements on a human prostate tissue sample, fixed with formalin, showed that the relative hardness measured with the tactile sensor correlated (R = -0.96, p < 0.001, N = 60) with the proposed hardness related to the histological composition of the prostate tissue. The results indicated that hardness of prostate tissue, and maybe hardness of human tissue in general, can be expressed according to the cone penetration standard and that the hardness can be measured with this tactile sensory system. These findings hold the promise of further development of a non-invasive tool for hardness measurement in a clinical situation
16.	Eklund, Anders, 1965-, et al. (författare) A resonator sensor for measurement of intraocular pressure : evaluation in an in vitro pig-eye model 2000 Ingår i: Physiological Measurement. - : IOP Publishing. - 0967-3334 .- 1361-6579. ; 21:3, s. 355-367 Tidskriftsartikel (refereegranskat)abstract Intraocular pressure (IOP) measurement is performed routinely at every eye clinic. High IOP, which can be a sign of glaucoma, can lead to degeneration of the retina and can cause blindness. In this study we developed a resonator sensor for IOP measurement based on an oscillator consisting of a piezoelectric element made of lead zirconate titanate, a flat contact piece of nylon and a feedback circuit. The aim of this study was to evaluate the new sensor's ability to determine lOP in an in vitro pig-eye model. Six eyes from four pigs were removed and fixed in agar. They were then pressurized by a saline column (10-35 cm H2O) through a cannula inserted into the vitreous chamber. The IOP was measured with the resonator sensor applied to cornea. An Alcon applanation pneumatonometer and a standard Viggo-Spectramed pressure sensor connected to the saline column were used as references. The IOP as measured with the resonator sensor correlated well with the pressure elicited by the saline column for individual eyes (r = 0.96-0.99, n = 60) and for all eyes (r = 0.92, n = 360). The correlation between the resonance sensor and the pneumatonometer was r = 0.92 (n = 360). The pneumatonometer also showed a good correlation with the saline column (r = 0.98, n = 360). We conclude that our in vitro pig-eye model made it possible to induce reproducible variation in IOP, and measurement of that pressure with the newly developed resonator sensor gave very promising results for development of a clinically applicable IOP tonometer with unique properties.
17.	Hellstrand Tang, Ulla, et al. (författare) Exploring the Role of Complexity in Health Care Technology Bottom-Up Innovations : Multiple-Case Study Using the Nonadoption, Abandonment, Scale-Up, Spread, and Sustainability Complexity Assessment Tool 2024 Ingår i: JMIR Human Factors. - : JMIR Publications. - 2292-9495. ; 11:1 Tidskriftsartikel (refereegranskat)abstract BACKGROUND: New digital technology presents new challenges to health care on multiple levels. There are calls for further research that considers the complex factors related to digital innovations in complex health care settings to bridge the gap when moving from linear, logistic research to embracing and testing the concept of complexity. The nonadoption, abandonment, scale-up, spread, and sustainability (NASSS) framework was developed to help study complexity in digital innovations.OBJECTIVE: This study aims to investigate the role of complexity in the development and deployment of innovations by retrospectively assessing challenges to 4 digital health care innovations initiated from the bottom up.METHODS: A multicase retrospective, deductive, and explorative analysis using the NASSS complexity assessment tool LONG was conducted. In total, 4 bottom-up innovations developed in Region Västra Götaland in Sweden were explored and compared to identify unique and shared complexity-related challenges.RESULTS: The analysis resulted in joint insights and individual learning. Overall, the complexity was mostly found outside the actual innovation; more specifically, it related to the organization's readiness to integrate new innovations, how to manage and maintain innovations, and how to finance them. The NASSS framework sheds light on various perspectives that can either facilitate or hinder the adoption, scale-up, and spread of technological innovations. In the domain of condition or diagnosis, a well-informed understanding of the complexity related to the condition or illness (diabetes, cancer, bipolar disorders, and schizophrenia disorders) is of great importance for the innovation. The value proposition needs to be clearly described early to enable an understanding of costs and outcomes. The questions in the NASSS complexity assessment tool LONG were sometimes difficult to comprehend, not only from a language perspective but also due to a lack of understanding of the surrounding organization's system and its setting.CONCLUSIONS: Even when bottom-up innovations arise within the same support organization, the complexity can vary based on the developmental phase and the unique characteristics of each project. Identifying, defining, and understanding complexity may not solve the issues but substantially improves the prospects for successful deployment. Successful innovation within complex organizations necessitates an adaptive leadership and structures to surmount cultural resistance and organizational impediments. A rigid, linear, and stepwise approach risks disregarding interconnected variables and dependencies, leading to suboptimal outcomes. Success lies in embracing the complexity with its uncertainty, nurturing creativity, and adopting a nonlinear methodology that accommodates the iterative nature of innovation processes within complex organizations.
18.	Karlsson, Mattias (författare) Model-based Analysis of Temporal Patterns in Atrioventricular Node Conduction During Atrial Fibrillation 2022 Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract The lifetime risk of developing atrial fibrillation (AF) is estimated to be between 1in 3 to 1 in 4 individuals, making it the most common arrhythmia in the world.For persistent AF, rate control drugs with the purpose to affect the conduction properties of the atrioventricular (AV) node are the most common treatment. The drug of choice varies between β-blockers and calcium channel blockers, often chosen empirically. This can lead to long periods of time before sufficient treatment is found. However, due to the physiological differences between the drug types, it could be possible to predict the effect of the drugs and thus assist in treatment selection. The main focus of this thesis is therefore to assess drug-dependent differences in the AV node, using non-invasive measurements. This thesis comprises an introduction to the subject as well as two papers. The first paper proposes a framework for assessing the conduction properties of the AV node non-invasively using a mathematical model of the AV node in combination with a genetic algorithm.The second paper is a continuation of the work in paper I, where the proposed workflow was adapted to assess the drug-dependent effect on the AV node of four different rate control drugs during a period of 24 hours.The methods presented in this thesis have made it possible to assess both the refractory period and the conduction delay in the AV node in a robust way using ECG, and by doing so found population-related differences in AV node conduction properties between drug types.
19.	Khodadad, Davood, 1985-, et al. (författare) Optimized breath detection algorithm in electrical impedance tomography 2018 Ingår i: Physiological Measurement. - : IOP Publishing. - 0967-3334 .- 1361-6579. ; 39:9 Tidskriftsartikel (refereegranskat)abstract Objective: This paper defines a method for optimizing the breath delineation algorithms used in electrical impedance tomography (EIT). In lung EIT the identification of the breath phases is central for generating tidal impedance variation images, subsequent data analysis and clinical evaluation. The optimisation of these algorithms is particularly important in neonatal care since the existing breath detectors developed for adults may give insufficient reliability in neonates due to their very irregular breathing pattern.Approach: Our approach is generic in the sense that it relies on the definition of a gold standard and the associated definition of detector sensitivity and specificity, an optimisation criterion and a set of detector parameters to be investigated. The gold standard has been defined by 11 clinicians with previous experience with EIT and the performance of our approach is described and validated using a neonatal EIT dataset acquired within the EU-funded CRADL project.Main results: Three different algorithms are proposed that improve the breath detector performance by adding conditions on (1) maximum tidal breath rate obtained from zero-crossings of the EIT breathing signal, (2) minimum tidal impedance amplitude and (3) minimum tidal breath rate obtained from time-frequency analysis. As a baseline a zero-crossing algorithm has been used with some default parameters based on the Swisstom EIT device.Significance: Based on the gold standard, the most crucial parameters of the proposed algorithms are optimised by using a simple exhaustive search and a weighted metric defined in connection with the receiver operating characterics. This provides a practical way to achieve any desirable trade-off between the sensitivity and the specificity of the detectors.
20.	Lind, Leili, et al. (författare) Re-organising care of elderly, multi-morbid COPD and heartfailure patients with low digital literacy : —a 4 year Swedishtelehealth intervention study 2016 Ingår i: Health—exploring complexity: an interdisciplinary systems approach HEC2016. - Munich, Germany. ; , s. 118-118 Konferensbidrag (refereegranskat)
21.	Molin, Jesper, 1987, et al. (författare) Slide navigation patterns among pathologists with long experience of digital review 2015 Ingår i: Histopathology. - : Wiley. - 0309-0167 .- 1365-2559. ; 67:2, s. 185-192 Tidskriftsartikel (refereegranskat)abstract Aims: In order to develop efficient digital pathologyworkstations, we studied the navigation patterns ofpathologists diagnosing whole-slide images. To gain abetter understanding of these patterns, we built aconceptual model based on observations. We alsodetermined whether or not new navigation patternshave emerged among pathologists with extensive digitalexperience.Methods and results: Five pathologists were asked todiagnose a set of four cases while thinking out loud.The navigation within the digital slides was recordedand divided into re-occurring navigation actions. Thepathologists reused the same type of actions, but theiroccurrence differed. The most common action was aslow panning that followed an edge structure orcovered an area systematically, which accounted for30.2% of all actions and had a median duration of7.2 s. Of all the actions, 49% were carried out withinthe navigation overview and 38% of the actionscould not have been performed with a conventionalmicroscope.Conclusions: The new navigation possibilities in thedigital workstation were used to a large extent. Thedivision of actions into different concepts can be usedto find and prioritize between existing user interfacedesigns as well as to understand the different navigationstyles used by different pathologists.
22.	Norell Pejner, Margaretha, 1958-, et al. (författare) Smart medication organizer – one way to promote self-management and safety in drug administration in elderly people 2017 Konferensbidrag (refereegranskat)
23.	Nyberg, Morgan, et al. (författare) A combined tactile and Raman probe for tissue characterization - Design considerations 2012 Ingår i: Measurement Science and Technology. - : IOP Publishing. - 0957-0233 .- 1361-6501. ; 23:6 Tidskriftsartikel (refereegranskat)abstract Histopathology is the golden standard for cancer diagnosis and involves the characterization of tissue components. It is labour intensive and time consuming. We have earlier proposed a combined fibre-optic near-infrared Raman spectroscopy (NIR-RS) and tactile resonance method (TRM) probe for detecting positive surgical margins as a complement to interoperative histopathology. The aims of this study were to investigate the effects of attaching an RS probe inside a cylindrical TRM sensor and to investigate how laser-induced heating of the fibre-optic NIR-RS affected the temperature of the RS probe tip and an encasing TRM sensor. In addition, the possibility to perform fibre-optic NIR-RS in a well-lit environment was investigated. A small amount of rubber latex was preferable for attaching the thin RS probe inside the TRM sensor. The temperature rise of the TRM sensor due to a fibre-optic NIR-RS at 270 mW during 20 s was less than 2 degrees C. Fibre-optic NIR-RS was feasible in a dimmed bright environment using a small light shield and automatic subtraction of a pre-recorded contaminant spectrum. The results are promising for a combined probe for tissue characterization.
24.	Pau, Ivan, et al. (författare) Home e-health system integration in the Smart Home through a common media server. 2009 Ingår i: EMBC: 2009 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-20. - 9781424432967 ; 2009, s. 6171-4 Konferensbidrag (refereegranskat)abstract Home e-health systems and services are revealed as one of the most important challenges to promote Quality of Life related to Health in the Information Society. Leading companies have worked on e-health systems although the majority of them are addressed to hospital or primary care settings. The solution detailed in this paper offers a personal health system to be integrated with Smart Home services platform to support home based e-care. Thus, the home e-health system and architecture detailed in this research work is ready to supply a seamless personal care solution both from the biomedical data analysis, service provision, security guarantee and information management s point of view. The solution is ready to be integrated within the Accessible Digital Home, a living lab managed by Universidad Politécnica de Madrid for R&D activities.
25.	Rigato, Cristina, 1989, et al. (författare) Audiometric comparison between Bone Anchored Hearing Aid and Bone Conduction Implant 2016 Ingår i: AudiologyNOW!2016. Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract Patients suffering from conductive or mixed hearing losses can often be successfully rehabilitated using bone conduction devices (BCDs). Percutaneous BCDs are widely used today, but the trend is to develop transcutaneous solutions able to providing equally good rehabilitation and less complications. Here, the transcutaneous Bone Conduction Implant was compared with percutaneous BCDs under the hypothesis that they are equally effective. Tone and speech audiometry and questionnaires were utilized to assess the overall performance. The outcome confirmed the initial hypothesis.
26.	Seoane, Fernando, et al. (författare) Slightly superior performance of bioimpedance spectroscopy over single frequency regression equations for assessment of total body water. 2015 Ingår i: Engineering in Medicine and Biology Society (EMBC), 2015 37th Annual International Conference of the IEEE. 25-29 Aug. 2015, Milan, Italy.. - : IEEE. - 1094-687X .- 1558-4615. - 9781424492718 - 9781424492701 ; 2015, s. 3707-10 Konferensbidrag (refereegranskat)abstract Electrical bioimpedance has been used for several decades to assess body fluid distribution and body composition by using single frequency and bioimpedance spectroscopic (BIS) techniques. It remains uncertain whether BIS methods have better performance compare to single frequency regression equations. In this work the performance of two BIS methods and four different 50 kHz single frequency prediction equations was studied in a data set of wrist-to-ankle tetrapolar BIS measurements (5-1000 kHz) together with reference values of total body water obtained by tritium dilution in 92 patients. Data were compared using regression techniques and Bland-Altman plots. The results of this study showed that all methods produced similarly high correlation and concordance coefficients, indicating good accuracy as a method. Limits of agreement analysis indicated that the population level performance of Sun's prediction equations was very similar to the performance of both BIS methods. However, BIS methods in practice have slightly better predictive performance than the single-frequency equations as judged by higher correlation and the limits of agreement from the Bland-Altman analysis. In any case, the authors believe that an accurate evaluation of performance of the methods cannot be done as long as the evaluation is done using Bland-Altman analysis, the commonly accepted technique for this kind of performance comparisons.
27.	Tomasic, Ivan, et al. (författare) Continuous remote monitoring of COPD patients—justification and explanation of the requirements and a survey of the available technologies 2018 Ingår i: Medical & Biological Engineering & Computing. - : Springer Science and Business Media LLC. - 0140-0118 .- 1741-0444. ; 56:4, s. 547-569 Tidskriftsartikel (refereegranskat)abstract Remote patient monitoring should reduce mortality rates, improve care, and reduce costs. We present an overview of the available technologies for the remote monitoring of chronic obstructive pulmonary disease (COPD) patients, together with the most important medical information regarding COPD in a language that is adapted for engineers. Our aim is to bridge the gap between the technical and medical worlds and to facilitate and motivate future research in the field. We also present a justification, motivation, and explanation of how to monitor the most important parameters for COPD patients, together with pointers for the challenges that remain. Additionally, we propose and justify the importance of electrocardiograms (ECGs) and the arterial carbon dioxide partial pressure (PaCO2) as two crucial physiological parameters that have not been used so far to any great extent in the monitoring of COPD patients. We cover four possibilities for the remote monitoring of COPD patients: continuous monitoring during normal daily activities for the prediction and early detection of exacerbations and life-threatening events, monitoring during the home treatment of mild exacerbations, monitoring oxygen therapy applications, and monitoring exercise. We also present and discuss the current approaches to decision support at remote locations and list the normal and pathological values/ranges for all the relevant physiological parameters. The paper concludes with our insights into the future developments and remaining challenges for improvements to continuous remote monitoring systems. [Figure not available: see fulltext.]
28.	Enejder, Annika, 1969, et al. (författare) SHG Imaging for Tissue Engineering Applications 2016 Ingår i: Second Harmonic Generation Imaging. - : CRC Press. - 9781439849156 - 9781439849149 ; , s. 409-426 Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract Treatment of lost tissue oen relies on transplantations, either of donor or of autologous tissue. Both alternatives have limitations; there is for example a limited supply of donor transplants, which also require immunosuppression therapy with possible side eects. Transplanted autologous tissue may lack some of the functions of the original tissue and the procedure may also introduce complications at the donor site. In some cases, articial substitutes manufactured from nonbiological materials can be used, for example, synthetic polymer blood vessels or joint replacement prostheses. However, these replacements have drawbacks such as risk for infections, limited material durability, and lack of mechanisms for repair, growth, and remodeling. For these reasons, development of advanced articial tissue constructs with adaptive capabilities is desirable.
29.	Y Banaem, Hossein, et al. (författare) Brain tumor modeling : glioma growth and interaction with chemotherapy 2011 Ingår i: International Conference on Graphic and Image Processing (ICGIP 2011). - : SPIE. ; 8285 Konferensbidrag (refereegranskat)abstract In last decade increasingly mathematical models of tumor growths have been studied, particularly on solid tumors which growth mainly caused by cellular proliferation. In this paper we propose a modified model to simulate the growth of gliomas in different stages. Glioma growth is modeled by a reaction-advection-diffusion. We begin with a model of untreated gliomas and continue with models of polyclonal glioma following chemotherapy. From relatively simple assumptions involving homogeneous brain tissue bounded by a few gross anatomical landmarks (ventricles and skull) the models have been expanded to include heterogeneous brain tissue with different motilities of glioma cells in grey and white matter. Tumor growth is characterized by a dangerous change in the control mechanisms, which normally maintain a balance between the rate of proliferation and the rate of apoptosis (controlled cell death). Result shows that this model closes to clinical finding and can simulate brain tumor behavior properly.
30.	Isaksson-Daun, Johan (författare) A Sound Approach Toward a Mobility Aid for Blind and Low-Vision Individuals 2023 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract Reduced independent mobility of blind and low-vision individuals (BLVIs) cause considerable societal cost, burden on relatives, and reduced quality of life for the individuals, including increased anxiety, depression symptoms, need of assistance, risk of falls, and mortality. Despite the numerous electronic travel aids proposed since at least the 1940’s, along with ever-advancing technology, the mobility issues persist. A substantial reason for this is likely several and severe shortcomings of the field, both in regards to aid design and evaluation.In this work, these shortcomings are addressed with a generic design model called Desire of Use (DoU), which describes the desire of a given user to use an aid for a given activity. It is then applied on mobility of BLVIs (DoU-MoB), to systematically illuminate and structure possibly all related aspects that such an aid needs to aptly deal with, in order for it to become an adequate aid for the objective. These aspects can then both guide user-centered design as well as choice of test methods and measures.One such measure is then demonstrated in the Desire of Use Questionnaire for Mobility of Blind and Low-Vision Individuals (DoUQ-MoB), an aid-agnostic and comprehensive patient-reported outcome measure. The question construction originates from the DoU-MoB to ensure an encompassing focus on mobility of BLVIs, something that has been missing in the field. Since it is aid-agnostic it facilitates aid comparison, which it also actively promotes. To support the reliability of the DoUQ-MoB, it utilizes the best known practices of questionnaire design and has been validated once with eight orientation and mobility professionals, and six BLVIs. Based on this, the questionnaire has also been revised once.To allow for relevant and reproducible methodology, another tool presented herein is a portable virtual reality (VR) system called the Parrot-VR. It uses a hybrid control scheme of absolute rotation by tracking the user’s head in reality, affording intuitive turning; and relative movement where simple button presses on a controller moves the virtual avatar forward and backward, allowing for large-scale traversal while not walking physically. VR provides excellent reproducibility, making various aggregate movement analysis feasible, while it is also inherently safe. Meanwhile, the portability of the system facilitates testing near the participants, substantially increasing the number of potential blind and low-vision recruits for user tests.The thesis also gives a short account on the state of long-term testing in the field; it being short is mainly due to that there is not much to report. It then provides an initial investigation into possible outcome measures for such tests by taking instruments in use by Swedish orientation and mobility professionals as a starting point. Two of these are also piloted in an initial single-session trial with 19 BLVIs, and could plausibly be used for long-term tests after further evaluation.Finally, a discussion is presented regarding the Audomni project — the development of a primary mobility aid for BLVIs. Audomni is a visuo-auditory sensory supplementation device, which aims to take visual information and translate it to sound. A wide field-of-view, 3D-depth camera records the environment, which is then transformed to audio through the sonification algorithms of Audomni, and finally presented in a pair of open-ear headphones that do not block out environmental sounds. The design of Audomni leverages the DoU-MoB to ensure user-centric development and evaluation, in the aim of reaching an aid with such form and function that it grants the users better mobility, while the users still want to use it.Audomni has been evaluated with user tests twice, once in pilot tests with two BLVIs, and once in VR with a heterogenous set of 19 BLVIs, utilizing the Parrot-VR and the DoUQ-MoB. 76 % of responders (13 / 17) answered that it was very or extremely likely that they would want use Audomni along with their current aid. This might be the first result in the field demonstrating a majority of blind and low-vision participants reporting that they actually want to use a new electronic travel aid. This shows promise that eventual long-term tests will demonstrate an increased mobility of blind and low-vision users — the overarching project aim. Such results would ultimately mean that Audomni can become an aid that alleviates societal cost, reduces burden on relatives, and improves users’ quality of life and independence.
31.	Abtahi, Farhad, 1981-, et al. (författare) Big Data & Wearable Sensors Ensuring Safety and Health @Work 2017 Ingår i: GLOBAL HEALTH 2017, The Sixth International Conference on Global Health Challenges. - 9781612086040 Konferensbidrag (refereegranskat)abstract —Work-related injuries and disorders constitute a major burden and cost for employers, society in general and workers in particular. We@Work is a project that aims to develop an integrated solution for promoting and supporting a safe and healthy working life by combining wearable technologies, Big Data analytics, ergonomics, and information and communication technologies. The We@Work solution aims to support the worker and employer to ensure a healthy working life through pervasive monitoring for early warnings, prompt detection of capacity-loss and accurate risk assessments at workplace as well as self-management of a healthy working life. A multiservice platform will allow unobtrusive data collection at workplaces. Big Data analytics will provide real-time information useful to prevent work injuries and support healthy working life
32.	Ajaxon, Ingrid, et al. (författare) Long-term degradation of brushite cements in three different liquids 2016 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
33.	Grishenkov, Dmitry, 1983-, et al. (författare) In search of the optimal ultrasound heart perfusion imaging platform 2015 Ingår i: Journal of ultrasound in medicine. - : Wiley. - 0278-4297 .- 1550-9613. ; 34:9, s. 1599-1605 Tidskriftsartikel (refereegranskat)abstract ObjectiveQuantification of the myocardial perfusion by contrast echocardiography (CEC) remains a challenge. Existing imaging phantoms used to evaluate the performance of ultrasound scanners do not comply with perfusion basics in the myocardium, where perfusion and motion are inherently coupled.MethodsTo contribute towards an improvement, we developed a CEC perfusion imaging platform based on isolated rat heart coupled to the ultrasound scanner. Perfusion was assessed using three different types of contrast agent: dextran-based Promiten®, phospholipid-shelled SonoVue®, and polymer-shelled MB-pH5-RT. The myocardial video-intensity was monitored over time from contrast administration to peak and two characteristic constants were calculated using exponential fit (A representing capillary volume and b representing inflow velocity).ResultsAcquired experimental evidence demonstrates that the application of all three types of contrast agent allow ultrasonic estimation of myocardial perfusion in the isolated rat heart. Video-intensity maps show that an increase in contrast concentration increases the late plateau values, A, mimicking increased capillary volume. Estimated values of the flow, proportional to Axb, increase when the pressure of the perfusate column increases from 80 to 110 cm of water. This finding is in agreement with the true values of the coronary flow increase measured by the flowmeter attached to the aortic cannula.ConclusionsThe described CEC perfusion imaging platform holds promise for standardized evaluation and optimization of ultrasound contrast perfusion imaging where real time inflow curves at low acoustic power semi-quantitatively reflect coronary flow.
34.	Kothapalli, Veera Venkata Satya Naray, 1985-, et al. (författare) Unique pumping-out fracturing mechanism of a polymer-shelled contrast agent : An acoustic characterization and optical visualization 2014 Ingår i: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. - 0885-3010 .- 1525-8955. ; 62:3, s. 451-462 Tidskriftsartikel (refereegranskat)abstract This work describes the fracturing mechanism of air-filled microbubbles (MBs) encapsulated by a cross-linked poly(vinyl alcohol) (PVA) shell. The radial oscillation and fracturing events following the ultrasound exposure were visualized with an ultrahigh-speed camera, and backscattered timedomain signals were acquired with the acoustic setup specific for harmonic detection. No evidence of gas emerging from defects in the shell with the arrival of the first insonation burst was found. In optical recordings, more than one shell defect was noted, and the gas core was drained without any sign of air extrusion when several consecutive bursts of 1 MPa amplitude were applied. In acoustic tests, the backscattered peak-to-peak voltage gradually reached its maximum and exponentially decreased when the PVA-based MB suspension was exposed to approximately 20 consecutive bursts arriving at pulse repetition frequencies of 100 and 500 Hz. Taking into account that the PVA shell is porous and possibly contains large air pockets between the cross-linked PVA chains, the aforementioned acoustic behavior might be attributed to pumping gas from these pockets in combination with gas release from the core through shell defects. We refer to this fracturing mechanism as pumping-out behavior, and this behavior could have potential use for the local delivery of therapeutic gases, such as nitric oxide.
35.	Lind, Carl, et al. (författare) Reducing postural load in order picking through a smart workwear system using real-time vibrotactile feedback 2020 Ingår i: Applied Ergonomics. - : Elsevier. - 0003-6870 .- 1872-9126. ; 89 Tidskriftsartikel (refereegranskat)abstract Vibrotactile feedback training may be one possible method for interventions that target at learning better work techniques and improving postures in manual handling. This study aimed to evaluate the short term effect of real-time vibrotactile feedback on postural exposure using a smart workwear system for work postures intervention in simulated industrial order picking. Fifteen workers at an industrial manufacturing plant performed order-picking tasks, in which the vibrotactile feedback was used for postural training at work. The system recorded the trunk and upper arm postures. Questionnaires and semi-structured interviews were conducted about the users’ experience of the system. The results showed reduced time in trunk inclination ≥20°, ≥30° and ≥45° and dominant upper arm elevation ≥30° and ≥45° when the workers received feedback, and for trunk inclination ≥20°, ≥30° and ≥45° and dominant upper arm elevation ≥30°, after feedback withdrawal. The workers perceived the system as useable, comfortable, and supportive for learning. The system has the potential of contributing to improved postures in order picking through an automated short-term training program. © 2020 Elsevier Ltd
36.	Márquez, Juan Carlos, et al. (författare) Textrode functional straps for bioimpedance measurements-experimental results for body composition analysis 2013 Ingår i: European Journal of Clinical Nutrition. - : Nature Publishing Group. - 0954-3007 .- 1476-5640. ; 67:Suppl 1, s. 22-27 Tidskriftsartikel (refereegranskat)abstract Background/Objectives:Functional garments for physiological sensing purposes have been used in several disciplines, that is, sports, firefighting, military and medicine. In most of the cases, textile electrodes (textrodes) embedded in the garment are used to monitor vital signs and other physiological measurements. Electrical bioimpedance (EBI) is a non-invasive and effective technology that can be used for the detection and supervision of different health conditions.EBI technology could make use of the advantages of garment integration; however, a successful implementation of EBI technology depends on the good performance of textrodes. The main drawback of textrodes is a deficient skin-electrode interface that produces a high degree of sensitivity to signal disturbances. This sensitivity can be reduced with a suitable selection of the electrode material and an intelligent and ergonomic garment design that ensures an effective skin-electrode contact area.Subjects/Methods:In this work, textrode functional straps for total right side EBI measurements for body composition are presented, and its measurement performance is compared against the use of Ag/AgCl electrodes. Shieldex sensor fabric and a tetra-polar electrode configuration using the ImpediMed spectrometer SFB7 in the frequency range of 3-500 kHz were used to obtain and analyse the impedance spectra and Cole and body composition parameters.Results:The results obtained show stable and reliable measurements; the slight differences obtained with the functional garment do not significantly affect the computation of Cole and body composition parameters.Conclusions:The use of a larger sensor area, a high conductive material and an appropriate design can compensate, to some degree, for the charge transfer deficiency of the skin-electrode interface.
37.	Martinez Avila, Hector, 1985 (författare) Biofabrication, Biomechanics and Biocompatibility of Nanocellulose-based Scaffolds for Auricular Cartilage Regeneration 2015 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract In about 2:10,000 births the external part of the ear, the auricle, is severely malformed or absent. Furthermore, tumors and trauma can cause defects to the auricle. For patients with dysplasia of the auricle, and especially for children, an inconspicuous outer appearance with life-like auricles is important for their psychological and emotional well being as well as their psycho-social development. Auricular reconstruction remains a great challenge due to the complexity of surgical reconstruction using rib cartilage. Despite the advances in stem cell technology and biomaterials, auricular cartilage tissue engineering (TE) is still in an early stage of development due to critical requirements demanding appropriate mechanical properties and shape stability of the tissue-engineered construct. This thesis has focused on developing patient-specific tissue-engineered auricles for one-step surgery using a novel biomaterial, bacterial nanocellulose (BNC), seeded with human nasoseptal chondrocytes (hNC) and bone marrow mononuclear cells (MNC).Biomechanical properties of human auricle cartilage were measured and used as a benchmark for tuning BNC properties. In order to meet the biomechanical requirements, a scaffold with bilayer architecture composed of a dense BNC support layer and a macroporous structure was designed. Firstly, the biocompatibility of the dense BNC layer was investigated, demonstrating a minimal foreign body response according to standards set forth in ISO 10993. Secondly, different methods to create macroporous BNC scaffolds were studied and the redifferentiation capacity of hNCs was evaluated in vitro; revealing that macroporous BNC scaffolds support cell ingrowth, proliferation and neocartilage formation. The bilayer BNC scaffold was biofabricated and tested for endotoxins and cytotoxicity before evaluating in long-term 3D culture, and subsequently in vivo for eight weeks—in an immunocompromised animal model. The results demonstrated that the non-pyrogenic and non- cytotoxic bilayer BNC scaffold offers a good mechanical stability and maintains a structural integrity, while providing a porous 3D environment that is suitable for hNCs and MNCs to produce neocartilage, in vitro and in vivo. Furthermore, patient-specific auricular BNC scaffolds with bilayer architecture were biofabricated and seeded with autologous rabbit auricular chondrocytes (rAC) for implantation in an immunocompetent rabbit model for six weeks. The results demonstrated the shape stability of the rAC-seeded scaffolds and neocartilage depositions in the immunocompetent autologous grafts. 3D bioprinting was also evaluated for biofabrication of patient-specific, chondrocyte-laden auricular constructs using a bioink composed of nanofibrillated cellulose and alginate. Bioprinted auricular constructs showed an excellent shape and size stability after in vitro culture. Moreover, this bioink supports redifferentiation of hNCs while offering excellent printability, making this a promising approach for auricular cartilage TE. Furthermore, the use of bioreactors is essential for the development of tissue-engineered cartilage in vitro. Thus, a compression bioreactor was utilized to apply dynamic mechanical stimulation to cell-seeded constructs as a means to enhance production of extracellular matrix in vitro.In this work, a potential clinical therapy for auricular reconstruction using tissue-engineered auricles is demonstrated; where BNC is proposed as a promising non-degradable biomaterial with good chemical and mechanical stability for auricular cartilage TE. Although the primary focus of this thesis is on auricular reconstruction, the methods developed are also applicable in the regeneration of other cartilage tissues such as those found in the nose, trachea, spine and articular joints.
38.	Pettersen, Emily, 1996, et al. (författare) Enhancing osteoblast survival through pulsed electrical stimulation and implications for osseointegration 2021 Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1 Tidskriftsartikel (refereegranskat)abstract Electrical stimulation has been suggested as a means for promoting the direct structural and functional bonding of bone tissue to an artificial implant, known as osseointegration. Previous work has investigated the impact of electrical stimulation in different models, both in vitro and in vivo, using various electrode configurations for inducing an electric field with a wide range of stimulation parameters. However, there is no consensus on optimal electrode configuration nor stimulation parameters. Here, we investigated a novel approach of delivering electrical stimulation to a titanium implant using parameters clinically tested in a different application, namely peripheral nerve stimulation. We propose an in vitro model comprising of Ti6Al4V implants precultured with MC3T3-E1 preosteoblasts, stimulated for 72 h at two different pulse amplitudes (10 mu A and 20 mu A) and at two different frequencies (50 Hz and 100 Hz). We found that asymmetric charge-balanced pulsed electrical stimulation improved cell survival and collagen production in a dose-dependent manner. Our findings suggest that pulsed electrical stimulation with characteristics similar to peripheral nerve stimulation has the potential to improve cell survival and may provide a promising approach to improve peri-implant bone healing, particularly to neuromusculoskeletal interfaces in which implanted electrodes are readily available.
39.	Borrelli, P., et al. (författare) Artificial intelligence-aided CT segmentation for body composition analysis: a validation study 2021 Ingår i: European Radiology Experimental. - : Springer Science and Business Media LLC. - 2509-9280. ; 5:1 Tidskriftsartikel (refereegranskat)abstract BackgroundBody composition is associated with survival outcome in oncological patients, but it is not routinely calculated. Manual segmentation of subcutaneous adipose tissue (SAT) and muscle is time-consuming and therefore limited to a single CT slice. Our goal was to develop an artificial-intelligence (AI)-based method for automated quantification of three-dimensional SAT and muscle volumes from CT images.MethodsEthical approvals from Gothenburg and Lund Universities were obtained. Convolutional neural networks were trained to segment SAT and muscle using manual segmentations on CT images from a training group of 50 patients. The method was applied to a separate test group of 74 cancer patients, who had two CT studies each with a median interval between the studies of 3days. Manual segmentations in a single CT slice were used for comparison. The accuracy was measured as overlap between the automated and manual segmentations.ResultsThe accuracy of the AI method was 0.96 for SAT and 0.94 for muscle. The average differences in volumes were significantly lower than the corresponding differences in areas in a single CT slice: 1.8% versus 5.0% (p <0.001) for SAT and 1.9% versus 3.9% (p < 0.001) for muscle. The 95% confidence intervals for predicted volumes in an individual subject from the corresponding single CT slice areas were in the order of 20%.Conclusions The AI-based tool for quantification of SAT and muscle volumes showed high accuracy and reproducibility and provided a body composition analysis that is more relevant than manual analysis of a single CT slice.
40.	Boyraz Baykas, Pinar, 1981, et al. (författare) Design of a Low-cost Tactile Robotic Sleeve for Autonomous Endoscopes and Catheters 2020 Ingår i: Measurement and Control. - : SAGE Publications. - 0020-2940. ; 53:3-4, s. 613-626 Tidskriftsartikel (refereegranskat)abstract Recent developments in medical robotics have been significant, supporting the minimally invasive operation requirements, such as smaller devices and more feedback available to surgeons. Nevertheless, the tactile feedback from a catheter or endoscopic type robotic device has been restricted mostly on the tip of the device and was not aimed to support the autonomous movement of the medical device during operation. In this work, we design a robotic sheath/sleeve with a novel and more comprehensive approach, which can function for whole-body or segment-based feedback control as well as diagnostic purposes. The robotic sleeve has several types of piezo-resistive pressure and extension sensors, which are embedded at several latitudes and depths of the silicone substrate. The sleeve takes the human skin as a biological model for its structure. It has a better tactile sensation of the inner tissues in the torturous narrow channels such as cardiovascular or endo-luminal tracts in human body thus can be used to diagnose abnormalities. In addition to this capability, using the stretch sensors distributed alongside its body, the robotic sheath/sleeve can perceive the ego-motion of the robotic backbone of the catheter and can act as a position feedback device. Because of the silicone substrate, the sleeve contributes toward safety of the medical device passively by providing a compliant interface. As an active safety measure, the robotic sheath can sense blood-clots or sudden turns inside a channel and by modifying the local trajectory, and can prevent embolisms or tissue rupture. In the future, advanced manufacturing techniques will increase the capabilities of the tactile robotic sleeve.
41.	Broman, Mikael, et al. (författare) Recirculation during veno-venous extra-corporeal membrane oxygenation - a simulation study 2015 Ingår i: International Journal of Artificial Organs. - : SAGE Publications. - 0391-3988 .- 1724-6040. ; 38:1, s. 23-30 Tidskriftsartikel (refereegranskat)abstract Purpose: Veno-venous ECMO is indicated in reversible life-threatening respiratory failure without life-threatening circulatory failure. Recirculation of oxygenated blood in the ECMO circuit decreases efficiency of patient oxygen delivery but is difficult to measure. We seek to identify and quantify some of the factors responsible for recirculation in a simulation model and compare with clinical data. Methods: A closed-loop real-time simulation model of the cardiovascular system has been developed. ECMO is simulated with a fixed flow pump 0 to 5 l/min with various cannulation sites -1) right atrium to inferior vena cava, 2) inferior vena cava to right atrium, and 3) superior+ inferior vena cava to right atrium. Simulations are compared to data from a retrospective cohort of 11 consecutive adult veno-venous ECMO patients in our department. Results: Recirculation increases with increasing ECMO-flow, decreases with increasing cardiac output, and is highly dependent on choice of cannulation sites. A more peripheral drainage site decreases recirculation substantially. Conclusions: Simulations suggest that recirculation is a significant clinical problem in veno-venous ECMO in agreement with clinical data. Due to the difficulties in measuring recirculation and interpretation of the venous oxygen saturation in the ECMO drainage blood, flow settings and cannula positioning should rather be optimized with help of arterial oxygenation parameters. Simulation may be useful in quantification and understanding of recirculation in VV-ECMO.
42.	Böhler, Christian, et al. (författare) Multilayer Arrays for Neurotechnology Applications (MANTA): Chronically Stable Thin-Film Intracortical Implants 2023 Ingår i: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 10:14 Tidskriftsartikel (refereegranskat)abstract Flexible implantable neurointerfaces show great promise in addressing one of the major challenges of implantable neurotechnology, namely the loss of signal connected to unfavorable probe tissue interaction. The authors here show how multilayer polyimide probes allow high-density intracortical recordings to be combined with a reliable long-term stable tissue interface, thereby progressing toward chronic stability of implantable neurotechnology. The probes could record 10–60 single units over 5 months with a consistent peak-to-peak voltage at dimensions that ensure robust handling and insulation longevity. Probes that remain in intimate contact with the signaling tissue over months to years are a game changer for neuroscience and, importantly, open up for broader clinical translation of systems relying on neurotechnology to interface the human brain.
43.	Cervin, Ida, et al. (författare) Improving the creation and reporting of structured findings during digital pathology review 2016 Ingår i: Journal of Pathology Informatics. - : Medknow Publications. - 2229-5089 .- 2153-3539. ; 7:1, s. 32-32 Tidskriftsartikel (refereegranskat)abstract Background: Today, pathology reporting consists of many separate tasks, carried out by multiple people. Common tasks include dictation during case review, transcription, verification of the transcription, report distribution, and report the key findings to follow-up registries. Introduction of digital workstations makes it possible to remove some of these tasks and simplify others. This study describes the work presented at the Nordic Symposium on Digital Pathology 2015, in Linköping, Sweden. Methods: We explored the possibility to have a digital tool that simplifies image review by assisting note-taking, and with minimal extra effort, populates a structured report. Thus, our prototype sees reporting as an activity interleaved with image review rather than a separate final step. We created an interface to collect, sort, and display findings for the most common reporting needs, such as tumor size, grading, and scoring. Results: The interface was designed to reduce the need to retain partial findings in the head or on paper, while at the same time be structured enough to support automatic extraction of key findings for follow-up registry reporting. The final prototype was evaluated with two pathologists, diagnosing complicated partial mastectomy cases. The pathologists experienced that the prototype aided them during the review and that it created a better overall workflow. Conclusions: These results show that it is feasible to simplify the reporting tasks in a way that is not distracting, while at the same time being able to automatically extract the key findings. This simplification is possible due to the realization that the structured format needed for automatic extraction of data can be used to offload the pathologists' working memory during the diagnostic review.
44.	Cubo, Rubén, et al. (författare) Electric field modeling and spatial control in Deep Brain Stimulation 2015 Ingår i: Proc. 54th Conference on Decision and Control. - Piscataway, NJ : IEEE. - 9781479978847 - 9781479978861 ; , s. 3846-3851 Konferensbidrag (refereegranskat)abstract Deep Brain Stimulation (DBS) is an established treatment, in e.g. Parkinson's Disease, whose underlying biological mechanisms are unknown. In DBS, electrical stimulation is delivered through electrodes surgically implanted into certain regions of the brain of the patient. Mathematical models aiming at a better understanding of DBS and optimization of its therapeutical effect through the simulation of the electrical field propagating in the brain tissue have been developed in the past decade. The contribution of the present study is twofold: First, an analytical approximation of the electric field produced by an emitting contact is suggested and compared to the numerical solution given by a Finite Element Method (FEM) solver. Second, the optimal stimulation settings are evaluated by fitting the field distribution to a target one to control the spread of the stimulation. Optimization results are compared to those of a geometric approach, maximizing the intersection between the target and the activated volume in the brain tissue and reducing the stimulated area beyond said target. Both methods exhibit similar performance with respect to the optimal stimuli, with the electric field control approach being faster and more versatile.
45.	Davidsson, Johan, 1967, et al. (författare) A Model for Research on Penetrating Traumatic Brain Injuries 2019 Ingår i: Neuromethods. - New York, NY : Springer New York. - 1940-6045 .- 0893-2336. ; 149, s. 47-59 Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract The animal model presented here produces high-speed penetrating traumatic brain injuries (pen-TBI) to simulate a form of neurotrauma that is severe and is the prevailing TBI in warzones and in areas with high incidence of violence. Commonly, these neurotraumas involve laceration of brain tissue, accompanying hemorrhage, edema, and inflammation. This also occurs in the pen-TBI model designed for rats that is presented here. During trauma, a probe, constructed in one single unit in aluminum and guided by a probe holder, is propelled by a lead bullet and penetrates at high speed into the brain parenchyma of the anesthetized animal. The animal’s head is held in position in a purposely built stereotactic frame. This frame can be adjusted in position relative the tip of the probe so that the tip of the probe is positioned on the exposed dura, using three orthogonally arranged horizontal slides. This procedure will facilitate high similarity in probe penetration location. By adjusting the air pressure in the air-driven accelerator used to accelerate the lead bullet, a large range of probe velocities can be achieved; 110 m/s probe velocity is commonly used. Several probe tip shapes are available for use in the pen-TBI model; pointy, blunt, and flat. The distance the probe penetrates the brain can be controlled. A typical distance is 5.5 mm, and this distance has been found to be almost independent of probe velocity and probe tip shape. After the probe has penetrated the animal, the pen-TBI device facilitates removal of the probe without causing additional brain damage. To do so, the animal is removed using the horizontal slider on the device that moves the animal’s head away from the probe in the direction of probe travel. The pen-TBI device is easy to operate and requires limited pre-trauma and post-trauma surgery. The device induces a small cavity, primary injury in a greater volume of the brain than the cavity and secondary injuries in an even greater volume that is several times that of the primary injury volume. The model appears to produce identical injuries in terms of appearance and dimensions in-between animals of same sex and body mass. The device also produces substantial but short-lived intracranial brain pressure changes, some 8-bar overpressure in the contralateral ventricle has been recorded, with high repeatability.
46.	Fredén Jansson, Karl-Johan, 1988, et al. (författare) Robustness and lifetime of the bone conduction implant - a pilot study 2019 Ingår i: Medical Devices: Evidence and Research. - 1179-1470. ; 12, s. 89-100 Tidskriftsartikel (refereegranskat)abstract Objectives: The objective of this study was to develop methods for evaluating the mechanical robustness and estimating the lifetime of the novel bone conduction implant (BCI) that is used in a clinical study. The methods are intended to be applicable to any similar device. Materials and methods: The robustness was evaluated using tests originally developed for cochlear implants comprising a random vibration test, a shock test, a pendulum test, and an impact test. Furthermore, magnetically induced torque and demagnetization during magnetic resonance imaging at 1.5 T were investigated using a dipole electromagnet. To estimate the lifetime of the implant, a long-term age-accelerated test was performed. Results: Out of all the tests, the pendulum and the impact tests had the largest effect on the electro-acoustic performance of the BCI implant, even if the change in performance was within acceptable limits (< 20%). In comparison with baseline data, the lower and higher resonance peaks shifted down in frequency by 13% and 18%, respectively, and with a loss in magnitude of 1.1 and 2.0 dB, respectively, in these tests. Conclusion: A complete series of tests were developed, and the BCI passed all the tests; its lifetime was estimated to be at least 26 years for patients who are using the implant for 12 hours on a daily basis.
47.	Grönlund, Christer, et al. (författare) Imaging two-dimensional mechanical waves of skeletal muscle contraction 2013 Ingår i: Ultrasound in Medicine and Biology. - : Elsevier BV. - 0301-5629 .- 1879-291X. ; 39:2, s. 360-369 Tidskriftsartikel (refereegranskat)abstract Skeletal muscle contraction is related to rapid mechanical shortening and thickening. Recently, specialized ultrasound systems have been applied to demonstrate and quantify transient tissue velocities and one-dimensional (1-D) propagation of mechanical waves during muscle contraction. Such waves could potentially provide novel information on musculoskeletal characteristics, function and disorders. In this work, we demonstrate two-dimensional (2-D) mechanical wave imaging following the skeletal muscle contraction. B-mode image acquisition during multiple consecutive electrostimulations, speckle-tracking and a time-stamp sorting protocol were used to obtain 1.4 kHz frame rate 2-D tissue velocity imaging of the biceps brachii muscle contraction. The results present novel information on tissue velocity profiles and mechanical wave propagation. In particular, counter-propagating compressional and shear waves in the longitudinal direction were observed in the contracting tissue (speed 2.8-4.4 m/s) and a compressional wave in the transverse direction of the non-contracting muscle tissue (1.2-1.9 m/s). In conclusion, analysing transient 2-D tissue velocity allows simultaneous assessment of both active and passive muscle tissue properties. (E-mail: christer.gronlund@vll.se) (C) 2013 World Federation for Ultrasound in Medicine & Biology.
48.	Håkansson, Bo, 1953, et al. (författare) VEMP using a new low-frequency bone conduction transducer 2018 Ingår i: Medical Devices: Evidence and Research. - 1179-1470. ; 11, s. 301-312 Tidskriftsartikel (refereegranskat)abstract Objective: A new prototype bone conduction (BC) transducer B250, with an emphasized low-frequency response, is evaluated in vestibular evoked myogenic potential (VEMP) investigations. The aim was to compare cervical (cVEMP) and ocular (oVEMP) responses using tone bursts at 250 and 500 Hz with BC stimulation using the B250 and the conventional B81 transducer and by using air conduction (AC) stimulation. Methods: Three normal subjects were investigated in a pilot study. BC stimulation was applied to the mastoids in cVEMP, and both mastoid and forehead in oVEMP investigations. Results: BC stimulation was found to reach VEMP thresholds at considerably lower hearing levels than in AC stimulation (30-40 dB lower oVEMP threshold at 250 Hz). Three or more cVEMP and oVEMP responses at consecutive 5 dB increasing mastoid stimulation levels were only obtained in all subjects using the B250 transducer at 250 Hz. Similar BC thresholds were obtained for both ipsilateral and contralateral mastoid stimulation. Forehead stimulation, if needed, may require a more powerful vibration output. Conclusion: Viable VEMP responses can be obtained at a considerably lower hearing level with BC stimulation than by AC stimulation. The cVEMP and oVEMP responses were similar when measured on one side and with the B250 attached to both ipsilateral and contralateral mastoids.
49.	Lindau, Björn, 1961, et al. (författare) Virtual fixturing: Inspection of a non-rigid detail resting on 3-points to estimate free state and over-constrained shapes 2020 Ingår i: ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE). ; 2B-2020 Konferensbidrag (refereegranskat)abstract When the geometry of a non-rigid part or pre-assembly is measured fully clamped (over-constrained) in a measurement fixture, the spring-back information and influence from gravity forces are usually lost in the collected data. From the 3D-measurement data, it is hard to understand built in tensions, and the detail's tendency to bend, twist and warp after release from the measurement fixture. These effects are however important to consider when analyzing each part´s contribution to geometrical deviations after assembly. In this paper a method is presented, describing how free state shape and over-constrained shape of a measured detail can be virtually estimated starting from acquired data when the part or the preassembly is resting on only 3-points. The objective is to minimize the information loss, to spare measurement resources and to allow for a wider use of the collected data, describing the geometry. Part stiffnesses, part to part contacts and gravity effects are considered in the proposed method. The method is based on 3D-scanning techniques to acquire the shape of the measured object. Necessary compensations for part stiffnesses and gravity effects are based upon Finite Element Analysis (FEA) and the Method of Influence Coefficients (MIC). The presented method is applied to an industrial case to demonstrate its potential. The results show that estimated over-constrained shapes show good resemblance with measurements acquired when part is over-constrained in its measurement fixture.
50.	Mendrik, AM, et al. (författare) MRBrainS Challenge: Online Evaluation Framework for Brain Image Segmentation in 3T MRI Scans 2015 Ingår i: Computational Intelligence and Neuroscience. - : Hindawi Publishing Corporation. - 1687-5265 .- 1687-5273. ; 2015 Tidskriftsartikel (refereegranskat)abstract Many methods have been proposed for tissue segmentation in brain MRI scans. The multitude of methods proposed complicates the choice of one method above others. We have therefore established the MRBrainS online evaluation framework for evaluating (semi)automatic algorithms that segment gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) on 3T brain MRI scans of elderly subjects (65–80 y). Participants apply their algorithms to the provided data, after which their results are evaluated and ranked. Full manual segmentations of GM, WM, and CSF are available for all scans and used as the reference standard. Five datasets are provided for training and fifteen for testing. The evaluated methods are ranked based on their overall performance to segment GM, WM, and CSF and evaluated using three evaluation metrics (Dice, H95, and AVD) and the results are published on the MRBrainS13 website. We present the results of eleven segmentation algorithms that participated in the MRBrainS13 challenge workshop at MICCAI, where the framework was launched, and three commonly used freeware packages: FreeSurfer, FSL, and SPM. The MRBrainS evaluation framework provides an objective and direct comparison of all evaluated algorithms and can aid in selecting the best performing method for the segmentation goal at hand.

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