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  • 151.
    Moy, Linda
    et al.
    New York University School of Medicine.
    Noz, Marilyn E.
    New York University School of Medicine.
    Maguire, Gerald Q., Jr.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Melsaether, Amy
    New York University School of Medicine.
    Deans, Abby E.
    New York University School of Medicine.
    Murphy-Walcott, Antoinette D.
    New York University School of Medicine.
    Ponzo, Fabio
    New York University School of Medicine.
    Role of Fusion of Prone FDG-PET and Magnetic Resonance Imaging of the Breasts in the Evaluation of Breast Cancer2010In: The Breast Journal, ISSN 1075-122X, E-ISSN 1524-4741, Vol. 16, no 4, p. 369-376Article in journal (Refereed)
    Abstract [en]

    The purpose of this study is to report further about the statistically significant results from a prospective study, which suggests that fusion of prone F-18 Fluoro-deoxy-glucose (FDG) positron emission tomography (PET) and magnetic resonance (MR) breast scans increases the positive predictive value (PPV) and specificity for patients in whom the MR outcome alone would be nonspecific. Thirty-six women (mean age, 43 years; range, 24-65 years) with 90 lesions detected on MR consented to undergo a FDG-PET scan. Two blinded readers evaluated the MR and the computer tomography (CT) attenuation-corrected prone FDG-PET scans side-by-side, then after the volumes were superimposed (fused). A semiautomatic, landmark-based program was used to perform nonrigid fusion. Pathology and radiologic follow-up were used as the reference standard. The sensitivity, specificity, PPV, negative predictive value (NPV), and accuracy (with 95% confidence intervals) for MR alone, FDG-PET alone, and fused MR and FDG-PET were calculated. The median lesion size measured from the MR was 2.5 cm (range, 0.5-10 cm). Histologically, 56 lesions were malignant, and 15 were benign. Nineteen lesions were benign after 20-47 months of clinical and radiologic surveillance. The sensitivity of MR alone was 95%, FDG-PET alone was 57%, and fusion was 83%. The increase in PPV from 77% in MR alone to 98% when fused and the increase in specificity from 53% to 97% were statistically significant (p < 0.05). The false-negative rate on FDG-PET alone was 26.7%, and after fusion this number was reduced to 9%. FDG-PET and MR fusions were helpful in selecting which lesion to biopsy, especially in women with multiple suspicious MR breast lesions.

  • 152. Murphy, M J
    et al.
    Isaakson, M
    Jaldén, Joakim
    KTH, Superseded Departments (pre-2005), Signals, Sensors and Systems.
    Adaptive filtering to predict lung tumor motion during free breathing2002In: CARS 2002: COMPUTER ASSISTED RADIOLOGY AND SURGERY, PROCEEDINGS, BERLIN: SPRINGER-VERLAG BERLIN , 2002, p. 539-544Conference paper (Refereed)
    Abstract [en]

    Breathing-induced tumor motion during radiation therapy can be compensated either by crating or correcting the pointing of the radiation beam, but these techniques involve time delays in the corrective response. We have analyzed the accuracy of adaptive filter algorithms in predicting tumor positions with sufficient lead time to compensate for these systematic delays. Tumor and chest motion during respiration has been recorded fluoroscopically for lung cancer patients, using gold fiducials implanted in the tumors to enhance visibility. The motions been analyzed for predictability up to 1.0 second in advance Using tapped delay line, Kalman filter, and neural network filter algorithms. Breathing patterns are not stationary in time. Both internal tumor and external chest movement can show amplitude and period modulations during a 30 second interval. Tapped delay line and other stationary filters cannot compensate for the changes and consequently have poor predictability. The predictive accuracy of adaptive filters has little dependence oil the type of algorithm, but depends mainly on the frequency of updating and deteriorates rapidly when predicting more than 0.2 seconds in advance of the breathing signal. Longer-period (e.g., 30 seconds) variability in breathing requires frequent adaptation of the filter parameters.

  • 153.
    Mårtensson, Mattias
    KTH, School of Technology and Health (STH), Medical Engineering.
    Evaluation of Errors and Limitations in Ultrasound Imaging Systems2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There are binding regulations requiring safety and efficacy aspects of medical devices. The requirements ask for documentation that the devices are safe and effective for their intended use, i.e. if a device has a measuring function it must be correct. In addition to this there are demands for quality systems describing development, manufacturing, labelling, and manufacturing of a device. The requirements are established to guarantee that non-defective medical devices are used in the routine clinical practice. The fast rates in which the imaging modalities have evolved during the last decades have resulted in numerous new diagnostic tools, such as velocity and deformation imaging in ultrasound imaging. However, it seems as if the development of evaluation methods and test routines has not been able to keep up the same pace. Two of the studies in this thesis, Study I and IV, showed that computed tomography-based and ultrasound based volume measurements can yield very disparate measurements, and that tissue Doppler imaging-based ultrasound measurements can be unreliable.

    Furthermore, the new ultrasound modalities impose higher demands on the ultrasound transducers. Transducers are known to be fragile, but defective transducers were less of a problem earlier when the ultrasound systems to a lesser extent were used for measurements. The two other studies, Study II and III, showed that serious transducer errors are very common, and that annual testing of the transducers is not sufficient to guarantee an error free function.

    The studies in the thesis indicate that the system with Notified Bodies, in accordance with the EU’s Medical Device Directive, checking the function and manufacturing of medical devices does not work entirely satisfactory. They also show that the evaluation of new methods have led to the undesirable situation, where new measuring tools, such as volume rendering from imaging systems, and tissue Doppler-based velocity and deformation imaging in echocardiography are available for clinicians without proven knowledge about their accuracy.

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  • 154.
    Mårtensson, Mattias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Bjällmark, Anna
    KTH, School of Technology and Health (STH), Medical Engineering.
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Evaluation of tissue Doppler-based velocity and deformation imaging: a phantom study of ultrasound systems.2011In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 12, no 6, p. 467-476Article in journal (Refereed)
    Abstract [en]

    AIMS: The objective of this study was to test the accuracy and diagnostic interchangeability of tissue Doppler-based displacement, velocity, strain, and strain rate measurements in commercially used ultrasound (US) systems. METHODS AND RESULTS: Using an in-house made phantom, four different US scanner models were evaluated. Two different scanners of the same model were tested, and one scanner acquisition was tested twice with two generations of the same workstation giving six test results in total. The scanners were in active clinical use and are subject to regular maintenance checks. There were three displacement and four velocity results that stood out from the rest and could be regarded as accurate and interchangeable. Among the deformation measurements, three acceptable strain results were found while there were no acceptable strain rate results. Furthermore, the study showed that measurements from scanners of the same model, same acquisition post-processed on different workstations and repeated measurements from the same scanner, can yield disparate results. CONCLUSION: Measurements that are accurate and of interchangeable use can be found for displacement and velocity measurements, but are less likely to be found for strain and strain rate measurements. It is strongly recommended that the ability of each individual US scanner to measure displacement, velocity, strain, and strain rate is evaluated before it is introduced into clinical practice, and it must always be evaluated together with the workstation the scanner is intended to be used in conjunction with.

  • 155.
    Mårtensson, Mattias
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Winter, Reidar
    Cederlund, Kerstin
    Ripsweden, Jonaz
    Mir-Akbari, Habib
    Nowak, Jacek
    Brodin, Lars-Åke
    KTH, School of Technology and Health (STH), Medical Engineering.
    Assessment of left ventricular volumes using simplified 3-D echocardiography and computed tomography - a phantom and clinical study2008In: Cardiovascular Ultrasound, E-ISSN 1476-7120, Vol. 6Article in journal (Refereed)
    Abstract [en]

    Objectives: To compare the accuracy of simplified 3-dimensional (3-D) echocardiography vs. multi-slice computed tomography (MSCT) software for the quantification of left ventricular (LV) volumes. Design: Three-D echocardiography (3-planes approach) and MSCT-CardIQ software were calibrated by measuring known volumes of 10 phantoms designed to closely mimic blood-endocardium interface. Subsequently, LV volumes were measured with both the methods in 9 patients referred routinely for coronary angiography and the agreement between the measurements was evaluated. Results: Simplified 3D-echocardiography provided higher degree of agreement between the measured and true phantom volumes (mean difference 0 +/- 1 ml, variation range + 4 to -4 ml) than MSCT software (mean difference 6 +/- 5 ml; variation range + 22 to -10 ml). The agreement between LV measurements in the patients was considerably poorer, with significantly larger volumes produced by MSCT (mean difference - 23 +/- 40 ml, variation between + 93 and -138 ml). Conclusion: Simplified 3-D echocardiography provides more accurate assessment of phantom volumes than MSCT-CardIQ software. The discrepancy between the results of LV measurements with the two methods is even greater and does not warrant their interchangeable diagnostic use.

  • 156.
    Najar, salwan
    KTH, School of Technology and Health (STH).
    Simulering av 1-Wire sensorer2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The 1-wire bus is a communication bus system which is designed to provide data, signals and power over a single signal with low data rates, a high resolution and a long range. It is typically used to communicate with small inexpensive devices, as temperature sensors, which is worked as a slave with the master computer (PC).

    The 1-wire bus system provides the sufficient control and operation signal, a unique ID serial number of each sensor and it supports multiple temperature sensors by a driving power (Parasite Power) on single line.

    On the 1-Wire bus system, temperature sensors are supplied by two types of power supplies, external Power supply and Parasitic Power.

    The aim of this project is to program the microprocessor (Arduino) by using Arduino programming language to work as a temperature sensor type DS18B20 and also as a slave on the 1-Wire bus system.

    This report explains the 1-Wire bus system techniques and how the communication is achieved between the master and the slave (sensors) to measure the temperature values.

    The measured temperature values are collected from the output of each active sensor on the 1-Wire bus. These data are displayed by the personal computer (PC) which is worked as a master on the 1-Wire bus, and the data are represent the measured temperature values from twelve active sensors on the bus system.

    In this thesis, the temperature values from the 12 active sensors can be read and displayed on the master (PC) by using the following programs: Open Logger One Wire (OLOW) program, One Wire Viewer, DigiTemp and OWFS and I validated all the temperature values from these active sensors which are read and monitored by the drive bus programs. The comparison is done among the measured temperature values to see if the active sensors are given accurate temperature values with different drive bus programs.

    The project shows that the sensors can be connected in a network with the master, by using 1-Wire bus techniques. This thesis will be used by Karolinska University Hospital, and it can also be developed for different requirements in the future.

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  • 157.
    Nolting, Andreas
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Sustainability and Industrial Dynamics.
    Companion Diagnostics Development and Commercialization: A Case Study from the Diagnostics’ Perspective2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The value proposition of Personalized Medicine is to deliver the “right drug, to the right patient, at the right time”. Companion diagnostics is the required tool for Personalized Medicine used to aid clinical decision making with the aim to identify patients who are most suitable for a given treatment approach and to avoid adverse effects. However, even 16 years after the first co-approval of a therapeutic drug and an associated diagnostic test (trastuzumab (Herceptin1) from Genentech and the HercepTest1 from Dako), the co-development and co-approval of drug-diagnostic pairs is a challenging task.This study has the aim to identify major challenges for diagnostics companies when developing and commercializing companion diagnostics. This is achieved by (1) a literature research and (2) an empirical case study in form of interviews with diagnostics companies. The collected data is analyzed and discussed with focus on current regulatory and reimbursement frameworks in the USA and European Union. The co-development strategies and business models of companion diagnostics developers are identified.The conclusion of this study is that the major hurdles for companion diagnostics development and commercialization are gaps in scientific evidence and lacking regulatory guidelines for co-development and clinical biomarker studies. Companion diagnostics commercialization is further challenged by poor reimbursement levels. The main strategy of diagnostics companies to address these challenges is the demonstration of a beneficial outcome for patients in form of clinical studies. Small companies with limited resources for clinical research receive funding from academic research grants, patient support groups, pharmaceutical industry, and governmental Innovation agencies.Finally the formation of a new “pharma-diagnostics” sectoral innovation system as a result of the emerging paradigm of stratified medicine has been proposed.

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  • 158.
    Nordberg, Axel
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Treatment of Bone Fractures Using Fibre Reinforced Adhesive Patches2009Doctoral thesis, comprehensive summary (Other academic)
  • 159.
    Nordberg, Axel
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Antoni, Per
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Fibre reinforced Thiol-Ene patch fixation of bone fracturesManuscript (preprint) (Other academic)
  • 160.
    Nordberg, Axel
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Halldin, Peter
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Evaluation of fiber reinforced adhesive fixation of vertebral fractures; an experimental and numerical studyManuscript (preprint) (Other academic)
  • 161.
    Nordberg, Axel
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Montañez, Maria I.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Ramakrishnan, Subashiyni
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Higly adhesive DOPA primers for fibre reinforced Thiol-Ene patch fixation of bone fractures.Manuscript (preprint) (Other academic)
  • 162.
    Nordberg, Axel
    et al.
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    von Holst, Hans
    KTH, School of Technology and Health (STH), Neuronic Engineering.
    Brolin, Karin
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Beckman, Anders
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Lightweight Structures.
    Vertebral fractures fixation with composite patch fibre reinforced adhesives2007In: Bio-medical materials and engineering, ISSN 0959-2989, E-ISSN 1878-3619, Vol. 17, no 5, p. 299-308Article in journal (Refereed)
    Abstract [en]

    Purpose: The aim is to investigate fixation of cervical vertebral fractures by patching it with a composite laminate of adhesive and fibres, in comparison with use of only adhesives. Material and methods: The composite fixation was tested on bonded roe deer vertebrae. 25 specimens were sawed in two halves, creating a generic fracture, and thereafter bonded. The adhesives used were a dental system, Scotchbond XT, and a cyanoacrylate, M-bond 200. The fibres used were unidirectional carbon fibres and randomly distributed E-glass fibres. The composites were applied as a 7 mm wide patch circumferential along the induced fracture. Reference specimens for comparison were also made. The ultimate tensile strength was tested in an Instron 5567. The failure site was examined with a microscope. Strain vectors were tracked using Digital Speckle Analysis. Results: Scotchbond XT + E-glass fibres gave best results, with a tensile strength of 3.5 N/mm circumferential length (24.3% of reference). All composites had lower stiffness than cortical bone. The dental adhesive fibre composites gave better results than the cyanoacrylate fibre composites. In all cases fibre reinforced adhesive composite gave better results than adhesive without fibre reinforcement. Conclusion: Fibre-adhesive composite is a promising technique for fixating cervical vertebral fractures.

  • 163.
    Nordling, Torbjörn E. M.
    et al.
    Department of Electrical Engineering and Automation, University of Vaasa.
    Koljonen, Janne
    Department of Electrical Engineering and Automation, University of Vaasa.
    Nyström, Josefina
    Bodén, Ida
    Lindholm-Sethson, Britta
    Geladi, Paul
    Alander, Jarmo T.
    Wavelength selection by genetic algorithms in near infrared spectra for melanoma diagnosis2005In: IFMBE Proceedings, Volume 11, 3rd European Medical & Biological Engineering Conference (EMBEC’05) in Prague (Czech Republic), 2005Conference paper (Refereed)
    Abstract [en]

    Early, reliable and fast diagnosis of melanoma is particularly important as the number of cases is increasing. In this paper, the potential of using near infrared spectroscopy for melanoma diagnosis is studied. The classification task is complicated by a low signal-to-noise ratio and the high dimensionality of the spectral data. Thus pre-selection of wavelength variables is required. Atypical naevi samples of patients were clinically classified, using the ABCD rule, and their near infrared spectra recorded. A nonlinear clustering model for spectral based classification was calibrated to the spectra and pathologist?s classification using a genetic algorithm. The genetic algorithm optimized the spectral based classification by selecting wavelengths correlated to melanoma. Some wavelength selections allowed correct classification of all samples in our dataset. The small size of the dataset and uncertainty in the clinical classification, however, limit the conclusions that can be drawn. Evidence for the existence of spectral regions that contain information needed for melanoma diagnosis is presented.

  • 164.
    Näsman, Per
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics, Safety Research.
    Risk, Risk Analysis and Decision-making with Reference to Biostatistics and the Field of Medicine2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Risk, risk analysis and decision-making are essential aspects of health care andmedicine, for patients as well as for physicians and for society as a whole, andthe concept of risk and risk analysis in decision-making has a long history. Theword risk has many different interpretations and has no commonly accepteddefinition. In this thesis, we shall let risk stand for the combination of randomor uncertain events with negative consequences for human health, life and/orwelfare and/or the environment together with some measures of the likelihoodof such events. We believe this is the dominant concept and understanding ofrisk, the risk being the likelihood or probability of an event followed by somenegative consequences or activities of that event.

    In this doctoral thesis, we focus on biostatistics, risks and risk analysis in thefield of medicine, a science which has been using methods from the area of riskanalysis for a long time. The seven papers (paper I - paper VII) presented inthis thesis, together with a general introduction to risk, risk analysis anddecision-making, will be used to illustrate and discuss risk analysis as a tool fordecision-making in the field of medicine. From my point a view, risk analysisin the field of medicine aims to reduce pain, raise the quality of life, reduce therisk of adverse events, compare cost efficiency between different treatmentregimes and prolong a healthy life. Based on results presented in the thesis, weconclude that biostatistics, risks and risk analysis used in the field of medicineare valuable methods for evaluation of hypotheses within the health care areaand a good basis for decision-making.

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  • 165. Odeberg, J
    et al.
    Ahmadian, A
    Williams, Cecilia
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Uhlén, M
    Pontén, F
    Lundeberg, J
    Context-dependent Taq-polymerase-mediated nucleotide alterations, as revealed by direct sequencing of the ZNF189 gene: implications for mutation detection.1999In: Gene, ISSN 0378-1119, E-ISSN 1879-0038, Vol. 235, no 1-2Article in journal (Refereed)
    Abstract [en]

    We have recently reported on the genetic organisation of a novel Krüppel-like zinc finger, ZNF189, located to 9q22-q31. In that study we found no mutations in the coding sequence when using ZNF189 as a candidate gene for sporadic basal cell cancer and squamous cell cancer. Here, by direct sequencing of the proximal promotor of ZNF189, mutations were found to appear in a small hot-spot region in over 50% of analysed tumour samples, the majority being G to A substitutions. The hot-spot region spans a 24bp G-rich region. Repeated analyses of the original sample lysates fail to confirm each of these mutations; and frequently new mutations appear at neighbouring positions. Subsequent analysis with serial dilutions of genomic DNA and a cosmid harbouring the wild-type ZNF189 gene demonstrate that these sequence-specific alterations arise in the outer PCR-amplification when 50 copies or less of template are used. Although the mechanism of how these context-specific alterations arise is not proven, the results demonstrate a previously unreported type of PCR-mediated sequence-specific alteration that easily could have been interpreted as being of clinical relevance. The phenomena observed show that mutations detected by direct sequencing can be caused by PCR-introduced alterations. Consequently, this should be of general caution in mutation analysis of disease gene candidates when using small amounts of template, such as microdissected biopsies.

  • 166.
    Ohlander, Anna
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Foil-based Lab-on-Chip technologies for advanced Point-of-Care molecular diagnostics2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Infectious diseases pose a serious threat to global health. Molecular diagnostics provide solutions for effective control and prevention of infections, however suffers from expensive laboratory equipment, and infrastructure to be fully implemented at point of care (POC), especially at low-resource settings. Lab-on-a-chip that aims to integrate complex biochemical analyses into automated systems is promising for POC analysis. A major challenge is the integration of a complete molecular diagnostic assay, generally translating into complex microfluidics, with the requirement of low fabrication cost. This thesis explores the use of flexible electronics, plastic foils and roll-to-roll manufacturing to enable low-cost microfluidic systems, for molecular diagnostic assays especially targeted towards infectious diseases. Many biochemical assays rely on heat; hence a first aspect in this thesis is the integration of a microheater into microfluidics. In a first project a system for SNP-genotyping is presented using solid phase melting curve analysis to discriminate mutations at a single base resolution. Starting with a glass based concept (paper I) which is further developed to a foil based system (paper II), detection of the polymorphism in the neuropeptide Y associated with increased risk of type II diabetes is demonstrated as a proof of principle. Further development and optimization of the microheater concept has enabled roll-to-roll manufacturing compatibility and multiplexing of targets (paper III). A bacterial sub-typing and multiresistance detection in clinical Staphylococcus Aureus samples is demonstrated for applications in infectious diseases diagnostics. Finally, the microheater concept is further developed to enable μPCR (paper IV). Detection of genomic HIV-1 is demonstrated and a portable detection setup based on an LED light source and low cost CMOS camera for detection was developed. A second aspect of this thesis is integration of light sources and optical detection (paper V-VI). A multilayer system integrating an electroluminescent light source, reactive sensor dyes and organic semiconductor transistor for detection is demonstrated. The system could be used for amine detection in gases (paper V). System was made further roll-to-roll compatible. The system uses an external LED light source and a photodetector processed in only one screen printing- and one dispensing step (paper VI). As a proof of principle, absorbance based DNA hybridization was detected. Collectively, roll-to-roll manufacturing compatible “lab on foil” systems have the potential to improve our ability to diagnose at POC especially at resource-limited settings.

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  • 167. Okamura, Allison M.
    et al.
    Mataric, Maja J.
    Christensen, Henrik I.
    Medical and Health-Care Robotics Achievements and Opportunities2010In: IEEE robotics & automation magazine, ISSN 1070-9932, E-ISSN 1558-223X, Vol. 17, no 3, p. 26-37Article in journal (Refereed)
  • 168.
    Olofsson, Karl
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Carannante, V.
    Frisk, Thomas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Kushiro, K.
    Takai, M.
    Lundquist, A.
    Önfelt, Björn
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Wiklund, Martin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Single cell resolution analysis of ultrasound-produced multi-cellular tumor spheroids2020In: 21st International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2017, Chemical and Biological Microsystems Society , 2020, p. 955-956Conference paper (Refereed)
    Abstract [en]

    We have previously presented an ultrasonic standing wave (USW) 3D culture platform enabling parallel production, staining and processing of 100 uniformly sized multi-cellular tumor spheroids (MCTS) [1]. Here, we use the system for single cell resolution analysis of A498 renal carcinoma MCTS by off-chip fluorescence-activated cell sorting (FACS) and on-chip automatic image analysis methods based on 3D confocal microscopy images.

  • 169.
    Orhan, Ibrahim
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Gonga, Antonio
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    An End-to-End Performance Meter for Applications in Wireless Body Sensor Networks2008In: 2008 5th International Summer School and Symposium on Medical Devices and Biosensors, Institute of Electrical and Electronics Engineers (IEEE), 2008, p. 295-298Conference paper (Refereed)
    Abstract [en]

    This paper presents a monitoring method and its implementation as a light-weight end-to-end performance meter for quality-demanding applications in wireless body sensor networks. The method is evaluated in a wireless sensor network testbed for healthcare applications.

  • 170.
    Orhan, Ibrahim
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Measurement-Based Admission Control in Wireless Sensor Networks2010In: 2010 FOURTH INTERNATIONAL CONFERENCE ON SENSOR TECHNOLOGIES AND APPLICATIONS (SENSORCOMM), IEEE , 2010, p. 447-452Conference paper (Refereed)
    Abstract [en]

    Wireless sensor networks have today emerged as a feasible infrastructure for healthcare applications. This paper addresses the non-trivial performance problems in contention-based wireless networks. We present a method for admission control in contention-based networks, implemented as a component of a performance management system. The test results show that admission control can improve the predictability and level of performance in wireless sensor networks. The system can be used as a tool for dimensioning and configuration as well as for real-time admission control. The often unpredictable dynamics in contention-based access networks means that continuous performance control is needed to maintain a desired quality of service.

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  • 171.
    Orhan, Ibrahim
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Measurement-based admission control in wireless sensor networks2010In: 2010 Eleventh International Conference on Mobile Data Management (MDM), IEEE , 2010, p. 426-431Conference paper (Refereed)
    Abstract [en]

    Wireless sensor networks have today emerged as a feasible infrastructure for healthcare applications. This paper addresses the non-trivial performance problems in contentionbased wireless networks. We present a method for admission control in contention-based networks, implemented as a component of a performance management system. The test results show that admission control can improve the predictability and level of performance in wireless sensor networks. The system can be used as a tool for dimensioning and configuration as well as for real-time admission control. The often unpredictable dynamics in contention-based access networks means that continuous performance control is needed to maintain a desired quality of service.

  • 172.
    Orhan, Ibrahim
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Measurement-Based Performance and Admission Controlin Wireless Sensor Networks2011In: International Journal on Advances in Systems and Measurements, E-ISSN 1942-261X, Vol. 4, no 1-2, p. 32-45Article in journal (Refereed)
    Abstract [en]

    This journal paper presents a measurement-basedperformance management system for contention-based wireless sensor networks. Its main features are admission andperformance control based on measurement data from lightweight performance meters in the endpoints. Test results showthat admission and performance control improve the predictability and level of performance. The system can also be used asa tool for dimensioning and configuration of services in wireless sensor networks. Among the rapidly emerging services inwireless sensor networks we focus on healthcare applications

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  • 173. Orlova, Anna
    et al.
    Tran, Thuy A.
    Ekblad, Torun
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Eriksson Karlström, Amelie
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Tolmachev, Vladimir
    Re-186-maSGS-Z(HER2:342), a potential Affibody conjugate for systemic therapy of HER2-expressing tumours2010In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 37, no 2, p. 260-269Article in journal (Refereed)
    Abstract [en]

    Affibody molecules are a novel class of tumour-targeting proteins, which combine small size (7 kDa) and picomolar affinities. The Affibody molecule Z(HER2:342) has been suggested for imaging of HER2 expression in order to select patients for trastuzumab therapy. When optimizing chelators for Tc-99m-labelling, we have found that synthetic Z(HER2:342) conjugated with mercaptoacetyl-glycyl-glycyl-glycyl (maGGG) and mercaptoacetyl-glycyl-seryl-glycyl (maGSG) chelators provides relatively low renal uptake of radioactivity and could be suitable for therapy. maGGG-Z(HER2:342) and maGSG-Z(HER2:342) were labelled with Re-186 and their biodistribution was studied in normal mice. Dosimetric evaluation and tumour targeting to HER2-overexpressed xenografts (SKOV-3) by Re-186-maGSG-Z(HER2:342) were studied. Gluconate-mediated labelling of maGGG-Z(HER2:342) and maGSG-Z(HER2:342) with Re-186 provided a yield of more than 95% within 60 min. The conjugates were stable and demonstrated specific binding to HER2-expressing SKOV-3 cells. Biodistribution in normal mice demonstrated rapid blood clearance, low accumulation of radioactivity in the kidney and other organs, accumulating free perrhenate. Both Re-186-maGGG-Z(HER2:342) and Re-186-maGSG-Z(HER2:342) demonstrated lower renal uptake than their Tc-99m-labelled counterparts. Re-186-maGSG-Z(HER2:342) provided the lowest uptake in healthy tissues. Biodistribution of Re-186-maGSG-Z(HER2:342) in nude mice bearing SKOV-3 xenografts showed specific targeting of tumours. Tumour uptake 24 h after injection (5.84 +/- 0.54%ID/g) exceeded the concentration in blood by more than 500-fold, and uptake in kidneys by about 8-fold. Preliminary dosimetric evaluation showed that dose-to-tumour should exceed dose-to-kidney by approximately 5-fold. Optimization of chelators improves biodistribution properties of rhenium-labelled small scaffold proteins and enables selection of promising radiotherapeutic agents based on the Affibody molecule.

  • 174.
    Pang, Zhibo
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    A Pervasive and Preventive Healthcare Solution for Medication Noncompliance and Daily Monitoring2009In: 2009 2ND INTERNATIONAL SYMPOSIUM ON APPLIED SCIENCES IN BIOMEDICAL AND COMMUNICATION TECHNOLOGIES (ISABEL 2009), NEW YORK: IEEE , 2009, p. 315-320Conference paper (Refereed)
    Abstract [en]

    Pervasive healthcare solution for medication noncompliance problem would help to save $177 billion annually in the United States. And the rapidly increasing demanding of daily monitoring with onsite diagnosis and prognosis is driving homecare solutions to integrate more and more sensing and data processing capacities. So a powerful system is needed not only to address the medication noncompliance but also to be used as a Pervasive Healthcare Station in home. In this paper, a pervasive and preventive healthcare solution for medication noncompliance and daily monitoring is proposed using an intelligent package sealed by Controlled Delamination Material (CDM) and controlled by Radio Frequency Identification (RFID). Onsite diagnosis and prognosis capacities for kinds of health parameters are supported due to scalable and intensive computing capacitance of the 2D-Mesh-NoC based multi-core architecture. Additionally, friendly human-machine interface is emphasized to make it usable for the elderly, disabled and patients due to enhanced multimedia performance. Experimental results of an implemented prototype confirmed the necessity of the multi-core architecture and approved the feasibility of the proposed intelligent package.

  • 175.
    Patel, Rita R.
    et al.
    Indiana University, Bloomington, IN, USA.
    Ternström, Sten
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Speech, Music and Hearing, TMH.
    Quantitative and Qualitative Electroglottographic Wave Shape Differences in Children and Adults Using Voice Map-Based Analysis2021In: Journal of Speech, Language and Hearing Research, ISSN 1092-4388, E-ISSN 1558-9102, ISSN 1092-4388, Vol. 64, no 8, p. 2977-2995Article in journal (Refereed)
    Abstract [en]

    Purpose: The purpose of this study is to identify the extent to which various measurements of contacting parameters differ between children and adults during habitual range and overlap vocal frequency/intensity, using voice map–based assessment of noninvasive electroglottography(EGG).

    Method: EGG voice maps were analyzed from 26 adults(22–45 years) and 22 children (4–8 years) during connected speech and vowel /a/ over the habitual range and the overlap vocal frequency/intensity from the voice range profile task on the vowel /a/. Mean and standard deviations of contact quotient by integration, normalized contacting speed, quotient of speed by integration, and cycle-rate sample entropy were obtained. Group differences were evaluated using the linear mixed model analysis for the habitual range connected speech and the vowel, whereas analysis of covariance was conducted for the overlap vocal frequency/intensity from the voice range profile task. Presence of a “knee” on the EGG wave shape was determined by visual inspection of the presence of convexity along the decontacting slope of the EGG pulse and the presence of the second derivative zero-crossing.

    Results: The contact quotient by integration, normalized contacting speed, quotient of speed by integration, and cycle-rate sample entropy were significantly different in children compared to (a) adult males for habitual range and(b) adult males and adult females for the overlap vocal frequency/intensity. None of the children had a “knee” on the decontacting slope of the EGG slope.

    Conclusion: EGG parameters of contact quotient by integration, normalized contacting speed, quotient of speed by integration, cycle-rate sample entropy, and absence of a “knee” on the decontacting slope characterize the waveshape differences between children and adults, whereas the normalized contacting speed, quotient of speed by integration, cycle-rate sample entropy, and presence of a “knee” on the downward pulse slope characterize the waveshape differences between adult males and adult females.

    Supplemental Material: https://doi.org/10.23641/asha.15057345

  • 176.
    Patel, Rita
    et al.
    University of Indiana, USA.
    Ternström, Sten
    KTH, School of Electrical Engineering and Computer Science (EECS), Intelligent systems, Speech, Music and Hearing, TMH.
    Electroglottographic voice maps of untrained vocally healthy adults with gender differences and gradients2019In: Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA): 11th International Workshop / [ed] Manfredi, C., Firenze, Italy: Firenze University Press, 2019, p. 107-110Conference paper (Refereed)
    Abstract [en]

    Baseline data from adult speakers are presented for time-domain parameters of EGG waveforms. 26 vocally healthy adults (13 males and 13 females) were recruited for the study. Four dependent variables were computed: mean contact quotient, mean peak-rate-of change in the contact area, index of contacting, and the audio crest factor. Small regions around the speech range distribution modes on the fo/SPL plane were used to define means and gradients. Males and females differed considerably in the audio crest factor of their speaking voice, and somewhat in their EGG contact quotient when measured at the mode point of the individual speech range profile. In males, contacting tended to increase somewhat with fo and SPL around the mode point, while in females it tended to decrease.

  • 177.
    Paulsson, Olivia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Heat detection in precurser of tennis elbow and other joint injuries2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: Joint injuries are a complex matter. Due to the low blood flow to the tendons and ligaments, they take months or even years to heal; some fail to heal. This can be devastating for the elite athlete as well as for the labour worker or everyday person. Today, the devices that can detect an upcoming inflammation or injury, cost 15 000 US dollars and more. A cheaper technology would increase the access. This project is investigating the possibility to detect an upcoming inflammation through measuring the local skin temperature.

    Method: A model of an arm was built in Comsol Multiphysics, where a tennis elbow (lateral epicondylitis) was simulated through local temperature increase. Clinical tests were pursued on two healthy subjects, in order to gain knowledge on how the skin temperature behaves on healthy subjects.

    Results: At an internal temperature increase in the LE of 0.25 K, a temperature difference on the skin of 0.18 K was detected in the model. The clinical tests on healthy subjects indicated a correlation between the temperatures on and around the elbow joint.

    Discussion: The model results does not include any error sources, such as deviation in room temperature and factors affecting the subject´s body temperature, such as time of day, eating and exercising routines. The clinical tests show a pattern of the temperature distribution on and around the elbow joint, in healthy subjects. The fact that a pattern is present, is a presumption enabling to find deviations, caused by upcoming inflammation.

    Conclusion: The model is indicating that a local temperature increase in the LE is detectable at the skin surface. The clinical test indicates that the noise in the temperature data of a healthy person, is small enough to enable to detect a local temperature deviation. At a local skin temperature increase of more than 0.5 K, the results are indicating that the deviation is detectable. Analysing the model data, 0.5 K in skin temperature increase would mean a local temperature increase at the LE of approximately 0.7 K. This is before the stage of inflammation according to literature, which occurs at an increase of 1.5 to 2.2 K.

    Further studies would be interesting to make, in purpose of developing an affordable device that can detect if an inflammation is about to occur, and thereby enable the subject to stop the course. A prototype should be developed in order to make tests on more subjects. The equine industry is also a target group – the prototype may therefore be developed to fit both humans and horses.

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  • 178.
    Pecorari, Claudio
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Ultrasound.
    Grishenkov, Dmitry
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Ultrasound.
    Characterization of ultrasound-induced fracture of polymer-shelled ultrasonic contrast agents by correlation analysis2008Conference paper (Other academic)
  • 179. Peolsson, Anneli
    et al.
    Brodin, Lars-Ake
    KTH, School of Technology and Health (STH), Medical Engineering.
    Peolsson, Michael
    KTH, School of Technology and Health (STH), Medical Engineering.
    A tissue velocity ultrasound imaging investigation of the dorsal neck muscles during resisted isometric extension2010In: Manual Therapy, ISSN 1356-689X, E-ISSN 1532-2769, Vol. 15, no 6, p. 567-573Article in journal (Refereed)
    Abstract [en]

    Persons with neck pain exhibit altered patterns of muscle patterning, but limited investigations have been carried out on these alterations or muscle patterning in healthy volunteers. This study investigated the tissue motion of the dorsal neck muscles at the C4 segmental level in 15 healthy subjects during manually resisted head extension. Doppler-based tissue velocity ultrasound imaging (TVI) was used to detect regional tissue deformation, providing indirect evidence of inter-muscular movement patterning. The deep muscles, multifidus and semispinalis, had different muscular movement patterning than the superficial muscles, especially the trapezius muscle. The semispinalis cervicis (SSCerv) was the first deformed upon exercise initiation, followed by multifidus and semispinalis capitis (SSCap). The semispinalis muscles, notably capitis, exhibited a high rate of deformation during the exercise. The trapezius muscle exhibited the least and lowest deformation rate. In conclusion, TVI provided detailed information on regional tissue activity and muscle movement patterning among the dorsal neck muscles. In future studies, data from patients with neck disorders will have to be matched to data from healthy volunteers in a variety of situations and activities.

  • 180. Pierce, David M.
    et al.
    Trobin, Werner
    Raya, Jose G.
    Trattnig, Siegfried
    Bischof, Horst
    Glaser, Christian
    Holzapfel, Gerhard A.
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Biomechanics.
    DT-MRI Based Computation of Collagen Fiber Deformation in Human Articular Cartilage: A Feasibility Study2010In: Annals of Biomedical Engineering, ISSN 0090-6964, E-ISSN 1573-9686, Vol. 38, no 7, p. 2447-2463Article in journal (Refereed)
    Abstract [en]

    Accurate techniques for simulating the deformation of soft biological tissues are an increasingly valuable tool in many areas of biomechanical analysis and medical image computing. To model the complex morphology and response of articular cartilage, a hyperviscoelastic (dispersed) fiber-reinforced constitutive model is employed to complete two specimen-specific finite element (FE) simulations of an indentation experiment, with and without considering fiber dispersion. Ultra-high field Diffusion Tensor Magnetic Resonance Imaging (17.6 T DT-MRI) is performed on a specimen of human articular cartilage before and after indentation to similar to 20% compression. Based on this DT-MRI data, we detail a novel FE approach to determine the geometry (edge detection from first eigenvalue), the meshing (semi-automated smoothing of DTI measurement voxels), and the fiber structural input (estimated principal fiber direction and dispersion). The global and fiber fabric deformations of both the un-dispersed and dispersed fiber models provide a satisfactory match to that estimated experimentally. In both simulations, the fiber fabric in the superficial and middle zones becomes more aligned with the articular surface, although the dispersed model appears more consistent with the literature. In the future, a multi-disciplinary combination of DT-MRI and numerical simulation will allow the functional state of articular cartilage to be determined in vivo.

  • 181.
    Plattén, Michael
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH). Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
    Martola, J.
    Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
    Fink, K.
    Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
    Ouellette, R.
    Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
    Piehl, F.
    Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
    Granberg, T.
    Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
    MRI-Based Manual versus Automated Corpus Callosum Volumetric Measurements in Multiple Sclerosis2019In: Journal of Neuroimaging, ISSN 1051-2284, E-ISSN 1552-6569Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND PURPOSE

    Corpus callosum atrophy is a neurodegenerative biomarker in multiple sclerosis (MS). Manual delineations are gold standard but subjective and labor intensive. Novel automated methods are promising but require validation. We aimed to compare the robustness of manual versus automatic corpus callosum segmentations based on FreeSurfer.

    METHODS

    Nine MS patients (6 females, age 38 ± 13 years, disease duration 7.3 ± 5.2 years) were scanned twice with repositioning using 3‐dimensional T1‐weighted magnetic resonance imaging on three scanners (two 1.5 T and one 3.0 T), that is, six scans/patient, on the same day. Normalized corpus callosum areas were measured independently by a junior doctor and neuroradiologist. The cross‐sectional and longitudinal streams of FreeSurfer were used to segment the corpus callosum volume.

    RESULTS

    Manual measurements had high intrarater (junior doctor .96 and neuroradiologist .96) and interrater agreement (.94), by intraclass correlation coefficient (P < .001). The coefficient of variation was lowest for longitudinal FreeSurfer (.96% within scanners; 2.0% between scanners) compared to cross‐sectional FreeSurfer (3.7%, P = .001; 3.8%, P = .058) and the neuroradiologist (2.3%, P = .005; 2.4%, P = .33). Longitudinal FreeSurfer was also more accurate than cross‐sectional (Dice scores 83.9 ± 7.5% vs. 78.9 ± 8.4%, P < .01 relative to manual segmentations). The corpus callosum measures correlated with physical disability (longitudinal FreeSurfer r = –.36, P < .01; neuroradiologist r = –.32, P < .01) and cognitive disability (longitudinal FreeSurfer r = .68, P < .001; neuroradiologist r = .64, P < .001).

    CONCLUSIONS

    FreeSurfer's longitudinal stream provides corpus callosum measures with better repeatability than current manual methods and with similar clinical correlations. However, due to some limitations in accuracy, caution is warranted when using FreeSurfer with clinical data.

  • 182.
    Poehlman, Melanie
    et al.
    University Baureight.
    Kothapalli, Veera Venkata Satya Naray
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Grishenkov, Dmitry
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging. Karolinska Institutet (KI), CLINTEC – Division of Medical Imaging and Technology.
    Härmark, Johan
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Structural Biotechnology.
    Hebert, Hans
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Structural Biotechnology.
    Philipp, A.
    Hoeller, Roland
    Seuss, M.
    Magerithelli, S.
    Paradossi, Gaio
    Diapartimento di Chimica, Università di Roma Tor Vergata.
    Fery, Andreas
    Magnetic microbubbles for multimodality imaging: the importance of the shell structure for low and high frequency mechanics2013Conference paper (Refereed)
    Abstract [en]

    There is a growing interest in magnetic microbubbles (MBs) for simultaneous enhanced ultrasound (US) and enhanced magnetic resonance imaging (MRI) to support well-established imaging procedures as well as new emerging diagnostic and therapeutic applications. However, the development of hybrid contrast agents is challenging, because their design needs to satisfy a variety of requirements such as a sufficient stability of the probe for the circulation within the cardiovascular system, the production of an adequate US echo signal and a reasonable reduced relaxation time of nearby located protons. The studied magnetic MBs consist of an air-filled core, which is encapsulated by a soft hydrogel-like shell composed of poly(vinyl alcohol) and superparamagnetic iron oxide nanoparticles (SPIONs)[1]. Two strategies were used to combine magnetic nanoparticles with the polymeric shell: SPIONs were either covalently attached to the shell surface via a post-chemical treatment or embedded physically inside the shell during the MBs’ synthesis. In particular, we were interested on the impact of the used SPIONs integration strategy on low and high frequency mechanics of the magnetic MBs. Therefore, we used a straightforward characterization of the MBs on the single particle level to correlate the synthesis with the MBs’ morphological properties and low frequency mechanics that were studied in quasi-static force measurements with atomic force microscopy. High frequency mechanics were investigated by exposure of an ensemble of MBs to an acoustic field. By further correlation of low and high frequency mechanics, we were able to bridge the gap between synthesis and the MBs macroscopic properties relevant for their application. The shown approach offers the possibility to sustainable design and optimize complex probes based on an improved understanding of structure/property relations.

  • 183. Popovic, Dejan B.
    et al.
    Bijelic, Goran
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Miler, Vera
    Dosen, Strahinja
    Popovic, Mirjana B.
    Schwirtlich, Laszlo
    Lumbar Stimulation Belt for Therapy of Low-Back Pain2009In: Artificial Organs, ISSN 0160-564X, E-ISSN 1525-1594, Vol. 33, no 1, p. 54-60Article in journal (Refereed)
    Abstract [en]

    We developed the STIMBELT, an electrical stimulation system that comprises a lumbar belt with up to eight pairs of embedded electrodes and an eight-channel electronic stimulator. The STIMBELT is an assistive system for the treatment of low-back pain (LBP). We describe here technical details of the system and summarize the results of its application in individuals with subacute and chronic LBP. The direct goals of the treatment were to relieve pain, reduce muscle spasms, increase strength and range of motion, and educate individuals with LBP in reducing the chances of its reoccurrence. The outcome measures include: a Visual Analogue Scale (VAS), the Oswestry LBP Disability Questionnaire, the Short Form (SF)-12 health survey, and the Manual Muscle Test. The results indicate significant benefits for individuals who use the STIMBELT in addition to the conventional therapy as opposed to only the conventional therapy.

  • 184. Privitera, Claudio
    et al.
    Sabesan, Ramkumar
    Winter, Simon
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Tiruveedhula, Pavan
    Roorda, Austin
    Eye-tracking technology for real-time monitoring of transverse chromatic aberration2016In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 41, no 8, p. 1728-1731Article in journal (Refereed)
    Abstract [en]

    Objective measurements of transverse chromatic aberration (TCA) between two or more wavelengths with an adaptive optics scanning laser ophthalmoscope (AOSLO) are very accurate, but frequent measurements are impractical in many experimental settings. Here, we demonstrate a pupil tracker that can accurately measure relative changes in TCA that are caused by small shifts in the pupil relative to the AOSLO imaging beam. Corrections for TCA caused by these shifts improve the measurement of TCA as a function of eccentricity, revealing a strong linear relationship. We propose that pupil tracking be integrated into AOSLO systems, where robust and unobtrusive control of TCA is required.

  • 185. Prot, V.
    et al.
    Skallerud, B.
    Sommer, G.
    Holzapfel, Gerhard A.
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Biomechanics.
    On modelling and analysis of healthy and pathological human mitral valves: Two case studies2010In: JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS, ISSN 1751-6161, Vol. 3, no 2, p. 167-177Article in journal (Refereed)
    Abstract [en]

    Biomechanical data and related constitutive modelling of the mitral apparatus served as a basis for finite element analyses to better understand the physiology of mitral valves in health and disease. Human anterior and posterior leaflets and chordae tendinae from an elderly heart showing no disease and a hypertrophic obstructive cardiomyopathic heart (HOCM) were mechanically tested by means of uniaxial cyclic extension tests under quasi-static conditions. Experimental data for the leaflets and the chordae tendinae showed highly nonlinear mechanical behaviours and the leaflets were anisotropic. The mitral valve from the HOCM heart exhibited a significantly softer behaviour than the valve from the healthy one. A comparison with porcine data was included because many previous mitral modelling studies have been based on porcine data. Some differences in mechanical response were observed. Material parameters for hyperelastic, transversely isotropic constitutive laws were determined. The experimental data and the related model parameters were used in two finite element studies to investigate the effects of the material properties on the mitral valve response during systole. The analyses showed that during systole the mitral valve from the HOCM heart bulged into the left atrium by taking on the shape of a balloon, whereas the anterior leaflet of the healthy valve remained in the left ventricle.

  • 186.
    Rana, Balwan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electromagnetic Engineering and Fusion Science.
    Dalarsson, Mariana
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering.
    Absorption Cross-section Analysis For Human Tissue With Embedded Gold Nanoparticles2023In: 17th International Congress on Artificial Materials for Novel Wave Phenomena, Metamaterials 2023, Institute of Electrical and Electronics Engineers Inc. , 2023, p. 285-287Conference paper (Refereed)
    Abstract [en]

    We present a parametric analysis of the absorption cross-section of small ellipsoidal composite structures (particles) with gold nanoparticles (GNP) embedded in lossy human tissue. The optimal permittivity of the ellipsoidal particle that maximizes the absorption at any given frequency, derived in our previous work with the surrounding tissue as a saline water, is used. We present new results for realistic tissue material parameters and for different GNP-host media and surrounding media. Present results are useful to assess the feasibility of the proposed radiotherapeutic hyperthermia-based methods to treat cancer, based on electrophoretic heating of gold nanoparticle suspensions using microwave radiation, as well as to improve the general understanding of plasmonic resonances in lossy media.

  • 187. Rodriguez, Jose F.
    et al.
    Martufi, Giampalo
    KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Biomechanics.
    Doblare, Manuel
    Finol, Ender A.
    The Effect of Material Model Formulation in the Stress Analysis of Abdominal Aortic Aneurysms2009In: Annals of Biomedical Engineering, ISSN 0090-6964, E-ISSN 1573-9686, Vol. 37, no 11, p. 2218-2221Article in journal (Refereed)
    Abstract [en]

    A reliable estimation of wall stress in Abdominal Aortic Aneurysms (AAAs), requires performing an accurate three-dimensional reconstruction of the medical image-based native geometry and modeling an appropriate constitutive law for the aneurysmal tissue material characterization. A recent study on the biaxial mechanical behavior of human AAA tissue specimens demonstrates that aneurysmal tissue behaves mechanically anisotropic. Results shown in this communication show that the peak wall stress is highly sensitive to the anisotropic model used for the stress analysis. In addition, the present investigation indicates that structural parameters (e.g., collagen fiber orientation) should be determined independently and not by means of non-linear fitting to stress-strain test data. Fiber orientation identified in this manner could lead to overestimated peak wall stresses.

  • 188.
    Rodríguez, Cristina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Measuring Shoulder Abduction in a Healthy and Young Population: A Feasibility Study2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The ability to maintain an independent living at higher age is closely linked to the physical function of an individual. The evaluation of the upper limbs, including the muscular strength of the shoulder, elbow or wrist has received little attention, yet arms are used in most daily tasks. The upper extremity physical performancecan be measured in several ways but none of them has the recognition to be theprimary method. The aim of this experimental study is to test the new devicedeveloped by Erik Almgren and assess whether this can be a valid tool to reliablyassess abduction shoulder strength.

    Fourteen healthy young subjects participated in this study. After placing in the left wrist the new device, they performed three types of tests: Full Range of Motion, Static measurements and Dynamic measurements. Three trials were done in each test with a recovery of 30 seconds.

    The results of the study showed that the Static measurements were similar to the ones obtained in previous studies in the past for both angles and force. For the first time, the study includes dynamic measurements of the moment of the shoulderjoint. Peak dynamic moments were found to be on average 6.43 N·m ± 1.00 N·mfor the females and 7.90 N·m ±2.33 N·m. This value is 6% lower than the test population’s average maximum static moments- result which in accordance withthe inverse relationship between force and velocity.

    The feasibility of this new device to be used outside a biomechanics lab has been proved, however, further research needs to be done in order to validate angles and measurements of the subjects.

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  • 189.
    Rosik, Daniel
    et al.
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Orlova, Anna
    Malmberg, Jennie
    Altai, Mohamed
    Varasteh, Zohreh
    Sandström, Mattias
    Eriksson Karlström, Amelie
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Tolmachev, Vladimir
    Direct comparison of In-111-labelled two-helix and three-helix Affibody molecules for in vivo molecular imaging2012In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 39, no 4, p. 693-702Article in journal (Refereed)
    Abstract [en]

    Radiolabelled Affibody molecules have demonstrated a potential for visualization of tumour-associated molecular targets. Affibody molecules (7 kDa) are composed of three alpha-helices. Recently, a smaller two-helix variant of Affibody molecules (5.1 kDa) was developed. The aim of this study was to compare two- and three-helix HER2-targeting Affibody molecules directly in vivo. The three-helix Affibody molecule ABY-002 and the two-helix Affibody molecule PEP09239 were labelled with In-111 at the N-termini via DOTA chelator. Tumour-targeting properties were directly compared at 1 and 4 h after injection in mice bearing SKOV-3 xenografts with high HER2 expression and LS174T xenografts with low HER2 expression. The dissociation constants (K (D)) for HER2 binding were 78 pM for the three-helix Affibody molecule and 2.1 nM for the two-helix Affibody molecule. In-111-PEP09239 cleared more rapidly from the blood. In xenografts with high HER2 expression, the uptake of In-111-ABY-002 was significantly higher than that of In-111-PEP09239. The tumour-to-blood ratio was higher for In-111-PEP09239 at 4 h after injection, while there was no significant difference in other tumour-to-organ ratios. The tumour uptake of In-111-ABY-002 was eightfold higher than that of In-111-PEP09239 in xenografts with low expression. Tumour-to-blood ratios were equal in this case, but other tumour-to-organ ratios were appreciably higher for the three-helix variant. For tumours with high HER2 expression, two-helix HER2-targeting Affibody molecules can provide higher tumour-to-blood ratio at the cost of lower tumour uptake. In the case of low expression, both tumour uptake and tumour-to-organ ratios are appreciably higher for three-helix than for two-helix HER2-targeting Affibody molecules.

  • 190.
    Rosik, Daniel
    et al.
    KTH, School of Biotechnology (BIO), Protein Technology.
    Thibblin, Alf
    Antoni, Gunnar
    Orlova, Anna
    Eriksson Karlström, Amelie
    KTH, School of Biotechnology (BIO), Protein Technology.
    Tolmachev, Vladimir
    Incorporation of a Triglutamyl Spacer Improves the Biodistribution of Synthetic Affibody Molecules Radiofluorinated at the N-Terminus via Oxime Formation with F-18-4-Fluorobenzaldehyde2014In: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 25, no 1, p. 82-92Article in journal (Refereed)
    Abstract [en]

    Affibody molecules are a class of affinity agents for molecular imaging based on a non-immunoglobulin protein scaffold. Previous studies have demonstrated high contrast for in vivo imaging of cancer-associated molecular abnormalities using Affibody molecules. Using the radionuclide F-18 for labeling and PET as the imaging modality, the sensitivity of molecular imaging using Affibody molecules can be further increased. The use of oxime formation between an aminooxy-functionalized peptide and F-18-fluorobenzaldehyde (F-18-FBA) is a promising way of radiolabeling of targeting peptides. However, previous studies demonstrated that application of this method to Affibody molecules is associated with high liver uptake. We hypothesized that incorporation of a triglutamyl spacer between the aminooxy moiety and the N-terminus of a synthetic Affibody molecule would decrease the hepatic uptake of the F-18-N-(4-fluorobenzylidine)oxime) (F-18-FBO)-labeled tracer. To verify this, we have produced two variants of the HER2-targeting Z(HER2:342) Affibody molecule by peptide synthesis: OA-PEP4313, where aminooxyacetic acid was conjugated directly to the N-terminal alanine, and OA-E-3-PEP4313, where a triglutamyl spacer was introduced between the aminooxy moiety and the N-terminus. We have found that the use of the spacer is associated with a minor decrease of affinity, from K-D = 49 pM to K-D = 180 pM. Radiolabeled F-18-FBO-E-3-PEP4313 demonstrated specific binding to HER2-expressing ovarian carcinoma SKOV-3 cells and slow internalization. Biodistribution studies in mice demonstrated that the use of a triglutamyl linker decreased uptake of radioactivity in liver 2.7-fold at 2 h after injection. Interestingly, radioactivity uptake in kidneys was also reduced (2.4-fold). Experiments in BALB/C nu/nu mice bearing SKOV-3 xenografts demonstrated HER2-specific uptake of F-18-FBO-E-3-PEP4313 in tumors. At 2 h pi, the tumor uptake (20 +/- 2% ID/g) exceeded uptake in liver 5-fold and uptake in kidneys 3.6-fold. The tumor-to-blood ratio was 21 +/- 3. The microPET/CT imaging experiment confirmed the biodistribution data. In conclusion, the use of a triglutamyl spacer is a convenient way to improve the biodistribution profile of Affibody molecules labeled at the N-terminus using F-18-FBA. It provides a tracer capable of producing high-contrast images of HER2-expressing tumors.

  • 191.
    Rosén, Robert
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Lundström, Linda
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Unsbo, Peter
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Influence of Optical Defocus on Peripheral Vision2011In: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 52, no 1, p. 318-323Article in journal (Refereed)
    Abstract [en]

    PURPOSE. Peripheral optical corrections are often thought to give few visual benefits beyond improved detection acuity. However, patients with central visual field loss seem to benefit from peripheral correction, and animal studies suggest a role for peripheral vision in the development of myopia. This study was conducted to bridge this gap by systematically studying the sensitivity to optical defocus in a wide range of peripheral visual tasks. METHODS. The spatial frequency threshold for detection and resolution in high and low contrast with stationary and drifting gratings were measured off-axis (20 nasal visual field) in five subjects with a peripheral optical correction that was varied systematically +/- 4 D. RESULTS. All visual tasks, except high-contrast resolution, were sensitive to optical defocus, particularly low-contrast resolution with an increase of up to 0.227 logMAR/D. The two myopic subjects exhibited a very low sensitivity to defocus by negative lenses for low-contrast tasks, whereas all subjects were equally affected by myopic defocus. Contrary to expectations, drifting gratings made little difference overall. CONCLUSIONS. Optical defocus as low as 1 D has a large impact on most peripheral visual tasks, with high-contrast resolution being the exception. Since the everyday visual scenery consists of objects at different contrast levels, it is understandable that persons with central visual field loss are helped by correction of peripheral refractive errors. The asymmetry in sensitivity to peripheral optical defocus in low-contrast tasks that was experienced by the myopic subjects in this study merits further investigation.

  • 192.
    Roxhed, Niclas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Griss, Patrick
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Membrane-sealed Hollow Microneedles and Related Administration Schemes for Transdermal Drug Delivery2008In: Biomedical microdevices (Print), ISSN 1387-2176, E-ISSN 1572-8781, Vol. 10, no 2, p. 271-279Article in journal (Refereed)
    Abstract [en]

    This paper presents fabrication and testing of membrane-sealed hollow microneedles. This novel concept offers the possibility of a sealed microneedle-based transdermal drug delivery system in which the drug is stored and protected from the environment. Sealed microneedles were fabricated by covering the tip openings of out-of-plane silicon microneedles with thin gold membranes. In this way a leak-tight seal was established which hinders both contamination and evaporation. To allow drug release from the microneedles, three different methods of opening the seals were investigated: burst opening by means of pressure; opening by applying a small voltage in the presence of physiological saline; and opening as a result of microneedle insertion into the skin. It was found that a 170 nm thick gold membrane can withstand a pressure of approximately 120 kPa. At higher pressures the membranes burst and the microneedles are opened up. The membranes can also be electrochemically dissolved within 2 min in saline conditions similar to interstitial fluid present in the skin. Moreover, through in vivo tests, it was demonstrated that 170 nm thick membranes break when the microneedles were inserted into skin tissue. The proposed concept was demonstrated as a feasible option for sealing hollow microneedles. This enables the realization of a closed-package transdermal drug delivery system based on microneedles.

  • 193.
    Roxhed, Niclas
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Samel, Björn
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Nordquist, Lina
    Department of Medical Cell Biology, Division of Integrative Physiology, Uppsala University.
    Griss, Patrick
    Zühlke Engineering AG, Zurich.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology.
    Painless Drug Delivery through Microneedle-based Transdermal Patches featuring Active Infusion2008In: IEEE Transactions on Biomedical Engineering, ISSN 0018-9294, E-ISSN 1558-2531, Vol. 55, no 3, p. 1063-1071Article in journal (Refereed)
    Abstract [en]

    This paper presents the first microneedle-based transdermal patch with integrated active dispensing functionality. The electrically controlled system consists of a low-cost dosing and actuation unit capable of controlled release of liquid in the microliter range at low flow-rates and minimally invasive, side-opened, microneedles. The system was successfully tested in vivo by insulin administration to diabetic rats. Active infusion of insulin at 2 mu l/h was compared to passive, diffusion-driven, delivery. Continuous active infusion caused significantly higher insulin concentrations in blood plasma. After a 3-h delivery period, the insulin concentration was five times larger compared to passive delivery. Consistent with insulin concentrations, actively administered insulin resulted in a significant decrease of blood glucose levels. Additionally, insertion and liquid injection was verified on human skin. This study shows the feasibility of a patch-like system with on-board liquid storage and dispensing capability. The proposed device represents a first step towards painless and convenient administration of macromolecular drugs such as insulin or vaccines.

  • 194.
    Rufo, Joseph
    et al.
    Duke Univ, Dept Mech Engn & Mat Sci, Durham, NC 27706 USA..
    Cai, Feiyan
    Chinese Acad Sci, Shenzhen Inst Adv Technol, Paul C Lauterbur Res Ctr Biomed Imaging, Shenzhen, Guangdong, Peoples R China..
    Friend, James
    Univ Calif San Diego, Dept Mech & Aerosp Engn, Jacobs Sch Engn, Ctr Med Device Engn & Biomech, La Jolla, CA 92093 USA.;Univ Calif San Diego, Sch Med, Dept Surg, La Jolla, CA 92093 USA..
    Wiklund, Martin
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biophysics.
    Huang, Tony Jun
    Duke Univ, Dept Mech Engn & Mat Sci, Durham, NC 27706 USA..
    Acoustofluidics for biomedical applications2022In: Nature Reviews Methods Primers, ISSN 2662-8449, Vol. 2, no 1, article id 30Article in journal (Refereed)
    Abstract [en]

    Acoustofluidic technologies utilize acoustic waves to manipulate fluids and particles within fluids, all in a contact-free and biocompatible manner. Over the past decade, acoustofluidic technologies have enabled new capabilities in biomedical applications ranging from the precise patterning of heterogeneous cells for tissue engineering to the automated isolation of extracellular vesicles from biofluids for rapid, point-of-care diagnostics. In this Primer, we explain the underlying physical principles governing the design and operation of acoustofluidic technologies and describe the various implementations that have been developed for biomedical applications. We aim to demystify the rapidly growing field of acoustofluidics and provide a unified perspective that will allow end users to choose the acoustofluidic technology that is best suited for their research needs. The experimental set-ups for each type of acoustofluidic device are discussed along with their advantages and limitations. In addition, we review typical types of data that are obtained from acoustofluidic experiments and describe how to model different forces acting on particles within an acoustofluidic device. We also discuss data reproducibility and the need to establish standards for the deposition of data sets within the field. Finally, we provide our perspective on how to optimize device performance and discuss areas of future development.

  • 195.
    Sandsjö, L.
    et al.
    National Institute of Working Life, Gothenburg.
    Berglin, L.
    School of Textiles, University of Borås.
    Wiklund, U.
    Engineering and Informatics, Univeristy Hospital of Umeå.
    Karlsson, M.
    Engineering and Informatics, Univeristy Hospital of Umeå.
    Östlund, N.
    Engineering and Informatics, Univeristy Hospital of Umeå.
    Bäcklund, T.
    Engineering and Informatics, Univeristy Hospital of Umeå.
    Lindecrantz, Kaj
    School of Engineering, University of Borås.
    Karlsson, S.
    Engineering and Informatics, Univeristy Hospital of Umeå.
    Self-Administered Longterm Ambulatory Monitoring of Electrophysiological Signals Based on Smart Textiles2006Conference paper (Refereed)
  • 196.
    Sandström, Niklas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Integrating Biosensors for Air Monitoring and Breath-Based Diagnostics2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The air we breathe is the concern of all of us but nevertheless we only know very little about airborne particles, and especially which biological microorganisms they contain. Today, we live in densely populated societies with a growing number of people, making us particularly vulnerable to air transmission of pathogens. With the recent appearance of highly pathogenic types of avian influenza in southeast Asia and the seasonal outbreaks of gastroenteritis caused by the extremely contagious norovirus, the need for portable, sensitive and rapid instruments for on-site detection and monitoring of airborne pathogens is apparent.

    Unfortunately, the integration incompatibility between state-of-the-art air sampling techniques and laboratory based analysis methods makes instruments for in-the-field rapid detection of airborne particles an unresolved challenge.

    This thesis aims at addressing this challenge by the development of novel manufacturing, integration and sampling techniques to enable the use of label-free biosensors for rapid and sensitive analysis of airborne particles at the point-of-care or in the field.

    The first part of the thesis introduces a novel reaction injection molding technique for the fabrication of high quality microfluidic cartridges. In addition, electrically controlled liquid aspiration and dispensing is presented, based on the use of a thermally actuated polymer composite integrated with microfluidic cartridges.

    The second part of the thesis demonstrates three different approaches of biosensor integration with microfluidic cartridges, with a focus on simplifying the design and integration to enable disposable use of the cartridges.

    The third part to the thesis presents a novel air sampling technique based on electrophoretic transport of airborne particles directly to microfluidic cartridges. This technique is enabled by the development of a novel microstructured component for integrated air-liquid interfacing. In addition, a method for liquid sample mixing with magnetic microbeads prior to downstream biosensing is demonstrated.In the fourth part of the thesis, three different applications for airborne particle biosensing are introduced and preliminary experimental results are presented.

    Download full text (pdf)
    Thesis
  • 197. Schneegass, Stefan
    et al.
    Hassib, Mariam
    Zhou, Bo
    Cheng, Jingyuan
    Seoane, Fernando
    Högskolan i Borås, Sweden.
    Amft, Oliver
    Lukowicz, Paul
    Schmidt, Albrecht
    SimpleSkin: towards multipurpose smart garments2015Conference paper (Refereed)
    Abstract [en]

    Smart textiles have been researched in the lab over thelast 20 years. However, the gap between research andavailable mass-market products is huge. We identifychallenges that are the core reasons for this gap. Totackle these challenges, we present our work towards amultipurpose smart textile with dierent sensingmodalities. It separates the concern of developing textiles,electronics, infrastructure, and applications. Furthermore,it uses a similar application model as current smart-phonesallowing developers to create applications for the smarttextiles. We believe that this approach is capable ofmoving smart textiles from niche to mainstream.

  • 198.
    Seoane, Fernando
    University of Borås.
    Electrical Bioimpedance Cerebral Monitoring: Effects of Hypoxia2005Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Electrical bioimpedance spectroscopy is one way to study the electrical properties of biological matter. Different applications of electrical bioimpedance measurements have already been used in both research and clinical scenarios i.e. impedance plethysmography, total body water contents, etc. The electrical properties of tissue reflect the electrical characteristics of the constituent elements of the tissue and depend on its structure. Thus study of the electrical properties not only makes it possible to differentiate among tissues but also to determine the tissue condition. During hypoxia/ischemia the cell activates a certain chain of mechanisms of cellular adaptation in response to the insult. A consequence of these response mechanisms is that the biochemical composition of the cellular environment is altered and the cells swell (cellular edema). These alterations affect the electrical properties of tissue and the changes can be observed through measurement of the electrical bioimpedance of the affected tissue. Based on these ideas, this research work studies the effects of hypoxia/ischemia on the brain electrical impedance. The aim is to obtain the fundamental knowledge that may lead to the development of useful clinical tools for cerebral monitoring based on electrical bioimpedance spectroscopy. 

    Download full text (pdf)
    FSM-LIC
  • 199.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Electrical Bioimpedance Cerebral Monitoring: Fundamental Steps towards Clinical Application2007Doctoral thesis, comprehensive summary (Other academic)
  • 200.
    Seoane, Fernando
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. University of Borås, Sweden.
    Atefi, seyed Reza
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Jens, Tomner
    Karolinska Hospital.
    Kostulas, Konstantinos
    Karolinska Institute, Department of Neurology.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Electrical Bioimpedance Spectroscopy on Acute Unilateral Stroke Patients: Initial Observations regarding Differences between Sides2015In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, Vol. 2015, article id 613247Article in journal (Refereed)
    Abstract [en]

    Purpose. Electrical Bioimpedance Cerebral Monitoring is assessment in real time of health of brain tissue through study of passive dielectric properties of brain. During the last two decades theory and technology have been developed in parallel with animal experiments aiming to confirm feasibility of using bioimpedance-based technology for prompt detection of brain damage. Here, for the first time, we show that electrical bioimpedance measurements for left and right hemispheres are significantly different in acute cases of unilateral stroke within 24 hours from onset. Methods. Electrical BIS measurements have been taken in healthy volunteers and patients suffering from acute stroke within 24 hours of onset. BIS measurements have been obtained using SFB7 bioimpedance spectrometer manufactured by Impedimed ltd. and 4-electrode method. Measurement electrodes, current, and voltage have been placed according to 10–20 EEG system obtaining mutual BIS measurements from 4 different channels situated in pairs symmetrically from the midsagittal line. Obtained BIS data has been analyzed, assessing for symmetries and differences regarding healthy control data.Results. 7 out of 10 patients for Side-2-Side comparisons and 8 out 10 for central/lateral comparison presented values outside the range defined by healthy control group. When combined only 1 of 10 patients exhibited values within the healthy range. Conclusions. If these initial observations are confirmed with more patients, we can foresee emerging of noninvasive monitoring technology for brain damage with the potential to lead to paradigm shift in treatment of brain stroke and traumatic brain damage.

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