Institut für Medizintechnik und Medizininformatik

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Tracking of a magnetically navigated millirobot with a magnetic-field camera
(IEEE, 10.04.2024) Vergne, Céline; Pinto Inácio, José Miguel; Quirin, Thomas; Sargent, David; Madec, Morgan; Pascal, Joris
A significant progress has been made in the development of magnetic micromanipulation for minimally invasive surgery. The development of systems to localize millimeter-sized robots during magnetic manipulation without line-of-sight detection remains, however, a challenging task. In this study, we focused on the development of a tracking system aiming to fill this gap. A robot, which consists of a cylindrical magnet of 1-mm diameter, is localized using a 2-D array of 3-D magnetoresistive sensors. The system, also called magnetic-field camera (MFC), provides tracking of the robot with a refresh rate of 2 Hz. The developed tracking algorithm reaches a mean absolute error (MAE) for the position and the orientation of, respectively, 0.56 mm and 5.13° in 2-D. This system can be added to the existing magnetic manipulation systems (MMSs) allowing closed-loop control of the navigation. The performances of the MFC are not affected by an exposure to strong magnetic fields. Exposures up to 3 T have been validated. Increasing the integrability of the MFC into MMSs. The presented tracking system makes it possible to target applications, such as minimally invasive eye surgery or drug delivery. The high spatial and magnetic resolutions allow the tracking of magnetic particles, down to 200- μm diameter, when placed close to the surface. The system could also be suitable for the localization of small objects for 2-D biomanipulation.
01A - Beitrag in wissenschaftlicher Zeitschrift
Kidins220 regulates the development of B cells bearing the λ light chain
(eLife Sciences Publications, 25.01.2024) Schaffer, Anna-Maria; Fiala, Gina Jasmin; Hils, Miriam; Natali, Eriberto; Babrak, Lmar; Herr, Laurenz Alexander; Romero-Mulero, Mari Carmen; Cabezas-Wallscheid, Nina; Rizzi, Marta; Miho, Enkelejda; Schamel, Wolfgang W.A.; Minguet, Susana
The ratio between κ and λ light chain (LC)-expressing B cells varies considerably between species. We recently identified Kinase D-interacting substrate of 220 kDa (Kidins220) as an interaction partner of the BCR. In vivo ablation of Kidins220 in B cells resulted in a marked reduction of λLC-expressing B cells. Kidins220 knockout B cells fail to open and recombine the genes of the Igl locus, even in genetic scenarios where the Igk genes cannot be rearranged or where the κLC confers autoreactivity. Igk gene recombination and expression in Kidins220-deficient B cells is normal. Kidins220 regulates the development of λLC B cells by enhancing the survival of developing B cells and thereby extending the time-window in which the Igl locus opens and the genes are rearranged and transcribed. Further, our data suggest that Kidins220 guarantees optimal pre-BCR and BCR signaling to induce Igl locus opening and gene recombination during B cell development and receptor editing.
01A - Beitrag in wissenschaftlicher Zeitschrift
Author Correction. The dengue-specific immune response and antibody identification with machine learning
(Nature, 20.01.2024) Natali, Eriberto Noel; Horst, Alexander; Meier, Patrick; Greiff, Victor; Nuvolone, Mario; Babrak, Lmar Marie; Fink, Katja; Miho, Enkelejda
Dengue virus poses a serious threat to global health and there is no specific therapeutic for it. Broadly neutralizing antibodies recognizing all serotypes may be an effective treatment. High-throughput adaptive immune receptor repertoire sequencing (AIRR-seq) and bioinformatic analysis enable in-depth understanding of the B-cell immune response. Here, we investigate the dengue antibody response with these technologies and apply machine learning to identify rare and underrepresented broadly neutralizing antibody sequences. Dengue immunization elicited the following signatures on the antibody repertoire: (i) an increase of CDR3 and germline gene diversity; (ii) a change in the antibody repertoire architecture by eliciting power-law network distributions and CDR3 enrichment in polar amino acids; (iii) an increase in the expression of JNK/Fos transcription factors and ribosomal proteins. Furthermore, we demonstrate the applicability of computational methods and machine learning to AIRR-seq datasets for neutralizing antibody candidate sequence identification. Antibody expression and functional assays have validated the obtained results.
01A - Beitrag in wissenschaftlicher Zeitschrift
The dengue-specific immune response and antibody identification with machine learning
(Nature, 20.01.2024) Natali, Eriberto Noel; Horst, Alexander; Meier, Patrick; Greiff, Victor; Nuvolone, Mario; Babrak, Lmar Marie; Fink, Katja; Miho, Enkelejda
Dengue virus poses a serious threat to global health and there is no specific therapeutic for it. Broadly neutralizing antibodies recognizing all serotypes may be an effective treatment. High-throughput adaptive immune receptor repertoire sequencing (AIRR-seq) and bioinformatic analysis enable in-depth understanding of the B-cell immune response. Here, we investigate the dengue antibody response with these technologies and apply machine learning to identify rare and underrepresented broadly neutralizing antibody sequences. Dengue immunization elicited the following signatures on the antibody repertoire: (i) an increase of CDR3 and germline gene diversity; (ii) a change in the antibody repertoire architecture by eliciting power-law network distributions and CDR3 enrichment in polar amino acids; (iii) an increase in the expression of JNK/Fos transcription factors and ribosomal proteins. Furthermore, we demonstrate the applicability of computational methods and machine learning to AIRR-seq datasets for neutralizing antibody candidate sequence identification. Antibody expression and functional assays have validated the obtained results.
01A - Beitrag in wissenschaftlicher Zeitschrift
Geometric cuts by an autonomous laser osteotome increase stability in mandibular reconstruction with free fibula grafts. A cadaver study
(Elsevier, 2024) Gottsauner, Maximilian; Morawska, Marta M.; Tempel, Simon; Müller-Gerbl, Magdalena; Dalcanale, Federico; de Wild, Michael; Ettl, Tobias
Background Nonunion and plate exposure represent a major complication after mandibular reconstruction with free fibula flaps. These drawbacks may be resolved by geometric osteotomies increasing intersegmental bone contact area and stability. Purpose The aim of this study was to compare intersegmental bone contact and stability of geometric osteotomies to straight osteotomies in mandibular reconstructions with free fibula grafts performed by robot-guided erbium-doped yttrium aluminum garnet laser osteotomy.
01A - Beitrag in wissenschaftlicher Zeitschrift
Geometric cuts by an autonomous laser osteotome increase stability in mandibular reconstruction with free fibula grafts. A cadaver study
(Elsevier, 2024) Gottsauner, Maximilian; Morawska, Marta M.; Tempel, Simon; Müller-Gerbl, Magdalena; Dalcanale, Federico; de Wild, Michael; Ettl, Tobias
01A - Beitrag in wissenschaftlicher Zeitschrift
Atlas-Based Segmentation Algorithm
(Hochschule für Life Sciences FHNW, 2024) Kohler, Roger; Vogel, Dorian; Linköpings Universitet
11 - Studentische Arbeit
Automatische Datenextraktion aus Anamnesebögen
(Hochschule für Life Sciences FHNW, 2024) Kamber, Lukas; Kahraman, Abdullah; Universität Zürich
11 - Studentische Arbeit
GPS für das Becken. 3D Visualisierung von anatomischen Strukturen
(Hochschule für Life Sciences FHNW, 2024) Bopp, Nicolas; Brodbeck, Dominique; Universitätsspital Zürich (USZ), Zürich
11 - Studentische Arbeit
Investigation of different quality assessment procedures for fast and reliable validation of CBCT-based synthetic CTs
(Hochschule für Life Sciences FHNW, 2024) Maurenbrecher, Joakim; Knopf, Antje; Paul Scherrer Institut, Villigen
11 - Studentische Arbeit
Robustness comparison of optimization techniques in Intensity Modulated Proton Therapy (IMPT)
(Hochschule für Life Sciences FHNW, 2024) Hagmann, Virgile; Knopf, Antje; Paul Scherrer Institut, Villigen
11 - Studentische Arbeit
Characterization of cells for In-Vitro Fertilization
(Hochschule für Life Sciences, 2024) Braun Ponce de Leon, Andreas; Nahum, Uri; Smart-Pick GmbH; Universitätsspital Basel, Basel
11 - Studentische Arbeit
Quantitative assessment of repetitive lower limb movements used in the MDS-UPDRS-III scale in healthy subjects
(Hochschule für Life Sciences FHNW, 2024) Hunziker, Sven; Hemm-Ode, Simone; Vogel, Dorian; Kalt, Denise; Kantonsspital Baden AG, Baden AG
11 - Studentische Arbeit
Stimmanalyse zur Evaluierung des Leidens bei Patienten mit Krebs
(Hochschule für Life Sciences FHNW, 2024) Dere, Türkmen; Hemm-Ode, Simone; Kantonsspital Baselland, Liestal; Palliativzentrum Hildegard, Basel
11 - Studentische Arbeit
Miniaturization of stent prototypes by µSLM
(Hochschule für Life Sciences FHNW, 2024) Wasmer, Larissa; de Wild, Michael; Seiler, Daniel; Politecnico di Torino
11 - Studentische Arbeit
Analysis of Patient Reported Outcome Measures (PROMs)
(Hochschule für Life Sciences FHNW, 2024) Schlumpf, Oliver; Kahraman, Abdullah; Luzerner Kantonsspital (LUKS); Swiss Sarcoma Network (SSN)
11 - Studentische Arbeit
Low-coercivity perpendicular spin transfer torque magnetic tunnel junctions as nanoscale magnetic sensors
(IEEE, 09/2023) Nicolas, Hugo; Sousa, Ricardo C.; Mora-Hernández, Ariam; Prejbeanu, Ioan-Lucian; Hebrard, Luc; Kammerer, Jean-Baptiste; Pascal, Joris
This paper presents the use of the spin transfer torque effect in perpendicular magnetic tunnel junctions to operate the devices as magnetic sensors. The junctions, specifically designed for sensing applications exhibit close to low-coercivity, allowing the sensitivity to be as high as 25 mV/mT for a large dynamic range of 20 mT. In addition, the junctions have diameters ranging from 20 to 100 nanometers, making them among the smallest magnetic sensing elements ever reported to our knowledge. A single operational amplifier operates the junction and outputs a voltage proportional to the external magnetic field. This paper opens the way to a monolithic integration of both the conditioning electronics and the perpendicular magnetic tunnel junction.
04B - Beitrag Konferenzschrift
Parameter optimization in a finite element mandibular fracture fixation model using the design of experiments approach
(Elsevier, 08/2023) Maintz, Michaela; Msallem, Bilal; de Wild, Michael; Seiler, Daniel; Herrmann, Sven; Feiler, Stefanie; Sharma, Neha; Dalcanale, Federico; Cattin, Philippe; Thieringer, Florian Markus
01A - Beitrag in wissenschaftlicher Zeitschrift
Solving the explainable AI conundrum by bridging clinicians’ needs and developers’ goals
(Nature, 22.05.2023) Bienefeld, Nadine; Boss, Jens Michael; Lüthy, Rahel; Brodbeck, Dominique; Azzati, Jan; Blaser, Mirco; Willms, Jan; Keller, Emanuela
Explainable artificial intelligence (XAI) has emerged as a promising solution for addressing the implementation challenges of AI/ML in healthcare. However, little is known about how developers and clinicians interpret XAI and what conflicting goals and requirements they may have. This paper presents the findings of a longitudinal multi-method study involving 112 developers and clinicians co-designing an XAI solution for a clinical decision support system. Our study identifies three key differences between developer and clinician mental models of XAI, including opposing goals (model interpretability vs. clinical plausibility), different sources of truth (data vs. patient), and the role of exploring new vs. exploiting old knowledge. Based on our findings, we propose design solutions that can help address the XAI conundrum in healthcare, including the use of causal inference models, personalized explanations, and ambidexterity between exploration and exploitation mindsets. Our study highlights the importance of considering the perspectives of both developers and clinicians in the design of XAI systems and provides practical recommendations for improving the effectiveness and usability of XAI in healthcare.
01A - Beitrag in wissenschaftlicher Zeitschrift
How sample size impacts probabilistic stimulation maps in deep brain stimulation
(MDPI, 03.05.2023) Nordin, Teresa; Blomstedt, Patric; Hemm-Ode, Simone; Wårdell, Karin
Probabilistic stimulation maps of deep brain stimulation (DBS) effect based on voxel-wise statistics (p-maps) have increased in literature over the last decade. These p-maps require correction for Type-1 errors due to multiple testing based on the same data. Some analyses do not reach overall significance, and this study aims to evaluate the impact of sample size on p-map computation. A dataset of 61 essential tremor patients treated with DBS was used for the investigation. Each patient contributed with four stimulation settings, one for each contact. From the dataset, 5 to 61 patients were randomly sampled with replacement for computation of p-maps and extraction of high- and low-improvement volumes. For each sample size, the process was iterated 20 times with new samples generating in total 1140 maps. The overall p-value corrected for multiple comparisons, significance volumes, and dice coefficients (DC) of the volumes within each sample size were evaluated. With less than 30 patients (120 simulations) in the sample, the variation in overall significance was larger and the median significance volumes increased with sample size. Above 120 simulations, the trends stabilize but present some variations in cluster location, with a highest median DC of 0.73 for n = 57. The variation in location was mainly related to the region between the high- and low-improvement clusters. In conclusion, p-maps created with small sample sizes should be evaluated with caution, and above 120 simulations in single-center studies are probably required for stable results.
01A - Beitrag in wissenschaftlicher Zeitschrift