Current Directions in Biomedical Engineering最新文献

{"title":"3D Hyperspectral Light-Field Imaging: a first intraoperative implementation","authors":"Eric L. Wisotzky, Peter Eisert, Anna Hilsmann","doi":"10.1515/cdbme-2023-1153","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1153","url":null,"abstract":"Abstract Hyperspectral imaging is an emerging technology that has gained significant attention in the medical field due to its ability to provide precise and accurate imaging of biological tissues. The current methods of hyperspectral imaging, such as filter-wheel, snapshot, line-scanning, and push-broom cameras have limitations such as low spatial and spectral resolution, slow acquisition time. New developments on the field of light field cameras show the potential to overcome these limitations. In this paper, we use a novel hyperspectral lightfield camera and try to combine the capability of hyperspectral and 3D analysis. For this purpose we calibrate our system and test it during two ENT-surgeries to show its potential for improving surgical outcomes. The micro-lenses of the camera map 66 spectral sub-images onto the sensor allowing to reconstruct the spectral behavior of the captured scene in the spectral range of 350-1000nm. In addition, we use the sensor data to apply a 3D camera calibration pipeline to allow 3D surface reconstruction. We captured 26 calibration images and achieved calibration results in accordance to stated company data. The best calibration showed a re-projection error of 0.55 px. Further, we tested the camera during a parotidectomy and a neck-dissection. The extracted reflectance spectra of the selected venal and arterial regions correspond perfectly to the spectrum of oxygenated and deoxygenated hemoglobin. For the first time, up to our knowledge, a hyperspectral lightfield camera has been used during a surgery. We were able to continuously capture images and analyze the reconstructed spectra of specific tissue types. Further, we are able to use the sensor data of the micro-lens projections to calibrate the multilens camera system for later intraoperative measurement tasks.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smartphone-Based Videonystagmography Using Artificial Intelligence","authors":"Sophia Reinhardt, Joshua Schmidt, Jonas Schneider, Michael Leuschel, Elena Schulte, Christiane Schüle, Jörg Schipper","doi":"10.1515/cdbme-2023-1132","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1132","url":null,"abstract":"Abstract Dizziness is a common symptom in medicine. The anamnesis and detection of a nystagmus is essential to distinguish a vertigo's pathogenesis. The diagnosis is complex, expensive, and not always available across the board. We present a novel location- and time-independent mobile application for videonystagmography (VNG) to support vertigo patients and medical staff. No additional hardware is necessary. The app uses artificial intelligence for eye tracking and to detect a horizontal nystagmus. A feasibility study of the mobile VNG with 13 healthy volunteers was performed. Each participant underwent a caloric vestibular testing to provoke the presence of a vestibular nystagmus. It could be shown that a smartphone-based VNG is possible.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of Uncertainty in Bolus Transit Time Measurement in Quantitative Fluorescence Angiography","authors":"Yang Gao, Miriam Weiß, Werner Nahm","doi":"10.1515/cdbme-2023-1155","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1155","url":null,"abstract":"Abstract During cerebral revascularization surgeries, blood flow values help surgeons to monitor the quality of the procedure, e.g., to avoid cerebral hyperperfusion syndrome due to excessively enhanced perfusion. The state-of-the-art technique is the ultrasonic flow probe that has to be placed around the blood vessel. This causes contact between probe and vessel, which, in the worst case, leads to rupture. The recently developed intraoperative indocyanine green (ICG) Quantitative Fluorescence Angiography (QFA) is an alternative technique that overcomes this risk. However, it has been shown by the developer that the calculated flow has deviations. After determining the bolus transit time as the most sensitive parameter in flow calculation, we propose a new two-step uncertainty reduction method for flow calculation. The first step is to generate more data in each measurement that results in functions of the parameters. Noise can then be reduced in a second step. Two methods for this step are compared. The first method fits the model for each parameter function separately and calculates flow from models, while the second one fits multiple parameter functions together. The latter method is proven to perform best by in silico tests. Besides, this method reduces the deviation of flow comparing to original QFA as expected. Our approach can be generally used in all QFA applications using two-point theory. Further development is possible if number of dimensions of the achieved parameter data are broadened that results in even more data for processing in the second step.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sobel edge detection for quantifying the effectiveness of focused ultrasound thalamotomy for tremor relief","authors":"Vered Aharonson, Michiel Postema, Robyn Gebbie, Jesse Van Der Merwe, Ilana Schlesinger","doi":"10.1515/cdbme-2023-1005","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1005","url":null,"abstract":"Abstract Focused ultrasound on the thalamus is employed to relieve tremor in movement disorders. The treatment efficacy is currently assessed by subjective observation of patient tremor during hand movements. The purpose of this study was to create a simple quantitative method to assess tremor based on traditional pen-and-paper spiral drawing that could be employed during treatment and follow-up visits. Image processing was employed to automatically and rapidly clean scanned spiral and line drawings and to isolate the minimal part of the drawing that could provide sufficient data for tremor detection. Sobel edge detection and easily-interpretable statistics of the distribution of edge-angle orientations in the spirals relative to the spiral centres were used as tremor measures. The method was applied to scanned drawings of 122 tremor patients before treatment and in follow-up visits. Discrimination analysis of the tremor measure between drawings in the session before treatment and the follow-up sessions was carried out. The processing yielded correctly cropped and clean spirals. The tremor measure demonstrated consistent tremor reduction in the treated hand drawings in all five follow-up visits during the first year following treatment date in 76 patients from the study cohort. In this study we developed a computational method that rapidly computed tremor severity estimate in an explainable and clinically useful manner from a traditional pen-and-paper spiral drawing. This rapid quantitative and objective tremor assessment can easily be implemented during focused ultrasound treatment and replace the subjective assessment currently employed.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fully automated normothermic machine perfusion system for kidney grafts supporting physiological motivated flow profiles","authors":"Marc Wiartalla, Frederik Berg, Jahn Kühn, Mateusz Buglowski, Stefan Kowalewski, André Stollenwerk, Christian Bleilevens","doi":"10.1515/cdbme-2023-1081","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1081","url":null,"abstract":"Abstract Research showed that the normothermic machine perfusion of kidneys can enable prolonged storage and improve conditions compared to traditional cold storage. For research in this area, there is a demand for a long-term in vitro perfusion setup. In this work, we present a fully automated normothermic machine perfusion (NMP) system as an experimental research platform. The perfusion system is intended as a tool for researching the effects of different perfusion strategies on the kidney. To enable the automation, the NMP system consists of a blood pressure control, a circulation volume level control and a pH-regulation component. The setup is realized as a medical cyber-physical system consisting of networked embedded microcontroller nodes.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accuracy of CT numbers and electron density calibration for mixtures of materials with low and high-atomic number","authors":"Zehra Ese, Daniel Erni, Waldemar Zylka","doi":"10.1515/cdbme-2023-1103","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1103","url":null,"abstract":"Abstract In computed tomography (CT) materials with high-atomic number Z cause image artefacts, thus, errors in CT numbers given in Hounsfield Units (HU). Also, the conventional HU scale (CHU) implemented in CT scanners is truncated, i.e., it does not cover high-Z materials. These restrictions lead to incorrect mapping of CT numbers to electron density, which are used in radiotherapy (RT) treatment planning systems (TPS). Even analytical conversion methods are only permissible for tissue-equivalent materials. In terms of HU-to-density conversion in RT TPS, we investigated the CT numbers of material mixtures up to Z<29 at the CHU and an extended-HU (EHU) scale, respectively, and quantify the systematic errors of image artefacts. In [1] the feasibility of a stoichiometric analytical calibration method were analyzed for metals and adapted for higher accurcy, for energies of 80 kV and 120 kV. In this work, we add results for 100 kV and 140 kV to cover the wide diagnostic range. The CT numbers are effected by physical and machine-based properties and depend strongly on the energy, e.g., for Cu a HU difference of 6 171HU at 80 kV and 140 kV occured. The analytical calibration parameters change with energy by a factor between 2 and 10 depending on the physical process. Although for high- Z materials our calibration procedure remains in conflict with rigorous physics [2], it offers an improved and a practical way to predict electron densities from CT numbers.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Core-Shell-Nanoparticles with Superparamagnetic Properties for Novel Applications as Biomaterials","authors":"Valentin Hagemann, Florian Klodwig, Timo Herrmann, Nina Ehlert, Laura Finck, Henning Menzel","doi":"10.1515/cdbme-2023-1167","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1167","url":null,"abstract":"Abstract Due to the increasing average age of the population, the number of implants is also increasing and with it the number of explantations. Therefore, facilitated implant removal is of great interest. A nanocomposite consisting of superparamagnetic core-shell nanoparticles (CSNPs) and a synthetic polymer is supposed to be used as implant coating, aiming for a stimulus-inducible modification of the composite’s rheological properties by hyperthermia. Here, the first steps following this concept, the synthesis and modification of the CSNP are reported. In this work magnetite nanoparticles build the core and are surrounded by a periodic mesoporous organisilica (PMO) shell. For this reason, the CSNP are referred to as magnetic PMO (mPMO) particles in the following.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135393945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation study of the effect of the geometrical parameters on the performance of a beta probe","authors":"Ali Pashazadeh, Christoph Hoeschen","doi":"10.1515/cdbme-2023-1075","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1075","url":null,"abstract":"Abstract An intraoperative probe is a small tool used to identify, locate, and dissect pathological lesions during surgery and confirm their removal. The most common type of probe is the gamma probe, which detects gamma-emitting sources. Despite the successful use of gamma probes in clinics, their application can be limited when the background radiation from healthy tissue nearby or the injection site is high. In these cases, the use of beta probes that detect beta-emitting radiotracers would be beneficial. The shorter range of beta radiation compared to gamma radiation would result in improved detection efficacy when background radiation is significant. In this simulation study, we examined how geometrical parameters may impact the performance of a beta probe. Our results showed that the source depth inside the phantom and detector size affected the performance of the beta probe. We also proposed and evaluated two designs of beta probes capable of adjusting their performance.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135394176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Training and education of young physicians and engineers in the field of endoscopy and laparoscopy – a review of Germany-wide joint cooperation and training possibilities","authors":"Dörte Wichmann, Benedikt Duckwort-Mothes, Bernhard Hirt, Dirk Wilhelm, Jana Steger, Martin Zweimüller, Armin Küllmer, Martin Raithel, Jürgen Maiss, Peter Pott, Thomas Wittenberg","doi":"10.1515/cdbme-2023-1136","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1136","url":null,"abstract":"Abstract Introduction: Application-related (hands-on) training and instruction is an essential component in the advanced education of physicians in residency. To teach and train required endoscopic examinations and interventions in a standardized manner, courses are offered by various societies. Within these courses the assistant endoscopists learn and train how to use the technical equipment and how to perform the examinations and related interventions. Similarly, for graduate biomedical engineering students with a job- or research-related interest in the field of endoand laparoscopy, an early involvement and practical introduction to the instrumentation and techniques - if possible already during their studies - can generate a fundamental understanding of the technical requirements as well needs of the physicians. Objective: As various such (hands-on) training-courses for flexible and rigid endoscopy specifically addressing young physicians, surgeons as well as engineers are offered by numerous institutes, this contribution tries do provide a structured overview on/over these possibilities. Material: Known cross-institutional courses in the field of endo- and laparoscopy currently offered in Germany in cooperation of physicians and engineers are listed and briefly described. Results: A total of n = 4 crossinstitutional courses for the introduction and training in flexible and rigid endoscopy have been identified. Discussion: The cross-institutional courses for physicians and technicians in the field of endo- and laparoscopy presented serve to provide a better understanding of the subject matter and the field of either discipline. Questions that arise in the field of endoscopy from physicians can be addressed at an early stage and, if necessary, worked on with little effort. Ideas for new instruments and even new interventions can arise and be pursued through an intensive exchange between technicians and physicians. Collaborations are established on a local basis which will foster national activities in this field and which allow to develop competencies relevant for the industrial sector of medical engineering.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135394259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of biomimetic antibacterial titanium surfaces by hydrothermal oxidation","authors":"Patrick Doll, Lea Kremer, Ralf Ahrens, Litsy Hüschelrath","doi":"10.1515/cdbme-2023-1178","DOIUrl":"https://doi.org/10.1515/cdbme-2023-1178","url":null,"abstract":"Abstract Within this paper we demonstrate a novel approach to create antibacterial nanostructures on the implant material titanium grade 23 by a high-pressure oxidation method. Titanium samples were oxidized and resulting nanostructures were characterized using scanning electron microscopy and contact angle measurements. Antibacterial properties were tested using Escherichia coli and Bacillus subtilis as common lab strains. In addition, cytotoxicity was determined according to ISO 10993-5 standards. Results reveal that the fabricated nanostructures have similar antibacterial properties known from different insect wings like dragonflies or cicadas and have no cytotoxic effect.","PeriodicalId":10739,"journal":{"name":"Current Directions in Biomedical Engineering","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135394420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}