- Dr. Ing. Axel Boese is an expert in medical device development and clinical application with years of experience. Bes... moreDr. Ing. Axel Boese is an expert in medical device development and clinical application with years of experience. Besides several developments, publications and patents in the field of image-guided therapies and instruments, he is a certified Quality Manager for ISO 13485 medical devices, an investigator for clinical studies and medical device testing, GCP, a Member of VDE, DGBMT and of the DIN Standardisation committee 063-01-02 AA. He is a co-founder of the companies M3DP, SURAG, EasyJector, RadPrint and CEO of MEDICS GmbH. Axel Boese is specialized in intraluminal interventions and devices (catheters, guide wires, access strategies, stents, flow diverter, imaging), endoscopic and robotic surgery (endoscopes, instruments, assistance systems) and needle-guided procedures (biopsy, puncture, needles, guidance systems). Additionally, he is an expert in medical device testing close to clinical application. Therefore he develops test setups and evaluation strategies including anatomical and physiological phantoms.edit
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Background The mTICI score used to assess the degree of reperfusion after mechanical thrombectomy is an independent predictor of patient outcome after acute ischemic stroke. Its inter-rater reliability, however, is low and... more
Background The mTICI score used to assess the degree of reperfusion after mechanical thrombectomy is an independent predictor of patient outcome after acute ischemic stroke. Its inter-rater reliability, however, is low and interventionalists often overrate their own performance.¹ Objectives We devised an image-processing based semi-automated grading for unbiased mTICI scoring. Methods Based on pixel-intensity features, we developed a semi-automated reperfusion grading on digital subtraction angiography (DSA) series. The internal carotid artery (ICA) curve was detected automatically in the first contrast fill-image and set as a reference point. The region of interest (ROI) was defined as the target downstream territory (TDT) of the middle cerebral artery (MCA) and divided into check-zones ranked as ‘perfused’ or ‘unperfused’ based on a predefined grid. Our software was applied to 50 patients after thrombectomy for acute ischemic stroke. The percentage of reperfusion was translated into mTICI grading. The scoring by the software was compared to the consensus reading by two experienced neuroradiologists. Results mTICI scores in our cohort ranged from 2a to 3, with mTICI ≥in 64.0\% (28/50). The software scored 44/50 patients correctly (88.0\%), with 25/27 (92.6\%) mTICI 3 accurately graded. Accuracy in mTICI {\textgreater}2c was 87.5\% (28/32). Correct division into mTICI 2a/2b/2c was achieved in 19/24 patients (79.2\%). 5 out of 6 disagreements occurred in mTICI 2c/3 gradings. Conclusion Semi-automated mTICI scoring based on image-processing is feasible and accurate. Our method is fast and easy to integrate into clinical routine. Application on larger cohorts will be needed to confirm our results. Reference • Zhang G, Treurniet KM, Jansen IGH, Emmer BJ, van den Berg R, Marquering HA, Uyttenboogaart M, Jenniskens SFM, Roos YBWEM, van Doormaal PJ, van Es ACGM, van der Lugt A, Vos JA, Lycklama À Nijeholt GJ, van Zwam WH, Shi H, Yoo AJ, Dippel DWJ, Majoie CBLM; MR CLEAN Registry Investigators. Operator versus core lab adjudication of reperfusion after endovascular treatment of acute ischemic stroke. Stroke 2018 Oct; 49 (10):2376–2382. Disclosure Nothing to disclose
Ultrasound imaging provides a 2D single slice that can be combined to a volume known as Tomographic US (TUS) employing various tracking methods. TUS is vital for three dimensional visualization of pathological structures and aids... more
Ultrasound imaging provides a 2D single slice that can be combined to a volume known as Tomographic US (TUS) employing various tracking methods. TUS is vital for three dimensional visualization of pathological structures and aids physicians in providing a better diagnosis of the condition. Freehand TUS scans have drawbacks such as overlapping of image slices, change in the angulation of the probe and deformation of structures below the epidermis due to a change in applied force. US scan acquisition is highly user dependent and therefore provides varying imaging quality. An assisted scan acquisition process is a possible solution to address and solve these issues and with that improve the 3D volume reconstruction. We propose the design, development and testing of a prototype device that enables assisted acquisition of US image slices, while addressing limitations of freehand TUS scans.
Die methodische Lösungsfindung ist in der Konstruktion und Produktentwicklung ein etabliertes Verfahren. Diese Methoden sind in Standardwerken der Konstruktion und Produktentwicklung und in den entsprechenden Richtlinien der Verbände... more
Die methodische Lösungsfindung ist in der Konstruktion und Produktentwicklung ein etabliertes Verfahren. Diese Methoden sind in Standardwerken der Konstruktion und Produktentwicklung und in den entsprechenden Richtlinien der Verbände hinlänglich dokumentiert. Auffällig ist, dass eine Beteiligung des Kunden, Anwenders oder Nutzers an der Lösungsfindung in dieser Methodik nicht konkret beschrieben wird. Gerade in Zeiten der Individualisierung von Produkten ist aber die Meinung und Akzeptanz des Nutzers entscheidend für den wirtschaftlichen Erfolg eines Produktes. Nutzerintegration in die Lösungsfindung und in die Produktentwicklung ist also eine logische Konsequenz aus dem Spannungsfeld Individualisierung, Preisdruck, Variantenvielfalt und Kundenerwartungen, dem der Konstrukteur und Entwickler gegenüber steht.Als Basis für die Nutzerintegration in den Entwicklungsprozess wird in dieser Arbeit die Workflowaufnahme im Operationssaal vorgestellt. Ziel ist es, den Bedarf und die Motivation einer Aufgabe oder Entwicklung zu verstehen und die dafür notwendigen Randbedingungen zu erfassen. Aus diesen Informationen können Anforderungen und Funktionen definiert und Lösungen erarbeitet werden. Ausgehend von der Workflowaufnahme werden für die Schritte Planung, Konzeption, Entwurf und Ausarbeitung iterative Feedbackschleifen zur Kommunikation mit dem Kunden eingeführt. Dieses Vorgehen wird in dieser Arbeit an vier Beispielen aus der Lösungsfindung für technische Bedarfe aus der Medizin demonstriert.
Boese, A. Chapter 06 Catheters in vascular therapy
The direct tactile assessment of surface textures during palpation is an essential component of open surgery that is impeded in minimally invasive and robot-assisted surgery. When indirectly palpating with a surgical instrument, the... more
The direct tactile assessment of surface textures during palpation is an essential component of open surgery that is impeded in minimally invasive and robot-assisted surgery. When indirectly palpating with a surgical instrument, the structural vibrations from this interaction contain tactile information that can be extracted and analysed. This study investigates the influence of the parameters contact angle α and velocity v→ on the vibro-acoustic signals from this indirect palpation. A 7-DOF robotic arm, a standard surgical instrument, and a vibration measurement system were used to palpate three different materials with varying α and v→. The signals were processed based on continuous wavelet transformation. They showed material-specific signatures in the time–frequency domain that retained their general characteristic for varying α and v→. Energy-related and statistical features were extracted, and supervised classification was performed, where the testing data comprised only signals acquired with different palpation parameters than for training data. The classifiers support vector machine and k-nearest neighbours provided 99.67\% and 96.00\% accuracy for the differentiation of the materials. The results indicate the robustness of the features against variations in the palpation parameters. This is a prerequisite for an application in minimally invasive surgery but needs to be confirmed in realistic experiments with biological tissues.
Ultrasound (US) imaging is used for the diagnosis and also evaluation of thyroid nodules. A Thyroid Imaging Reporting and Data System (TIRADS) is used for the risk stratification of thyroid nodules through US images. The composition of... more
Ultrasound (US) imaging is used for the diagnosis and also evaluation of thyroid nodules. A Thyroid Imaging Reporting and Data System (TIRADS) is used for the risk stratification of thyroid nodules through US images. The composition of thyroid nodules plays an important role in the risk-stratification process. The percentages of cystic and solid components in a thyroid nodule are one of the features that are can be indicative of the risk of malignancy. In this work, we attempt to classify and estimate solid and cystic regions within nodules. 20x20 texture patches were extracted from solid and cystic regions and converted into signals. These signals are decomposed into low, mid, and high-frequency bands using Continuous Wavelet Transform (CWT). A total of 36 features were extracted from the decomposed signals using Auto- Regressive Modeling. The features were fed into three different Machine Learning (ML) algorithms (Artificial Neural Networks, K-Nearest Neighbors, and Random Forest Classifier) to provide us with a classification of solid versus cystic regions in thyroid nodule US images. The Random Forest Classifier obtained an Accuracy, Sensitivity, and Specificity of 90.41\%, 99\% and 91\% respectively which was the highest among the three chosen ML algorithms. Additionally, the output from the classification phase was also be used to determine the percentage of cystic and solid regions with a given thyroid nodule US image.
This paper presents the proof-of-concept study of an adaptor allowing the combination of a gamma probe with ultrasound (US) imaging, intending to improve the detectability of sentinel lymph nodes (SLNs). The performance of the adaptor in... more
This paper presents the proof-of-concept study of an adaptor allowing the combination of a gamma probe with ultrasound (US) imaging, intending to improve the detectability of sentinel lymph nodes (SLNs). The performance of the adaptor in US imaging, in terms of depth of penetration and distance accuracy, and gamma scanning, in terms of sensitivity and spatial resolution, was investigated. We observed that the quality of the US imaging through the adaptor was promising and close to that of normal US imaging. However, the performance of the gamma probe through the adaptor was fairly poor, necessitating the improvement in the design of the adaptor for better gamma scanning. This study shall provide a basis for the development of a handheld gamma-US scanner for interventional procedures and small field-of-view (FOV) imaging in the future.
Knee arthroplasty follow-up involves only a limited number of X-ray-based implant condition assessments at extended intervals. Polyethylene (PE) wear of knee endoprosthesis often progresses unnoticed until symptomatic adverse effects... more
Knee arthroplasty follow-up involves only a limited number of X-ray-based implant condition assessments at extended intervals. Polyethylene (PE) wear of knee endoprosthesis often progresses unnoticed until symptomatic adverse effects become apparent or implant failure occurs. A PE wear measuring concept, consisting of an implanted passive sensor and an extracorporeal readout unit, was previously presented by our group. This system is intended to enable patients to regularly check their knee implants’ condition at home. In this context, an appropriate product design for the readout unit is essential to enable the user to record correct measurements. An experimental investigation of the optimized positioning of the system's readout unit was conducted and the measurement data were analyzed. The findings were then implemented in a prototype for readout unit attachment. A sleeve with Velcro and a sewn-in readout unit has been fabricated. A cutout for the patella ensures intuitive correct alignment of the measurement system according to the experimental results. A hardware housing incorporates the electronics.
Retractors are used in surgery for the displacement of tissue and organs and to keep the surgical area open. The retraction can lead to a tissue compression that can cause irritation on nerves, perfusion deficits, hematoma or late... more
Retractors are used in surgery for the displacement of tissue and organs and to keep the surgical area open. The retraction can lead to a tissue compression that can cause irritation on nerves, perfusion deficits, hematoma or late sequelae like wound healing disorders, pain and numbness. The retraction force and thus the load on the tissue can not be measured with retraction systems today. We present a new concept for a retractor with an integrated spring element and an indicator to visualize retraction force and allow an adjustment of the organ compression. The new retractor was designed considering organ compression limits, requirements on sterility and easy manufacturing. Two retractors were built up as a prototype by 3D printing and tested in a distinguished test setup. The first test of the retractors was performed on a force measurement test bench using a fixed retractor, and in a second test, a liver specimen in a bowl. Tests were repeated for both retractor variants. The tests showed how different spring characteristics could be realized with the new retractor design. Depending on the spring characteristics, the compression could be limited to a certain level and flexibility that can compensate for unwanted patient motion. An indicator is integrated into the design showing the applied load on the retraction system. The presented concept can help to increase patient safety and reduce tissue trauma and late sequelae. The indicator is an easy way to visualize applied forces and allow adaption of the setup to the surgeon's needs.
For treatment decision of Eustachian tube (ET) dysfunction, a reliable diagnosis of the reason for this dysfunction is of interest. Imaging methods like CT or MRI do not show enough details today. Endoscopy is challenging but can show at... more
For treatment decision of Eustachian tube (ET) dysfunction, a reliable diagnosis of the reason for this dysfunction is of interest. Imaging methods like CT or MRI do not show enough details today. Endoscopy is challenging but can show at least superficial structures at the pharyngeal orifice. To look into the deeper tissue layers vascular imaging methods like IVUS and OCT were evaluated already. But these procedures are not made and certified for this application and come with risks for the patient. To overcome this issue, we propose the use of an additional closed end guide catheter that can be advanced into the ET. An OCT catheter can be placed inside without touching the patient’s tissue. In this paper we evaluate this approach on a sheep cadaver head and a human cadaver head.
Minimal-invasive procedures come with significant advantages for the patient. They also come with problems as the navigation/guidance of the devices to a target location is either based on pre-operatively acquired images and then... more
Minimal-invasive procedures come with significant advantages for the patient. They also come with problems as the navigation/guidance of the devices to a target location is either based on pre-operatively acquired images and then performed free-hand or is accompanied by intraoperative imaging such as MRI or CT that is expensive, complicated and produces artifacts. Using robotic systems for moving and guiding these interventional and therapeutic devices adds additional issues like lack of palpation sensation and missing tissue feedback. While it is possible to add sensors to the distal tip, this creates other obstacles concerning reduced functionality, cables, sterility issues and added complexity and cost. We propose to use a proximally attached audio sensor to record the tissue tool interaction and provide real-time feedback to the clinician. This paper reports on initial attempts to use this technology with robotic arms for surface characterization and interventional vascular procedures that gain increased attention in combination with robotic devices. In summary, Proximal Audio Sensing could be a versatile, cost-effective and powerful tool to guide minimally invasive needle interventions and enable (semi-) autonomous robot-assisted surgery.
Creating surgical access is a critical step in laparoscopic surgery. Surgeons have to insert a sharp instrument such as the Veress needle or a trocar into the patient’s abdomen until the peritoneal cavity is reached. They solely rely on... more
Creating surgical access is a critical step in laparoscopic surgery. Surgeons have to insert a sharp instrument such as the Veress needle or a trocar into the patient’s abdomen until the peritoneal cavity is reached. They solely rely on their experience and distorted tactile feedback in that process, leading to a complication rate as high as 14\% of all cases. Recent studies have shown the feasibility of surgical support systems that provide intraoperative feedback regarding the insertion process to improve laparoscopic access outcomes. However, to date, the surgeons’ requirements for such support systems remain unclear. This research article presents the results of an explorative study that aimed to acquire data about the information that helps surgeons improve laparoscopic access outcomes. The results indicate that feedback regarding the reaching of the peritoneal cavity is of significant importance and should be presented visually or acoustically. Finally, a solution should be straightforward and intuitive to use, should support or even improve the clinical workflow, but also cheap enough to facilitate its usage rate. While this study was tailored to laparoscopic access, its results also apply to other minimally invasive procedures.
One of the most applied imaging methods in medicine is endoscopy. A highly specialized image modality has been developed since the first modern endoscope, the “Lichtleiter” of Bozzini was introduced in the early 19th century. Multiple... more
One of the most applied imaging methods in medicine is endoscopy. A highly specialized image modality has been developed since the first modern endoscope, the “Lichtleiter” of Bozzini was introduced in the early 19th century. Multiple medical disciplines use endoscopy for diagnostics or to visualize and support therapeutic procedures. Therefore, the shapes, functionalities, handling concepts, and the integrated and surrounding technology of endoscopic systems were adapted to meet these dedicated medical application requirements. This survey gives an overview of modern endoscopic technology’s state of the art. Therefore, the portfolio of several manufacturers with commercially available products on the market was screened and summarized. Additionally, some trends for upcoming developments were collected.
Evaluation of the vascular stent position, shape and correct expansion has a high relevance in therapy and diagnosis. Hence, the wall apposition in vessel areas with differing diameters and the appearance of torsions or structural defects... more
Evaluation of the vascular stent position, shape and correct expansion has a high relevance in therapy and diagnosis. Hence, the wall apposition in vessel areas with differing diameters and the appearance of torsions or structural defects of the implant body caused by catheter based device dropping are of special interest. Neurovascular implants like braided flow diverter and laser cut stents consist of metal struts and wires with diameters of about 40 µm. Depending on the implants material composition, visibility is poor with conventional 2D X-ray fluoroscopic and radiographic imaging. The metal structures of the implants also lead to artifacts in 3D X-ray images and can hamper the assessment of the device position. We investigated intravascular optical coherence tomography (OCT) as a new imaging tool for the evaluation of the vascular stent position, its shape and its correct expansion for 3 different vascular implants.
Polyethylene (PE) inlays of knee endoprostheses are exposed to constant mechanical stress causing particle abrasion and volumetric wear. With the current inlay surveillance strategy, significant change often can be only detected when the... more
Polyethylene (PE) inlays of knee endoprostheses are exposed to constant mechanical stress causing particle abrasion and volumetric wear. With the current inlay surveillance strategy, significant change often can be only detected when the implant has already failed. To reduce medical complications arising from implant malposition or failure, early and accurate assessment of the implant condition is of great value. We present a novel concept to monitor PE inlays based on an implanted sensor. Requirements of sensor integration into endoprostheses were discussed and specified for an inlay monitoring concept. A planar eddy current sensor for measuring the gradual descent of the femoral component was proposed where inductive and capacitive sensor elements form a resonant circuit. The potential sensitivity of the proposed measuring method was tested in an experimental setup using an RFID tag as a sensor substitute. A measurement concept, including the sensor and an extracorporal readout coil, was described and the validity was verified using finite element method (FEM) simulation of a simplified knee model. The experiments showed that a significant resonant frequency shift occurs in the sensor with decreasing distance to the femoral component. FEM simulation demonstrated that the sensor could be powered and readout extracorporeally through inductive coupling with an external readout coil. The proposed concept is a promising solution for feasible and accurate reading of the implant status designed to meet medical requirements. It can enable autonomous and routine monitoring as well as early detection of critical inlay deformation with a home-use device.
Today's healthcare challenges with unmet clinical needs, high regulation and certification standards, and increasing costs demand faster innovation and technical translation. To address this challenge, Stanford released a fellowship... more
Today's healthcare challenges with unmet clinical needs, high regulation and certification standards, and increasing costs demand faster innovation and technical translation. To address this challenge, Stanford released a fellowship called Biodesign, where need-based healthcare innovation is taught with the approach identify, invent and implement. Since then, different European institutions have adopted the Biodesign innovation approach and organized within the Biomedical Engineering- Innovation, Design, and Entrepreneurship Alliance (BMEidea EU). The generation of successful healthcare innovation isn't only based on participating in an Innovation teaching program. It is much more a matter of having the right innovation ecosystem with an open creative mindset, experts, the respective stakeholders, and access to essential resources within reach (close to clinic). Through a qualitative survey, seven Biodesign based teaching programs in the EU were examined. The study from an academic perspective contains information covering Resources, Activities, Academic Performance, and Transfer Performance. The demand for new healthcare innovations, and especially innovation training programs that address challenges, developed collaboratively with the respective stakeholders, is increasing. Additionally, there is a growing expectation that innovation needs to reach the market quickly and be implemented accordingly. A Healthcare Innovation Ecosystem, where different entities function as a productive unit with a shared vision and committed to application-driven research and technology transfer, will increase innovation's success and adaptation.
Introduction : The grade of reperfusion after endovascular treatment of ischemic stroke e.g. mechanical thrombectomy is determined based on the mTICI score. The mTICI score shows significant interrater variability; it is usually biased... more
Introduction : The grade of reperfusion after endovascular treatment of ischemic stroke e.g. mechanical thrombectomy is determined based on the mTICI score. The mTICI score shows significant interrater variability; it is usually biased towards better reperfusion results if selfassessed by the operator. We therefore developed a semiautomated image processing technique for assessing and evaluating the degree of reperfusion independently, resulting in a more objective mTICI score. Methods : Fifty angiography datasets of patients who were treated with mechanical thrombectomy for middle cerebral artery (MCA) occlusion were selected from our database. Image datasets were standardized by adjustment of field of view and orientation. Based on pixel intensity features, the internal carotid artery (ICA) curve was detected automatically and used as a starting point for identifying the target downstream territory (TDT) of the MCA on the DSA series. Furthermore, a grid with predefined dimensions was used to divide the TDT into checkzones and be classified as perfused or unperfused. Results: The algorithm detected the TDT and classified each zone of the grid as perfused or unperfused. Lastly, the percentage of the perfused area in the TDT was calculated for each patient and compared to the grading of experienced clinical users. Conclusion : A semi-automatic image-processing workflow was developed to evaluate perfusion rate based on angiographic images. The approach can be used for the objective calculation of the mTICI score. The semi-automatic grading is currently feasible for MCA occlusion but can be extended for other brain territories. The work shows a starting point for a machine learning approach to achieve a fully automated system that can evaluate and give an accurate mTICI score to become a common AI-based grading standard in the coming near future.
Ultrasound (US) imaging is used as a preliminary diagnostic tool for the detection, risk-stratification and classification of thyroid nodules. In order to perform the risk stratification of nodules in US images physicians first need to... more
Ultrasound (US) imaging is used as a preliminary diagnostic tool for the detection, risk-stratification and classification of thyroid nodules. In order to perform the risk stratification of nodules in US images physicians first need to effectively detect the nodules. This process is affected due to the presence of inter-observer and intra-observer variability and subjectivity. Computer Aided Diagnostic tools prove to be a step in the right direction towards reducing the issue of subjectivity and observer variability. Several segmentation techniques have been proposed, from these Deep Learning techniques have yielded promising results. This work presents a comparison between four state of the art (SOTA) Deep Learning segmentation algorithms (UNet, SUMNet, ResUNet and Attention UNet). Each network was trained on the same dataset and the results are compared using performance metrics such as accuracy, dice coefficient and Intersection over Union (IoU) to determine the most effective in terms of thyroid nodule segmentation in US images. It was found that ResUNet performed the best with an accuracy, dice coefficient and IoU of 89.2\%, 0.857, 0.767. The aim is to use the trained algorithm in the development of a Computer Aided Diagnostic system for the detection, riskstratification and classification of thyroid nodules using US images to reduce subjectivity and observer variability
Irreversible Electroporation (IRE) is a non-thermal tumor ablation treatment applicable for prostate cancer. IRE uses ultra-short but strong electrical pulses to destroy cancer cells nonthermally [1]. Clinically available IRE therapy... more
Irreversible Electroporation (IRE) is a non-thermal tumor ablation treatment applicable for prostate cancer. IRE uses ultra-short but strong electrical pulses to destroy cancer cells nonthermally [1]. Clinically available IRE therapy requires two or more needle electrodes placed around the target tissue to apply the electric fields. A pre-requirement to achieve successful and effective ablation is an accurate and parallel needle placement to cover the tumor zone. Differences in tissue density, organ surface curvature as well as organ and patient motion in combination with long and highly flexible needle electrodes causes’ difficulties to achieve the desired target accuracy during needle placement process. We propose a concept of a shooting mechanism in combination with a grid template support to improve the parallel needle placement process for prostate cancer treatment. Instead of conventionally inserting the needle in the body by hand, it can be placed with high speed using a shooting device setup, that works similar like a biopsy gun.
Auscultation methods allow a non-invasive diagnosis of cardiovascular diseases like atherosclerosis based on blood flow sounds of the carotid arteries. Since this process is highly dependent on the clinician’s experience, it is of great... more
Auscultation methods allow a non-invasive diagnosis of cardiovascular diseases like atherosclerosis based on blood flow sounds of the carotid arteries. Since this process is highly dependent on the clinician’s experience, it is of great interest to develop automated data processing techniques for objective assessment. We have recently proposed a computerassisted auscultation system that we use to acquire carotid blood flow sounds. In this work, we present an approach for detecting artifacts within the blood flow sound caused by swallowing or coughing events. For this purpose, we first decompose the signal using a discrete wavelet transform (DTW). Then, we compute an energy ratio between the DWT scales associated with the signal information with and without artifacts using a sliding window of 1 s length. Evaluation based on Kruskal-Wallis and Wilcoxon rank-sum tests shows a statistically significant difference (p-value\<.0001) between the signal with and without artifact. Therefore, the proposed method allows the identification of the studied signal artifacts.
Auscultation methods allow the non-invasive diagnosis of pathological conditions (e.g., of the lung, heart or blood vessels) based on sounds that the body produces (e.g., breathing, heartbeat, swallowing or the blood flow). Through... more
Auscultation methods allow the non-invasive diagnosis of pathological conditions (e.g., of the lung, heart or blood vessels) based on sounds that the body produces (e.g., breathing, heartbeat, swallowing or the blood flow). Through regular homebased examinations and Big Data combined with Machine learning techniques like Deep Learning, these could help detect diseases in an early stage, thus preventing serious health conditions and subsequently ensuring optimal therapy through continuous monitoring. This paper presents BODYTUNE, a novel inexpensive multi-auscultation system that aims at providing a tool for establishing a baseline of audio signal derived classification parameters that could be used for the self-monitoring of personal health for everybody through the analysis of deviations from that baseline. In the future, Big Data analysis could additionally lead to prediction and early detection of disease events.
The use of catheters and guide-wires in minimally invasive therapeutic approaches is an important part of clinical practice. In the neurovascular field, the unique nature of cerebral blood vessels necessitates very thin-walled and... more
The use of catheters and guide-wires in minimally invasive therapeutic approaches is an important part of clinical practice. In the neurovascular field, the unique nature of cerebral blood vessels necessitates very thin-walled and flexible catheters. The blood vessels in question are highly branched and at the same time can be less than one millimetre in diameter. This results in high demands on micro-catheters and guide-wires for successful endovascular therapy. The interaction of these surgical tools and the vessel wall is of especial interest. Depending on the catheter stiffness, this interaction can be friction, punctual collision or straightening. The work aims to design and implement a test setup for evaluation of these interactions with the vessel wall. For this purpose, a standardized vessel course with representative characteristics is necessary. Furthermore, by implementing suitable measuring equipment, an endovascular intervention can be simulated.
About 50 \% of complications during laparoscopy occur when surgical access is created. The Veress needle and proposed technical alternatives do not provide reliable information to support the surgeons in guiding the needle, or the... more
About 50 \% of complications during laparoscopy occur when surgical access is created. The Veress needle and proposed technical alternatives do not provide reliable information to support the surgeons in guiding the needle, or the feedback is not clearly perceivable. Based on acoustic emissions, Surgical Audio Guidance (SURAG) proposes a non-invasive and efficient way to enhance the perception of guidance information through acoustic and visual feedback displayed in real-time. This article demonstrates that the developed feedback matches the information about tissue layer crossings provided by force measurements. This indicates that SURAG can provide an effective means to make laparoscopic access more precise and safe, especially in pediatric surgery, where space for placing the needle is minimal.
We have witnessed impressive advances in preoperative imaging of cancer and the development of dualmodality scanners. However, there is a need for a scanner with functional and anatomical imaging capability suitable for surgical settings... more
We have witnessed impressive advances in preoperative imaging of cancer and the development of dualmodality scanners. However, there is a need for a scanner with functional and anatomical imaging capability suitable for surgical settings and radioguided surgery. The current paper introduces a handheld gamma-ultrasound scanner prototype and illustrates the initial result of testing its very first version. The result of the testing was promising and encouraging in continuing the further development of the prototype.
(1) Background: Contact Endoscopy (CE) and Narrow Band Imaging (NBI) are optical imaging modalities that can provide enhanced and magnified visualization of the superficial vascular networks in the laryngeal mucosa. The similarity of... more
(1) Background: Contact Endoscopy (CE) and Narrow Band Imaging (NBI) are optical imaging modalities that can provide enhanced and magnified visualization of the superficial vascular networks in the laryngeal mucosa. The similarity of vascular structures between benign and malignant lesions causes a challenge in the visual assessment of CE-NBI images. The main objective of this study is to use Deep Convolutional Neural Networks (DCNN) for the automatic classification of CE-NBI images into benign and malignant groups with minimal human intervention. (2) Methods: A pretrained Res-Net50 model combined with the cut-off-layer technique was selected as the DCNN architecture. A dataset of 8181 CE-NBI images was used during the fine-tuning process in three experiments where several models were generated and validated. The accuracy, sensitivity, and specificity were calculated as the performance metrics in each validation and testing scenario. (3) Results: Out of a total of 72 trained and tested models in all experiments, Model 5 showed high performance. This model is considerably smaller than the full ResNet50 architecture and achieved the testing accuracy of 0.835 on the unseen data during the last experiment. (4) Conclusion: The proposed fine-tuned ResNet50 model showed a high performance to classify CE-NBI images into the benign and malignant groups and has the potential to be part of an assisted system for automatic laryngeal cancer detection.
Percutaneous needle insertion is one of the most common minimally invasive procedures. The clinician’s experience and medical imaging support are essential to the procedure’s safety. However, imaging comes with inaccuracies due to... more
Percutaneous needle insertion is one of the most common minimally invasive procedures. The clinician’s experience and medical imaging support are essential to the procedure’s safety. However, imaging comes with inaccuracies due to artifacts, and therefore sensor-based solutions were proposed to improve accuracy. However, sensors are usually embedded in the needle tip, leading to design limitations. A novel concept was proposed for capturing tip–tissue interaction information through audio sensing, showing promising results for needle guidance. This work demonstrates that this audio approach can provide important puncture information by comparing audio and force signal dynamics during insertion.
Background: Biometric sensing is a security method for protecting information and property. State-of-the-art biometric traits are behavioral and physiological in nature. However, they are vulnerable to tampering and forgery. Methods: The... more
Background: Biometric sensing is a security method for protecting information and property. State-of-the-art biometric traits are behavioral and physiological in nature. However, they are vulnerable to tampering and forgery. Methods: The proposed approach uses blood flow sounds in the carotid artery as a source of biometric information. A handheld sensing device and an associated desktop application were built. Between 80 and 160 carotid recordings of 11 s in length were acquired from seven individuals each. Wavelet-based signal analysis was performed to assess the potential for biometric applications. Results: The acquired signals per individual proved to be consistent within one carotid sound recording and between multiple recordings spaced by several weeks. The averaged continuous wavelet transform spectra for all cardiac cycles of one recording showed specific spectral characteristics in the time-frequency domain, allowing for the discrimination of individuals, which could potentially serve as an individual fingerprint of the carotid sound. This is also supported by the quantitative analysis consisting of a small convolutional neural network, which was able to differentiate between different users with over 95\% accuracy. Conclusion: The proposed approach and processing pipeline appeared promising for the discrimination of individuals. The biometrical recognition could clinically be used to obtain and highlight differences from a previously established personalized audio profile and subsequently could provide information on the source of the deviation as well as on its effects on the individual’s health. The limited number of individuals and recordings require a study in a larger population along with an investigation of the long-term spectral stability of carotid sounds to assess its potential as a biometric marker. Nevertheless, the approach opens the perspective for automatic feature extraction and classification.
Under-staffing of nurses is a significant problem in most countries. It is expected to rise in the coming years, making it challenging to perform crucial tasks like assessing a patient's condition, assisting the surgeon in medical... more
Under-staffing of nurses is a significant problem in most countries. It is expected to rise in the coming years, making it challenging to perform crucial tasks like assessing a patient's condition, assisting the surgeon in medical procedures, catheterization and Blood Transfusion etc., Automation of some essential tasks would be a viable idea to overcome this shortage of nurses. One such task intended to automate is the role of a 'Scrub Nurse' by using a robotic arm to hand over the surgical instruments. In this project, we propose to use a Collaborative Robotic-arm as a Scrub nurse that can be controlled with voice commands. The robotic arm was programmed to reach the specified position of the instruments placed on the table equipped with a voice recognition module to recognize the requested surgical instrument. When the Surgeon says "Pick Instrument", the arm picks up the instrument from the table and moves it over to the prior defined handover position. The Surgeon can take over the instrument by saying the command "Drop". Safe pathways for automatic movement of arm and handover position will be predefined by the Surgeon manually. This concept was developed considering the convenience of the Surgeon and the patient's safety, tested for collision, noisy environments, positioning failures and accuracy in grasping the instruments. Limitations that need to be considered in future work are the recognition of voice commands which as well as the returning of the instruments by the surgeon in a practical and safe way.
Background: Feature extraction is an essential part of a Computer-Aided Diagnosis (CAD) system. It is usually preceded by a pre-processing step and followed by image classification. Usually, a large number of features is needed to end up... more
Background: Feature extraction is an essential part of a Computer-Aided Diagnosis (CAD) system. It is usually preceded by a pre-processing step and followed by image classification. Usually, a large number of features is needed to end up with the desired classification results. In this work, we propose a novel approach for texture feature extraction. This method was tested on larynx Contact Endoscopy (CE)—Narrow Band Imaging (NBI) image classification to provide more objective information for otolaryngologists regarding the stage of the laryngeal cancer. Methods: The main idea of the proposed methods is to represent an image as a hilly surface, where different paths can be identified between a starting and an ending point. Each of these paths can be thought of as a Tour de France stage profile where a cyclist needs to perform a specific effort to arrive at the finish line. Several paths can be generated in an image where different cyclists produce an average cyclist effort representing important textural characteristics of the image. Energy and power as two Cyclist Effort Features (CyEfF) were extracted using this concept. The performance of the proposed features was evaluated for the classification of 2701 CE-NBI images into benign and malignant lesions using four supervised classifiers and subsequently compared with the performance of 24 Geometrical Features (GF) and 13 Entropy Features (EF). Results: The CyEfF features showed maximum classification accuracy of 0.882 and improved the GF classification accuracy by 3 to 12 percent. Moreover, CyEfF features were ranked as the top 10 features along with some features from GF set in two feature ranking methods. Conclusion: The results prove that CyEfF with only two features can describe the textural characterization of CE-NBI images and can be part of the CAD system in combination with GF for laryngeal cancer diagnosis.
The endoscopic detection of perpendicular vascular changes (PVC) of the vocal folds has been associated with vocal fold cancer, dysplastic lesions, and papillomatosis, according to a classification proposed by the European Laryngological... more
The endoscopic detection of perpendicular vascular changes (PVC) of the vocal folds has been associated with vocal fold cancer, dysplastic lesions, and papillomatosis, according to a classification proposed by the European Laryngological Society (ELS). The combination of contact endoscopy with narrow-band imaging (NBI-CE) allows intraoperatively a highly contrasted, real-time visualization of vascular changes of the vocal folds. Aim of the present study was to determine the association of PVC to specific histological diagnoses, the level of interobserver agreement in the detection of PVC, and their diagnostic effectiveness in diagnosing laryngeal malignancy. The evaluation of our data confirmed the association of PVC to vocal fold cancer, dysplastic lesions, and papillomatosis. The level of agreement between the observers in the identification of PVC was moderate for the less-experienced observers and almost perfect for the experienced observers. The identification of PVC during NBI-CE proved to be a valuable indicator for diagnosing malignant and premalignant lesions.
Injection And Infusion Technology Disruption For Use In MRI
Innovative Hospital Management: Tracking of Radiological Protection Equipment: 10.4018/IJBCE.2020010103: The healthcare industry is consistently developing a constant supply of medical equipment, e.g. radiation protection wear. These must... more
Innovative Hospital Management: Tracking of Radiological Protection Equipment: 10.4018/IJBCE.2020010103: The healthcare industry is consistently developing a constant supply of medical equipment, e.g. radiation protection wear. These must be inspected regularly
Ex vivo lung perfusion (EVLP) is a preservation method for donor lungs, which keep lungs viable in a physiological environment outside of a body for a short period of time. EVLP is established clinically for lung transplantation.... more
Ex vivo lung perfusion (EVLP) is a preservation method for donor lungs, which keep lungs viable in a physiological environment outside of a body for a short period of time. EVLP is established clinically for lung transplantation. Experimental applications for EVLP are e.g. lung cancer research or medical device development and testing. For preservation, a lung is ventilated artificially in an organ chamber and perfused antegrade through the pulmonary artery. Here we introduce a thermoregulation system for an experimental EVLP system to be used for translational research approaches as well as for training medical staff. To implement physiological culture conditions that are a prerequisite for lung preservation and tissue homeostasis, a thermoregulation is needed to rewarm the explanted lung tissue (storage temperature 4°C). Technically, the EVLP system must be thermally insulated, so loss of caloric is avoided. For monitoring, temperature sensors are integrated within the lung, in the organ chamber and in the afferent perfusate tube, whereby the measured values determine the thermoregulation. Initial tests using thermal packs (cooled to 4-6°C) placed on a heating mat, as a part of the perfusion circuit, showed that the perfusate temperature falls to 34°C, but restores after approximately 60 minutes (36.5°C), whereby the thermal pack is warmed. With this setup longer perfusion times should be obtained rather than without thermoregulation due to normothermic perfusion of the lung.
Thermographic imaging is a known technology to detect temperature differences. For medical applications, the patterns of heat distribution are used for diagnosis. It is already tested to visualize blood supply, inflammatory processes, and... more
Thermographic imaging is a known technology to detect temperature differences. For medical applications, the patterns of heat distribution are used for diagnosis. It is already tested to visualize blood supply, inflammatory processes, and superficial or more extensive tumors, e.g. in the breast tissue. This method was promoted for breast screening purposes and as a substitute for mammography for mid aged women, but the results were not convincing for younger women, where tissue density is higher, tumor growth is often connected to local temperature increase and radiation-based mammography is not an option. Infrared (IR) thermography can support tumor screening. The screening should allow the early detection of small lesions even in the depth. Therefor we evaluated the feasibility of dynamic cooling in combination with IR imaging in a phantom study. A temperature-controllable gel phantom including a heating plate, a depth-adjustable heat source mimicking a tumor, and three sensors for temperature monitoring was built up. A raspberry pi device serves as a control unit to create a stable temperature balance comparable to a human breast. For the experiments, the tumor was placed in various depth. After cooling, the thermal recovery phase of the phantom was imaged using an IR camera and a webcam. A pixel-wise analysis of the IR data detects a higher gradient of temperature change in the tumor region. The experiments demonstrated the feasibility of tumor detection based on dynamic cooling and IR imaging.
Cerebrovascular diseases such as stenosis, atherosclerosis or distention of the carotid artery are accountable for about 1 million death per year across Europe. Diagnostic tools like ultrasound imaging, angiography or magnetic... more
Cerebrovascular diseases such as stenosis, atherosclerosis or distention of the carotid artery are accountable for about 1 million death per year across Europe. Diagnostic tools like ultrasound imaging, angiography or magnetic resonance-based imaging require specific hardware and highly depend on the experience of the examining clinician. In contrast auscultation with a stethoscope can be used to screen for carotid bruits - audible vascular sounds associated with turbulent blood flow - a method called phonoangiography. A reliable auscultation setup is prerequisite to ensure high signal quality, adequate processing and the objective evaluation of this audible signal. We propose a computer assisted auscultation system for the acquisition of vascular sounds of the carotid. The system comprises of an auscultation device, a smartphone-based control application and cloud-based signal analysis and storage. It is designed to facilitate the objective assessment, screening and monitoring of long-term changes in the vessel condition based on auscultation of the carotid artery.
For imaging of the vascular structure, angiography is state of the art. This can be done by contrast enhanced XRay, CT or MR imaging. But these modalities typically only show the blood flow and do not allow a depiction of the vasculature... more
For imaging of the vascular structure, angiography is state of the art. This can be done by contrast enhanced XRay, CT or MR imaging. But these modalities typically only show the blood flow and do not allow a depiction of the vasculature itself. To provide information about the vessel walls and plaques narrowing the blood flow, catheter based intra vascular ultrasound or vascular optical coherence tomography can be used. Optical endoscopic imaging is rarely used in vascular diagnosis. But endoscopic imaging can depict superficial inflammations or defects of the intima vessel layer and the real anatomical shape of the inner vasculature e.g. at bifurcations or aneurysms. Since OCT and endoscopic imaging both need a flushing to remove the blood for a short time, a combination of both modalities seems viable. For combining the two modalities, various background studies were performed including the selection of a feasible fibre endoscope, light source and camera system. A new pull-back and flushing device was designed and created for realizing the synchronous image acquisition using the two modalities. For calibration of the system and definition of the pullback and imaging parameters, first tests on artificial phantoms were performed. Then vascular and tissue models were imaged in a combined pullback mode after using the flush for complete blood removal. Endoscopic images were acquired in a video mode. The analysis of the images was done subjectively. As expected, the OCT provided structural information of the wall. The endoscopic images in combination with pullback appear blurry in video mode. The flushing liquid hinders the automatic focusing of the camera. Thus, smaller details could not be identified but bifurcations were visible. Even though the results were not good as expected, the study showed the potential of a bimodal system and addressed the issues faced in the initial implementation.
NITINOL-based actuator for device control even in high-field MRI environment
Robotic minimally invasive surgery (RMIS) has played an important role in the last decades. In traditional surgery, surgeons rely on palpation using their hands. However, during RMIS, surgeons use the visual-haptics technique to... more
Robotic minimally invasive surgery (RMIS) has played an important role in the last decades. In traditional surgery, surgeons rely on palpation using their hands. However, during RMIS, surgeons use the visual-haptics technique to compensate the missing sense of touch. Various sensors have been widely used to retrieve this natural sense, but there are still issues like integration, costs, sterilization and the small sensing area that prevent such approaches from being applied. A new method based on acoustic emission has been recently proposed for acquiring audio information from tool-tissue interaction during minimally invasive procedures that provide user guidance feedback. In this work the concept was adapted for acquiring audio information from a RMIS grasper and a first proof of concept is presented. Interactions of the grasper with various artificial and biological texture samples were recorded and analyzed using advanced signal processing and a clear correlation between audio spectral components and the tested texture were identified.
Purpose The automatic detection of epileptic seizures in EEG data from extended recordings can make an important contribution to the diagnosis of epilepsy as it can efficiently reduce the workload of medical staff. Methods This paper... more
Purpose The automatic detection of epileptic seizures in EEG data from extended recordings can make an important contribution to the diagnosis of epilepsy as it can efficiently reduce the workload of medical staff. Methods This paper describes how features based on cross-bispectrum can help with the detection of epileptic seizure activity in EEG data. Features were extracted from multi-channel intracranial EEG (iEEG) data from the Freiburg iEEG recordings of 21 patients with focal epilepsy. These features were used as a support vector machine classifier input to discriminate ictal from inter-ictal states. A post-processing method was applied to the classifier output in order to improve classification accuracy. Results A sensitivity of 95.8\%, specificity of 96.7\%, and accuracy of 96.8\% were achieved. The false detection rate (FDR) was zero for 10 patients and very low for the rest. Conclusions The results show that the proposed method distinguishes better between ictal and inter-ictal iEEG epochs than other seizure detection methods. The proposed method has a higher accuracy index than achievable with a number of previously described approaches. Also, the method is rapid and easy and may be helpful in online epileptic seizure detection and prediction systems.
Artery perforation during a vascular catheterization procedure is a potentially life threatening event. It is of particular importance for the surgeons to be aware of hidden or non-obvious events. To minimize the impact it is crucial for... more
Artery perforation during a vascular catheterization procedure is a potentially life threatening event. It is of particular importance for the surgeons to be aware of hidden or non-obvious events. To minimize the impact it is crucial for the surgeon to detect such a perforation very early. We propose a novel approach to identify perforations based on the acquisition and analysis of audio signals on the outside proximal end of a guide wire. The signals were acquired using a stethoscope equipped with a microphone and attached to the proximal end of the guide wire via a 3D printed adapter. Bispectral analysis was employed to extract acoustic signatures in the signal and several features were extracted from the bispectrum of the signal. Finally, three machine learning algorithms - K-nearest Neighbor, Support Vector Machine (SVM), and Artificial Neural Network (ANN)- were used to classify a signal as a perforation or as an artifact. The bispectrum-based features resulted in valuable features allowing a perforation to be clearly identifiable from other occurring events. A perforation leaves a clear audio signal trace in the time-frequency domain. The recordings were classified as perforation, friction or guide wire bump using SVM with 97\% (polykernel) and 98.62\% (RBF) accuracy, k-nearest Neighbor an accuracy of 98.28\% and ANN with accuracy of 98.73\% was obtained. The presented approach shows that interactions starting at the tip of a guide wire can be picked up at its proximal end providing a valuable additional information that could be used during a guide wire procedure.
In orthopedic hand surgeries C-arms are the standard imaging modalities for procedure and tool guidance. However, the currently used systems have a large footprint and high weight, which can lead to workspace restrictions and difficult... more
In orthopedic hand surgeries C-arms are the standard imaging modalities for procedure and tool guidance. However, the currently used systems have a large footprint and high weight, which can lead to workspace restrictions and difficult positioning of the device at the desired imaging position. The aim of this paper is to present a prototype of a new, flexible, lightweight and small footprint X-ray system, which is capable to create 2D projection images from different orientations. The new design includes a miniaturized Xray tube covered in a custom-made case mounted on a flexible holding arm attached to the standard OR table rail. With that, fast positioning and fixation for the subsequent image acquisition is achieved. A flat panel detector is placed in an adjustable metal sheet construction below the table. For safety aspects an overlay of the X-ray cone beam with an integrated light source visualizes the irradiation area. The acquired images are visualized on a 2-in-1 netbook. A foot pedal initiates the imaging process. A prototype of the free movable miniaturized X-ray system FlexScan was build. Workspace restriction, usability and general imaging needs were simulated and tested. FlexScan has the potential to improve X-ray guided interventions on extremities especially for small private surgery centers. It fulfills the general imaging needs and is capable of producing 2D projection images from different orientations within a small and lightweight setup.
Radiation therapy is a valuable option for treatment of skin cancer. In order to deliver the radiation dose to the superficial skin tumor, an X-ray source, electron beam radiation therapy or a radioisotope is applied. The effectiveness of... more
Radiation therapy is a valuable option for treatment of skin cancer. In order to deliver the radiation dose to the superficial skin tumor, an X-ray source, electron beam radiation therapy or a radioisotope is applied. The effectiveness of these procedures is well established in the literature. Findings of some recent studies have indicated that beta particles can be of particular interest in suppressing skin tumor growth. Betaemitting radioisotopes are favorable because of the short penetration depth of their emitted particles. Beta radiation can induce significant damage in superficial skin tumor, and at the same time, result in enhanced protection of the underlying healthy tissues. In this study, we propose the design of a patch that can be used in beta radiation therapy of skin cancer patients. For that, we describe the components of this radioactive patch, as well as a proposal for the subsequent clinical application procedure. A scaffold was used as a substrate for embedding the desired beta-emitting radioisotope, and two layers of hydrogel to provide protection and shielding for the radioactively labelled scaffold. The proposed design could provide a universal platform for all beta-emitting radioisotopes. Depending on the depth of the tumor spread, a suitable beta emitter for that specific tumor can be selected and used. This is of particular and critical importance in cases where the tumor is located directly on top of the bone and for which the depth of penetration of radiation should be limited to only the tumor volume. The proposed design has the mechanical flexibility to adapt to curved body regions so as to allow the use in anatomically challenging areas of the body.
At present transoral laryngeal interventions are mainly observed and controlled by an external two dimensional direct microscopic view. This modality provides an overall view on the surgery situs in a straight line of sight. For treatment... more
At present transoral laryngeal interventions are mainly observed and controlled by an external two dimensional direct microscopic view. This modality provides an overall view on the surgery situs in a straight line of sight. For treatment planning and appropriate documentation, an endoscopic inspection is mandatory prior to surgery. Nowadays a detailed endoscopic work-up of laryngeal lesions can be performed by contact endoscopy in combination with structure enhancement like Narrow Band Imaging. High resolution and magnification of up to 150 times provide detailed visualization of vascular structures and pathological changes of the tissue surface. In these procedures it is difficult however to localize the evaluated areas on large scale scenes like the microscopic view used for surgery. To provide a fast and easy image matching an automated vessel pattern recognition and allocation is presented. Endoscopic images depicting representative vessel structures of the vocal folds are selected out of contact endoscopy video scenes. These images are pre-processed for background homogenization. A Frangi Vessel Segmentation filter and morphological operations are used to extract the vessel structure and match it to the microscopic image. Using this method 4 detailed contact endoscopy images could be allocated in different scenes of the microscope video. This method can be used to simplify treatment planning and to prepare image data for documentation.
We propose a new and complementary approach to image guidance for monitoring medical interventional devices (MID) with human tissue interaction and surgery augmentation by acquiring acoustic emission data from the proximal end of the MID... more
We propose a new and complementary approach to image guidance for monitoring medical interventional devices (MID) with human tissue interaction and surgery augmentation by acquiring acoustic emission data from the proximal end of the MID outside the patient to extract dynamical characteristics of the interaction between the distal tip and the tissue touched or penetrated by the MID. We conducted phantom based experiments (n = 955) to show dynamic tool/tissue interaction during tissue needle passage (a) and vessel perforation caused by guide wire artery perforation (b). We use time-varying auto-regressive (TV-AR) modelling to characterize the dynamic changes and time-varying maximal energy pole (TV-MEP) to compute subsequent analysis of MID/tissue interaction characterization patterns. Qualitative and quantitative analysis showed that the TV-AR spectrum and the TV-MEP indicated the time instants of the needle path through different phantom objects (a) and clearly showed a perforation versus other generated artefacts (b). We demonstrated that audio signals acquired from the proximal part of an MID could provide valuable additional information to surgeons during minimally invasive procedures.
The invention relates to a material for the 3-dimensional printing of scaffold structures on a 3D printer as well as to a medical implant (1) made of this type of material and the use of this type of material for manufacturing a medical... more
The invention relates to a material for the 3-dimensional printing of scaffold structures on a 3D printer as well as to a medical implant (1) made of this type of material and the use of this type of material for manufacturing a medical implant (1) of this type. According to the invention, the material has integrated microspheres (5) which emit radioactive rays.
There is a hurdle between the creative innovator and the successful business creator in the medical device industry: the standards and laws regulating market access!
The endoscopic examination of subepithelial vascular variations of vocal folds can provide complementary diagnostic information for clinicians regarding the development of benign and malignant laryngeal lesions. As one novel technique,... more
The endoscopic examination of subepithelial vascular variations of vocal folds can provide complementary diagnostic information for clinicians regarding the development of benign and malignant laryngeal lesions. As one novel technique, Contact Endoscopy combined with Narrow Band Imaging (CE-NBI) can provide real-time and enhanced visualization of these vascular structures. Several studies have addressed the concern of subjective evaluation of CE-NBI images, resulting in the development of multiple computer-based solutions. We introduce the CE-NBI data set, the first publicly available data set with enhanced and magnified visualization of vocal fold subepithelial blood vessels. It comprises 11144 images of 210 adult patients with benign and malignant lesions in the vocal fold. Image annotations include as following for all images of every patient: Diagnosed laryngeal histopathology label. Lesion type benign-malignant label. Leukoplakia diagnosis label. The dataset consists of two main categories: benign and malignant images. In each category, the images of every patient are ordered according to the laryngeal histopathology class. Additionally, one Excel file is provided to map the image files of each patient to three image labels and image dimensions. This data has successfully been used to perform clinical evaluations as well as design and develop multiple Machine Learning (ML)-based algorithms for laryngeal cancer assessment.
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This work describes an initial design concept for a spinal needle using new materials to optimize their visualization in magnetic resonance imaging. Common MRI needles made of Nickel-Titanium alloys still show poor visibility in imaging... more
This work describes an initial design concept for a spinal needle using new materials to optimize their visualization in magnetic resonance imaging. Common MRI needles made of Nickel-Titanium alloys still show poor visibility in imaging because they generate susceptibility artifacts due to material’s interactions with the magnetic environment. The use of non-metallic materials can reduce these artifacts. However, so far no non-metallic needle design has made it to clinical routine due to sharpness and cost issues. We propose a design of a coaxial needle with a fiber enforced inner core and an outer hollow sheet. The concept has been evaluated in the MRI environment. Additionally, mechanical tests were performed to examine and quantify the variation between a conventional spinal needle and our proposed design.
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There is a hurdle between the creative innovator and the successful business creator in the medical device industry: the standards and laws regulating market access!
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Aus der Einführung: "Eine systematische Vorgehensweise entsprechend der Konstruktionsmethodik gilt als zielführender Ansatz bei der Findung von technischen Lösungen und der Entwicklung von Produkten. In der Literatur finden sich dazu... more
Aus der Einführung: "Eine systematische Vorgehensweise entsprechend der Konstruktionsmethodik gilt als zielführender Ansatz bei der Findung von technischen Lösungen und der Entwicklung von Produkten. In der Literatur finden sich dazu zahlreiche Veröffentlichungen z. B. Feldhusen & Grote 2013; Ehrlenspiel 2014; Ehrlenspiel 2009; Roth 1994 und Livotov 2013. Die VDI Richtlinie 2221 „Methodik zum Entwickeln und Konstruieren technischer Systeme und Produkte“ (VDI 1993) beschreibt ebenfalls allgemeingültige Regeln bei der systematischen Lösungsfindung. Iterativ wird in mehreren Teilschritten eine zuvor definierte Aufgabe in eine Lösung überführt. Dabei werden die Phasen der Planung, der Konzeption, des Entwurfes und der Ausarbeitung durchschritten. In der Literatur und den Richtlinien ist jedoch keine explizite Rückkopplung mit dem Nutzer gefordert oder angedacht. Gerade vor dem Hintergrund der voranschreitenden Individualisierung der Produkte und kann hierin ein entscheidender Vorte...
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Current methods of prostate cancer diagnosis and therapy rely on accurate imaging of the prostate using real-time ultrasound. Transurethral ultrasound (TUUS) may improve upon the current gold standard through improved 3D visualization and... more
Current methods of prostate cancer diagnosis and therapy rely on accurate imaging of the prostate using real-time ultrasound. Transurethral ultrasound (TUUS) may improve upon the current gold standard through improved 3D visualization and co-registration (fusion) with CT and MRI. A prototype transurethral ultrasound (TUUS) catheter-based transducer array and system was developed, featuring 32 elements with a diameter of 18F (6mm). A robust, multi-channel ultrasound transceiver was also developed to enable TUUS imaging using pulse-echo and frequency-based signal processing methods. The feasibility of a TUUS imaging system suitable for multi-modal image fusion and novel ultrasound signaling techniques was demonstrated.
Research Interests: Computer Science, Magnetic Resonance Imaging, Ultrasound, Medicine, Biopsy, and 13 moreLibrary and Information Studies, Humans, Image fusion, Pubmed, Feasibility Studies, Male, Three Dimensional Imaging, Prostate, Public health systems and services research, Transducer, Combined Modality Therapy, Prostatic neoplasms, and Urinary catheterization
Boese, A. Chapter 06 Catheters in vascular therapy
This paper presents an improved solution for vibroarthrographic measurements. Four different setups for sensor attachment to the knee were assessed with a focus on the stability and reproducibility of the measured signals. By means of... more
This paper presents an improved solution for vibroarthrographic measurements. Four different setups for sensor attachment to the knee were assessed with a focus on the stability and reproducibility of the measured signals. By means of power spectral density estimates, the main signal components were compared and afterwards evaluated by conducting a cross-correlation analysis.
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TURBT (transurethral resection of bladder tumor) is a standard treatment for bladder cancer. Gas bubble formation is caused by the heating of the RF-electrode from the resectoscope, which causes visual impairments and can also lead to... more
TURBT (transurethral resection of bladder tumor) is a standard treatment for bladder cancer. Gas bubble formation is caused by the heating of the RF-electrode from the resectoscope, which causes visual impairments and can also lead to explosive gas formation. The purpose of this work is to find a proper technical solution for removing the air bubbles and toxic gases during electro-resection thereby providing patient safety as well as better operating comfort for surgeons. A continuously controlled irrigation system and catheter based simultaneous suction system was designed, implemented and tested, with an average removal rate of 70% of the air bubbles and gases that appeared inside the urinary bladder. The setup was tested using a dedicated phantom.
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Thieme E-Books \&amp; E-Journals
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Digital pathology can be thought of as a model composed of 3 main elements; classification algorithm, Graphical User Interface (GUI) and the pathologists. Currently there is only a one way interaction from the classification algorithm to... more
Digital pathology can be thought of as a model composed of 3 main elements; classification algorithm, Graphical User Interface (GUI) and the pathologists. Currently there is only a one way interaction from the classification algorithm to the pathologist. This paper, proposes an additional backward path which is a new feedback-based method, aimed to improve the performance of the classification algorithms by utilizing the feedback of the pathologists. The GUI developed for this purpose, is aimed to be simple and adaptive to different classification algorithms. The method showed significant improvement in the classification performance of the applied Convolutional Neural Network (CNN) algorithm. The 25% quantile of the probability score of the predictions increased from 0.48 to 0.89 and the median of the data increased from 0.95 to 0.99.
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BackgroundRadiation therapy using beta particles is an interesting treatment for very superficial skin lesions. Due to their low penetration in tissue and rapid dose fall‐off, beta particles can protect underlying bony structures and... more
BackgroundRadiation therapy using beta particles is an interesting treatment for very superficial skin lesions. Due to their low penetration in tissue and rapid dose fall‐off, beta particles can protect underlying bony structures and surrounding healthy tissue while irradiating the skin tumor. In the current work, a simple method for the fabrication of a radioactive patch for use in skin cancer therapy based on a beta‐emitting isotope is presented.Materials and methodsThe beta radiation sources were Y‐90 microspheres currently used for catheter‐based radioembolization of unresectable liver tumors. The microspheres were filtered through a syringe filter to trap them on the cellulose nitrate paper of the filter and create a radioactive patch. In the current study, to avoid the need for a hot laboratory, the experiment was done using nonradioactive microspheres. An optical microscope was used to verify the distribution of the particles on the filter paper.ResultsVisual evaluation of th...
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These are the proceedings for the 9th International Interventional MRI Symposium. The overall goal of this workshop series is to report clinical and technological advances in the field of iMRI.
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According to [1]-[3], the healthcare systems are suffering from severe personnel shortages with a lack of medical care workers, operating room nurses, and surgical technicians. This deficiency will become worse in the upcoming decades.... more
According to [1]-[3], the healthcare systems are suffering from severe personnel shortages with a lack of medical care workers, operating room nurses, and surgical technicians. This deficiency will become worse in the upcoming decades. Automatization of highly standardized procedures could be a promising approach to address this issue. We designed a new concept for the automated handover and return of surgical instruments to the surgeon in an operating theater scenario to relieve operating room personnel from their workload. In this setup, the surgical instruments are delivered pre-sorted in an upright position by the sterilization unit in an instrument basket or drum. A single-use, doublelayered, brushy conveyor belt system mounted on a robot arm acts as the connector between pick-position (instrument basket) and individually pre-definable hand-over-position. The system is placed next to the table inside the operation room (OR). Based on voice commands, the conveyor intake moves ov...
Retractors are used in surgery for the displacement of tissue and organs and to keep the surgical area open. The retraction can lead to a tissue compression that can cause irritation on nerves, perfusion deficits, hematoma or late... more
Retractors are used in surgery for the displacement of tissue and organs and to keep the surgical area open. The retraction can lead to a tissue compression that can cause irritation on nerves, perfusion deficits, hematoma or late sequelae like wound healing disorders, pain and numbness. The retraction force and thus the load on the tissue can not be measured with retraction systems today. We present a new concept for a retractor with an integrated spring element and an indicator to visualize retraction force and allow an adjustment of the organ compression. The new retractor was designed considering organ compression limits, requirements on sterility and easy manufacturing. Two retractors were built up as a prototype by 3D printing and tested in a distinguished test setup. The first test of the retractors was performed on a force measurement test bench using a fixed retractor, and in a second test, a liver specimen in a bowl. Tests were repeated for both retractor variants. The tes...
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Ultrasound imaging provides a 2D single slice that can be combined to a volume known as Tomographic US (TUS) employing various tracking methods. TUS is vital for three dimensional visualization of pathological structures and aids... more
Ultrasound imaging provides a 2D single slice that can be combined to a volume known as Tomographic US (TUS) employing various tracking methods. TUS is vital for three dimensional visualization of pathological structures and aids physicians in providing a better diagnosis of the condition. Freehand TUS scans have drawbacks such as overlapping of image slices, change in the angulation of the probe and deformation of structures below the epidermis due to a change in applied force. US scan acquisition is highly user dependent and therefore provides varying imaging quality. An assisted scan acquisition process is a possible solution to address and solve these issues and with that improve the 3D volume reconstruction. We propose the design, development and testing of a prototype device that enables assisted acquisition of US image slices, while addressing limitations of freehand TUS scans.
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The use of catheters and guide-wires in minimally invasive therapeutic approaches is an important part of clinical practice. In the neurovascular field, the unique nature of cerebral blood vessels necessitates very thin-walled and... more
The use of catheters and guide-wires in minimally invasive therapeutic approaches is an important part of clinical practice. In the neurovascular field, the unique nature of cerebral blood vessels necessitates very thin-walled and flexible catheters. The blood vessels in question are highly branched and at the same time can be less than one millimetre in diameter. This results in high demands on micro-catheters and guide-wires for successful endovascular therapy. The interaction of these surgical tools and the vessel wall is of especial interest. Depending on the catheter stiffness, this interaction can be friction, punctual collision or straightening. The work aims to design and implement a test setup for evaluation of these interactions with the vessel wall. For this purpose, a standardized vessel course with representative characteristics is necessary. Furthermore, by implementing suitable measuring equipment, an endovascular intervention can be simulated.
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Surface brachytherapy is an effective method in the treatment of skin cancer. Current skin brachytherapy techniques are based on the placement of a source of gamma or X-ray photons in a close distance from the skin to irradiate the... more
Surface brachytherapy is an effective method in the treatment of skin cancer. Current skin brachytherapy techniques are based on the placement of a source of gamma or X-ray photons in a close distance from the skin to irradiate the lesion. Due to the nature of photons, radiation dose in these methods may affect healthy tissue as well as sensitive structures around the target. In order to minimize unwarranted and incidental exposure, we propose a new skin brachytherapy applicator based upon beta particles which have penetration ranges of a few millimeters in tissue. The proposed concept is radioactive gel housed within a pre-designed tumor-specific applicator matching the topology of the skin lesion. The particles mixed with the gel showed a uniform distribution pattern, which is an essential prerequisite in having a uniform dose profile on the skin surface. Based on the dose calculation data from the proposed concept, the dose delivered to the depth of 4500 µm in skin tissue is 10% of the dose delivered to the surface of the tumor, making it suitable is treating thin skin tumors especially when located on top of the bone. Through the innovative combination of radioactive gel and tumor-specific applicator, the radiation entering the skin surface can be personalized while minimizing the adverse effects of undesired exposure to the surrounding healthy tissue.
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Additive manufacturing is widely used in the meantime for medical device developments. Specially the BioDesign process with strong user integration and feedback loops benefits from fast prototyping. In this work, an innovative conceptual... more
Additive manufacturing is widely used in the meantime for medical device developments. Specially the BioDesign process with strong user integration and feedback loops benefits from fast prototyping. In this work, an innovative conceptual design of revolving biopsy needle is CAD modelled using SolidWorks software and subsequently 3D printed. The material properties of the resins were fit to use for fabrication of the different mechanisms that the prototype requires. 3D printing is a very good method of quickly checking different design ideas, to present functionalities to clinical partners, to optimize and define the ideal design. Even delicate structures are possible.
Research Interests:
Research Interests:
Workflowanalysen werden zur Beschreibung eines Arbeitsprozesses eingesetzt. Im medizinischen Bereich liegt der Schwerpunkt dabei bei der Optimierung des Patientenflusses, der Gerateauslastung oder der Operationsbedingungen [1].... more
Workflowanalysen werden zur Beschreibung eines Arbeitsprozesses eingesetzt. Im medizinischen Bereich liegt der Schwerpunkt dabei bei der Optimierung des Patientenflusses, der Gerateauslastung oder der Operationsbedingungen [1]. Workflowanalysen konnen aber auch als methodisches Werkzeug in der Entwicklung von Medizinprodukten eigesetzt werden. Dabei liegt der Focus auf der Feststellung von Produktdefiziten, der Aufnahme von Anforderungen an ein Produkt oder von moglichen Handlungsabfolgen. Die voranschreitende Miniaturisierung im Medizintechnikbereich eroffnet neue Moglichkeiten zum Design und zur Entwicklung von minimalinvasiven Instrumenten. Im Projekt „Intelligente Katheter“ (INKA) werden an der Otto-vonGuericke-Universitat Magdeburg Systeme und Verfahren fur die interventionelle Radiologie entwickelt. Wesentlicher Bestandteil der Entwicklungsstrategie ist der konsequente Einsatz von Workflowstudien zur Unterstutzung von Anforderungsanalysen fur Katheter, Nadeln und andere minima...
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Novel challenges and developments require adaptations on skill set, content, and associated education. A biomedical engineer will require a broad range of skills - which to a large extent are currently not taught - in the coming years to... more
Novel challenges and developments require adaptations on skill set, content, and associated education. A biomedical engineer will require a broad range of skills - which to a large extent are currently not taught - in the coming years to meet the development needs of future healthcare: intensive interdisciplinary team work, advanced communication skills, team management and coaching capabilities, advanced project management, learn how to learn, visionary and forward looking thinking, understanding of health economics, entrepreneurship and leadership. But above all empathy towards the clinical user and patients is needed as well as a basic understanding of the current and future clinical workflows that can globally vary. An innovation process for a healthcare related product or service will likely only create value through the consideration and implementation of several of these points. Even though techniques for the development of innovation and enhancing creativity in individuals a...
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Research Interests:
Purpose For the treatment of malignant diseases of the oral cavity and the larynx, a total or partial resection is the standard therapy, while in special cases chemo- and/or external radiation therapy is considered. Transoral access... more
Purpose For the treatment of malignant diseases of the oral cavity and the larynx, a total or partial resection is the standard therapy, while in special cases chemo- and/or external radiation therapy is considered. Transoral access reduces trauma and hospitalization time. Transoral surgery is usually executed using external microscopic imaging. Therefore, the microscope is placed in the visual line of the opening of the mouth and throat. However, specific anatomical structures like the posterior commissure (dorsal end of the vocal cords) are not visible in these procedures. An endoscopic approach can improve this problem. We introduce a new prototype system for endoscopic assisted transoral surgery. Methods Based on clinical observation and discussions with professional users and surgeons, the clinical need was identified and specified. A general concept or an endoscopic manipulator to assist microlaryngeal surgery was designed. For that a steerable rigid endoscope was combined wit...
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Research Interests:
Research Interests:
During a magnetic resonance imaging (MRI) exam, a respiratory signal can be required for different purposes, e.g. for patient monitoring, motion compensation or for research studies such as in functional MRI. In addition, respiratory... more
During a magnetic resonance imaging (MRI) exam, a respiratory signal can be required for different purposes, e.g. for patient monitoring, motion compensation or for research studies such as in functional MRI. In addition, respiratory information can be used as a biofeedback for the patient in order to control breath holds or shallow breathing. To reduce patient preparation time or distortions of the MR imaging system, we propose the use of a contactless approach for gathering information about the respiratory activity. An experimental setup based on a commercially available laser range sensor was used to detect respiratory induced motion of the chest or abdomen. This setup was tested using a motion phantom and different human subjects in an MRI scanner. A nasal airflow sensor served as a reference. For both, the phantom as well as the different human subjects, the motion frequency was precisely measured. These results show that a low cost, contactless, laser-based approach can be us...