Papers by Gernot Kronreif
Possibility assessment of CBCT metal artifact reduction based on PICCS reconstruction and trajectory optimization
Medical Imaging 2022: Image-Guided Procedures, Robotic Interventions, and Modeling
504 Improving Precision of Resection Limits in Surgery for High-grade Gliomas: Preliminary Experience with an In Vivo Raman Spectroscopy Probe
Neurosurgery
Development of a miniaturized robotic guidance device for stereotactic neurosurgery
Journal of Neurosurgery, 2021
OBJECTIVE Consistently high accuracy and a straightforward use of stereotactic guidance systems a... more OBJECTIVE Consistently high accuracy and a straightforward use of stereotactic guidance systems are crucial for precise stereotactic targeting and a short procedural duration. Although robotic guidance systems are widely used, currently available systems do not fully meet the requirements for a stereotactic guidance system that combines the advantages of frameless surgery and robotic technology. The authors developed and optimized a small-scale yet highly accurate guidance system that can be seamlessly integrated into an existing operating room (OR) setup due to its design. The aim of this clinical study is to outline the development of this miniature robotic guidance system and present the authors’ clinical experience. METHODS After extensive preclinical testing of the robotic stereotactic guidance system, adaptations were implemented for robot fixation, software usability, navigation integration, and end-effector application. Development of the robotic system was then advanced in ...
Ophthalmology Science, 2021
Purpose: To assess the efficacy of an instrument-integrated OCT (iiOCT)-based distance sensor dur... more Purpose: To assess the efficacy of an instrument-integrated OCT (iiOCT)-based distance sensor during robotic vitreoretinal surgery using the Preceyes Surgical System (PSS; Preceyes B.V.). Design: Single-center interventional study. Participants: Patients requiring vitreoretinal surgery. Methods: Five patients were enrolled. Standard preoperative OCT images were obtained. After vitrectomy, a predefined set of actions was performed using the iiOCT-based sensor. Images then were processed to assess the signal-to-noise ratio (SNR) at various angles to the retina and at different distances between the instrument tip and the retinal surface. Preoperative and intraoperative OCT images were compared qualitatively and quantitatively. Main Outcomes Measures: The feasibility in performing surgical tasks using the iiOCT-based sensor during vitreoretinal surgery, the SNR when imaging the retina, differences among intraoperative and preoperative OCT images, and characteristics of intraoperative retinal movements detected with the iiOCT-based probe. Results: Surgeons were able to perform all the tasks but one. The PSS was able to maintain a fixed distance. The SNR of the iiOCT-based sensor signal was adequate to determine the distance to the retina and to control the PSS. Analysis of iiOCT-based sensor A-scans identified 3 clearly distinguishable retinal layers, including the inner retinal boundary and the interface at the retinal pigment epitheliumeBruch's membrane. Thickness values differed by less than 5% from that measured by preoperative OCT, indicating its accuracy. The Fourier analysis of iiOCTbased sensor recordings identified anteroposterior retinal movements attributed to heartbeat and respiration. Conclusions: This iiOCT-based sensor was tested successfully and promises reliable use during robotassisted surgery. An iiOCT-based sensor is a promising step toward OCT-guided robotic retinal surgery.
PURPOSE: Neurosurgical registration using optical tracking in prone position is problematic due t... more PURPOSE: Neurosurgical registration using optical tracking in prone position is problematic due to a lack of anatomical landmarks on the posterior skull. The current method of registration involves insertion of screws into the skull. Surface registration using ultrasound has been proposed as a less invasive method of registration. Obtaining full access to the posterior skull would require patient hair removal, which is not favored by patients as it can cause an increased risk of surgical site infection and a less aesthetic outcome. We performed ultrasound scans on participants with no hair removal to evaluate the visibility of the mastoid processes and occipital base of the posterior skull in ultrasound imaging. METHODS: Participants were scanned using a linear and a curvilinear ultrasound probe. Scans were taken at the maximum and minimum frequency of each probe. Ultrasound scans captured the region around each mastoid process, the external occipital protuberance, and the occipital...
Neurosurgery, 2018
CNS ORAL PRESENTATIONS the U-CH1 chordoma cell line. Reconstitution of immune cells in NSG mice w... more CNS ORAL PRESENTATIONS the U-CH1 chordoma cell line. Reconstitution of immune cells in NSG mice was confirmed 8 wk post-transplantation and then each animal was injected with U-CH1 subcutaneously. Next, they were treated for 4 wk as follows: (A) control (n = 3), (B) anti-human-PD-1 antibodies (n = 4), (C) RT + isotype antibodies (n = 3, 8 Gy × 4), (D) anti-human-PD-1 antibodies and RT (n = 5). Anti-tumor activities were monitored via tumor size, flow cytometry, qRT-PCR, and immunohistochemistry. RESULTS: One week after the treatment, on the irradiated side, (D) demonstrated lowest tumor volume, highest number of human PBMCs, highest % of CD8 + human T cells, highest % of CD45RO+CD4 + human T cells, and lowest % of PD-1+CD8 + human T cells in the tumors via flow cytometry, and highest IFN-gamma in the tumors via qRT-PCR, compared to the other groups with statistical significance. CONCLUSION: We demonstrated that this humanized mouse model could be a revolutionary platform to investigate IT against rare cancers such as chordomas, where murine equivalents are unavailable. The direct synergistic effect between IT and RT against chordoma was observed, evidenced by lowest tumor volume, highest cytotoxic T cells, and memory T cells.
Transrectal Ultrasound for Cervix Cancer Brachytherapy: Combining Ultrasound-Based Target Definition and CT-Based Treatment Planning
Brachytherapy, 2016
Automatic event handling during robot assisted eye surgery
2017 International Conference and Workshop on Bioinspired Intelligence (IWOBI), 2017
Medical eye surgery robots are supporting the surgery process in many ways, they primarily can he... more Medical eye surgery robots are supporting the surgery process in many ways, they primarily can help the surgeon during surgery procedure, they can provide valuable status information about the environment, about the patient and about the forthcoming steps of the surgical process, and by definition they need to protect the patient too. During eye surgery we can differentiate phases of the process and we can identify generic workflows and states for each type of treatments. Transitions between the states or between the workflow steps are triggered by events. Such events can be initiated by any of the surgery the medical expert, by the environment or patient status parameters, or by any components of the system. We have developed an Event handling framework for robot surgery devices. We have evaluated our solution using two different eye surgery robot device. In this paper we are providing information about the framework, its implementations, and detail some evaluation results.
Patient specific quality assurance can be improved using an independent dose calculation system. ... more Patient specific quality assurance can be improved using an independent dose calculation system. In addition, the implementation of such a system may support light ion beam therapy facilities in reducing the needs for beam time, by substituting some of the experimental patient-specific quality assurance procedures by independent dose calculation. The GATE-RTion-based IDEAL system for light ion beam therapy was developed for this purpose. It was built in a DICOM-in, DICOM-out fashion, for easy integration into a state-of-the-art technology-based workflow for scanned ion beam therapy. This article describes the IDEAL system, followed by its clinical implementation at MedAustron for proton and carbon ion beams. Medical physics acceptance and commissioning steps are presented together with key results: for 3D proton and carbon ion reference boxes, 97% of the points agreed within 5% from the measurements. Experimental validation of stopping powers using real pig samples were between 1.8%...
Toward 3D-TRUS image-guided interstitial brachytherapy for cervical cancer
Brachytherapy
3D printed patient-specific thorax phantom with realistic heterogenous bone radiopacity using filament printer technology
Zeitschrift für Medizinische Physik
A novel miniature robotic guidance device for stereotactic neurosurgical procedures: Preliminary experience of the iSys-1
Objective: Stereotactic interventions are amongst the most frequent procedures in cranial neurosu... more Objective: Stereotactic interventions are amongst the most frequent procedures in cranial neurosurgery. To overcome the limitations of frame-based, frame-less arm-based, or free-hand techniques, robotic arms have been introduced with the goal to make these surgeries even more accurate and safe. However,[for full text, please go to the a.m. URL]
iSYS1 robot system for neurosurgical applications
Objective: Neurosurgery was one of the first clinical applications of robotics and continues to b... more Objective: Neurosurgery was one of the first clinical applications of robotics and continues to be a topic of current interest. Neurosurgical stereotactic applications require high spatial accuracy and precise targeting to reach the anatomy of interest while minimizing collateral damage. The modular[for full text, please go to the a.m. URL]
Open source software platform for interstitial ablation treatment planning
Medical Imaging 2020: Image-Guided Procedures, Robotic Interventions, and Modeling
2017 Design of Medical Devices Conference
Image-guided adaptive brachytherapy (IGABT) is a promising method for precise targeting and treat... more Image-guided adaptive brachytherapy (IGABT) is a promising method for precise targeting and treatment of cervical and prostate cancer where one can adapt the radiation delivery according to tumor spread and organs at risk (OAR). The currently developing procedural modality incorporating optical tracking and transrectal ultrasound (TRUS) for superior soft tissue contrast, later combined with CT data, will likely develop into a readily affordable option, as the use of MRI will become unnecessary [1]. This is especially relevant for developing countries (mainly in SE Africa and S America) where the MRI scanners are scarce and the occurrence specifically of cervical cancer is the highest worldwide [2]. In brachytherapy, the procedure requires either the use of an active source (cervix) or implantation of radioactive seeds (prostate) in an accurate way as to enable sufficient safety margin with respect to the OAR. The sources irradiate the tissue of interest through gynecological (GYN) a...
Journal of imaging, 2021
This paper presents the design of NaviPBx, an ultrasound-navigated prostate cancer biopsy system.... more This paper presents the design of NaviPBx, an ultrasound-navigated prostate cancer biopsy system. NaviPBx is designed to support an affordable and sustainable national healthcare program in Senegal. It uses spatiotemporal navigation and multiparametric transrectal ultrasound to guide biopsies. NaviPBx integrates concepts and methods that have been independently validated previously in clinical feasibility studies and deploys them together in a practical prostate cancer biopsy system. NaviPBx is based entirely on free open-source software and will be shared as a free open-source program with no restriction on its use. NaviPBx is set to be deployed and sustained nationwide through the Senegalese Military Health Service. This paper reports on the results of the design process of NaviPBx. Our approach concentrates on "frugal technology", intended to be affordable for low-middle income (LMIC) countries. Our project promises the wide-scale application of prostate biopsy and will...
Perkutane Nadelprozeduren haben sich zu wichtigen medizinischen Verfahren in Diagnostik und Thera... more Perkutane Nadelprozeduren haben sich zu wichtigen medizinischen Verfahren in Diagnostik und Therapie entwickelt. Zu den gebräuchlichsten Anwendungen gehören die Gewebsentnahme für diagnostische Zwecke (Biopsie) sowie Behandlungsmethoden wie RF-Ablation, Kryo-Ablation, Schmerzbehandlung, Drainagen und andere. Da es während der Platzierung des Werkzeugs – also der Nadel — keinen direkten Sichtkontakt zum Zielbereich gibt, werden diese Verfahren durch präund/oder intra-operative Bildgebung unterstützt. Dieser Bericht beschreibt die Kombination einer neuartigen Roboter-Zielvorrichtung mit dem bildgebenden Verfahren der "Cone-Beam-Computertomographie" (CBCT). Der Schwerpunkt des Artikels liegt auf dem entwickelten Work-Flow für eine nahtlose Integration des Robotersystems in die klinische Umgebung. Ebenso werden Ergebnisse einer ersten multizentrischen Evaluationsstudie dargestellt. Schlüsselworte: Medizin-Robotik, bildgestüzte Diagnose und Therapie, interventionelle Radiologie
Medical robotics — State-of-the-art and future trends
2016 IEEE 20th Jubilee International Conference on Intelligent Engineering Systems (INES), 2016
Summary form only given. The article includes a short introduction into medical robot systems in ... more Summary form only given. The article includes a short introduction into medical robot systems in general, but with a strong focus to surgical applications. Topics include issues such as kinematic configurations, interfaces to existing surgical equipment, but also matters related to standards and regulations. One key aspect for (future) medical robots is related to its main operation principle. Current commercial robot systems are either directly controlled by a human operator or strictly follow a pre-defined path. Automated systems are limited to setups where no direct contact between robot and/or the guided tool takes place, e.g. to compensate (to a certain degree) breathing motion in external radiotherapy or for imaging purposes. On the cognitive side, a long thought-after feature is to estimate what the surgeon would like to do next. This could be taken into account when planning and executing the next movement of the robotized tool or camera. Addition of cognitive capabilities t...
PO-1701: Optimized source-detector trajectories for low dose CBCT
When translating medical technology from concept phase toward a certified product, one will face ... more When translating medical technology from concept phase toward a certified product, one will face many stumbling blocks along the road. Especially in medical robotics, many of the laboratory prototypes described in literature finally failed to show their real potential in clinical use. The presentation outlines some of the lessons learned based on two medical robotic systems with ACMIT involvement. Topics will include technical aspects, standardisation/regulatory aspects, as well as achieved results.
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Papers by Gernot Kronreif