1
|
Schoovaerts M, Ourak M, Borghesan G, Putzeys T, Poorten EV, Verhaert N. OCT-based intra-cochlear imaging and 3D reconstruction: ex vivo validation of a robotic platform. Int J Comput Assist Radiol Surg 2024:10.1007/s11548-024-03081-7. [PMID: 38436923 DOI: 10.1007/s11548-024-03081-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/15/2024] [Indexed: 03/05/2024]
Abstract
PURPOSE The small size of the cochlea, and its location deeply embedded in thick temporal bone, poses a challenge for intra-cochlear guidance and diagnostics. Current radiological imaging techniques are not able to visualize the cochlear microstructures in detail. Rotational optical coherence tomography (OCT) fibers show great potential for intra-cochlear guidance. The generated images could be used to map, and study, the tiny cochlear microstructures relevant for hearing. METHODS This work describes the design of a rotational OCT probe with an outer diameter of 0.9 mm. It further discusses a robotic system, which features a remote center of motion mechanism, dedicated to the probe's positioning, fine manipulation and stable insertion into the cochlear micro-spaces. Furthermore, the necessary calibration steps for 3D reconstruction are described, followed by a detailed quantitative analysis, comparing the 3D reconstructions using a synthetic, 2:1 scaled scala tympani model with a reconstruction from micro-CT, serving as the ground truth. Finally, the potential of the system is demonstrated by scanning a single ex vivo cadaveric human cochlea. RESULTS The study investigates five insertions in the same 2:1 scaled tympani model, along with their corresponding 3D reconstruction. The comparison with micro-CT results in an average root-mean-square error of 74.2 µm, a signed distance error of 38.1 µm and a standard deviation of 63.6 µm. The average F-score of the reconstructions, using a distance threshold of 100 and 74.2 µm, resulted in 83.0% and 71.8%, respectively. Insertion in the cadaveric human cochlea showed the challenges for straight insertion, i.e., navigating the hook region. CONCLUSION Overall, the system shows great potential for intra-cochlear guidance and diagnostics, due to the system's capability for precise and stable insertion into the basal turn in the scala tympani. The system, combined with the calibration procedure, results in detailed and precise 3D reconstructions.
Collapse
Affiliation(s)
- Maarten Schoovaerts
- Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300, 3001, Leuven, Belgium.
- Department of Neurosciences, KU Leuven, Herestraat 49, 3001, Leuven, Belgium.
| | - Mouloud Ourak
- Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300, 3001, Leuven, Belgium
| | - Gianni Borghesan
- Department of Mechanical Engineering, KU Leuven, Celestijnenlaan 300, 3001, Leuven, Belgium
- Flanders Make, KU Leuven, Celestijnenlaan 300, 3001, Leuven, Belgium
| | - Tristan Putzeys
- Department of Neurosciences, KU Leuven, Herestraat 49, 3001, Leuven, Belgium
- Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200, 3001, Leuven, Belgium
| | | | - Nicolas Verhaert
- Department of Neurosciences, KU Leuven, Herestraat 49, 3001, Leuven, Belgium
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Leuven, Herestraat 49, 3001, Leuven, Belgium
| |
Collapse
|
2
|
Schulte B, Göb M, Singh AP, Lotz S, Draxinger W, Heimke M, Pieper M, Heinze T, Wedel T, Rahlves M, Huber R, Ellrichmann M. High-resolution rectoscopy using MHz optical coherence tomography: a step towards real time 3D endoscopy. Sci Rep 2024; 14:4672. [PMID: 38409328 PMCID: PMC10897148 DOI: 10.1038/s41598-024-55338-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 02/22/2024] [Indexed: 02/28/2024] Open
Abstract
Colonoscopy and endoscopic ultrasound play pivotal roles in the assessment of rectal diseases, especially rectal cancer and inflammatory bowel diseases. Optical coherence tomography (OCT) offers a superior depth resolution, which is a critical factor for individualizing the therapeutic concept and evaluating the therapy response. We developed two distinct rectoscope prototypes, which were integrated into a 1300 nm MHz-OCT system constructed at our facility. The rapid rotation of the distal scanning probe at 40,000 revolutions per minute facilitates a 667 Hz OCT frame rate, enabling real-time endoscopic imaging of large areas. The performance of these OCT-rectoscopes was assessed in an ex vivo porcine colon and a post mortem human in-situ colon. The OCT-rectoscope consistently distinguished various layers of the intestinal wall, identified gut-associated lymphatic tissue, and visualized a rectal polyp during the imaging procedure with 3D-reconstruction in real time. Subsequent histological examination confirmed these findings. The body donor was preserved using an ethanol-glycerol-lysoformin-based technique for true-to-life tissue consistency. We could demonstrate that the novel MHZ-OCT-rectoscope effectively discriminates rectal wall layers and crucial tissue characteristics in a post mortem human colon in-situ. This real-time-3D-OCT holds promise as a valuable future diagnostic tool for assessing disease state and therapy response on-site in rectal diseases.
Collapse
Affiliation(s)
- Berenice Schulte
- Interdisciplinary Endoscopy, Medical Department 1, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Madita Göb
- Institute of Biomedical Optics, University of Luebeck, Luebeck, Germany
| | | | - Simon Lotz
- Institute of Biomedical Optics, University of Luebeck, Luebeck, Germany
| | | | - Marvin Heimke
- Center of Clinical Anatomy, Institute of Anatomy, Christian-Albrechts University Kiel, Kiel, Germany
| | - Mario Pieper
- Institute of Anatomy, University of Luebeck, Luebeck, Germany
- Airway Research Center North (ARCN), German Center for Lung Research (DZL), Luebeck, Germany
| | - Tillmann Heinze
- Center of Clinical Anatomy, Institute of Anatomy, Christian-Albrechts University Kiel, Kiel, Germany
| | - Thilo Wedel
- Center of Clinical Anatomy, Institute of Anatomy, Christian-Albrechts University Kiel, Kiel, Germany
| | - Maik Rahlves
- Institute of Biomedical Optics, University of Luebeck, Luebeck, Germany
| | - Robert Huber
- Institute of Biomedical Optics, University of Luebeck, Luebeck, Germany
| | - Mark Ellrichmann
- Interdisciplinary Endoscopy, Medical Department 1, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
| |
Collapse
|
3
|
Singh AP, Göb M, Ahrens M, Eixmann T, Schulte B, Schulz-Hildebrandt H, Hüttmann G, Ellrichmann M, Huber R, Rahlves M. Virtual Hall sensor triggered multi-MHz endoscopic OCT imaging for stable real-time visualization. OPTICS EXPRESS 2024; 32:5809-5825. [PMID: 38439298 DOI: 10.1364/oe.514636] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/18/2024] [Indexed: 03/06/2024]
Abstract
Circumferential scanning in endoscopic imaging is crucial across various disciplines, and optical coherence tomography (OCT) is often the preferred choice due to its high-speed, high-resolution, and micron-scale imaging capabilities. Moreover, real-time and high-speed 3D endoscopy is a pivotal technology for medical screening and precise surgical guidance, among other applications. However, challenges such as image jitter and non-uniform rotational distortion (NURD) are persistent obstacles that hinder real-time visualization during high-speed OCT procedures. To address this issue, we developed an innovative, low-cost endoscope that employs a brushless DC motor for scanning, and a sensorless technique for triggering and synchronizing OCT imaging with the scanning motor. This sensorless approach uses the motor's electrical feedback (back electromotive force, BEMF) as a virtual Hall sensor to initiate OCT image acquisition and synchronize it with a Fourier Domain Mode-Locked (FDML)-based Megahertz OCT system. Notably, the implementation of BEMF-triggered OCT has led to a substantial reduction in image jitter and NURD (<4 mrad), thereby opening up a new window for real-time visualization capabilities. This approach suggests potential benefits across various applications, aiming to provide a more accurate, deployable, and cost-effective solution. Subsequent studies can explore the adaptability of this system to specific clinical scenarios and its performance under practical endoscopic conditions.
Collapse
|
4
|
Robotic needle steering: state-of-the-art and research challenges. INTEL SERV ROBOT 2022. [DOI: 10.1007/s11370-022-00446-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
5
|
Liao G, Caravaca-Mora O, Rosa B, Zanne P, Dall Alba D, Fiorini P, de Mathelin M, Nageotte F, J. Gora M. Distortion and Instability Compensation with Deep Learning for Rotational Scanning Endoscopic Optical Coherence Tomography. Med Image Anal 2022; 77:102355. [DOI: 10.1016/j.media.2022.102355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 12/22/2021] [Accepted: 01/06/2022] [Indexed: 11/27/2022]
|
6
|
Zhang Z, Rosa B, Caravaca-Mora O, Zanne P, Gora MJ, Nageotte F. Image-Guided Control of an Endoscopic Robot for OCT Path Scanning. IEEE Robot Autom Lett 2021. [DOI: 10.1109/lra.2021.3087085] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
7
|
Zeng Y, Chapman WC, Lin Y, Li S, Mutch M, Zhu Q. Diagnosing colorectal abnormalities using scattering coefficient maps acquired from optical coherence tomography. JOURNAL OF BIOPHOTONICS 2021; 14:e202000276. [PMID: 33064368 PMCID: PMC8196414 DOI: 10.1002/jbio.202000276] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/08/2020] [Accepted: 10/11/2020] [Indexed: 05/30/2023]
Abstract
Optical coherence tomography (OCT) has shown potential in differentiating normal colonic mucosa from neoplasia. In this study of 33 fresh human colon specimens, we report the first use of texture features and computer vision-based imaging features acquired from en face scattering coefficient maps to characterize colorectal tissue. En face scattering coefficient maps were generated automatically using a new fast integral imaging algorithm. From these maps, a gray-level cooccurrence matrix algorithm was used to extract texture features, and a scale-invariant feature transform algorithm was used to derive novel computer vision-based features. In total, 25 features were obtained, and the importance of each feature in diagnosis was evaluated using a random forest model. Two classifiers were assessed on two different classification tasks. A support vector machine model was found to be optimal for distinguishing normal from abnormal tissue, with 94.7% sensitivity and 94.0% specificity, while a random forest model performed optimally in further differentiating abnormal tissues (i.e., cancerous tissue and adenomatous polyp) with 86.9% sensitivity and 85.0% specificity. These results demonstrated the potential of using OCT to aid the diagnosis of human colorectal disease.
Collapse
Affiliation(s)
- Yifeng Zeng
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, USA
| | - William C Chapman
- Department of Surgery, Section of Colon and Rectal Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Yixiao Lin
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, USA
| | - Shuying Li
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, USA
| | - Matthew Mutch
- Department of Surgery, Section of Colon and Rectal Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Quing Zhu
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, USA
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
8
|
Multimodal imaging with integrated auto-fluorescence and optical coherence tomography for identification of neck tissues. Lasers Med Sci 2020; 36:1023-1029. [PMID: 32895854 DOI: 10.1007/s10103-020-03139-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/27/2020] [Indexed: 10/23/2022]
Abstract
We report a multimodal optical system by combining OCT with autofluorescence imaging for identifying neck tissues, which can use the advantages of large field of view and high sensitivity for identifying parathyroid glands of fluorescence imaging, and high-resolution structural imaging of OCT to confirm them and identify lymph nodes and metastatic lymph nodes at the same time. It is proven that this multimodal optical system can be used to identify different neck tissues effectively and efficiently. We think that integrated auto-fluorescence and OCT imaging have the great potential in the application of navigation and assistant diagnosis of thyroid surgery.
Collapse
|