Improving instrument detection for a robotic scrub nurse using multi-view voting

Purpose: A basic task of a robotic scrub nurse is surgical instrument detection. Deep learning techniques could potentially address this task; nevertheless, their performance is subject to some degree of error, which could render them unsuitable for real-world applications. In this work, we aim to demonstrate how the combination of a trained instrument detector with an instance-based voting scheme that considers several frames and viewpoints is enough to guarantee a strong improvement in the instrument detection task. Methods: We exploit the typical setup of a robotic scrub nurse to collect RGB data and point clouds from different viewpoints. Using trained Mask R-CNN models, we obtain predictions from each view. We propose a multi-view voting scheme based on predicted instances that combines the gathered data and predictions to produce a reliable map of the location of the instruments in the scene. Results: Our approach reduces the number of errors by more than 82% compared with the single-view case. On average, the data from five viewpoints are sufficient to infer the correct instrument arrangement with our best model. Conclusion: Our approach can drastically improve an instrument detector’s performance. Our method is practical and can be applied during an actual medical procedure without negatively affecting the surgical workflow. Our implementation and data are made available for the scientific community (https://github.com/Jorebs/Multi-view-Voting-Scheme)

Effect of neoadjuvant chemoradiation and postoperative radiotherapy on expression of heat shock protein 70 (HSP70) in head and neck vessels

<p>Abstract</p> <p>Background</p> <p>Preoperative radiotherapy and chemotherapy in patients with head and neck cancer result in changes to the vessels that are used to construct microsurgical anastomoses. The aim of the study was to investigate quantitative changes and HSP70 expression of irradiated neck recipient vessels and transplant vessels used for microsurgical anastomoses.</p> <p>Methods</p> <p>Of 20 patients included in this study five patients received neoadjuvant chemoradiation, another five received conventional radiotherapy and 10 patients where treated without previous radiotherapy. During surgical procedure, vessel specimens where obtained by the surgeon. Immunhistochemical staining of HSP70 was performed and quantitative measurement and evaluation of HSP70 was carried out.</p> <p>Results</p> <p>Conventional radiation and neoadjuvant chemoradiation revealed in a thickening of the intima layer of recipient vessels. A increased expression of HSP70 could be detected in the media layer of the recipient veins as well as in the transplant veins of patients treated with neoadjuvant chemoradiation. Radiation and chemoradiation decreased the HSP70 expression of the intima layer in recipient arteries. Conventional radiation led to a decrease of HSP70 expression in the media layer of recipient arteries.</p> <p>Conclusion</p> <p>Our results showed that anticancer drugs can lead to a thickening of the intima layer of transplant and recipient veins and also increase the HSP70 expression in the media layer of the recipient vessels. In contrast, conventional radiation decreased the HSP70 expression in the intima layer of arteries and the media layer of recipient arteries and veins. Comparing these results with wall thickness, it was concluded, that high levels of HSP70 may prevent the intima layer of arteries and the media layer of vein from thickening.</p

Deep-learning-based instrument detection for intra-operative robotic assistance

Purpose: Robotic scrub nurses have the potential to become an attractive solution for the operating room. Surgical instrument detection is a fundamental task for these systems, which is the focus of this work. We address the detection of the complete surgery set for wisdom teeth extraction, and propose a data augmentation technique tailored for this task. Methods: Using a robotic scrub nurse system, we create a dataset of 369 unique multi-instrument images with manual annotations. We then propose the Mask-Based Object Insertion method, capable of automatically generating a large amount of synthetic images. By using both real and artificial data, different Mask R-CNN models are trained and evaluated. Results: Our experiments reveal that models trained on the synthetic data created with our method achieve comparable performance to that of models trained on real images. Moreover, we demonstrate that the combination of real and our artificial data can lead to a superior level of generalization. Conclusion: The proposed data augmentation technique is capable of dramatically reducing the labelling work required for training a deep-learning-based detection algorithm. A dataset for the complete instrument set for wisdom teeth extraction is made available for the scientific community, as well as the raw information required for the generation of the synthetic data (https://github.com/Jorebs/Deep-learning-based-instrument-detection-for-intra operative-robotic-assistance)

No Significant Bone Resorption after Open Treatment of Mandibular Condylar Head Fractures in the Medium-Term

Open treatment of condylar head fractures (CHF) is considered controversial. In this retrospective cohort study our primary objective was therefore to assess bone resorption and remodeling as well as patients function after open treatment of CHF in a medium-term follow-up (15.1 ± 2.2 months). We included 18 patients with 25 CHF who underwent open reduction and internal fixation, between 2016 and 2021, in our analysis. The clinical data and cone-beam computed tomography (CBCT) datasets were analyzed. The condylar processes were segmented in the postoperative (T1) and follow-up (T2) CBCT scans. Volumetric and linear bone changes were the primary outcome variables, measured by using a sophisticated 3D-algorithm. The mean condylar head volume decreased non-significantly from 3022.01 ± 825.77 mm3 (T1) to 2878.8 ± 735.60 mm3 (T2; p = 0.52). Morphological alterations indicated remodeling and resorption. The pre-operative maximal interincisal opening (MIO) was 19.75 ± 3.07 mm and significantly improved to 40.47 ± 1.7 mm during follow-up (p = 0.0005). Low rates of postoperative complications were observed. Open reduction of CHF leads to good clinical outcomes and low rates of medium-term complications. This study underlines the feasibility and importance of open treatment of CHF and may help to spread its acceptance as the preferred treatment option

Myxolipoma in the tongue - A clinical case report and review of the literature

In this article, we present our experience with a case of myxolipoma of the tongue

Alendronate reduces periosteal microperfusion in vivo

OBJECTIVES: Bisphosphonates are known to induce a severe adverse effect known as medication-related osteonecrosis of the jaw (MRONJ). Previous studies have proven the impact of bisphosphonates on microperfusion; therefore, this study aimed to investigate alendronate-induced microcirculatory reactions in the calvarial periosteum of rats. STUDY DESIGN: Bone chambers were implanted into 48 Lewis rats. Microhemodynamics, inflammatory parameters, functional capillary density and defect healing were examined after alendronate treatment for two and six weeks using repetitive intravital fluorescence microscopy for two weeks. RESULTS: Microhemodynamics remained unchanged. In alendronate-treated rats, inflammation was slightly increased, functional capillary density was significantly reduced (day 10: controls 100.45 ± 5.38 cm/cm$^{2}$, two weeks alendronate treatment 44.77 ± 3.55 cm/cm$^{2}$, six weeks alendronate treatment 27.54 ± 2.23 cm/cm$^{2}$) and defect healing was decelerated. The changes in functional capillary density and defect healing were dose-dependent. CONCLUSION: The bisphosphonate alendronate has a significant negative impact on periosteal microperfusion in vivo. This could be a promising target for the treatment of MRONJ

Increase in periosteal angiogenesis through heat shock conditioning

<p>Abstract</p> <p>Objective</p> <p>It is widely known that stress conditioning can protect microcirculation and induce the release of vasoactive factors for a period of several hours. Little, however, is known about the long-term effects of stress conditioning on microcirculation, especially on the microcirculation of the periosteum of the calvaria. For this reason, we used intravital fluorescence microscopy to investigate the effects of heat shock priming on the microcirculation of the periosteum over a period of several days.</p> <p>Methods</p> <p>Fifty-two Lewis rats were randomized into eight groups. Six groups underwent heat shock priming of the periosteum of the calvaria at 42.5°C, two of them (n = 8) for 15 minutes, two (n = 8) for 25 minutes and two (n = 8) for 35 minutes. After 24 hours, a periosteal chamber was implanted into the heads of the animals of one of each of the two groups mentioned above. Microcirculation and inflammatory responses were studied repeatedly over a period of 14 days using intravital fluorescence microscopy. The expression of heat shock protein (HSP) 70 was examined by immunohistochemistry in three further groups 24 hours after a 15-minute (n = 5), a 25-minute (n = 5) or a 35-minute (n = 5) heat shock treatment. Two groups that did not undergo priming were used as controls. One control group (n = 8) was investigated by intravital microscopy and the other (n = 5) by immunohistochemistry.</p> <p>Results</p> <p>During the entire observation period of 14 days, the periosteal chambers revealed physiological microcirculation of the periosteum of the calvaria without perfusion failures. A significant (p < 0.05) and continuous increase in functional capillary density was noted from day 5 to day 14 after 25-minute heat shock priming. Whereas a 15-minute exposure did not lead to an increase in functional capillary density, 35-minute priming caused a significant but reversible perfusion failure in capillaries. Non-perfused capillaries in the 35-minute treatment group were reperfused by day 10. Immunohistochemistry demonstrated an increase in cytoprotective HSP70 expression in the periosteum after a 15-minute and a 35-minute heat shock pretreatment when compared with the control group. The level of HSP70 expression that was measured in the periosteum after 25 minutes of treatment was significantly higher than the levels observed after 15 or 35 minutes of heat shock exposure.</p> <p>Conclusion</p> <p>A few days after heat shock priming over an appropriate period of time, a continuous increase in functional capillary density is seen in the periosteum of the calvaria. This increase in perfusion appears to be the result of the induction of angiogenesis.</p