Robot assisted stapedotomy ex vivo with an active handheld instrument

Micron is a fully handheld active micromanipulator that helps to improve position accuracy and precision in microsurgery by cancelling hand tremor. This work describes adaptation, tuning, and testing of the Micron system for stapedotomy, a microsurgical procedure performed in the middle ear to restore hearing that requires accurate manipulation in narrow spaces. Two end-effectors, a handle, and a brace (or rest) were designed and prototyped. The control system was adapted for the new hardware. The system was tested ex vivo in stapedotomy procedure comparing manually-performed and Micron-assisted surgical tasks. Tremor amplitude was found to be reduced significantly. Further testing is needed in order to obtain statistically significant results regarding other parameters dealing with regularity of the fenestra shap

Temporal Matching in Endoscopic Images for Remote-Controlled Robotic Surgery

Temporal matching is applied in the frame of the formation of high-level entities in remote-controlled robotic surgery. The objective is to track tumor boundaries over time to improve the segmentation stage in each image of the sequence to facilitate the tracking and localization of the tumor. It makes use of an attributed string matching technique to find the correspondence between tumor boundaries over time. Relationships are then exploited to reconstitute the tumor boundaries and remove the inconsistencies coming from the detection errors. Input data are free form shapes of different length representing the tumor boundary, extracted at a previous stage

The future of robotic surgery

© 2018 Royal College of Surgeons.For 20 years Intuitive Surgical’s da Vinci® system has held the monopoly in minimally invasive robotic surgery. Restrictive patenting, a well-developed marketing strategy and a high-quality product have protected the company’s leading market share.1 However, owing to the nuances of US patenting law, many of Intuitive Surgical’s earliest patents will be expiring in the next couple of years. With such a shift in backdrop, many of Intuitive Surgical’s competitors (from medical and industrial robotic backgrounds) have initiated robotic programmes – some of which are available for clinical use now. The next section of the review will focus on new and developing robotic systems in the field of minimally invasive surgery (Table 1), single-site surgery (Table 2), natural orifice transluminal endoscopic surgery (NOTES) and non-minimally invasive robotic systems (Table 3).Peer reviewedFinal Published versio

Potential of silicon nanowires structures as nanoscale piezoresistors in mechanical sensors.

This paper presents the design of a single square millimeter 3-axial accelerometer for bio-mechanics measurements that exploit the potential of silicon nanowires structures as nanoscale piezoresistors. The main requirements of this application are miniaturization and high measurement accuracy. Nanowires as nanoscale piezoresistive devices have been chosen as sensing element, due to their high sensitivity and miniaturization achievable. By exploiting the electro-mechanical features of nanowires as nanoscale piezoresistors, the nominal sensor sensitivity is overall boosted by more than 30 times. This approach allows significant higher accuracy and resolution with smaller sensing element in comparison with conventional devices without the need of signal amplification

Potential of silicon nanowires structures as nanoscale piezoresistors in mechanical sensors

This paper presents the design of a single square millimeter 3-axial accelerometer for bio-mechanics measurements that exploit the potential of silicon nanowires structures as nanoscale piezoresistors. The main requirements of this application are miniaturization and high measurement accuracy. Nanowires as nanoscale piezoresistive devices have been chosen as sensing element, due to their high sensitivity and miniaturization achievable. By exploiting the electro-mechanical features of nanowires as nanoscale piezoresistors, the nominal sensor sensitivity is overall boosted by more than 30 times. This approach allows significant higher accuracy and resolution with smaller sensing element in comparison with conventional devices without the need of signal amplification

Comparative Evaluation of Monocular Augmented-Reality Display for Surgical Microscopes

Abstract-Medical augmented reality has undergone much development recently. However, there is a lack of studies quantitatively comparing the different display options available. This paper compares the effects of different graphical overlay systems in a simple micromanipulation task with "soft" visual servoing. We compared positioning accuracy in a real-time visually-guided task using Micron, an active handheld tremor-canceling microsurgical instrument, using three different displays: 2D screen, 3D screen, and microscope with monocular image injection. Tested with novices and an experienced vitreoretinal surgeon, display of virtual cues in the microscope via an augmented reality injection system significantly decreased 3D error (p < 0.05) compared to the 2D and 3D monitors when confounding factors such as magnification level were normalized

Composition-Dependent Mechanisms of Multiscale Tendon Mechanics

Tendons serve as an integral part of the musculoskeletal system by transferring loads from muscle to bone and providing joint mobility and stability. From the physiologically-loading perspective, while progress has been made in evaluating mechanical behavior of different types of tendons in tension, further work is needed to relate tendon mechanics to compositional and microstructural properties, particularly under non-tensile loading modalities (i.e., shear, compression). This information is vital to explore mechanisms of how mechanical signals lead to changes in tendon structure and composition to enable these tissues to function properly, including in in vivo multiaxial loading conditions. From the structural perspective, tendon exhibits a hierarchical organization as collagen is bundled into fibrils, fibers, fascicles, and finally full tissue. Within this hierarchy, linking components are believed to act as connections to maintain mechanical integrity. Three linking components have been proposed, namely elastic fibers, proteoglycans, and collagen crosslinks, however conclusions about their specific mechanical roles, assessed using experimental and computational approaches, are inconsistent. In addition, it remains unknown whether/how these linking components regulate tendon microscale behavior (i.e., at the level of cells) and mechanical signal transfer across length scales. Therefore, this study aimed to (1) develop a protocol that combined a biomechanical test device with two-photon microscopy to measure tendon mechanical strength and multiscale deformation; (2) apply this experimental approach to evaluate region-dependent biomechanics of tendons and related physical mechanisms governing their microscale behavior; (3) determine the role of proteoglycans and elastic fibers in tendon multiscale mechanical behavior using enzyme-treated tendons; and (4) elucidate the contribution of collagen crosslinks to tendon mechanics using in vivo treatment and in vitro culture. We found that different regions of bovine flexor tendon exhibited distinct elasticity, but not viscosity, when subjected to shear and compression, and that fiber sliding and reorganization were the primary modes of microscale deformation. Elastic fibers contributed to supraspinatus tendon (SST) mechanical strength in shear, while proteoglycans appeared to not contribute to SST multiscale biomechanics. Rat SST with decreased collagen crosslink density showed inferior mechanical properties, demonstrating the role of collagen crosslinks on tendon mechanical behavior. Taken together, these results have illustrated tendon composition-mechanics relationships by evaluating mechanical contribution of specific linking components at different length scales. In addition, this work provides insight into mechanical consequences that may accompany extracellular matrix changes during tissue injury/degeneration, and as well provides useful data to aid the design of biomimetic engineered tissues with appropriate structure and composition