Добірка наукової літератури з теми "Surgical microgripper"

Traditional open surgery complications are typically due to trauma caused by accessing the procedural site rather than the procedure itself. Minimally invasive surgery allows for fewer complications as microdevices operate through small incisions or natural orifices. However, current minimally invasive tools typically have restricted maneuverability, accessibility, and positional control of microdevices. Thermomagnetic-responsive microgrippers are microscopic multi-fingered devices that respond to temperature changes due to the presence of thermal-responsive polymers. Polymeric devices, made of poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM-AAc) and polypropylene fumarate (PPF), self-fold due to swelling and contracting of the hydrogel layer. In comparison, soft metallic devices feature a pre-stressed metal bilayer and polymer hinges that soften with increased temperature. Both types of microdevices can self-actuate when exposed to the elevated temperature of a cancerous tumor region, allowing for direct targeting for biopsies. Microgrippers can also be doped to become magnetically responsive, allowing for direction without tethers and the retrieval of microdevices containing excised tissue. The smaller size of stimuli-responsive microgrippers allows for their movement through hard-to-reach areas within the body and the successful extraction of intact cells, RNA and DNA. This review discusses the mechanisms of thermal- and magnetic-responsive microdevices and recent advances in microgripper technology to improve minimally invasive surgical techniques.

SUMMARYThis paper presents a new type of forceps that consist of two microgrippers with the capability of direct force sensing, which enables grasping and manipulating forces at the tip of surgical instrument for minimally invasive robotic surgery. For the prototype design of the forceps, a double E-type vertical elastomer with four strain beams is presented, whose force-sensing principle is expounded. Thus, the forceps with the elastomer can be considered a compliant component, which provides tiny displacements that allow large strain, and the overall diameter is 10 mm. The sizes of the elastomer and forceps are successively determined by analyzing the relationship of several parameters and strain. Then, the linearity analysis of strain beams determines the positions to apply gauges for sensing. The two-dimensional force decoupling models for a single microgripper are proposed based on piecewise analytical polynomials of the strain difference and employed to develop a new three-dimensional force nonlinear decoupling algorithm based on double microgrippers, which realizes single-axial grasping and three-axial pulling forces. Finally, the required force-sensing performance of the proposed method is successfully verified in theory using finite-element simulations.

Micro Electro Mechanical Systems (MEMS)-Technology based micro mechanisms usually operate within a protected or encapsulated space and, before that, they are fabricated and analyzed within one Scanning Electron Microscope (SEM) vacuum specimen chamber. However, a surgical scenario is much more aggressive and requires several higher abilities in the microsystem, such as the capability of operating within a liquid or wet environment, accuracy, reliability and sophisticated packaging. Unfortunately, testing and characterizing MEMS experimentally without fundamental support of a SEM is rather challenging. This paper shows that in spite of large difficulties due to well-known physical limits, the optical microscope is still able to play an important role in MEMS characterization at room conditions. This outcome is supported by the statistical analysis of two series of measurements, obtained by a light trinocular microscope and a profilometer, respectively.

Abstract This review article provides an overview of some challenges that arise when developing new medical robotic microgrippers. The main challenges are due to miniaturization and are present in the manufacturing and assembly processes, the types of mechanisms, the biomaterials used, the actuation principles, and the compliance with some standards and regulations. The main medical fields where these microgrippers are used are in MIS and biomedical applications. Therefore, taking these two large groups into account, this review presents a microgrippers classification according to the type of mechanism used (traditional rigid-body mechanisms and complaint mechanisms). Moreover, parameters such as applications, functionalities, DOF, sizes, range of motion, biomaterial used, and proposed methods are highlighted. In total, the analysis of 21 microgrippers among commercial and developed by research institutes is presented.

AbstractMicrogrippers, a branch of micro/nanorobots, refer to motile miniaturized machines that are of a size in the range of several to hundreds of micrometers. Compared with tethered grippers or other microscopic diagnostic and surgical equipment, untethered microgrippers play an indispensable role in biomedical applications because of their characteristics such as miniaturized size, dexterous shape tranformation, and controllable motion, which enables the microgrippers to enter hard‐to‐reach regions to execute specific medical tasks for disease diagnosis and treatment. To date, numerous medical microgrippers are developed, and their potential in cell manipulation, targeted drug delivery, biopsy, and minimally invasive surgery are explored. To achieve controlled locomotion and efficient target‐oriented actions, the materials, size, microarchitecture, and morphology of microgrippers shall be deliberately designed. In this review, the authors summarizes the latest progress in untethered micrometer‐scale grippers. The working mechanisms of shape‐morphing and actuation methods for effective movement are first introduced. Then, the design principle and state‐of‐the‐art fabrication techniques of microgrippers are discussed. Finally, their applications in the precise medicine are highlighted, followed by offering future perspectives for the development of untethered medical microgrippers.

Ce travail de recherche porte sur la modélisation et l'analyse de la dégradation d'une micropince pour la chirurgie intracorporelle. Nous avons d'abord mené une revue de la littérature pour identifier les limites de la mise en œuvre du pronostic et de la gestion de santé dans les microsystèmes médicaux. Deuxièmement, une méthodologie basée sur la gestion des risques selon la norme ISO 14971 pour les dispositifs médicaux a été développée afin de sélectionner les composants critiques de la micro-pince. Ensuite, les données ont été collectées sur la cinématique du système de micro-pince, en considérant les variables de position angulaire, de vitesse, d'accélération et de jerk, à travers une méthodologie incluant les exigences en matière de données, les méthodes et les protocoles. Une fois les données disponibles, une analyse des données a été réalisée, ce qui a permis de comprendre le comportement de dégradation du système de micro-pince. Cette analyse a conduit à l'identification de trois étapes distinctes de dégradation, classées en trois zones : sécurité, dégradation et critique. En outre, il a été identifié que plus la plage de fermeture est grande, plus le nombre de cycles avant l'apparition de la défaillance est faible. Enfin, pour prédire la durée de vie utile du système de micro-pince, une approche basée sur le Gradient Boosting et le réseau de neurones (acronyme anglais LSTM) a été mise en œuvre. La performance de l'approche proposée a été validée par les résultats de certaines métriques, ainsi que par la mise en œuvre de la prédiction en ligne de la vie restante
This research work deals with the degradation modeling and analysis for a microgripper for intracorporeal surgery. We first conducted a literature review to identify limitations for Prognostics and Health Management (PHM) implementation in medical microsystems. Secondly, a methodology based on risk management according to ISO 14971 for medical devices was developed to select the critical components of the microgripper. Thirdly, the data was collected on the microgripper system's kinematics, considering the angular position, velocity, acceleration, and jerk variables through a methodology that included data requirements, methods, and protocols. Once data were available, data analysis was performed, which allowed an understanding of the degradation behavior of the microgripper system, this understanding led to the identification of three distinct stages of degradation, which were categorized into three zones: safety, degradation, and critical. Moreover, it was identified the larger the closing range, the lower the number of cycles before failure occurs. Lastly, to predict the remaining useful life (RUL) of the microgripper system, a machine learning and deep learning approach was implemented. This approach consisted of fusing Gradient Boosting and Long short-term memory (LSTM) results to predict the RUL. The proposed approach performance was validated by the results of the RMSE, MAE, and R^2 metrics, as well as the online RUL implementation