53 research outputs found

    Force-based assessment of tissue handling skills

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    In laparoscopic surgery, special instruments with long and slender shafts are inserted through small incisions in the abdominal wall. A laparoscope is used for a clear vision inside the inflated abdominal cavity while laparoscopic graspers and cutters are used for manipulation of tissue. The use of long instruments makes it difficult to ā€œfeelā€ the force exerted on tissue during manipulation especially when friction factors disturb the force sensation even further. Tissue manipulation plays an important role in surgery and there is relatively little knowledge of forces applied on tissue during surgery. The main objectives of this thesis were to develop force measurement systems to measure the forces during training, to combine motion and force measurements to come to objective assessment of training of basic MIS skills, and finally to develop force feedback systems to improve force application during training. The first part of this thesis focuses on the force exerted by the instrument tips during placement of surgical sutures. In many educational programs in surgery, the suture task is used to test the technical skills of the trainee. We proved that the force exerted on the suture pad can be recorded without modification of the instruments or suture pad if a 3DOF force sensor is placed under the suture pad in a box trainer. We showed that performance parameters can be calculated from recorded force data to expose skills important for safe tissue handling during suturing. A validation study showed that it is possible to classify participants with an accuracy of 84% if only force parameters are used. The second part of this thesis describes a method to reduce the tissue handling force of trainees. By generating a virtual arrow in the laparoscopic image that represents the size and direction of the exerted force during suturing in real time, we found that training with well explained visual feedback can help trainees to minimize the interaction force during needle insertion in a box trainer. For training of wound suturing outside the box trainer, we found that colours, representing the exerted force on the tissue, can help trainees to balance forces between the two tensioned threads during knot tying and to improve the quality of the knot. In another study we showed that it is possible to inform the surgeon about the pulling force during surgery if a small and lightweight sensor is used that can be easily attached to the tensioned thread. The third part of this thesis we integrated the TrEndo and a force platform into ForMoST, a box trainer that measures both tissue handling force as instrument motion. For this box trainer we developed and validated two new bimanual training tasks for training of tissue handling. The validation study performed with novices, intermediates and experts indicated that force parameters are not strongly correlated to motion parameters and that force and motion parameters have similar discriminative power in both tasks. A study performed with novices that received visual force feedback or visual time feedback during training indicated that visual force feedback during training reduces the tissue manipulation force significantly even when a post task is performed that is different from the training task. We showed that training with visual force feedback improves tissue handling skills with no negative effect on task time and instrument motion and that training with visual time feedback improves instrument motion and task time, but does not improve tissue manipulation skills. This thesis contributes to the field of training of surgical skills in multiple ways. Mechanical force sensors were developed that can be used for training of tissue handling, to find force thresholds for traction on tissues or for safety monitoring during suturing of incisions. It is shown that force parameters that reflect tissue handling or suture tension, can now be used to inform surgeons about the risk of tissue damage while training laparoscopic skills or suturing tissues.BioMechanical EngineeringMechanical, Maritime and Materials Engineerin

    Surgical Instrument

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    The present invention relates to a surgical instrument for minimall-invasive surgery, comprising a handle, a shaft and an actuating part, characterised by a gastight cover surrounding the shaft, wherein the cover is provided with a coupler that has a feed- through opening with a loskable seal, through which feed- through opening, after the seal is unlocked, the shaft with the actuating part can reach.Mechanical, Maritime and Materials Engineerin

    Surgical device, in particular for minimally invasive surgery

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    Surgical device, in particular for minimally invasive surgery, provided with a shaft having a distal end to which a surgical instrument is mounted or mountable and a proximal end equipped for handling the instrument, wherein the shaft is hollow and the surgical instrument is mounted or mountable on inserts that are longitudinally movable in the said shaft parallel to the longitudinal axis of the shaft, which inserts are provided diametrically opposed to each other within said shaft. The shaft comprises an outer tube and an inner tube which are rotatable in opposite directions with respect to the longitudinal axis of the shaft, and the inserts are coupled to the outer tube and the inner tube so as to convert rotational movement of said tubes into longitudinal movement of the inserts.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin

    Duurzame robotchirurgie

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    Chirurgische robotsystemen winnen aanzienlijk aan populariteit in de medische wereld vanwege hun voordelen op het gebied van precisie, comfort en behendigheid voor de chirurg, wat resulteert in een verbeterd chirurgisch resultaat. Deze voordelen gelden voor ziekenhuizen over de hele wereld, maar zijn niet overal even toegankelijk. Complexe systemen vereisen meer onderhoud, meer training voor gebruik, een aanzienlijke hoeveelheid ruimte, een grote financiƫle investering en ingewikkelde reinigings- en sterilisatieprocessen. Hierdoor is het integreren van deze robotsystemen toch vaak een uitdaging door de beperkte financiƫn en infrastructuur in kleinere ziekenhuizen. Dergelijke barricades leiden er vaak toe dat de technologie onbereikbaar wordt in omgevingen die het soms het hardste nodig hebben. De ontwikkeling van goedkope robotsystemen lijkt daarom de sleutel voor minder bedeelde ziekenhuizen om toch toegang te krijgen tot de voordelen die robotchirurgie kent.Medical Instruments & Bio-Inspired Technolog

    Differences in abdominal force between conventional and single port laparoscopy

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    In laparoendoscopic single-site surgery (LESS), only one single incision is used to introduce all instruments into the abdominal cavity. The introduction of multi-channel single-port devices enabled insertion of laparoscopic instruments and laparoscope through one single entry point instead of multiple entry points in conventional laparoscopic surgery (CLS). From recent studies is known that the distance between instruments influences the force exerted on tissue during manipulation. To investigate whether this force difference can also be found on the abdominal wall, a two-dimensional force measurement mechanism was designed and incorporated in a standard trainer box. The sensors were used to measure the abdominal force exerted by either the standard trocar or the single-port device on the artificial skin that mimics the abdominal wall. A randomized crossover study consisted of 16 students and three experienced surgeons was conducted. The subjects were asked to perform a task with two different instrument configurations (CLS and LESS) in randomized order. The results showed that when performing a force-related task with LESS configuration, the maximum abdominal force was significantly higher compared with the conventional twoport CLS configuration.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin

    SATA-LRS: A modular and novel steerable hand-held laparoscopic instrument platform for low-resource settings<sup>ā˜†</sup>

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    Background: Hospitals in low resource settings (LRS) can benefit from modern laparoscopic methodologies. However, cleaning, maintenance and costs requirements play a stronger role while training and technology are less available. Steerable laparoscopic instruments have additional requirements in these settings and need extra identified adaptations in their design. Method: Several modular detachability and tip steerability features were applied to the SATA-LRS instrument platform designed specifically for LRS. Ten subjects participated a dis- and reassembly experiment to validate the modularity, and in a steering experiment using a custom made set-up to validate steering. Results: A new steerable SATA-LRS instrument was developed with the ability to exchange end-effectors through a disassembly of the shafts. Experiments showed an average 34 and 90 s for complete dis- and reassembly, respectively. Participants were able to handle the instrument independently after a single demonstration and 4 rounds of repetitions. Precise tip-target alignment in the box set-up showed a very short learning-curve of 6 repetitions. Conclusion: A novel instrument platform with articulating and rotating end-effector was designed for LRS. Within a minute the SATA-LRS can be disassembled to component level for inspection, cleaning, maintenance and repair, and can be autonomously reassembled by novices after a minimal training. The modular buildup is expected to reduce purchasing and repair costs. The instrument has been shown intuitive by use without extensive training.Medical Instruments & Bio-Inspired Technolog

    Creating a circular healthcare economy: Circular strategies for sustainable healthcare

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    Our world is the only planet, as far as we know, which harbors life. The number of humans on our planet has grown tremendously in recent centuries. In 1800 one billion humans occupied our earth; on 15 November 2022, this number reached 8 billion.A result of this growth, the emissions of carbon dioxide (CO2), the primary greenhouse gas emitted by human activities, drastically increased. The increased concentrations of greenhouse gases in our atmosphere foster the long-term increase of our earthā€™s temperatures, also referred to as global warming.While the earthā€™s population grew, so did our mass consumption society. After the Second World War humanity witnessed gigantic global economic development with great technological improvements. Computers, laptops, airplanes, tablets and Internet of Things connected humans all over the world. The hunger for plastics and steel grew as all products had to be manufactured in ever-increasing volumes. As the economy developed, our consumption grew apace.The healthcare sector has seen the same increase of consumption. The number of patients grew, and so did the number of single-use medical products. As products become more complex and more different materials were combined., recycling became more difficult. Thus, hospitals transformed into waste factories with ever-growing waste streams. The consumption of (disposable) medical devices takes up scarce raw materials and contributes to the growing CO2 emissions.In this book, Van Straten, Alvino and Horeman present their findings on how to create a sustainable healthcare economy by introducing different circular strategies. In 9 chapters, they present a wide variation of studies as practical cases to show what strategies and actions can be taken in order to implement sustainable strategies for a circular healthcare.This book was written in line with the courses the authors developed at TU Extension School, the open online education edX platform of Delft University of Technology/TU Delft, a leading university in science and technology, recognized for its world-class research. This book is a manual for everyone who follows the online course ā€˜Circular strategies for a sustainable healthcareā€™, but certainly also for everyone who wants to discover more about circular strategies and wants to understand the principles and practices of circular economy and urban mining. This book is suitable for students, researchers, policymakers and practitioners in the fields of healthcare sustainability, management, business and economics.Medical Instruments & Bio-Inspired Technolog

    Validation of the portable virtual reality training system for robotic surgery (PoLaRS): a randomized controlled trial

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    Background: As global use of surgical robotic systems is steadily increasing, surgical simulation can be an excellent way for robotic surgeons to acquire and retain their skills in a safe environment. To address the need for training in less wealthy parts of the world, an affordable surgical robot simulator (PoLaRS) was designed. Methods: The aim of this pilot study is to compare learning curve data of the PoLaRS prototype with those of Intuitive Surgicalā€™s da Vinci Skills Simulator (dVSS) and to establish face- and construct validity. Medical students were divided into two groups; the test group (n = 18) performing tasks on PoLaRS and dVSS, and the control group (n = 20) only performing tasks on the dVSS. The performance parameters were Time, Path length, and the number of collisions. Afterwards, the test group participants filled in a questionnaire regarding both systems. Results: A total of 528 trials executed by 38 participants were measured and included for analyses. The test group significantly improved in Time, Path Length and Collisions during the PoLaRS test phase (P ā‰¤ 0.028). No differences was found between the test group and the control group in the dVSS performances during the post-test phase. Learning curves showed similar shapes between both systems, and between both groups. Participants recognized the potential benefits of simulation training on the PoLaRS system. Conclusions: Robotic surgical skills improved during training with PoLaRS. This shows the potential of PoLaRS to become an affordable alternative to current surgical robot simulators. Validation with similar tasks and different expert levels is needed before implementing the training system into robotic training curricula.Medical Instruments & Bio-Inspired TechnologySupport Biomechanical Engineerin

    The MISLI-Drive, a modular sterilizable robotic driver for steerable laparoscopic instruments

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    Introduction: Based on the success of the former ā€œShaft-Actuated, Tip-Articulatedā€ SATA-Drive, a prototype robotic instrument driver for modular, steerable, laparoscopic instruments, a new driver is designed and tested to improve previously lacking features concerning cleanability, instrument adaptation, practical application and control. The design of the driver engages these issues with a modular design aimed at re-use of both the instrument and the driver, for which a set of design requirements are established.Methods: A new modular design has been developed to improve cleanability through separation of the electro-motors and the instrument mechanism which clutches the instrument. Contamination of the driverā€™s robotic side is prevented though a combination of a drape and a Sterile barrier interface, while the instrument side is made sterilizable. A novel instrument clutching mechanism enables quick-release features, while a motor-axis latching mechanism enables plug-and-play assembly. Embedded sensors allow precise and fast control. A user-experiment was conducted on instrument exchange and assembly time, while mechanical and electrical tests were conducted on the driverā€™s responsiveness.Results: The driver has proven its ability to control the instrument, after which it can be disassembled for cleaning and inspection. The driver is designed for re-use through disassembled sterilization where all possibly contaminated surfaces are exposable for cleaning and inspection. The new standardized instrument clutches allow easy instrument (dis-)assembly. Instrument exchange is possible in two methods, the fastest of which is a median of 11 (6.3ā€“14.6) seconds. The driverā€™s instrument mechanism is separated in a median of 3.7 (1.8ā€“8.1) seconds. After assembly, the driver is operational in less than 2 s.Discussion: Instrument exchange times are similar to the semi-reusable Da Vinci systems, yet the MISLI-Drive is designed for sterilization, inspection and continual re-use. The modular build of the driver also allows easier parts replacement during maintenance, and requires minimal adaptation to different future scenarios, which is expected to reduce the overall cost of use.Medical Instruments & Bio-Inspired Technolog
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