scholarly journals Steerable Laparoscopic Cable-Ring Forceps

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Paul Breedveld

Laparoscopic surgery is carried out using long and slender endoscopes and instruments that are inserted through small incisions in the abdominal wall. Current endoscopes and instruments are rigid and have the drawback that their motion is restricted to 4-degrees of freedom (DOF). This paper describes a 6-DOF steerable laparoscopic grasping forceps incorporating a novel and very simple “cable-ring” mechanism consisting out of a ring of cables surrounded by two coil springs. Methods are described to increase stiffness and to improve manual control, resulting in a well-working prototype suitable for commercialization. The paper ends with a discussion on a number of cable-ring variants suitable for challenging new steerable designs in the future.

2004 ◽  
Vol 126 (1) ◽  
pp. 2-5 ◽  
Author(s):  
Paul Breedveld ◽  
Shigeo Hirose

Visual feedback during laparoscopic surgery is provided by an endoscope with a camera that is inserted through a small incision in the abdominal wall. The incision restricts the endoscope movements to 4 degrees of freedom (DOF), making it impossible to observe organs from different sides. This paper describes two 6 DOF steerable endoscopes that contain a new spatial parallelogram-mechanism to transform the handgrip movements into movements of the steerable tip. Part of the mechanism is a new kind of spring that combines high torsion stiffness with a low bending stiffness. The endoscopes and the spring have been applied for two international patents.


2018 ◽  
Vol 18 (03) ◽  
pp. 1850025
Author(s):  
JUNPENG SUN ◽  
KOTARO TADANO

Overshooting during trocar insertion may injury patient viscera and arteries or even lead to death. It has been extensively cited as a kind of common medical negligence. Hence, this paper investigated the force characteristics during a trocar inserted into the abdominal wall and developed strategies for effective stopping upon the trocar penetrated out of the abdominal wall. First, an experimental platform with two degrees of freedom was assembled. Second, two insertion methods were compared and the insertion forces using three types of trocars were measured respectively. Subsequently, we interpreted the force characteristics in terms of insertion principle and the abdominal structure. And based on the force characteristics, we generated two algorithms for the two insertion methods, which can be utilized to stop inserting effectively upon the trocar penetrated out of the abdominal wall. Finally, we evaluated the merits and demerits of the two algorithms. This paper proposed the interpretation of force characteristics during trocar insertion and achieved effective stopping to avoid overshooting. It provides foundations for the development of automatic trocar insertion device in the future.


2021 ◽  
pp. 155335062110310
Author(s):  
Aryaman Gupta ◽  
Erin Brown ◽  
Joseph T. Davis ◽  
John Sekabira ◽  
Nimmi Ramanujam ◽  
...  

Background. Despite favorable outcomes of laparoscopic surgery in high-income countries, its implementation in low- and middle-income countries (LMICs) is challenging given a shortage of consumable supplies, high cost, and risk of power outages. To overcome these barriers, we designed a mechanical retractor that provides vertical tension on the anterior abdominal wall. Methods. The retractor design is anatomically and mathematically optimized to provide exposure similar to traditional gas-based insufflation methods. Anatomical data from computed tomography scans were used to define retractor size. The retractor is constructed of biocompatible stainless steel rods and paired with a table-mounted lifting system to provide 5 degrees of freedom. Structural integrity was assessed through finite element analysis (FEA) and load testing. Functional testing was performed in a laparotomy model. Results. A user guide based on patient height and weight was created to customize retractor size, and 4 retractor sizes were constructed. FEA data using a 13.6 kg mass (15 mm Hg pneumoperitoneum) show a maximum of 30 mm displacement with no permanent deformation. Physical load testing with applied weight from 0 to 13.6 kg shows a maximum of 60 mm displacement, again without permanent deformation. Retraction achieved a 57% larger field of view compared to an unretracted state in a laparotomy model. Conclusions. The KeyLoop retractor maintains structural integrity, is easily sterilized, and can be readily manufactured, making it a viable alternative to traditional insufflation methods. For surgeons and patients in LMICs, the KeyLoop provides a means to increase access to laparoscopic surgery.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohammed Obaid ◽  
Qianwei Zhang ◽  
Scott J. Adams ◽  
Reza Fotouhi ◽  
Haron Obaid

Abstract Background Telesonography systems have been developed to overcome barriers to accessing diagnostic ultrasound for patients in rural and remote communities. However, most previous telesonography systems have been designed for performing only abdominal and obstetrical exams. In this paper, we describe the development and assessment of a musculoskeletal (MSK) telesonography system. Methods We developed a 4-degrees-of-freedom (DOF) robot to manipulate an ultrasound probe. The robot was remotely controlled by a radiologist operating a joystick at the master site. The telesonography system was used to scan participants’ forearms, and all participants were conventionally scanned for comparison. Participants and radiologists were surveyed regarding their experience. Images from both scanning methods were independently assessed by an MSK radiologist. Results All ten ultrasound exams were successfully performed using our developed MSK telesonography system, with no significant delay in movement. The duration (mean ± standard deviation) of telerobotic and conventional exams was 4.6 ± 0.9 and 1.4 ± 0.5 min, respectively (p = 0.039). An MSK radiologist rated quality of real-time ultrasound images transmitted over an internet connection as “very good” for all telesonography exams, and participants rated communication with the radiologist as “very good” or “good” for all exams. Visualisation of anatomic structures was similar between telerobotic and conventional methods, with no statistically significant differences. Conclusions The MSK telesonography system developed in this study is feasible for performing soft tissue ultrasound exams. The advancement of this system may allow MSK ultrasound exams to be performed over long distances, increasing access to ultrasound for patients in rural and remote communities.


2020 ◽  
Author(s):  
Sebastijan Veselic ◽  
Claudio Zito ◽  
Dario Farina

Designing robotic assistance devices for manipulation tasks is challenging. This work aims at improving accuracy and usability of physical human-robot interaction (pHRI) where a user interacts with a physical robotic device (e.g., a human operated manipulator or exoskeleton) by transmitting signals which need to be interpreted by the machine. Typically these signals are used as an open-loop control, but this approach has several limitations such as low take-up and high cognitive burden for the user. In contrast, a control framework is proposed that can respond robustly and efficiently to intentions of a user by reacting proactively to their commands. The key insight is to include context- and user-awareness in the controller, improving decision making on how to assist the user. Context-awareness is achieved by creating a set of candidate grasp targets and reach-to grasp trajectories in a cluttered scene. User-awareness is implemented as a linear time-variant feedback controller (TV-LQR) over the generated trajectories to facilitate the motion towards the most likely intention of a user. The system also dynamically recovers from incorrect predictions. Experimental results in a virtual environment of two degrees of freedom control show the capability of this approach to outperform manual control. By robustly predicting the user’s intention, the proposed controller allows the subject to achieve superhuman performance in terms of accuracy and thereby usability.


2019 ◽  
Vol 80 (10) ◽  
pp. 1882-1887
Author(s):  
Hirohiko SATO ◽  
Daichi ISHIKAWA ◽  
Tsuyoshi TOYOTA ◽  
Kazuhito TAKAMURA ◽  
Murato MIURA

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