A Steerable Neuroendoscopic Instrument Using Compliant Contact-Aided Joints and Monolithic Articulation

2020 ◽  
Vol 14 (2) ◽  
Author(s):  
Kyle W. Eastwood ◽  
Arushri Swarup ◽  
Peter Francis ◽  
Alexander N. Alvara ◽  
Honzer Chen ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Joint Stiffness ◽  
Third Ventriculostomy ◽  
Outer Diameter ◽  
Tumor Biopsy ◽  
Narrow Channels ◽  
Compliant Joint ◽  
Bending Radius ◽  
In Series ◽  
Gear Contact

Abstract This work presents the design of an articulate neuroendoscopic instrument (ANI), a handheld tool for use in minimally invasive neurosurgery. The instrument consists of a handle and a steerable tube-shaft with a distal end-effector. The design aims to increase the reach of surgeons operating through narrow channels within the center of the brain when approaching multiple targets from a single incision point. The steerable tube-shaft consists of a 1.6- mm notch-tube compliant joint mechanism augmented with contact-aids modeled after a gear geometry. The contact-aid geometry aims to address the performance tradeoff between stiffness, range-of-motion (RoM), and joint compactness for millimeter-scale notched-tube joints; it increases blocking force without sacrificing RoM. Finite element modeling (FEM) was used to refine design features, and the joint stiffness and RoM are assessed experimentally for three prototypes. The joint is incorporated into a tube-shaft instrument, and the assembled tool's stiffness properties are characterized. The prototype was then assessed in a validated neurosurgical simulator. An individual 1.24-mm outer-diameter notch-tube compliant joint with gear contact-aids is capable of 30 deg maximum bending and can sustain a 0.55 N blocking force with 0.5 mm displacement. A functional instrument shaft with a 15.5- mm-long articulating section was constructed from three joints in series with an external flexible stainless-steel sheath. It achieves a 6.7-mm bending radius at 75 deg maximum bending angle. In preclinical testing with an endoscopic third ventriculostomy and endoscopic tumor biopsy (ETV-ETB) simulator, the tool successfully completes the biopsy and fenestration maneuvers from a single burr-hole entry point. The ANI prototype uses contact-aid geometry incorporated into a compliant nitinol notched-tube joint to produce an articulate biopsy instrument for minimally invasive neurosurgical applications.

A new method of ultrasonic guidance of neuroendoscopic procedures

2002 ◽  
Vol 96 (3) ◽  
pp. 628-632 ◽  
Author(s):  
Martin Strowitzki ◽  
Michael Kiefer ◽  
Wolf-Ingo Steudel
Keyword(s):  
Third Ventricle ◽  
Tumor Resection ◽  
Colloid Cyst ◽  
Third Ventriculostomy ◽  
Outer Diameter ◽  
Intraventricular Tumor ◽  
Tumor Biopsy ◽  
Foramen Of Monro ◽  
Content Type ◽  
Fine Print

✓ The authors present a newly designed device for ultrasonic guidance of neuroendoscopic procedures. It consists of a puncture adapter that attaches to a rigid endoscope having an outer diameter of 6 mm and is mounted on a small, bayonet-shaped ultrasound probe. This adapter directs the movement of the endoscope precisely within the ultrasonic field of view. The targeted region is identified by transdural insonation via an enlarged single burr-hole approach, and the endoscope is tracked in real time throughout its approach to the target. The procedure has been performed in 10 patients: endoscopic ventriculocystostomy in four cases; removal of a colloid cyst of the third ventricle in two cases; and intraventricular tumor biopsy, intraventricular tumor resection, third ventriculostomy, and removal of an intraventricular hematoma in one case each. The endoscope was depicted on ultrasonograms as a hyperechoic line without disturbing echoes and, consequently, the target (cyst, ventricle, or tumor) was safely identified in all but one case, in which intraventricular air hid a colloid cyst in the foramen of Monro. The method presented by the authors proved to be very effective in the guidance and control of neuroendoscopic procedures. Combining this method with image guidance is recommended to define the entry point of the endoscope precisely.

scholarly journals Efficacy and safety of condylectomy with minimally invasive surgery in the treatment of interdigital corns of the lesser toes compared to conservative treatment

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Luis M. Marti-Martinez ◽  
Rubén Lorca-Gutierrez ◽  
Salvador Pedro Sánchez-Pérez ◽  
Jonatan Garcia-Campos ◽  
Nadia Fernández Ehrling ◽  
...  
Keyword(s):  
Minimally Invasive Surgery ◽  
Surgical Treatment ◽  
Treatment Group ◽  
Conservative Treatment ◽  
Minimally Invasive ◽  
Functional Status ◽  
Invasive Surgery ◽  
Joint Stiffness ◽  
Efficacy And Safety ◽  
Clinical And Functional Status

Abstract Background Minimally invasive surgery (MIS) procedures cause less trauma to the patient and might improve recovery. This study aimed to determine the efficacy and safety of condylectomy with MIS to treat interdigital corns of the lesser toes. Methods This prospective cohort study was conducted in seven podiatry centers. Patients with interdigital corns of the lesser toes, progressing for more than a year, with one or more recurrences in the last year following conservative treatments were eligible. The recruited patients were classified according to their treatment: conservative or surgical (condylectomy with MIS) and were compared. Patient satisfaction, pain, the clinical and functional status of the foot and the appearance of sequelae were assessed at 3 and 6 months after treatment. Results At 6 months, patients in the surgical treatment group showed no pain on pressure, which significantly differed from the conservative treatment group (p <  0.001). They also improved clinical and functional status of the foot, reaching values comparable to those of the standard population. No paresthesia, joint stiffness or instability, toe malalignment, or corn transfer to a contiguous site resulted from the surgical treatment. Conclusions Condylectomy with MIS is effective and safe to treat interdigital corns of the lesser toes.

scholarly journals Nonlinear Axial Stiffness Characteristics of Axisymmetric Bolted Joints

1990 ◽  
Vol 112 (3) ◽  
pp. 442-449 ◽  
Author(s):  
I. R. Grosse ◽  
L. D. Mitchell
Keyword(s):  
Finite Element ◽  
Linear Theory ◽  
Design Theory ◽  
Joint Stiffness ◽  
Bolted Joints ◽  
Axial Stiffness ◽  
Outer Diameter ◽  
Bolted Joint ◽  
Element Analysis ◽  
Stiffness Characteristics

A critical assessment of the current design theory for bolted joints which is based on a linear, one-dimensional stiffness analysis is presented. A detailed nonlinear finite element analysis of a bolted joint conforming to ANSI standards was performed. The finite element results revealed that the joint stiffness is highly dependent on the magnitude of the applied load. The joint stiffness changes continuously from extremely high for small applied loads to the bolt stiffness during large applied loads, contrary to the constant joint stiffness of the linear theory. The linear theory is shown to be inadequate in characterizing the joint stiffness. The significance of the results in terms of the failure of bolted joints is discussed. A number of sensitivity studies were carried out to assess the effect of various parameters on the axial joint stiffness. The results revealed that bending and rotation of the joint members, interfacial friction, and the bolt/nut threading significantly influence the axial stiffness characteristics of the bolted joint. The two-dimensional, axisymmetric finite element model includes bilinear gap elements to model the interfaces. Special orthotropic elements were used to model the bolt/nut thread interaction. A free-body-diagram approach was taken by applying loads to the outer diameter of the joint model which correspond to internal, uniformly distributed line-shear and line-moment loads in the joint. A number of convergence studies were performed to validate the solution.

scholarly journals Design and Analysis of a Novel Variable Stiffness Joint for Robot

2018 ◽  
Vol 249 ◽  
pp. 03005
Author(s):  
Xiang Zhang ◽  
Twan Capehart ◽  
Carl A. Moore
Keyword(s):  
High Frequency ◽  
Joint Stiffness ◽  
Variable Stiffness ◽  
Robotic Systems ◽  
Compliant Joint ◽  
Variable Transmission ◽  
Application Requirements ◽  
Base Application ◽  
Robotic Applications ◽  
Human Robotic Interaction

As people pay more attention to the safety of human-robotic interaction, the flexibility of machine joints is becoming more and more important. To address the needs of future robotic applications, many kinds of variable stiffness mechanisms have been designed by scientists. But most of the structures are complex. By studying and comparing many different mechanism designs of variable stiffness joint, we recognize the need to miniaturization and reduce weight of variable stiffness joints with high frequency operation. To address this, need a continuously Variable Compliant Joint (CVCJ) was designed. The core of the joint is based on the structure of the spherical continuously variable transmission (SCVT) which is the catalyst to change the stiffness continuously and smoothly. In this paper, we present a compact variable stiffness joint structure to meet the volume and weight requirements of the future robotic systems. We show the connection between the joint stiffness coefficient and the structure parameters by making mathematical analysis, modelling and simulation for the system to verify the ability to satisfy the base application requirements of the compliant joint.

scholarly journals Burr hole microsurgery in treatment of patients with intracranial lesions: Experience of 44 clinical cases

2020 ◽  
Vol 11 ◽  
pp. 255
Author(s):  
Levan Teymurazovich Lepsveridze ◽  
Maksim Sergeevich Semenov ◽  
Armen Samvelovich Simonyan ◽  
Salome Zurabovna Pirtskhelava ◽  
Georgy Garikovich Stepanyan ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Minimally Invasive ◽  
Burr Hole ◽  
Invasive Technique ◽  
Subtotal Resection ◽  
Hemorrhagic Complication ◽  
Tumor Biopsy ◽  
Cavernous Angiomas ◽  
Intracranial Lesions ◽  
Surgical Duration

Background: Modern technical capabilities have made minimally invasive surgery increasingly popular. Small incisions can reduce surgical duration and the degree of tissue trauma, which reduces the risk of complications. Burr hole microsurgery is a relatively new minimally invasive technique used in neurosurgery. The objective of this study was to assess the feasibility and outcomes of using burr hole microsurgery for the management of intracranial lesions. Methods: Forty-four adults were treated with burr hole microsurgery. Patients were divided into groups according to the presence of (1) brain tumors (n = 20); (2) congenital brain cysts (n = 16); (3) cavernous angiomas (n = 3); and (4) neurovascular conflicts of the 5th cranial nerve (n = 5). All surgical interventions were performed using the “MARI” device. Results: The transcortical approach was used to remove 16 brain tumors, and 2 brain tumors were biopsied. In the two tumor biopsy cases, the parasagittal interhemispheric route was used. Gross total resection was achieved in 10 cases (62.5%) when tumor size reached up to 4 cm, subtotal resection was achieved in four cases (25%) in large tumors, and partial resection in two cases (12.5%). In patients with congenital cysts, cavernous angiomas, trigeminal neuralgia, and symptomatic regression were noted the postoperative period. The surgical duration was 30–180 min (median, 75 min). A hemorrhagic complication was observed in one case. Significant postoperative complications and mortality were not observed. Conclusion: Burr hole microsurgery can treat different intracranial lesions effectively. Despite a smaller craniotomy diameter of 11–14 mm compared with keyhole approaches, surgery was successful.

Miniaturized Cutting Tool With Triaxial Force Sensing Capabilities for Minimally Invasive Surgery

2007 ◽  
Vol 1 (3) ◽  
pp. 206-211 ◽  
Author(s):  
Pietro Valdastri ◽  
Keith Houston ◽  
Arianna Menciassi ◽  
Paolo Dario ◽  
Arne Sieber ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Cutting Tool ◽  
Haptic Feedback ◽  
Ex Vivo ◽  
Force Sensor ◽  
Outer Diameter ◽  
Muscular Tissue ◽  
Force Output ◽  
Force Range ◽  
Minimally Invasive Robotic Surgery

This paper reports a miniaturized triaxial force sensorized cutting tool for minimally invasive robotic surgery. This device exploits a silicon-based microelectromechanical system triaxial force sensor that acts as the core component of the system. The outer diameter of the proposed device is less than 3mm, thus enabling the insertion through a 9 French catheter guide. Characterization tests are performed for both normal and tangential loadings. A linear transformation relating the sensor output to the external applied force is introduced in order to have a triaxial force output in real time. Normal force resolution is 8.2bits over a force range between 0N and 30N, while tangential resolution is 7 bits over a range of 5N. Force signals with frequencies up to 250Hz can successfully be detected, enabling haptic feedback and tissue mechanical properties investigation. Preliminary ex vivo muscular tissue cutting experiments are introduced and discussed in order to evaluate the device overall performances.

One- vs Two-Burr-Hole Technique for Combined Endoscopic Third Ventriculostomy and Pineal Region Biopsy: Volumetric Analysis of Brain at Risk

2020 ◽  
Vol 19 (2) ◽  
pp. 175-180
Author(s):  
Brandon D Liebelt ◽  
Fangxiang Chen ◽  
Antonio Biroli ◽  
Xiaochun Zhao ◽  
Peter Nakaji
Keyword(s):  
At Risk ◽  
Endoscopic Third Ventriculostomy ◽  
Brain Parenchyma ◽  
Pineal Region ◽  
Burr Hole ◽  
Third Ventriculostomy ◽  
Tumor Biopsy ◽  
Burr Holes ◽  
The Brain ◽  
The Ideal

Abstract BACKGROUND Pineal region tumors are associated with the ventricular system. Endoscopic third ventriculostomy (ETV) is often performed at the same time as tumor biopsy. OBJECTIVE To investigate the volume of brain possibly undergoing injury and forniceal stretching during ETV and tumor biopsy. METHODS We performed a retrospective review of preoperative magnetic resonance imagings (MRIs) and computed tomography (CTs) of patients with pineal region masses and used volumetric image-guided navigation to simulate a 1-burr-hole vs a 2-burr-hole approach through the brain parenchyma. We compared the volumes of parenchyma and fornix at the risk of injury. RESULTS The ideal entry point for ETV using 2 burr holes was a mean ± standard deviation (SD) of 25.8 ± 6 mm from the midline and 11.4 ± 9 mm behind the coronal suture. The ideal entry point using 2 burr holes for tumor biopsy was 25.7 ± 8 mm from the midline and 53.7 ± 14 mm anterior to the coronal suture. With 1 burr hole, the mean ± SD volume of brain parenchyma at risk was 852 ± 440 mm3. The volume of brain parenchyma at risk with 2 burr holes was 2159 ± 474 mm3 (P &lt; .001; paired t-test). The use of 1 burr hole predisposed the fornix to 14 ± 3 mm of possible stretch, which was minimized with the 2-burr-hole approach. CONCLUSION Using 1 burr hole for both the ETV and tumor biopsy is less likely to traumatize the brain parenchyma than using 2 burr holes. However, 1 burr hole predisposes the fornix to stretch injury. We recommend tailoring the entry to each patient according to their anatomy rather than using a 1-size-fits-all approach.

scholarly journals Water Jet Applicator for Interface Tissue Removal in Minimally Invasive Hip Refixation: Testing the Principle and Design of Prototype

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Gert Kraaij ◽  
Arjo J. Loeve ◽  
Jenny Dankelman ◽  
Rob G. H. H. Nelissen ◽  
Edward R. Valstar
Keyword(s):  
Theoretical Analysis ◽  
Minimally Invasive ◽  
Water Pressure ◽  
Minimal Invasive ◽  
Outer Diameter ◽  
Experimental Setup ◽  
Technical Requirements ◽  
Tissue Removal ◽  
Further Development

Mechanical loosening of implants is in the majority accompanied with a periprosthetic interface membrane, which has to be removed during revision surgery. The same is true if a minimal invasive (percutaneous) refixation of a loose implant is done. We describe the requirements for a waterjet applicator for interface tissue removal for this percutaneous hip refixation technique. The technical requirements were either obtained from a literature review, a theoretical analysis, or by experimental setup. Based on the requirements, a waterjet applicator is designed which is basically a flexible tube (outer diameter 3 mm) with two channels. One channel for the water supply (diameter 0.9 mm) and one for suction to evacuate water and morcellated interface tissue from the periprosthetic cavity. The applicator has a rigid tip (length 6 mm), which directs the water flow to create two waterjets (diameter 0.2 mm), both focused into the suction channel. The functionality of this new applicator is demonstrated by testing a prototype of the applicator tip in an in vitro experimental setup. This testing has shown that the designed applicator for interface tissue removal will eliminate the risk of water pressure buildup; the ejected water was immediately evacuated from the periprosthetic cavity. Blocking of the suction opening was prevented because the jets cut through interface tissue that gets in front of the suction channel. Although further development of the water applicator is necessary, the presented design of the applicator is suitable for interface tissue removal in a minimally invasive hip refixation procedure.

Significance Analysis of Processing Parameters on Wall Thinning in Tube Bending

2012 ◽  
Vol 622-623 ◽  
pp. 437-441
Author(s):  
Heng Li ◽  
Kai Peng Shi ◽  
He Yang ◽  
Yu Li Tian
Keyword(s):  
Coupling Effect ◽  
Processing Parameters ◽  
Al Alloy ◽  
Outer Diameter ◽  
Tube Bending ◽  
Significance Analysis ◽  
Wall Thinning ◽  
Complex Process ◽  
Bending Radius ◽  
Extension Length

Tube bending is a complex process with multi-factor coupling effect and multiple defects occurring. The wall thinning, as one of the important defects in tube bending, determines the bending quality. In this study, taking thin-walled 6061-T4 Al-alloy tube with Φ50.8×t0.889×R101.6mm (outer diameter D × wall thickness t × bending radius R) as the objective, the significance of processing parameters on the wall thinning degree is studied using the orthogonal test under ABAQUS/Explicit platform. The results show that: 1) the bending radius, the clearance between the tube and the pressure die, the friction between the tube and the pressure die, the clearance between the tube and the pressure die, the clearance between the tube and the mandrel and the friction between the tube and the mandrel affect the wall thinning significantly, while the coefficient of boost velocity, the number of mandrel balls, the friction between the tube and the wiper die, the mandrel extension length and the friction between the tube and the bending die have little effect on the wall thinning degree.

Sign in / Sign up

Export Citation Format

Share Document