scholarly journals A Robust Wheel Interface With a Novel Adaptive Controller for Computer/Robot-Assisted Motivating Rehabilitation

2012 ◽  
Author(s):  
Andrew R. Theriault ◽  
Mark L. Nagurka ◽  
Michelle J. Johnson
Keyword(s):  
Force Field ◽  
Force Feedback ◽  
Low Cost ◽  
Motor Impairment ◽  
Adaptive Controller ◽  
Patient Specific ◽  
Target Point ◽  
Computer Gaming ◽  
End Effector ◽  
Limited Range Of Motion

TheraDrive is an effective system for post-stroke upper extremity rehabilitation. This system uses off-the-shelf computer gaming wheels with force feedback to help reduce motor impairment and improve function in the arms of stroke survivors. Preliminary results show that the TheraDrive system lacks a robust mechanical linkage that can withstand the large forces exerted by patients, and it lacks a patient-specific adaptive controller to deliver personalized therapy. It is also not capable of delivering effective therapy to severely low-functioning patients. A new low-cost, high-force haptic robot with a single degree of freedom has been developed to address these concerns. The resulting TheraDrive consists of an actuated hand crank with a compliant transmission. Actuation is provided by a brushed DC motor, geared to output up to 23 kgf at the end effector. To enable a human to interact with this system safely, a special compliant element was developed to double as a failsafe torque limiter. A set of strain gauges in the handle of the crank are used to determine the interaction forces between human and robot for use by the robot’s impedance controller. The impedance controller is used to render a one-dimensional force field that attracts or repels the end effector from a moving target point that the human must track during therapy exercises. As exercises are performed, an adaptive controller monitors patient performance and adjusts the force field accordingly. This allows the robot to compensate for gravity, variable mechanical advantage, limited range of motion, and other factors. More importantly, the adaptive controller ensures that exercises are difficult but doable, which is important for maintaining patient motivation. Experiments with a computer model of human and robot show the adaptive controller’s ability to maintain difficulty of exercises after a period of initial calibration.

FlexDex™: A Minimally Invasive Surgical Tool With Enhanced Dexterity and Intuitive Control

2010 ◽  
Vol 4 (3) ◽  
Author(s):  
Shorya Awtar ◽  
Tristan T. Trutna ◽  
Jens M. Nielsen ◽  
Rosa Abani ◽  
James Geiger
Keyword(s):  
Minimally Invasive ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Technology Development ◽  
Low Cost ◽  
End Effector ◽  
Minimally Invasive Surgical ◽  
Surgical Tool ◽  
Design Paradigm ◽  
Rotational Degrees Of Freedom

This paper presents a new minimally invasive surgical (MIS) tool design paradigm that enables enhanced dexterity, intuitive control, and natural force feedback in a low-cost compact package. The paradigm is based on creating a tool frame that is attached to the surgeon’s forearm, making the tool shaft an extension of the latter. Two additional wristlike rotational degrees of freedom (DoF) provided at an end-effector that is located at the end of the tool shaft are manually actuated via a novel parallel-kinematic virtual center mechanism at the tool input. The virtual center mechanism, made possible by the forearm-attached tool frame, creates a virtual two-DoF input joint that is coincident with the surgeon’s wrist, allowing the surgeon to rotate his/her hand with respect to his/her forearm freely and naturally. A cable transmission associated with the virtual center mechanism captures the surgeon’s wrist rotations and transmits them to the two corresponding end-effector rotations. This physical configuration allows an intuitive and ergonomic one-to-one mapping of the surgeon’s forearm and hand motions at the tool input to the end-effector motions at the tool output inside the patient’s body. Moreover, a purely mechanical construction ensures low-cost, simple design, and natural force feedback. A functional decomposition of the proposed physical configuration is carried out to identify and design key modules in the system—virtual center mechanism, tool handle and grasping actuation, end-effector and output joint, transmission system, tool frame and shaft, and forearm brace. Development and integration of these modules leads to a proof-of-concept prototype of the new MIS tool, referred to as FlexDex™, which is then tested by a focused end-user group to evaluate its performance and obtain feedback for the next stage of technology development.

scholarly journals Design and Analysis of a Symmetric Articulated Single-Port Laparoscopic Surgical Device

2017 ◽  
Author(s):  
Rohan Katoch ◽  
Boao Xia ◽  
Yoshinori Yamakawa ◽  
Jun Ueda ◽  
Hiroshi Honda
Keyword(s):  
Force Feedback ◽  
Haptic Feedback ◽  
Single Port ◽  
Operating Experience ◽  
Economic Benefits ◽  
Driving Mechanism ◽  
End Effector ◽  
Limited Range Of Motion ◽  
Functional Features ◽  
Laparoscopic Device

Laparoscopic surgery is a practice of minimally invasive surgery (MIS) performed in the abdominal area. Prior to surgery, instead of exposing the target region to air as in a typical conventional open surgery, “key holes” are opened for positioning ports, through which surgical tools (e.g. laparoscope, needle drivers, etc.) are inserted. MIS therefore minimizes trauma and reduces the risk of hemorrhaging and infection. MIS also generates economic benefits such as shorter hospitalization time for patients and better utilization of operating rooms and wards for hospitals. MIS procedures, however, require extra dexterity from surgeons: they must use instruments with little to none haptic feedback to remotely manipulate tissue within a limited range of motion, assisted by an indirect view from laparoscope. Such unintuitive operations not only require additional training, but also increase the risk of medical errors. Thus, the development of novel surgical devices that can provide a better operating experience will allow surgeons to deliver safer and more effective surgeries. At the advent of MIS only rigid straight laparoscopic instruments were available. Therefore, surgeons used multiple incisions to position the tools and achieve triangulation. In single port laparoscopic surgeries (SPLS), only one incision is made for positioning a port. Two rigid straight instruments inserted through one incision cannot provide sufficient triangulation for operations. Rigid bent, or articulated, instruments can achieve triangulation, but the tools must intersect at a point. The mapping to control the end-effector, therefore, must be inverted such that the right hand controls the left end-effector, and vice versa [1]. Given this inverted mapping, surgeons need to undergo extra training to intuitively control the end-effector, and greater attention is required toward operating the device, which can potentially detract from the ability of surgeons to focus on procedures. The disadvantage of an inverted mapping can be overcome by providing additional mobility with flexible tools and actuating structures [2]. For example, Transenterix has developed a flexible laparoscopic device which utilizes a cable-driven system for articulation of the end-effectors. However, using flexible elements as the driving mechanism can result in new problems such as diminished force feedback [3]. In 2015, a novel design of an articulated single port laparoscopic device was presented with 6 degrees of freedom (DOF). The system provides intuitive control, accurate force feedback, and sufficient manipulation for laparoscopic procedures. The design proposed in this paper keeps much of the functional features in the previous model, including 1:1 mapping and force feedback, while incorporating flexible hydraulic graspers. The articulated mechanism was redesigned to have a symmetrical structure, which is more intuitive to control and provides better operating angles for surgeons. Joint structures are redesigned for enhanced robustness and misalignment prevention. Kinematic analysis is presented for the proposed mechanisms, which is used to determine the manipulator workspace.

Vision Based Force Sensing for Nanorobotic Manipulation

2006 ◽  
Author(s):  
Abhishek Gupta ◽  
Volkan Patoglu ◽  
Marcia K. O'Malley
Keyword(s):  
Visual Feedback ◽  
Force Feedback ◽  
Low Cost ◽  
Primary Component ◽  
Force Sensing ◽  
End Effector ◽  
Nanoscale Structures ◽  
Force Microscopy ◽  
Mechanics Model ◽  
Primary Advantage

Over the last decade, considerable interest has been generated in building and manipulating nanoscale structures. Applications of nanomanipulation include study of nanoparticles, molecules, DNA and viruses, and bottom-up nanoassembly. We propose a Nanomanipulation System using the Zyvex S100 nanomanipulator, which operates within a scanning electron microscope (SEM), as its primary component. The primary advantage of the S100 setup over standard scanning probe microscopy based nanomanipulators is the ability to see the object during manipulation. Relying on visual feedback alone to control the nanomanipulator is not preferable due to perceptual limitations of depth and contact within the SEM. To improve operator performance over visual feedback alone, an impedance-controlled bilateral teleoperation setup is envisioned. Lack of on-board force sensors on the S100 system is the primary hindrance in the realization of the proposed architecture. In this paper, we present a computer vision based force sensing scheme. The advantages of this sensing strategy include its low cost and lack of requirement of hardware modification(s). Force sensing is implemented using an atomic force microscopy (AFM) probe attached to the S100 end-effector. Deformation of the cantilever probe is monitored using a Hough transform based algorithm. These deformations are mapped to corresponding end-effector forces following the Euler-Bernoulli beam mechanics model. The forces thus sensed can be used to provide force-feedback to the operator through a master manipulator.

FlexDex™: A Minimally Invasive Surgical Tool With Enhanced Dexterity and Intuitive Actuation

2009 ◽  
Author(s):  
Shorya Awtar ◽  
Tristan T. Trutna ◽  
Rosa Abani ◽  
Jens M. Nielsen ◽  
Andrew B. Mansfield
Keyword(s):  
Minimally Invasive ◽  
Force Feedback ◽  
Mechanical Design ◽  
Low Cost ◽  
Tool Design ◽  
System Level ◽  
End Effector ◽  
Minimally Invasive Surgical ◽  
Surgical Tool ◽  
Design Paradigm

This paper presents the design and fabrication of a novel minimally invasive surgical (MIS) tool — FlexDex™ — that provides enhanced dexterity, intuitive actuation, and natural force feedback in a cost-effective compact package. These attributes are accomplished by means of a fundamentally new MIS tool design paradigm that employs a tool reference attached to the surgeon’s arm, and utilizes a virtual center at the tool input that coincides with the surgeon’s wrist. The resulting physical configuration enables a highly intuitive one-to-one mapping of the surgeon’s arm and hand motions at the tool input to the end-effector motions at the tool output inside the patient’s body. Furthermore, a purely mechanical design ensures low-cost, simple construction, and natural force feedback. A functional decomposition of the proposed design paradigm and associated physical configuration is carried out to identify key modules in the system. This allows for the conceptual and detailed design of each module, followed by system-level integration. The key innovative aspects of the tool design include a three-dimensional parallel-kinematic virtual center mechanism, a decoupled 2DoF end-effector design, and the associated transmissions system.

scholarly journals Magnetic Driven Two-Finger Micro-Hand with Soft Magnetic End-Effector for Force-Controlled Stable Manipulation in Microscale

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 410
Author(s):  
Dan Liu ◽  
Xiaoming Liu ◽  
Pengyun Li ◽  
Xiaoqing Tang ◽  
Masaru Kojima ◽  
...  
Keyword(s):  
Magnetic Force ◽  
Force Feedback ◽  
Soft Magnetic ◽  
End Effector ◽  
Force Microscopy ◽  
System A ◽  
Atomic Force ◽  
Afm Probe ◽  
End Effectors ◽  
Fixed End

In recent years, micromanipulators have provided the ability to interact with micro-objects in industrial and biomedical fields. However, traditional manipulators still encounter challenges in gaining the force feedback at the micro-scale. In this paper, we present a micronewton force-controlled two-finger microhand with a soft magnetic end-effector for stable grasping. In this system, a homemade electromagnet was used as the driving device to execute micro-objects manipulation. There were two soft end-effectors with diameters of 300 μm. One was a fixed end-effector that was only made of hydrogel, and the other one was a magnetic end-effector that contained a uniform mixture of polydimethylsiloxane (PDMS) and paramagnetic particles. The magnetic force on the soft magnetic end-effector was calibrated using an atomic force microscopy (AFM) probe. The performance tests demonstrated that the magnetically driven soft microhand had a grasping range of 0–260 μm, which allowed a clamping force with a resolution of 0.48 μN. The stable grasping capability of the magnetically driven soft microhand was validated by grasping different sized microbeads, transport under different velocities, and assembly of microbeads. The proposed system enables force-controlled manipulation, and we believe it has great potential in biological and industrial micromanipulation.

scholarly journals An Innovative and Cost-Advantage CAD Solution for Cubitus Varus Surgical Planning in Children

2021 ◽  
Vol 11 (9) ◽  
pp. 4057
Author(s):  
Leonardo Frizziero ◽  
Gian Maria Santi ◽  
Christian Leon-Cardenas ◽  
Giampiero Donnici ◽  
Alfredo Liverani ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Low Cost ◽  
Cost Effective ◽  
Varus Deformity ◽  
Patient Specific ◽  
Cubitus Varus ◽  
Surgical Guide ◽  
Traditional Procedure ◽  
Custom Made ◽  
Patient Specific Instruments

The study of CAD (computer aided design) modeling, design and manufacturing techniques has undergone a rapid growth over the past decades. In medicine, this development mainly concerned the dental and maxillofacial sectors. Significant progress has also been made in orthopedics with pre-operative CAD simulations, printing of bone models and production of patient-specific instruments. However, the traditional procedure that formulates the surgical plan based exclusively on two-dimensional images and interventions performed without the aid of specific instruments for the patient and is currently the most used surgical technique. The production of custom-made tools for the patient, in fact, is often expensive and its use is limited to a few hospitals. The purpose of this study is to show an innovative and cost-effective procedure aimed at prototyping a custom-made surgical guide for address the cubitus varus deformity on a pediatric patient. The cutting guides were obtained through an additive manufacturing process that starts from the 3D digital model of the patient’s bone and allows to design specific models using Creo Parametric. The result is a tool that adheres perfectly to the patient’s bone and guides the surgeon during the osteotomy procedure. The low cost of the methodology described makes it worth noticing by any health institution.

GPU-Based Haptic Simulator for Dental Bone Drilling

2011 ◽  
Author(s):  
Fei Zheng ◽  
WenFeng Lu ◽  
Yoke San Wong ◽  
Kelvin Weng Chiong Foong
Keyword(s):  
Real Time ◽  
Graphics Processing Units ◽  
Force Feedback ◽  
Mandibular Canal ◽  
Structure Design ◽  
Patient Specific ◽  
Force Model ◽  
Bone Drilling ◽  
The Real ◽  
Drill Bits

Dental bone drilling is an inexact and often a blind art. Dentist risks damaging the invisible tooth roots, nerves and critical dental structures like mandibular canal and maxillary sinus. This paper presents a haptics-based jawbone drilling simulator for novice surgeons. Through the real-time training of tactile sensations based on patient-specific data, improved outcomes and faster procedures can be provided. Previously developed drilling simulators usually adopt penalty-based contact force models and often consider only spherical-shaped drill bits for simplicity and computational efficiency. In contrast, our simulator is equipped with a more precise force model, adapted from the Voxmap-PointShell (VPS) method to capture the essential features of the drilling procedure. In addition, the proposed force model can accommodate various shapes of drill bits. To achieve better anatomical accuracy, our oral model has been reconstructed from Cone Beam CT, using voxel-based method. To enhance the real-time response, the parallel computing power of Graphics Processing Units is exploited through extra efforts for data structure design, algorithms parallelization, and graphic memory utilization. Preliminary results show that the developed system can produce appropriate force feedback at different tissue layers.

scholarly journals Hybrid Spine Simulator Prototype for X-ray Free Pedicle Screws Fixation Training

2021 ◽  
Vol 11 (3) ◽  
pp. 1038
Author(s):  
Sara Condino ◽  
Giuseppe Turini ◽  
Virginia Mamone ◽  
Paolo Domenico Parchi ◽  
Vincenzo Ferrari
Keyword(s):  
Augmented Reality ◽  
Low Cost ◽  
Lumbar Vertebrae ◽  
Pedicle Screws ◽  
Simulation Software ◽  
Patient Specific ◽  
Innovative Strategy ◽  
X Ray ◽  
3D Printed ◽  
Harmful Radiation

Simulation for surgical training is increasingly being considered a valuable addition to traditional teaching methods. 3D-printed physical simulators can be used for preoperative planning and rehearsal in spine surgery to improve surgical workflows and postoperative patient outcomes. This paper proposes an innovative strategy to build a hybrid simulation platform for training of pedicle screws fixation: the proposed method combines 3D-printed patient-specific spine models with augmented reality functionalities and virtual X-ray visualization, thus avoiding any exposure to harmful radiation during the simulation. Software functionalities are implemented by using a low-cost tracking strategy based on fiducial marker detection. Quantitative tests demonstrate the accuracy of the method to track the vertebral model and surgical tools, and to coherently visualize them in either the augmented reality or virtual fluoroscopic modalities. The obtained results encourage further research and clinical validation towards the use of the simulator as an effective tool for training in pedicle screws insertion in lumbar vertebrae.

scholarly journals Accessing 3D Printed Vascular Phantoms for Procedural Simulation

2021 ◽  
Vol 7 ◽  
Author(s):  
Jasamine Coles-Black ◽  
Damien Bolton ◽  
Jason Chuen
Keyword(s):  
3D Printing ◽  
Endovascular Procedures ◽  
Low Cost ◽  
3D Models ◽  
Routine Care ◽  
Aortic Aneurysms ◽  
Patient Specific ◽  
Ct Angiogram ◽  
Abdominal Aortic ◽  
3D Printed

Introduction: 3D printed patient-specific vascular phantoms provide superior anatomical insights for simulating complex endovascular procedures. Currently, lack of exposure to the technology poses a barrier for adoption. We offer an accessible, low-cost guide to producing vascular anatomical models using routine CT angiography, open source software packages and a variety of 3D printing technologies.Methods: Although applicable to all vascular territories, we illustrate our methodology using Abdominal Aortic Aneurysms (AAAs) due to the strong interest in this area. CT aortograms acquired as part of routine care were converted to representative patient-specific 3D models, and then printed using a variety of 3D printing technologies to assess their material suitability as aortic phantoms. Depending on the technology, phantoms cost $20–$1,000 and were produced in 12–48 h. This technique was used to generate hollow 3D printed thoracoabdominal aortas visible under fluoroscopy.Results: 3D printed AAA phantoms were a valuable addition to standard CT angiogram reconstructions in the simulation of complex cases, such as short or very angulated necks, or for positioning fenestrations in juxtarenal aneurysms. Hollow flexible models were particularly useful for device selection and in planning of fenestrated EVAR. In addition, these models have demonstrated utility other settings, such as patient education and engagement, and trainee and anatomical education. Further study is required to establish a material with optimal cost, haptic and fluoroscopic fidelity.Conclusion: We share our experiences and methodology for developing inexpensive 3D printed vascular phantoms which despite material limitations, successfully mimic the procedural challenges encountered during live endovascular surgery. As the technology continues to improve, 3D printed vascular phantoms have the potential to disrupt how endovascular procedures are planned and taught.

scholarly journals A Comprehensive 3D-Molded Bone Flap Protocol for Patient-Specific Cranioplasty

2021 ◽  
Author(s):  
Raphael Bertani ◽  
Caio Moreno Perret Novo ◽  
Pedro Henrique Freitas ◽  
Amanda Amorin Nunes ◽  
Thiago Nunes Palhares ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Operating Time ◽  
Ct Scanning ◽  
Patient Specific ◽  
Manufacturing Cost ◽  
Post Processing ◽  
Cross Sectional ◽  
Cranial Defect

Abstract We present a detailed step-by-step approach for the low-cost production and surgical implantation of cranial prostheses, aimed at restoring aesthetics, cerebral protection, and facilitating neurological rehabilitation. This protocol uses combined scan computed tomography (CT) cross-sectional images, in DICOM format, along with a 3D printing (additive manufacturing) setup. The in-house developed software InVesalius®️ is an open-source tool for medical imaging manipulation. The protocol describes image acquisition (CT scanning) procedures, and image post-processing procedures such as image segmentation, surface/volume rendering, mesh generation of a 3D digital model of the cranial defect and the desired prostheses, and their preparation for use in 3D printers. Furthermore, the protocol describes a detailed powder bed fusion additive manufacturing process, known as Selective Laser Sintering (SLS), using Polyamide (PA12) as feedstock to produce a 3-piece customized printed set per patient. Each set consists of a “cranial defect printout” and a “testing prosthesis” to assemble parts for precision testing, and a cranial “prostheses mold” in 2 parts to allow for the intraoperative modeling of the final implant cast using the medical grade Poly(methyl methacrylate) (PMMA) in a time span of a few min. The entire 3D processing time, including modelling, design, production, post-processing and qualification, takes approximately 42 h. Modeling the PMMA flap with a critical thickness of 4 mm by means of Finite Element Method (FEM) assures mechanical and impact properties to be slightly weaker than the bone tissue around it, a safety design to prevent fracturing the skull after a possible subsequent episode of head injury. On a parallel track, the Protocol seeks to provide guidance in the context of equipment, manufacturing cost and troubleshooting. Customized 3D PMMA prostheses offers a reduced operating time, good biocompatibility, and great functional and aesthetic outcomes. Additionally, it offers greater than 15-fold cost advantage over the usage of other materials, including metallic parts produced by additive manufacturing.

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