Design and Prototyping of a Force-Reflecting Hand-Controller for Ultrasound Imaging

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Farshid Najafi ◽  
Nariman Sepehri
Keyword(s):  
Ultrasound Imaging ◽  
Static Friction ◽  
Parallel Mechanisms ◽  
Detailed Design ◽  
Remote Locations ◽  
Output Force ◽  
And Performance ◽  
Drive Systems ◽  
Robotic Wrist ◽  
Fixed Center

This paper presents detailed design, analysis, prototyping, and testing of a novel force-reflecting hand-controller allowing physicians to control a robotic wrist and perform ultrasound examinations on patients in remote locations. The proposed device is a four degree-of-freedom mechanism with a fixed center-of-motion and uses symmetric parallel mechanisms. All movements of the device are kinematically decoupled, i.e., the hand-controller has independent drive systems for each standard ultrasound motion. A technique has been adapted to statically balance the weight of the device over its entire workspace using a single tension spring. The prototype of the device has been constructed and evaluated for ultrasound imaging of kidney and spleen. Maximum and accuracy of the output force are analytically determined and performance of the device in terms of static balancing, static-friction break-away force, and maximum achievable impedances are experimentally evaluated.

scholarly journals Review on automated follicle identification for polycystic ovarian syndrome

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
A A Nazarudin ◽  
Noraishikin Zulkarnain ◽  
A. Hussain ◽  
S. S. Mokri ◽  
I. N. A. M. Nordin
Keyword(s):  
Performance Evaluation ◽  
Ultrasound Imaging ◽  
Polycystic Ovarian Syndrome ◽  
Speckle Noise ◽  
Future Research ◽  
Health Treatment ◽  
Time Consumption ◽  
Non Invasive ◽  
And Performance ◽  
Ovarian Syndrome

Polycystic Ovarian Syndrome (PCOS), is a condition of the ovary consisting numerous follicles. Accurate size and number of follicles detected are crucial for treatment. Hence the diagnosis of this condition is by measuring and calculating the size and number of follicles existed in the ovary. For diagnosis, ultrasound imaging has become an effective tool as it is non-invasive, inexpensive and portable. However, the presence of speckle noise in ultrasound imaging has caused an obstruction for manual diagnosis which are high time consumption and often produce errors. Thus, image segmentation for ultrasound imaging is critical to identify follicles for PCOS diagnosis and proper health treatment. This paper presents different methods proposed and applied in automated follicle identification for PCOS diagnosis by previous researchers. In this paper, the methods and performance evaluation are identified and compared. Finally, this paper also provided suggestions in developing methods for future research.

Type Synthesis of Two Degrees-of-Freedom Rotational Parallel Mechanisms With a Fixed Center-of-Rotation Based on a Graphic Approach

2012 ◽  
Author(s):  
K. Wu ◽  
J. J. Yu ◽  
S. Z. Li ◽  
G. H. Zong ◽  
Xianwen Kong
Keyword(s):  
High Performance ◽  
Degrees Of Freedom ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Two Degrees Of Freedom ◽  
Center Of Rotation ◽  
Parasitic Motion ◽  
Performance Requirements ◽  
Rotary Stage ◽  
Fixed Center

Mechanisms usually have to be particularly designed to meet the high-performance requirements in terms of different applications. For instance, Two degrees of freedom (DOF) rotational parallel mechanisms (RPMs) with a fixed center-of-rotation can eliminate parasitic motion and could provide the rotary stage with excellent dynamic stability, good controllability and easy operation. Therefore, this paper mainly aims at synthesizing 2-DOF RPMs with fixed center-of-rotation, a class of special RPMs with potential excellent performances. A graphic approach based on freedom and constraint spaces is introduced firstly. The constraint spaces of a class of the existing 2-DOF RPMs are illustrated, and the corresponding type synthesis patterns are summarized by comparing the geometric properties of those spaces with the mechanism characteristic. After fully decomposing the four-dimensional constraint space into sub-constraint spaces, a general type synthesis procedure is proposed based on the freedom and constraint topology. Two novel 2-DOF RPMs with fixed center-of-rotation are constructed based on the proposed method and procedure. The proposed graphic approach proves to be effective and simple to synthesizing those parallel mechanisms with some special performance.

scholarly journals On the Design of Mobile Parallel Robots for Large Workspace Applications

2011 ◽  
Author(s):  
Hai Yang ◽  
Se´bastien Krut ◽  
Franc¸ois Pierrot ◽  
Ce´dric Baradat
Keyword(s):  
Parallel Robots ◽  
Legged Robots ◽  
Parallel Mechanisms ◽  
Mobility Analysis ◽  
Design Constraints ◽  
And Performance ◽  
Forward Kinematic

In this paper, several considerations for designing industry oriented robots which combine the mobility of legged robots and advantages of parallel mechanisms are outlined. For designing such optimized robots in terms of simplicity and performance, a topology study is done based on the mobility analysis. Applying some design constraints, potential topologies of such robots are identified. One architecture is chosen for designing a tripod robot. Both inverse and forward kinematic problems of this robot are derived in order to simulate its gait motion. The analysis and simulations show that: integrating some clamping devices and some lockable passive joints, six actuators are enough to build a legged manipulator which can not only perform 6-axis machining but can also walk on a curved supporting media.

Kinematics and Performance Analysis of Two Types of 3-RPS Parallel Mechanisms

2017 ◽  
pp. 1309-1321
Author(s):  
Yongfeng Wang ◽  
Shuncheng Fan ◽  
Xiaojun Zhang ◽  
Guangda Lu ◽  
Jing Yang
Keyword(s):  
Performance Analysis ◽  
Parallel Mechanisms ◽  
And Performance

scholarly journals Design and Development of a Compact High-Torque Robotic Actuator for Space Mechanisms

2017 ◽  
Vol 9 (6) ◽  
Author(s):  
Elias Brassitos ◽  
Nader Jalili
Keyword(s):  
Gear Ratio ◽  
System Level ◽  
Force Transmission ◽  
Torque Density ◽  
Output Force ◽  
Short Development Time ◽  
Transmission Structure ◽  
Drive Systems ◽  
Two Stages ◽  
Space Mechanisms

Space robots require compact joint drive systems (JDSs), typically comprising of actuator, transmission, joint elements that can deliver high torques through stiff mechanical ports. Today's conventional space drive systems are made from off-the-shelf actuators and multistage transmissions that generally involve three to six stages. This current practice has certain benefits such as short development time due to the availability of mechanical components. However, it lacks a system-level integration that accounts for the actuator structure, size and output force, transmission structure, gear-ratio, and strength, and often leads to long and bulky assemblies with large number of parts. This paper presents a new robotic hardware that integrates the robot's JDS into one compact device that is optimized for its size and maximum torque density. This is done by designing the robotic joint using a special transmission which, when numerically optimized, can produce unlimited gear-ratios using only two stages. The design is computerized to obtain all the solutions that satisfy its kinematic relationships within a given actuator diameter. Compared to existing robotic actuators, the proposed design could lead to shorter assemblies with significantly lower number of parts for the same output torque. The theoretical results demonstrates the potential of an example device, for which a proof-of-concept plastic mockup was fabricated, that could deliver more than 200 N·m of torque in a package as small as a human elbow joint. The proposed technology could have strong technological implications in other industries such as powered prosthetics and rehabilitation equipment.

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