Fabrication and Characterization of a Balloon Actuator Array for Haptic Feedback in Robotic Surgery

2008 ◽  
Vol 2 (4) ◽  
Author(s):  
Chih-Hung King ◽  
Miguel Franco ◽  
Martin O. Culjat ◽  
Adrienne T. Higa ◽  
James W. Bisley ◽  
...  

Robot-assisted surgery is characterized by a total loss of haptic feedback, requiring surgeons to rely solely on visual cues. A pneumatically-driven balloon actuator array, suitable for mounting on robotic surgical master controls, has been developed to provide haptic feedback to surgeons. The actuator arrays consist of a molded polydimethylsiloxane substrate with cylindrical channels and a spin-coated silicone film that forms the array of balloons. Preliminary human perceptual studies have demonstrated that balloon diameters greater than 1.0mm may provide effective haptic feedback to the index finger. Before conducting further human perceptual tests, refinements of the fabrication process and performance data of the actuator are required. Balloons with diameters ranging between 1.5mm and 4.0mm were fabricated with film thicknesses of 200μm and 300μm. Inflation pressure versus balloon deflection tests and cyclic actuation tests were performed to characterize each balloon type. The results demonstrated a high linearity between inflation pressure and balloon deflection (R2>0.93) and negligible hysteresis effects between inflation and deflation over 100,000cycles. The studies indicated that 300μm films are optimal for 3.0mm and 4.0mm diameter balloons, and 200μm films are optimal for 1.5mm, 2.0mm, and 2.5mm diameter balloons. Due to its compact size and high performance, the described pneumatic actuator can provide sensory input that is otherwise unavailable during robotic surgery.

2020 ◽  
Vol 263 ◽  
pp. 120113
Author(s):  
Zhu Zhang ◽  
Jiusu Li ◽  
Zhengyuan Wang ◽  
Shiyu Long ◽  
Shunjun Jiang ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4109
Author(s):  
Jianwei Tu ◽  
Kamran Makarian ◽  
Nicolas J. Alvarez ◽  
Giuseppe R. Palmese

A well-defined resin system is needed to serve as a benchmark for 3D printing of high-performance composites. This work describes the design and characterization of such a system that takes into account processability and performance considerations. The Grunberg–Nissan model for resin viscosity and the Fox equation for polymer Tg were used to determine proper monomer ratios. The target viscosity of the resin was below 500 cP, and the target final Tg of the cured polymer was 150 °C based on tan-δ peak from dynamic mechanical analysis. A tri-component model resin system, termed DA-2 resin, was determined and fully characterized. The printed polymer exhibited good thermal properties and high mechanical strength after post-cure, but has a comparatively low fracture toughness. The model resin will be used in additive manufacturing of fiber reinforced composite materials as well as for understanding the fundamental processing–property relationships in light-based 3D printing.


2020 ◽  
Vol 34 (23) ◽  
pp. 1491-1505
Author(s):  
Min Li ◽  
Yueyan Zhuo ◽  
Jiazhou Chen ◽  
Bo He ◽  
Guanghua Xu ◽  
...  

2009 ◽  
Vol 419-420 ◽  
pp. 597-600 ◽  
Author(s):  
Xiao Xia Chen ◽  
Shu Zhong Lin ◽  
Jing Zhong Xing

Harmonic drive has widespread applications for its compact size and high reduction ratios. It is often favored for electro-mechanical systems with space and weight limitation. In order to minimize the volume and improve its transmission capacity, more and more aborative design technologies are adopted. For structural analyses in assembly state and in transmission stage, Finite Element Analysis (FEA) can be widely applied to get proper parameters and performance. Flexspline usually endures large deformation under assembly force from wave generator. In transmission state, driving force leads to multiple tooth mesh contact between flexspline and circular spline teeth. In this paper, shell element is applied to build flexspline cone, and tapered beam element is used to model the teeth on the flexspline. Contact relation between flexspline and wave generator is simulated by contact element. Forced displacement of flexspline is imposed by contact analysis. Transmission forces are acted at the teeth tips on the flexspline in mesh state, whose values are determined according to experimental distribution. Simulations of assembly state and transmission state are computed in ANSYS. Deformation and stress distribution in assembly state are compared with that in transmission state. Some suggestions for long life and high performance design are present.


2019 ◽  
Author(s):  
Vinícius Klôh ◽  
Matheus Gritz ◽  
Bruno Schulze ◽  
Mariza Ferro

Performance and energy efficiency are now critical concerns in high performance scientific computing. It is expected that requirements of the scientific problem should guide the orchestration of different techniques of energy saving, in order to improve the balance between energy consumption and application performance. To enable this balance, we propose the development of an autonomous framework to make this orchestration and present the ongoing research to this development, more specifically, focusing in the characterization of the scientific applications and the performance modeling tasks using Machine Learning.


Author(s):  
D. E. Newbury ◽  
R. D. Leapman

Trace constituents, which can be very loosely defined as those present at concentration levels below 1 percent, often exert influence on structure, properties, and performance far greater than what might be estimated from their proportion alone. Defining the role of trace constituents in the microstructure, or indeed even determining their location, makes great demands on the available array of microanalytical tools. These demands become increasingly more challenging as the dimensions of the volume element to be probed become smaller. For example, a cubic volume element of silicon with an edge dimension of 1 micrometer contains approximately 5×1010 atoms. High performance secondary ion mass spectrometry (SIMS) can be used to measure trace constituents to levels of hundreds of parts per billion from such a volume element (e. g., detection of at least 100 atoms to give 10% reproducibility with an overall detection efficiency of 1%, considering ionization, transmission, and counting).


1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.


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