Design and Modeling of a Three-Degree-of-Freedom Articulating Robotic Microsurgical Forceps for Trans-Oral Laser Microsurgery

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Manish Chauhan ◽  
Nikhil Deshpande ◽  
Darwin G. Caldwell ◽  
Leonardo S. Mattos
Keyword(s):  
Degree Of Freedom ◽  
Preliminary Evaluation ◽  
Laser Microsurgery ◽  
Single Degree Of Freedom ◽  
Control Interface ◽  
Tissue Manipulation ◽  
Manual Handling ◽  
Three Degree Of Freedom ◽  
Tool Rotation ◽  
Poor Efficacy

Trans-oral laser microsurgery (TLM) is a surgical procedure for removing malignancies (e.g., cysts, polyps, tumors) of the laryngeal region through laser ablation. Intraoperative microsurgical forceps (i.e., microforceps) are used for tissue manipulation. The microforceps are rigid, single degree-of-freedom (DOF) devices (open–close) with precurved jaws to access different parts of the curved cylindrical laryngeal region. These microforceps are manually handled and are subject to hand tremors, poor reachability, and nonergonomic use, resulting in poor efficacy and efficiency in the surgery. A novel 3DOF motorized microforceps device is presented here, integrated with a 6DOF serial robotic manipulator. The device, referred to as RMF-3, offers three motorized DOFs: (i) open–close forceps jaw; (ii) tool rotation; and (iii) tool-tip articulation. It is designed to be compliant with TLM spatial constraints. The manual handling is replaced by tele-operation device, the omega.7. The design of the RMF-3 is characterized through theoretical and experimental analysis. The device shows a maximum articulation of 38 deg and tool rotation of 100 deg. Its performance is further evaluated through user trials using the ring-in-loop setup. The user trials demonstrate benefits of the 3DOF workspace of the device along with its teleoperation control. RMF-3 offers an improved workspace and reachability within the laryngeal region. Surgeons, in their preliminary evaluation of the device, appreciated the ability to articulate the tip, along with rotation, for hard-to-reach parts of the surgical site. RMF-3 offers an ergonomic robotic teleoperation control interface which overcomes hand tremors and extreme wrist excursion which leads to surgeon pain and discomfort.

Instabilities Arising From the Frictional Interaction of a Pin-Disk System Resulting in Noise Generation

1976 ◽  
Vol 98 (1) ◽  
pp. 81-86 ◽  
Author(s):  
S. W. E. Earles ◽  
C. K. Lee
Keyword(s):  
Angular Speed ◽  
Degree Of Freedom ◽  
Noise Generation ◽  
Disk System ◽  
Single Degree Of Freedom ◽  
Disk Brake ◽  
Thin Steel ◽  
Three Degree Of Freedom ◽  
Squeal Noise ◽  
Experimental Rig

A steel pin, supported on a flexible cantilever, is pressed against a thin steel disk which rotates at a uniform angular speed. The orientation of the pin’s central axis to the plane of the disk, the bending and torsional stiffnesses of the pin support, the stiffness of the disk, and the line of action of the resultant interactive force are all shown to affect the self-induced coupled frequencies and modes generated. The analysis of the experimental arrangement in terms of a three-degree-of-freedom pin subsystem and a single-degree-of-freedom disk element suggests that the system is unstable for certain combinations of the variables. The instabilities are shown to belong to a class of “geometrically induced” or “kinematic constraint” instability. The region of squeal-noise generation within the experimental rig is shown to correspond to the oscillatory unstable region predicted theoretically. The noise generated is similar to disk-brake squeal, and so the work furthers the understanding of this practical problem.

Energy Transfer and Dissipation in a Three-Degree-of-Freedom System With Stribeck Friction

2005 ◽  
Author(s):  
Nguyen Do ◽  
Aldo A. Ferri
Keyword(s):  
Energy Transfer ◽  
Low Frequency ◽  
Friction Model ◽  
Degree Of Freedom ◽  
Simulation Studies ◽  
Transfer Energy ◽  
Interconnected System ◽  
Single Degree Of Freedom ◽  
Low Frequency Motion ◽  
Three Degree Of Freedom

Friction at connecting joints is a key mechanism by which passive damping occurs in built-up structures. This paper explores the ability of friction to transfer energy between subsystems of an interconnected system. Two single-degree-of-freedom (SDOF) systems are used to represent separate subsystems and a third mass is used to represent the connecting joint. A Stribeck friction model is used to represent the resistive force acting on this coupling mass. Through numerical simulation studies, the influence of the subsystem dynamics on the overall energy dissipation levels is investigated. In particular, it is seen that favorable tuning conditions exist that result in a “pumping” of energy from the low-frequency motion of one subsystem to the higher-frequency motion of the other subsystem. It is also seen that one-way energy transfer can occur in such a system due to the eventual joint lock-up that can occur when the connecting mass sticks.

scholarly journals Inelastic Responses of Two-Way Asymmetric-Plan Structures under Bidirectional Ground Excitations—Part II: Response Spectra

2012 ◽  
Vol 28 (1) ◽  
pp. 141-157 ◽  
Author(s):  
Jui-Liang Lin ◽  
Wen-Chia Yang ◽  
Keh-Chyuan Tsai
Keyword(s):  
Vibration Mode ◽  
Response Spectra ◽  
Companion Paper ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Ductility Demand ◽  
Inelastic Responses ◽  
Constant Strength ◽  
Three Degree Of Freedom ◽  
Modal Systems

Based on the studies in the companion paper, this paper presents the inelastic response spectra for asymmetrical structures (SAS) under bidirectional ground excitations. Firstly, the constant-strength SAS were constructed and compared with the corresponding conventional constant-strength response spectra. It was found that the modal ductility demands of an asymmetric-plan structure could be significantly overestimated from the conventional constant-strength response spectra as the nonlinear “modal” rotation and translations may not be proportional. Furthermore, the translation-rotation interaction effect is not considered in the conventional constant-strength response spectra. Secondly, the influences of the three-degree-of-freedom (3DOF) modal parameters on the ductility demand were extensively studied. Thirdly, the normalized peak edge translation spectra were also investigated. It was found that the normalized peak edge translation resulting from a single vibration mode may be overestimated twofold by using the single-degree-of-freedom (SDOF) modal systems.

scholarly journals Development of a Compound Speckle Interferometer for Precision Three-Degree-of-Freedom Displacement Measurement

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1828
Author(s):  
Hung-Lin Hsieh ◽  
Bo-Yen Sun
Keyword(s):  
Speckle Interferometry ◽  
Degree Of Freedom ◽  
Heterodyne Interferometry ◽  
Beam Splitting ◽  
Speckle Interferometer ◽  
Real World Applications ◽  
Three Degree Of Freedom ◽  
Contact Displacement ◽  
Displacement Measurements ◽  
Measurement Capabilities

In this study, a compound speckle interferometer for measuring three-degree-of-freedom (3-DOF) displacement is proposed. The system, which combines heterodyne interferometry, speckle interferometry and beam splitting techniques, can perform precision 3-DOF displacement measurements, while still having the advantages of high resolution and a relatively simple configuration. The incorporation of speckle interferometry allows for non-contact displacement measurements by detecting the phase of the speckle interference pattern formed from the convergence of laser beams on the measured rough surface. Experiments were conducted to verify the measurement capabilities of the system, and the results show that the proposed system has excellent measurement capabilities suitable for future real-world applications.

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