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- Cho, Jang Ho, et al.
(författare)
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Enhancement of Human Operator's Perceptual Sensitivity for Telesurgical Systems via Polytopic System Approach
- 2012
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Ingår i: 4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob), 2012. - 9781457711992 ; , s. 75-80
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Konferensbidrag (refereegranskat)abstract
- A suturing including knot tying is one of the more difficult operations to learn in telesurgical systems. Apprentice surgeons commonly suffer from suture breakage or knot failure. The difficulty, generally, comes from the absence of feedback of interaction force cues in a medical device (e.g., a needle and a thread) . Even if there is haptic feedback to the operator, the operator may have a difficulty to detect a specific force such as suture breakage force. To deal with this problem, we propose a control method which can detect a suture breakage force more sensitively by considering human perception characteristics. A performance objective of the control method is designed according to the human perceptual factor, just noticeable difference. By convex optimization of the performance indices, a stabilizing H_inf controller is proposed for the telesurgical system. Finally, the proposed control scheme is validated via a simulation study.
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| 2. |
- Cho, Jang Ho, et al.
(författare)
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Gain-Scheduling Control of Teleoperation Systems Interacting With Soft Tissues
- 2013
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Ingår i: IEEE Transactions on Industrial Electronics. - 0278-0046. ; 60:3, s. 946-957
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Tidskriftsartikel (refereegranskat)abstract
- Surgical teleoperation systems are being increasingly deployed recently. There are, however, some unsolved issues such as nonlinear characteristics of the interaction between the slave robot and soft tissues and difficulty in employing force sensors in the surgical end-effectors of the slave. These issues make it difficult to generalize any approach to develop a control for the system. This paper addresses these issues by proposing a H-infinity suboptimal controller preserving robust stability and performance. The environment, i.e., soft tissues, is characterized with the nonlinear Hunt-Crossley model. This nonlinear characteristics of soft tissues are expressed with an affine combination of linear models within a predefined parameter polytope. For this linear parameter-varying system, a gain-scheduling control scheme is employed to design a suboptimal controller while guaranteeing its stability. To avoid using any force measurement in slave, we used position-position (PP) control architecture. The developed gain-scheduling control is validated with quantitative experimental results. The developed gain-scheduling PP control scheme shows good tracking capacity and high transparency for varied experimental conditions. Error of the transmitted impedance is significantly lower compared with other conventional control schemes for frequencies less than 2 Hz, which is frequently recommended for surgical teleoperation.
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| 3. |
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| 4. |
- Son, Hyoung Il, et al.
(författare)
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A psychophysical evaluation of haptic controllers: viscosity perception of soft environments
- 2014
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Ingår i: Robotica. - 0263-5747. ; 32:1, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, human viscosity perception in haptic teleoperation systems is thoroughly analyzed. An accurate perception of viscoelastic environmental properties such as viscosity is a critical ability in several contexts, such as telesurgery, telerehabilitation, telemedicine, and soft-tissue interaction. We study and compare the ability to perceive viscosity from the standpoint of detection and discrimination using several relevant control methods for the teleoperator. The perception-based method, which was proposed by the authors to enhance the operator's kinesthetic perception, is compared with the conventional transparency-based control method for the teleoperation system. The fidelity-based method, which is a primary method among perception-centered control schemes in teleoperation, is also studied. We also examine the necessity and impact of the remote-site force information for each of the methods. The comparison is based on a series of psychophysical experiments measuring absolute threshold and just noticeable difference for all conditions. The results clearly show that the perception-based method enhances both detection and discrimination abilities compare with other control methods. The results further show that the fidelity-based method confers a better discrimination ability than the transparency-based method, although this is not true with respect to detection ability. In addition, we show that force information improves viscosity detection for all control methods, as predicted from previous theoretical analysis, but improves the discrimination threshold only for the perception-based method.
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