Real-Time Sclera Force Feedback for Enabling Safe Robot-Assisted Vitreoretinal Surgery

et al. 2020

Trans. Vis. Sci. Tech.

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This study aims to map force interaction between instrument and sclera of in vivo rabbits during retinal procedures, and verify if a robotic active force control could prevent unwanted increase of forces on the sclera. Methods: Experiments consisted in the performance of intraocular movements of a force sensing instrument, adjacent to the retinal surface, in radial directions, from the center to the periphery and back, and compared manual manipulations with robotic assistance and also robotic assistance with an active force control. This protocol was approved by the Animal Use and Ethical Committee and experiments were according to ARVO Statement of Animal Use. Results: Mean forces using manual manipulations were 115 ± 51 mN. Using robotic assistance, mean forces were 118 ± 49 mN. Using an active force control method, overall mean forces reduced to 69 ± 15, with a statistical difference compared with other methods (P < 0.001). Comparing intraocular directions, superior sector required higher forces and the force control method reduced differences in forces between users and retained the same force pattern between them. Conclusions: Results validate that the introduction of robotic assistance might increase the dynamic interactions between instrument and sclera, and the addition of an active force control method reduces the forces at levels lower than manual manipulations. Translational Relevance: All marketing benefits from extreme accuracy and stability from robots, however, redundancy of safety mechanisms during intraocular manipulations, especially on force control and surgical awareness, would allow all utility of robotic assistance in ophthalmology.

Section: Discussionmentioning

confidence: 77%

Robotic Retinal Surgery Impacts on Scleral Forces: In Vivo Study

Urias

et al. 2020

Trans. Vis. Sci. Tech.

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“…After being alerted of the excessive forces, the surgeon should react accordingly and reduce the sclera force by intuitively reorienting the tool toward correct directions. Auditory feedback was proved beneficial in increasing tip force safety and also sclera force safety as reported by [19] and [20], respectively. In our recent study [20], we came up with the upper safe bound of 120 mN for the magnitude of sclera force.…”

Section: B Sclera Force Safety For Freehandmentioning

confidence: 85%

“…Cutler et al assessed the effect of auditory feedback in limiting tool tip forces within safe levels in robot-assisted phantom membrane peeling task [19]. Ebrahimi et al [20] evaluated the advantage of providing haptic force feedback and audio feedback for restricting the sclera forces. Matinfar et al ussed a novel sonification method to convey useful information during ophthalmic procedures [21].…”

Section: Introductionmentioning

confidence: 99%

Towards securing the sclera against patient involuntary head movement in robotic retinal surgery

Urias

2019 28th IEEE International Conference on Robot and Human Interactive Communication (RO-MAN)

et al. 2019

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Retinal surgery involves manipulating very delicate tissues within the confined area of eyeball. In such demanding practices, patient involuntary head movement might abruptly raise tool-to-eyeball interaction forces which would be detrimental to eye. This study is aimed at implementing different force control strategies and evaluating how they contribute to attaining sclera force safety while patient head drift is present. To simulate patient head movement, a piezoelectric-actuated linear stage is used to produce random motions in a single direction in random time intervals. Having an eye phantom attached to the linear stage then an experienced eye surgeon is asked to manipulate the eye and repeat a mock surgical task both with and without the assist of the Steady-Hand Eye Robot. For the freehand case, warning sounds were provided to the surgeon as auditory feedback to alert him about excessive slclra forces. For the robot-assisted experiments two variants

“…Sclera force measurements, robot position, velocity and other required data are collected and manipulated through the software package (developed using the CISST framework, a collection of libraries for development of computer-assisted intervention systems; InfinityQS, Fairfax). The unsafe upper bound level of sclera force was set to be 120 mN according to what is explained in [15]. Therefore, we put the levels of L 1 , L 2 and L 3 which were defined in the passive control of sclera force to be 80 mN, 100 mN and 120 mN, respectively.…”

Section: Experimental Setup and Methodsmentioning

confidence: 99%

Sclera Force Control in Robot-assisted Eye Surgery: Adaptive Force Control vs. Auditory Feedback

2019 International Symposium on Medical Robotics (ISMR)

et al. 2019

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Surgeon hand tremor limits human capability during microsurgical procedures such as those that treat the eye. In contrast, elimination of hand tremor through the introduction of microsurgical robots diminishes the surgeons tactile perception of useful and familiar tool-to-sclera forces. While the large mass and inertia of eye surgical robot prevents surgeon microtremor, loss of perception of small scleral forces may put the sclera at risk of injury. In this paper, we have applied and compared two different methods to assure the safety of sclera tissue during robot-assisted eye surgery. In the active control method, an adaptive force control strategy is implemented on the Steady-Hand Eye Robot in order to control the magnitude of scleral forces when they exceed safe boundaries. This autonomous force compensation is then compared to a passive force control method in which the surgeon performs manual adjustments in response to the provided audio feedback proportional to the magnitude of sclera force. A pilot study with three users indicate that the active control method is potentially more efficient.