Highly accurate control of movement is fundamental to the performance of microsurgery. Vitreoretinal microsurgery in particular is among the most demanding of specialties in terms of positioning accuracy, and is likely to become more so due to the increasing interest in retinal microvascular interventions. Of similar importance when dealing with delicate tissues is precise control of applied force. The lack of it leads to complications such as iatrogenic retinal breaks and hemorrhage. As a result, surveys taken to identify directions for improvement in ophthalmic procedures have indicated that both positioning accuracy and tactile (or force) perception have high importance. In order to address the need for enhanced control of movement and force in vitreoretinal microsurgery while also maintaining the natural feel, ease of use, and direct patient contact of handheld surgical instruments, our group has developed an active handheld micromanipulator known as Micron. Micron is a fully handheld system that performs active compensation of hand tremor and other erroneous motion. We have developed novel patient-specific vision-guided position-input virtual fixtures (like a virtual stencil) that can be used with Micron for enhanced accuracy. We have also demonstrated force control of Micron. To date, however, tests of Micron (like most of the field of vitreoretinal surgical robotics) have usually been ex vivo and greatly simplified, e.g., using retina open-sky rather than an eyeball. One of the main reasons for this is the great difficulty of quantitative stereo in the nonlinear optics of the eye. We address this herein with a novel monocular structured-light approach to depth sensing. At the present stage of development of Micron, the time has now come for clinically useful interventions under realistic conditions. In this project we focus on accomplishing two which have good prospects of maximizing the benefits of Micron, and then demonstrating them in vivo. Therefore, the specific aims of this proposal are as follows: 1. To develop a complete retinal vessel cannulation system and technique using Micron that is realizable in an intact eye in vivo. This procedure will utilizea position-input virtual fixture based on microscope video and structured light projected from the tool tip. Motion scaling will help guide the surgeon to the target vessel, and avoidance zones will help prevent entry into subretinal areas. Force control will help the surgeon to avoid damaging surrounding tissue while targeting the desired vessel with a microfabricated needle. 2. To develop a complete membrane peeling system and technique using Micron that is realizable in an intact eye in vivo. This virtual fixture will enhance control of position, force, and peeling velocity. 3. To demonstrate retinal vessel cannulation and membrane peeling using Micron in a rabbit model in vivo. Performance will be evaluated in terms of tremor amplitude, applied force, and operation time, and amount of intraoperative bleeding. Postoperative SD-OCT and histology will be used to assess tissue damage.

Public Health Relevance

This research aims to develop technology that will improve public health outcomes by enhancing the micromanipulation capabilities of microsurgeons. Vitreoretinal microsurgery is the main surgical focus of the project, but the technologies developed are applicable also to otolaryngology, neurosurgery, and other specialties. The active handheld micromanipulator developed in this project will counteract the hand tremor of microsurgeons, providing them with greatly improved control over the position of the surgical instrument tip and the force applied to tissue. The result will be the ability to work safely and accurately on smaller tissues, and to avoid damaging other tissues.

National Institute of Health (NIH)
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Research Project (R01)
Project #
Application #
Study Section
Bioengineering, Technology and Surgical Sciences Study Section (BTSS)
Program Officer
Krosnick, Steven
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Carnegie-Mellon University
Biostatistics & Other Math Sci
Schools of Arts and Sciences
United States
Zip Code
Braun, Daniel; Yang, Sungwook; Martel, Joseph N et al. (2018) EyeSLAM: Real-time simultaneous localization and mapping of retinal vessels during intraocular microsurgery. Int J Med Robot 14:
Moccia, Sara; Foti, Simone; Routray, Arpita et al. (2018) Toward Improving Safety in Neurosurgery with an Active Handheld Instrument. Ann Biomed Eng 46:1450-1464
Gonenc, Berk; Patel, Niravkumar; Iordachita, Iulian (2018) Evaluation of a Force-Sensing Handheld Robot for Assisted Retinal Vein Cannulation. Conf Proc IEEE Eng Med Biol Soc 2018:1-5
Song, Jingzhou; Gonenc, Berk; Guo, Jiangzhen et al. (2017) Intraocular Snake Integrated with the Steady-Hand Eye Robot for Assisted Retinal Microsurgery. IEEE Int Conf Robot Autom 2017:6724-6729
Gonenc, Berk; Chamani, Alireza; Handa, James et al. (2017) 3-DOF Force-Sensing Motorized Micro-Forceps for Robot-Assisted Vitreoretinal Surgery. IEEE Sens J 17:3526-3541
Gonenc, Berk; Chae, Jeremy; Gehlbach, Peter et al. (2017) Towards Robot-Assisted Retinal Vein Cannulation: A Motorized Force-Sensing Microneedle Integrated with a Handheld Micromanipulator †. Sensors (Basel) 17:
MacLachlan, Robert A; Hollis, Ralph L; Jaramaz, Branislav et al. (2017) Multirate Kalman Filter Rejects Impulse Noise in Frequency-Domain-Multiplexed Tracker Measurements. Proc IEEE Sens 2017:
Gonenc, Berk; Gehlbach, Peter; Taylor, Russell H et al. (2017) Safe Tissue Manipulation in Retinal Microsurgery via Motorized Instruments with Force Sensing. Proc IEEE Sens 2017:
Channa, Roomasa; Iordachita, Iulian; Handa, James T (2017) Robotic Vitreoretinal Surgery. Retina 37:1220-1228
Mukherjee, Shohin; Yang, Sungwook; MacLachlan, Robert A et al. (2017) Toward Monocular Camera-Guided Retinal Vein Cannulation with an Actively Stabilized Handheld Robot. IEEE Int Conf Robot Autom 2017:2951-2956

Showing the most recent 10 out of 69 publications