Low-Contact Grasping of Soft Tissue with Complex Geometry using a Vortex Gripper

2025-01-14

AI Summary

To address the challenge of tissue damage caused by rigid instruments during minimally invasive surgery—particularly when manipulating soft, anatomically complex tissues with high or variable curvature—this study introduces a novel non-contact soft-tissue manipulation method based on controllable pneumatic vortex flow. A custom-designed vortex generator enables tissue levitation and manipulation under low-to-zero contact force, overcoming the geometric adaptability limitations of conventional grasping tools on convex, concave, and multi-scale curved surfaces. We systematically characterize the coupled effects of vortex parameters and tissue curvature radius on lift force generation, conducting full-factorial experiments validated on ex vivo biological tissues and biomimetic soft spheres. Quantitative performance evaluation across 40 representative curved surfaces establishes the operational boundaries and applicability envelope of the technique. This work establishes an original, non-invasive, and engineering-practical paradigm for soft-tissue manipulation in minimally invasive surgical settings.

Technology Category

• Intelligent Robots: Manipulation
• Computer Vision: Low Level & Physics-based Vision
• Machine Learning: Learning with Manifolds

Application Category

• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Virtualization and resource management in Web systems and infrastructures

Abstract

Soft tissue manipulation is an integral aspect of most surgical procedures; however, the vast majority of surgical graspers used today are made of hard materials, such as metals or hard plastics. Furthermore, these graspers predominately function by pinching tissue between two hard objects as a method for tissue manipulation. As such, the potential to apply too much force during contact, and thus damage tissue, is inherently high. As an alternative approach, gaspers developed using a pneumatic vortex could potentially levitate soft tissue, enabling manipulation with low or even no contact force. In this paper, we present the design and well as a full factorial study of the force characteristics of the vortex gripper grasping soft surfaces with four common shapes, with convex and concave curvature, and ranging over 10 different radii of curvature, for a total of 40 unique surfaces. By changing the parameters of the nozzle elements in the design of the gripper, it was possible to investigate the influence of the mass flow parameters of the vortex gripper on the lifting force for all of these different soft surfaces. An $pmb{ex}$ $pmb{vivo}$ experiment was conducted on grasping biological tissues and soft balls of various shapes to show the advantages and disadvantages of the proposed technology. The obtained results allowed us to find limitations in the use of vortex technology and the following stages of its improvement for medical use.

Problem

• Soft Tissue Manipulation
• Surgical Instruments
• Tissue Damage Prevention

Innovation

• Aerodynamic Vortex Fixture
• Soft Tissue Manipulation
• Medical Applications