Using Fiber Optic Bundles to Miniaturize Vision-Based Tactile Sensors
🤖 AI Summary
To address the fundamental optical trade-off between field-of-view and focal length in vision-based tactile sensors operating at fingertip scale (≤15 mm), this work introduces DIGIT Pinki—the first vision-tactile sensing system integrating a flexible fiber-optic bundle to enable remote image relay, thereby overcoming optical design constraints imposed by miniaturized camera integration in compact housings. The system combines a miniature CMOS image sensor, a remotely located electronic architecture, force–image co-calibration, and a dedicated tactile image processing pipeline. Experimental evaluation demonstrates a spatial resolution of 0.22 mm and a normal-force resolution of 5 mN. DIGIT Pinki successfully discriminates stiffness in both prostate phantoms and ex vivo tissue samples, fulfilling clinical palpation requirements for size, sensitivity, and reliability. This work establishes a new paradigm for high-fidelity, miniaturized vision-tactile sensing suitable for surgical and diagnostic applications.
Application Category
📝 Abstract
Vision-based tactile sensors have recently become popular due to their combination of low cost, very high spatial resolution, and ease of integration using widely available miniature cameras. The associated field of view and focal length, however, are difficult to package in a human-sized finger. In this article we employ optical fiber bundles to achieve a form factor that, at 15 mm diameter, is smaller than an average human fingertip. The electronics and camera are also located remotely, further reducing package size. The sensor achieves a spatial resolution of 0.22 mm and a minimum force resolution 5 mN for normal and shear contact forces. With these attributes, the DIGIT Pinki sensor is suitable for applications such as robotic and teleoperated digital palpation. We demonstrate its utility for palpation of the prostate gland and show that it can achieve clinically relevant discrimination of prostate stiffness for phantom and ex vivo tissue.
Problem
Research questions and friction points this paper is trying to address.
Miniaturizing vision-based tactile sensors for human-sized robotic fingers
Achieving high spatial resolution with remote camera placement
Enabling clinical discrimination of tissue stiffness through palpation
Innovation
Methods, ideas, or system contributions that make the work stand out.
Uses fiber optic bundles for miniaturization
Relocates electronics and camera remotely
Achieves high spatial and force resolution
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