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This paper proposes a novel flexible pneumatic valve adapter that seeks inspiration from vascular systems found in nature. Evolved vascular systems, such as the human cardiovascular system, pump fluid through a complex system composed of a single reservoir/pump. These systems regulate flow by systematically closing and opening valves appropriately through soft biological material constriction. The proposed pneumatic valve emulates this with two concentric flexible tubes with a single hole on the inner tube and patterned holes on the outer tube. This allows it to decrease the quantity of tubes and valves required for pneumatically actuated soft robots, with the trade-off being increased motion of the valve spool (the inner tube). Previous versions of this adapter used rigid members which decreased the number of tubes tethering the robot to a pressure source, but also hindered the soft robotic nature and movement. This adapter utilizes flexible materials to minimize the valve’s effect on the robot’s range of motion. The tubes have holes that are patterned by custom design determined by the needs of the soft robot with which it is to be used. The inner tube can be moved rotationally or translationally within the outer tube to align with designated holes to pressurize and depressurize chambers in a soft robot with only a single lightweight valve.
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This content will become publicly available on December 1, 2026
Tendon-Actuated Concentric Tube Endonasal Robot (TACTER)
Endoscopic endonasal approaches (EEA) have become more prevalent for minimally invasive skull base and sinus surgeries. However, rigid scopes and tools significantly decrease the surgeon’s ability to operate in tight anatomical spaces and avoid critical structures such as the internal carotid artery and cranial nerves. This paper proposes a novel tendon-actuated concentric tube endonasal robot (TACTER) design in which two tendon-actuated robots are concentric to each other, resulting in an outer and inner robot that can bend independently. The outer robot is a unidirectionally asymmetric notch (UAN) nickel-titanium robot, and the inner robot is a 3D-printed bidirectional robot, with a nickel–titanium bending member. In addition, the inner robot can translate axially within the outer robot, allowing the tool to traverse through structures while bending, thereby executing follow-the-leader motion. A Cosserat-rod-based mechanical model is proposed that uses tendon tension of both tendon-actuated robots and the relative translation between the robots as inputs and predicts the TACTER tip position for varying input parameters. The model is validated with experiments, and a human cadaver experiment is presented to demonstrate maneuverability from the nostril to the sphenoid sinus. This work presents the first tendon-actuated concentric tube (TACT) dexterous robotic tool capable of performing follow-the-leader motion within natural nasal orifices to cover workspaces typically required for a successful EEA.
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- Award ID(s):
- 2125528
- PAR ID:
- 10651497
- Publisher / Repository:
- World Scientific Publishing Company
- Date Published:
- Journal Name:
- Journal of Medical Robotics Research
- Volume:
- 10
- Issue:
- 03n04
- ISSN:
- 2424-905X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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