Background
Minimally invasive surgery has transformed patient care by reducing trauma, accelerating recovery, and improving outcomes, especially in delicate fields such as fetal surgery, pediatric procedures, and advanced endoscopy. These procedures demand instruments that can navigate tightly constrained and highly curved anatomical pathways with exceptional precision.
However, existing robotic and manual tools face major limitations that restrict their usefulness in complex environments. Rigid instruments cannot bend sufficiently, pneumatic systems often respond slowly and introduce tremors, concentric tube robots risk tube snapping, and magnetic systems can interfere with fetal imaging and raise safety concerns. Many tendon-driven designs also suffer from tendon shearing and mechanical complexity, reducing reliability in high-stakes procedures.
These challenges underscore the need for a soft, flexible, and controllable robotic system that provides high dexterity without compromising safety or structural integrity.
Technology overview
This technology is a bio-inspired tendon-driven continuum robot that uses a novel ellipsoidal joint architecture to achieve highly flexible and precise motion for minimally invasive surgery. The system consists of interconnected ellipsoidal tendon-routing rings that mimic the behavior of human condyloid joints, enabling smooth sliding movements with a flexion range over 180 degrees and up to 230 degrees. The robot provides omnidirectional bending with two degrees of freedom while the ellipsoidal geometry minimizes torsion and protects the tendons from external forces.
A central hollow channel accommodates surgical instruments, enhancing procedural versatility. Actuation is achieved using three nylon-coated stainless steel tendon wires driven by DC motors equipped with Series Elastic Actuators for controlled force output. An Arduino-based control platform with PID control and integrated force sensing enables precise adjustment of tendon length and tension. Built from SLA 3D-printed resin components, the compact 14mm × 12mm prototype achieves a bending radius of 21.16 cm and a workspace volume of 39,685.84 cm³, demonstrating high dexterity and control suited for delicate surgical tasks.
Benefits
- Highly flexible design delivers over 180 degrees of smooth, controllable flexion
- Ellipsoidal geometry reduces torsion and prevents tendon shearing
- Central hollow channel supports integrated tool delivery
- Precise motion control enabled by PID-based tendon actuation
- Compact, lightweight structure suited for delicate minimally invasive procedures
Applications
- Fetal surgery
- Pediatric minimally invasive surgery
- Endoscopic and laparoscopic procedures
- Soft robotic surgical systems
- Advanced telesurgery tools
Opportunity
- Addresses critical limitations in dexterity, safety, and control for next-generation surgical robotics
- Offers a flexible, mechanically robust design compatible with a wide range of minimally invasive procedures
- Provides strong potential for co-development, clinical validation, and integration into robotic surgical platforms
- Available for exclusive licensing
Intellectual property
U.S. Provisional application serial no. 63/689,246 filed on 08/30/2024
PCT application serial no. PCT/US2025/043943 filed on 08/28/2025
