Adjusting Tissue Puncture Omnidirectionally In Situ with Pneumatic Rotatable Biopsy Mechanism and Hierarchical Airflow Management in Tortuous Luminal Pathways

2025-06-03

AI Summary

Conventional endoscopic biopsy catheters suffer from friction-induced hysteresis and spatial constraints, impeding precise, multi-directional in situ biopsy within tortuous luminal pathways. Method: This study proposes a pneumatically actuated robotic intraluminal biopsy catheter featuring a distally mounted pneumatic bending actuator integrated with a Pneumatically Rotatable Biopsy Mechanism (PRBM). A novel hierarchical airflow management strategy enables bidirectional functionality—low-flow actuation for steering and high-flow delivery for needle insertion—using a single pneumatic channel. Contribution/Results: Mechanical modeling, puncture force characterization, and phantom experiments in anatomically realistic tortuous pathways demonstrate that the PRBM achieves stable, controllable six-directional biopsy at 0.3 MPa, with repeatable deployment and sampling. The design eliminates catheter torsion, enables full 360° azimuthal sampling, and overcomes directional limitations and response latency inherent in existing technologies.

Technology Category

• Intelligent Robots: Manipulation
• Planning, Routing, and Scheduling: Activity and Plan Recognition
• Search and Optimization: Sampling/Simulation-based Search

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation

Abstract

In situ tissue biopsy with an endoluminal catheter is an efficient approach for disease diagnosis, featuring low invasiveness and few complications. However, the endoluminal catheter struggles to adjust the biopsy direction by distal endoscope bending or proximal twisting for tissue sampling within the tortuous luminal organs, due to friction-induced hysteresis and narrow spaces. Here, we propose a pneumatically-driven robotic catheter enabling the adjustment of the sampling direction without twisting the catheter for an accurate in situ omnidirectional biopsy. The distal end of the robotic catheter consists of a pneumatic bending actuator for the catheter's deployment in torturous luminal organs and a pneumatic rotatable biopsy mechanism (PRBM). By hierarchical airflow control, the PRBM can adjust the biopsy direction under low airflow and deploy the biopsy needle with higher airflow, allowing for rapid omnidirectional sampling of tissue in situ. This paper describes the design, modeling, and characterization of the proposed robotic catheter, including repeated deployment assessments of the biopsy needle, puncture force measurement, and validation via phantom tests. The PRBM prototype has six sampling directions evenly distributed across 360 degrees when actuated by a positive pressure of 0.3 MPa. The pneumatically-driven robotic catheter provides a novel biopsy strategy, potentially facilitating in situ multidirectional biopsies in tortuous luminal organs with minimum invasiveness.

Problem

• Enables omnidirectional tissue biopsy without catheter twisting
• Addresses friction and space constraints in tortuous luminal organs
• Uses pneumatic control for precise in-situ sampling direction adjustment

Innovation

• Pneumatic rotatable biopsy mechanism for omnidirectional adjustment
• Hierarchical airflow control for precise tissue sampling
• Pneumatic bending actuator for deployment in tortuous lumens