We are excited to share our paper “OSSAR: Towards Open-Set Surgical Activity Recognition in Robot-assisted Surgery” which has been accepted for IEEE International Conference on Robotics and Automation (ICRA) 2024!

In this work, we tackle the challenge of open-set recognition in surgical robotics. Our novel OSSAR framework improves the ability to classify known surgical activities while also detecting unknown activities that weren’t seen during training.

Key contributions:

โ€ข A hyperspherical reciprocal point strategy to better separate known and unknown classes

โ€ข A calibration technique to reduce overconfident misclassifications 

โ€ข New open-set benchmarks on the JIGSAWS dataset and our novel DREAMS dataset for endoscopic procedures

โ€ข State-of-the-art performance on open-set surgical activity recognition tasks

This research takes an important step towards more robust and generalizable AI systems for surgical robots. We hope it will help pave the way for safer and more capable robot-assisted surgeries.

Thank all the amazing co-authors Long Bai, Guankun Wang, Jie Wang, Xiaoxiao Yang, Huxin Gao, Xin Liang, An Wang, Mobarakol Islam, and Hongliang Ren

and our institutions (The Chinese University of Hong Kong, Beijing Institute of Technology, Qilu Hospital of Shandong University, Tongji University, University College London, National University of Singapore) for their support.

You can find more details in our paper https://lnkd.in/gDsjVDSP

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We are thrilled to share our work “Lightweight Pneumatically Elastic Backbone Structure with Modular Construction and Nonlinear Interaction for Soft Actuators” published on Soft Robotics ๐ŸŽ‰๐ŸŽ‰

The paper is available at https://lnkd.in/gfS5fGSw

The research is the result of a remarkable collaboration between Yang Yang from CUHK and ZJU, Sam, Jiewen Lai from CUHK, Chaochao Xu from NUS, Zhiguo He and Pengcheng Jiao from ZJU, and Hongliang Ren from CUHK and NUS.

๐Ÿ‘‡ Open the below article for more details!!!

There has been a growing need for soft robots operating various force-sensitive tasks due to their environmental adaptability, satisfactory controllability, and nonlinear mobility unique from rigid robots. It is of desire to further study the system instability and strongly nonlinear interaction phenomenon that are the main influence factors to the actuations of lightweight soft actuators.

Here, we present a design principle on lightweight pneumatically elastic backbone structure (PEBS) with the modular construction for soft actuators, which contains a backbone printed as one piece and a common strip balloon. We build a prototype of a lightweight (<80 g) soft actuator, which can perform bending motions with satisfactory output forces (~ 20 times self-weight).

Experiments are conducted on the bending effects generated by interactions between the hyper-elastic inner balloon and the elastic backbone. We investigated the nonlinear interaction and system instability experimentally, numerically and parametrically. To overcome them, we further derived a theoretical nonlinear model and a numerical model. Satisfactory agreements are obtained between the numerical, theoretical and experimental results. The accuracy of the numerical model is fully validated. Parametric studies are conducted on the backbone geometry and stiffness, balloon stiffness, thickness, and diameter. The accurate controllability, operation safety, modularization ability, and collaborative ability of the PEBS are validated by designing PEBS into a soft laryngoscope, a modularized PEBS library for a robotic arm, and a PEBS system that can operate remote surgery. The reported work provides a further applicability potential of soft robotics studies.

FIG. 1. Illustrative demonstration of the PEBS: (a) the detailed structure and dimensions of the PEBS, (b) the design principle that can be divided into the separation stage and the interaction stage, and (c) the design principle that can be specifically divided into the separation stage, the insufficient interaction stage, the full interaction stage, and the excessive interaction stage, based on the interaction conditions.

FIG. 2. Nonlinear interaction phenomenon analyses: (a) the free oscillation phenomenon of the backbone structure generated by the structural asymmetric stress responses to gravity, (b) the interaction performances of the backbone structure and the density plot showing the relationship between the gap numbers, pressures, and bending angles, (c) the interaction performances of the balloon and the relationships between the pressures and expansion ratios regarding the radial and axial expansion ratios, respectively, (d) relationships between the pressures and stresses regarding the backbone structure and balloon, respectively.

FIG. 3. Applications of PEBS demonstrate unique advantages of accurate controllability, operation safety, modularization ability, and collaborative ability. (a) A PEBS soft laryngoscope that can operate laryngeal diagnosis. (b) Real-time images captured by the integrated image sensor. (c) Modularized PEBS library that can be installed onto a robot arm. (d) A PEBS grasper that can operate various grasping tasks. (e) The PEBS system can be potentially applied to operate a debridement.