A multi-chamber soft robot for transesophageal echocardiography: continuous kinematic matching control of soft medical robots

Abstract

OBJECTIVES: This research investigates designing a continuum soft robot and proposing a kinematic matching control to enable the robot to perform a specified medical task, which in this paper is the transesophageal echocardiography (TEE). METHODS: A multi-chamber soft robot was designed and fabricated based on the molding of separate layers. The method of transformation matrices was used to develop the kinematic models, and a control method using Jacobian matrices was proposed to manipulate the robot. RESULTS: A prototype was made based on a multi-chamber multi-layer design. The system contains three segments that can be actuated independently to mimic the active bending part of the respective probe. Kinematic models were developed. Negative pressure (vacuum) was used as actuation input. An open-loop controller inspired by a redundancy resolution technique was proposed to make the soft robot tip follow the desired path, i.e. the path of the rigid ultrasound probe. CONCLUSIONS: It is concluded that the soft solution can perform the required task as the reachable points of the TEE tip cover the proposed robot workspace and the proposed control can be used for maneuvering in arbitrary trajectories.