UC San Diego

In this thesis, 3D printing is employed to design a detachable bronchoscope consisting of an articulating arm, a detachable mechanism, a handle with an embedded gearbox, and a micro-transmission located in the arm. The micro-transmission is a novel screw system that converts a rotational degree of freedom from the attached handle to a linear degree of freedom to articulate the distal tip. Essential to the micro-transmission, the design of the screw thread has been analytically and experimentally investigated. The rotational input of the screw's ability to convert to linear movement is calculated. The operator's torque input necessary to rotate the distal end of a bronchoscopes linkage system is evaluated with consideration of the forces required to deflect this distal tip. These outcomes depend on the screw design parameters that include pitch, thread angle, and material properties. A mathematical model has been derived from the foundational power mechanics equations which were then confirmed experimentally. The experiment contained various screw thread designs with the use of stereolithography 3D printing methods that were compared to determine the force output. The detachable bronchoscope prototype enables the operator to fully operate the device with the transmission system incorporated which will be covered in detail within this paper.