  Nasopharyngeal (NP) swab sampling is an effective approach for the diagnosis
of coronavirus disease 2019 (COVID-19). Medical staffs carrying out the task of
collecting NP specimens are in close contact with the suspected patient,
thereby posing a high risk of cross-infection. We propose a low-cost miniature
robot that can be easily assembled and remotely controlled. The system includes
an active end-effector, a passive positioning arm, and a detachable swab
gripper with integrated force sensing capability. The cost of the materials for
building this robot is 55 USD and the total weight of the functional part is
0.23kg. The design of the force sensing swab gripper was justified using Finite
Element (FE) modeling and the performances of the robot were validated with a
simulation phantom and three pig noses. FE analysis indicated a 0.5mm magnitude
displacement of the gripper's sensing beam, which meets the ideal detecting
range of the optoelectronic sensor. Studies on both the phantom and the pig
nose demonstrated the successful operation of the robot during the collection
task. The average forces were found to be 0.35N and 0.85N, respectively. It is
concluded that the proposed robot is promising and could be further developed
to be used in vivo.
