An Automatic Implementation of Oropharyngeal Swab Sampling for Diagnosing Respiratory Infectious Diseases via Soft Robotic End-Effectors

The most widely adopted method for diagnosing respiratory infectious diseases is to conduct polymerase chain reaction(PCR)assays on patients’respiratory specimens,which are collected through either nasal or oropharyngeal swabs.The manual swab sampling process poses a high risk to the examiner and may cause false-negative results owing to improper sampling.In this paper,we propose a pneumatically actuated soft end-effector specifically designed to achieve all of the tasks involved in swab sampling.The soft end-effector utilizes circumferential instability to ensure grasping stability,and exhibits several key properties,including high load-to-weight ratio,error tolerance,and variable swab-tip stiffness,leading to successful automatic robotic oropharyngeal swab sampling,from loosening and tightening the transport medium tube cap,holding the swab,and conducting sampling,to snapping off the swab tail and sterilizing itself.Using an industrial collaborative robotic arm,we integrated the soft end-effector,force sensor,camera,lights,and remote-control stick,and developed a robotic oropharyngeal swab sampling system.Using this swab sampling system,we conducted oropharyngeal swab-sampling tests on 20 volunteers.Our Digital PCR assay results(RNase P RNA gene absolute copy numbers for the samples)revealed that our system successfully collected sufficient numbers of cells from the pharyngeal wall for respiratory disease diagnosis.In summary,we have developed a pharyngeal swab-sampling system based on an“enveloping”soft actuator,studied the sampling process,and imple-mented whole-process robotic oropharyngeal swab-sampling.

State of the art in flexible SERS sensors toward label-free and onsite detection:From design to applications

Surface-enhanced Raman scattering(SERS)as a powerful non-invasive spectroscopic technique has been intensively used in bio/chemical sensing,enabling ultrasensitive detection of various analytes and high specificity with a fingerprint-like characteristic.Flexible SERS sensors conformally adapting to nonplanar surfaces and allowing swab-sampling or in-situ detection of analytes,which are not achievable for rigid SERS sensors,greatly meet the demand of onsite and real-time diagnostics.However,the rational design and fabrication of flexible SERS-based sensors for point-of-care diagnostics aiming to simultaneously achieve extremely high sensitivity,stability,and good signal reproducibility remain many challenges.We present a state-of-the-art review of the flexible SERS sensors.Attentions are devoted to engineering plasmonic substrates for improving the performance of flexible SERS devices.Strategies of constructing the flexible SERS sensors toward point-of-care detection are investigated in depth.Advanced algorithms assisting the SERS data process are also presented for intelligently distinguishing the species and contents of analytes.The promising applications of flexible SERS sensors in medical diagnostics,environmental analyses,food safety,and forensic science are displayed.The flexible SERS devices serving as powerful analytical tools shed new light on the in-situ and point-of-care detection of real-world analytes in a convenient,facile,and non-destructive manner,and especially are conceivable to serve as next-generation wearable sensors for healthcare.