Autonomous swab robot for naso- and oropharyngeal COVID-19 screening

Abstract

The COVID-19 outbreak has triggered a global health and economic crisis, necessitating widespread testing to control viral spread amidst rising cases and fatalities. The recommended testing method, a combined naso- and oropharyngeal swab, poses risks and demands limited protective gear. In response to the COVID-19 pandemic, we developed and tested the first autonomous swab robot station for Naso- and Oropharyngeal Coronavirus Screening (SR-NOCS). A force-sensitive robot running under a Cartesian impedance controller is employed to drive the swab to the sampling area. This groundbreaking device underwent two clinical studies-one conducted during the initial pandemic lockdown in Europe (early 2021) and the other, more recently, in a public place after the pandemic had subsided earlier in the year 2023. In total, 52 patients suspected of COVID-19 infection were included in these clinical studies. The results revealed a complete positive correlation between autonomous and manual sampling. The test subjects exhibited a high acceptance rate, all expressing a willingness to undergo future tests with SR-NOCS. Based on our findings, such systems could enhance testing capabilities, potentially conducting up to 300 tests per robot per day with consistent precision. The tests can be carried out with minimal supervision, reducing infection risks and effectively safeguarding patients and healthcare workers.

Figure 1

Swab robot for NP and OP Covid-19 screening. (a) Modular swab stations that can be easily interconnected and installed in a compact area. (b) Detailed specifications of the swab station (see also “Methods” section).

Figure 2

The swab robot for NP and OP COVID-19 screening and example procedure. Photos were taken during the actual study and in a pre-test. (a) Subject during NP swabbing. (b,c) A depiction and actual robotic system for the OP swab procedure, respectively. (d,e) A depiction and actual robotic system for the NP swab procedure, respectively. (f–i) Snapshots of a healthcare worker supervising the station and performing the necessary support actions, such as handling new material, disinfecting, and sorting samples.

Figure 3

Clinical studies within Experiment 1 and 2. (a,b) The nose and throat disposable fixation used during swab sampling in the clinical study. The fixture design can be adapted for both NP (a) and OP (b) screening procedures. (c) Clinical study within Experiment 1. The autonomous swab robot for NP / OP Corona screening is being performed for one of the test subjects (right in c), while the operator (center of c, in fully protective equipment) observes with his finger ready on the control device (see “Test workflow” method); a hospital physician (left in c) observes the test from a safe distance. (d,e) Public visitors engaging with the swabbing robot station at the Deutsches Museum in Munich within Experiment 2. (d) depicts an internal view, while (e) shows an external perspective. The image is partially blurred to preserve anonymity.

Figure 4

Robot force and position plot over time during a test procedure. A complete test routine (test subject 26) is shown including all three swab sequences and a handover motion at the end of the procedure. In each sequence, the robot moves to the swab’s initial position (a), waits for confirmation from the patient and operator (b), and performs the swab motion (c). The programmed and executed robot positions indicate horizontal displacements in the robot’s forward direction in world coordinates (towards the test subject). The divergence between them indicates a contact and coincides with an increased value of the estimated contact force.

Figure 5

Test subjects’ survey. (a) A box plot representation of the answers to the Likert scale questions, from 1 (least favorable assessment) to 5 (most favorable assessment). Thick (center) lines show the medians; box limits indicate the correlated variances; whiskers visualize the minimum and maximum ratings (n = 31). (b,c) The number of yes/no answers for questions (iii) and (vii), respectively. The respective pieces display percentages of the whole.

Figure 6

Robot force and position data within subject Coronal plane (y- and z-axes) during OP swab procedure conducted within experiment 2. Orange and red bold lines represent the mean and gray lines represent the standard deviation across 21 subjects. (i and iii) panels represent force data and (ii and iv) panel represents position data.

Figure 7

Post-experiment 2 questionnaire response rates, reflecting the extent to which participants followed the established protocol.