# Development of Robot-Assisted Untact Swab Sampling System for Upper Respiratory Disease
## 4 Discussion  
The main advantage of telerobotic sample collection is eliminating the risk of the infection of medical personnel that may occur during the collection process. However, the proposed robotic sample collection system does not support a fully \"untact\" sample collection process. Since the developed system allows only the process of swab sampling itself to be performed remotely, a paramedic staff member is required near the slave system to place the swab in the holder, disinfect the robot after sample collection, and reinstall a new swab. To build a fully automated sample collection system, other teleoperated systems, such as a telenursing robot [21], should be incorporated. The proposed slave robot is designed to cover a subject's facial area; the size and kinematic structure of the slave robot are optimized for swab sampling from the upper respiratory tract while maintaining dexterity and accuracy in the facial workspace. In particular, the slave robot is designed not to be a burden to patients compared with systems that use an industrial serial robot arm, which can require large joint movements to determine the position of the swab and generate the swab insertion motion. To achieve this compact structure, however, the systems at both the master and slave sites are separated into two devices, one for position and one for insertion of swab. In the slave robot, the lengths of all six legs must be longer to cover a greater depth of swab insertion. By mounting the swab insertion unit on a Stewart platform, the insufficient Z-directional workspace of the parallel robot is complemented while maintaining the advantages of parallel robotics. For the master subsystem, two master devices have been developed for each slave unit to simplify the control method through the correspondent matching of the kinematic structures. However, in the future, these master devices will be integrated into a single unit for more intuitive operation. In experiments, we checked whether the developed slave robot can cover the required facial workspace for NP swabbing. Additionally, experiments concerning the motion tracking accuracy of telerobotic control were conducted, and we found that the developed slave robot can track the motion of the master device with an error of 3.41 mm (RMSE). A life-size head phantom model was then used to test the success of sample collection using NP swabs; a virtual specimen (a cotton ball soaked with orange ink) was installed on the posterior nasopharynx wall of the model, and we tested whether our system could effectively sample the ink. By monitoring the force information sensed by the swab holder, we could recognize when the tip of the swab was pressing onto the soft cotton ball. The experimental results show that NP swabbing of the phantom could be performed successfully, thus also showing the possibility that the proposed telerobotic system could be used as an effective and safe remote sample collection system. Since the basic feature of telerobotics is telepresence, the developed system also includes teleconference codecs that enable audiovisual communication between the slave and master sites. Data for patient imaging, robot control, and sensor monitoring are also transmitted through the teleconference system. However, due to the hardware limitations of the currently implemented teleconference system, the data transmission speed between the slave and master sites is limited to 30 Hz, i.e., 33 ms of delay exists between the master device and the slave robot. These teleconference codecs will be upgraded for telerobotics, reducing the time delay between the two sites, to enable faster and more accurate visual feedback control. In addition, we plan to implement a force feedback capability to allow the master operator to feel the force generated when the swab contacts an anatomical structure during insertion.