Poster V16 - Designing a Remotely Operated Intraoral Camera System with Precise Motion Control

Introduction: Dentists have recently started using intraoral cameras to reveal hidden and overlooked defects in teeth as well as display and record dental pictures as a part of a patient's medical records [1-2]. Research has also shown that patient outcomes improve when a dentist explains the status of their dental health with real-time video evidence. However, since current commercially available intraoral cameras are bulky with inflexible handles, they are used only before and after, but not during dental work. The absence of a real-time display of the oral condition during a dental procedure limits effective communication between the patient and the dentist. The objective of this study is to develop a compact and flexible intraoral camera (IOC) system with precise camera control that a dentist can operate to provide a high-quality video of the dental details in real-time and can be used by the dentist during the dental procedure without any additional training. This device is expected to free the hands of the dentist and provide a convenient display of dental details, which is beneficial for both the dentist and the patient. With a robotic mount unit to control movements of the intraoral camera inside the mouth, the system will be easy to use, require little training, and potentially become a standard part of dentistry operations and training.

Materials and

Methods: The design criteria include the following: the intraoral camera should be sufficiently small and flexible to be used during dental procedures, should have acceptable resolution for video/image display and recording; and the position and viewing angle of the intraoral camera should be precisely controllable using a simple input device. A sufficiently small camera with appropriate focus is procured from a commercial vendor. This unit has two switchable cameras located on the side and bottom of the unit. The video feed is displayed on a monitor with a USB connection. The camera is secured in a small 3D-printed tube that can be axially translated and rotated around its axis. The translational and rotational motions are realized by two additional concentric tubes and appropriate gear designs; and are actuated by a DC motor and a servo motor, respectively. Structural parts are designed using CAD software, printed by a low-cost 3-D printer, and assembled using nylon machine screws and heat-set threaded inserts. 3-D printed gears are used to enable force transmission and conversion from the DC motor rotation to camera vertical motion, and from servo rotation to camera rotation. An Arduino-based embedded system is developed to control the two motors. The input signal is generated by a commercially available PS4 controller that is wirelessly connected to the Arduino. A flat mounting surface with screw holes on the device casing offers a simple and versatile way to position the device securely.

Results, Conclusions, and Discussions: Figure 1 shows the prototype of the developed device tested in a simulated mouth. Two cameras attached to a flexible thin wire with a diameter of 5 mm capture dental details with sufficient resolution, via streaming the real-time video to a conveniently located monitor. The camera is small enough to provide a view inside the confined space of the mouth without inhibiting any dental procedure. The 3-D printed unit is made of PLA, which is sufficiently rigid to minimize the deflection of the camera during motion. The high resolution of the 3-D printing enables the smooth meshing of the gears for precise control. The user input from the joysticks on the controller is converted into linear and rotational speeds of the servo and motor to control the motion of the camera. In particular, the right joystick's forward-backward motion controls the camera's linear advance into the mouth, and the left joystick's left-right motion controls the camera's rotation. With the incorporated actuators, the entire control unit is 13 cm long with 5 cm by 5 cm cross-section dimensions. We tested the developed device and found smooth axial and rotational motions of the camera inside the simulated mouth. The system also provided uninterrupted signal conversion from the joysticks to the actuators in the control unit.
In conclusion, we designed and developed a prototype of a remotely operated intraoral camera system with precise motion control. The prototype satisfied the design goal of a compact camera with its motion-controlled remote with a joystick. This device is easy to manufacture using 3-D printing and other commonly available parts for a low overall cost. Although our experiments have demonstrated its compact size and smooth and fine motion of the camera, more work is needed to test its performance in dental offices.

Acknowledgements (Optional): This research was supported by the UMBC Technology Catalyst fund.