ABSTRACT
Specialized vibrotactile actuators are widely used to output haptic sensations due to their portability and robustness; some models are expensive and capable, while others are economical but weaker and less expressive. To increase the accessibility of high-quality haptics, we designed a cost-effective actuation approach called the rotating motor actuator (RMA): it uses a small DC motor to generate vibrotactile cues on a rigid stylus. We conducted a psychophysical experiment where eighteen volunteers matched the RMA's vibration amplitudes with those from a high-quality reference actuator (Haptuator Mark II) at twelve frequencies from 50 Hz to 450 Hz. The average error in matching acceleration magnitudes was 10.2%. More current was required for the RMA than the reference actuator; a stronger DC motor would require less current. Participants also watched a video of a real tool-mediated interaction with playback of recorded vibrotactile cues from each actuator. 94.4% of the participants agreed that the RMA delivered realistic vibrations and audio cues during this replay. 83.3% reported that the RMA vibrations were pleasant, compared to 66.7% for the reference. A possible cause for this significant difference may be that the reference actuator (which has a mechanical resonance) distorts low-frequency vibrations more than the RMA does.
Subject(s)
Vibration , HumansABSTRACT
BACKGROUND: Augmented reality (AR) has been widely researched for use in healthcare. Prior AR for robot-assisted minimally invasive surgery has mainly focussed on superimposing preoperative three-dimensional (3D) images onto patient anatomy. This article presents alternative interactive AR tools for robotic surgery. METHODS: We designed, built and evaluated four voice-controlled functions: viewing a live video of the operating room, viewing two-dimensional preoperative images, measuring 3D distances and warning about out-of-view instruments. This low-cost system was developed on a da Vinci Si, and it can be integrated into surgical robots equipped with a stereo camera and a stereo viewer. RESULTS: Eight experienced surgeons performed dry-lab lymphadenectomies and reported that the functions improved the procedure. They particularly appreciated the possibility of accessing the patient's medical records on demand, measuring distances intraoperatively and interacting with the functions using voice commands. CONCLUSIONS: The positive evaluations garnered by these alternative AR functions and interaction methods provide support for further exploration.
