| Popis: |
To compensate for severe shortage of scrub nurses, we have been developing the Scrub Nurse Robot (SNR) system that is able to perform like an ‘ideal’ scrub nurse, if one exists. To make the SNR know which surgical instruments are being used in the operative field, we developed an automatic system of acquiring information on use of instruments by using RFID technology. Briefly, when an instrument with an RFID tag is inserted into a trocar cannula with an RFID antenna, the system identifies the instrument and also acquires the clock time of insertion. However, this simple algorithm termed ‘basic’ algorithm mistakes interruption of RF communication caused by use of electric knife for extraction of the instrument. To prevent such incorrect recognition, we previously reported a software-based solution characterized by an algorithm against electromagnetic interference (AAEI). The AAEI, however, delayed judgment of extraction only when an electric knife was used. In this paper, we proposed two hardware-based solutions to ensure real-time detection of inserting and extracting all instruments including the electric knife: 1) detecting occupancy of a trocar cannula and 2) detecting conclusive proof of use of electric knife. Both methods still used the RFID-based system with the ‘basic’ algorithm for identification of instruments. In the former method, we used a reflective photosensor to detect presence of instrument inside a trocar cannula. In the latter one, we developed a device containing a coil to detect electromotive force induced in the coil by alternating electric currents flowing back to an indifferent electrode when the electric knife was switched on. In conclusion, the latter method was superior in real-time responsiveness. |
