Hiromi Takahata

Thoracoscopic surgery support system using passive RFID marker

This paper proposes a RFID based thoracoscopic surgery support system, which is capable of marking a tumor inside organ tissue. The marker composed of small RFID-tags is implanted in the vicinity of tumor found in the endoscopy test. In the thoracoscopic surgery operation for removing the tumor, an RFID detector determines the accurate position of the implanted RFID-tag markers by measuring the strength of the signal emitted from the target tag. Due to limitation in the size of RFID-tag, the proposed system employs a passive RFID. To activate the passive tag implanted in the organ tissue, this paper designs a saddle-shape efficient power supply antenna. A sensitive and frequency-selective receiver is then designed for detecting the weak signal from the tag. The feasibility test confirms that the proposed method is capable of determining the accurate location of RFID tags implanted in the patients organ tissue.

Particle filter assisted RFID tag location method for surgery support system

This paper proposes a particle filter assisted RFID (Radio Frequency Identification) [1] tag location method for surgery support system. It is difficult to locate early stage small tumors during the intraoperative period. A part of authors has already proposed an RFID-based tumor location system, which implanted miniature RFID tags in the vicinity of the target tumor [2]. The operator search for the RFID tag using the sensor antenna. Although the proposed method can find the tag location exactly, it requires a skilled operator. In order to simplify the location procedure. The proposed particle filter assisted RFID tag location system is capable of identifying the tag location with simple motion of the sensor antenna. Computer simulation result shows that the proposed method can provide the precise estimate of the location of the tag.

Particle filter-assisted positioning method for identifying RFID-tag implanted in the organism

This paper proposes a three-dimensional positioning method using particle filter for identifying a miniature RFID (Radio Frequency Identification) tag implanted in the organism. The RFID-based tumor marker for identifying the position and size of the tumor has been proposed. Although it is efficient in some applications, it takes a long time to point out the position because of scanning the sensor antenna for wide area of interest. Furthermore, the position is often lost due to motion of the organism. In order to find and track the RFID-tag position, this paper introduces a particle filter-assisted three-dimensional positioning method. The likelihood function, which is not only take into account the received signal power, but also the attitude and position of the sensor antenna and the motion of the RFID-tag, is applied to the particle filter to estimate the position. Computer simulation result shows that the proposed scheme is capable of estimating the three-dimensional position of the RFID-tag.

Joint Estimation of Position and Gain for RFID-Tag Assisted Surgery Support System

Joint estimation of RFID-tag position and gain is proposed for RFID-assisted surgery support system. Although various RFID-tag positioning schemes have been proposed, gain variations in RFID-tag could affect the accuracy in the positioning. This paper uses a non-linear optimization method to estimate the gain and position of RFID-tag simultaneously. Computer simulation result shows that the proposed scheme is capable of estimating the tag position accurately.