# Low-Power, High Data-Rate Digital Capsule Endoscopy Using Human Body Communication
## 6 Conclusions  
In this paper, we proposed a new, low-power capsule endoscopy system with high data rate, using HBC technology. The proposed CEHBC system uses three kinds of discrimination. The first technique is FSDT, which was used to support the low speed mode and high speed mode to increase the data transmission rate. The CEHBC system has benefits in that the receiving signal has a spread effect with the FSDT modulation that makes it less susceptible to wideband noise. The second technique involves  
\begin{table}
\begin{tabular}{c c c} \hline
**Specification** & **MiroCam [1,22]** & **CEHBC Tx Capsule** \\ \hline communication & \multicolumn{2}{c}{human body communication} \\ \hline image sensor & \
\begin{tabular}{c} customized CMOS image sensor \\ with 320 \(\times\) 320 pixel array) \\ \end{tabular} &
\begin{tabular}{c} PIXERPLUS PO8030D VGS single chip CMOS \\ image sensor with 640 \(\times\) 480 pixel array \\ \end{tabular} \\ pixel & 102,400 (=320 \(\times\) 320) & 230,400 (=480 \(\times\) 480) \\ frame rate & 3 frames/s & 3.13 frame/s \\ data rate & 3 Mbps & 6 Mbps \\ field of view & 150 degrees & – \\ battery & – & 3 V, 160 mAh Coin battery \\ battery life & 11 h & 8.3 h \\ lighting & 6 LEDs & 6 LEDs \\ size & 11 \(\times\) 24 mm & 13 \(\times\) 27 mm \\ weight & 3.4 \(\pm\) 0.05 g & 6.1 g \\ \hline \end{tabular}
\end{table}
Table 6: Performance comparison of the capsule endoscope using human body communication (HBC).  
the use of an algorithm to select the best combination of electrodes among the plurality, to select the best channel condition. The third technique involves the use of the LineSync algorithm to determine data synchronization and polarization to improve the reception accuracy of the data, even for long data transfer sections. The methods presented in this paper have the merit of implementing the capsule endoscope configured only as digital logic. The presented capsule endoscope was easily implemented using the FPGA device. Therefore, it is possible to fabricate lower power capsule endoscopes using advanced processes with lower operating voltage rather than of the FPGA. This architecture has an additional advantage that it is less affected by process variation because it is implemented as digital logic. As can be seen from comparison with other capsule endoscopes, the proposed method can support a relatively high data rate in spite of using its clock a few tens of MHz slower. In the future, it is predicted that image data with a higher data rate could be transmitted if the image compression method is used. The CEHBC-TXD system provides low power (3.7 mW) and high data rate (6 Mbps) performance while it supports high resolution images of 480 x 480 bytes at 3.13 f/s.  
All authors contributed to developing the measurement equipment, designing and performing measurements, data analysis, scientific discussions, and writing the paper.  
This work was supported by Electronics and Telecommunications Research Institute (ETRI) grant funded by the Korean government (18 ZB1200, Development of Core Technologies for Implantable Active Devices).  
Thank you for the technical support of the Intromedic Corporation.  
The authors declare no conflict of interest.