Communication channel modeling of human forearm with muscle fiber tissue characteristics

Measuring upper limb movement to analyze intra-body communication channel attenuation characteristics

BACKGROUND

This experiment was designed to study the respective effects of the closed-state human palm and dynamic arm bending on intra-body communication channel attenuation.

METHODS

We selected the right upper arm of a healthy adult male as the experimental object to measure channel attenuation variation in a closed or open palm, and when the arm was bent, so as to analyze channel characteristics.

CONCLUSIONS

The experiment showed that, in a quasi-static stable system, the effects of a closed palm on channel attenuation were negligibly minimal. In contrast, the physiological signal of the living body significantly interfered with the channel in the low-frequency mode. In the dynamic arm-bending experiment, we found that the attenuation variation range corresponds to the intersection angle (90∘⩽θ⩽ 180∘) of the upper arm and forearm; these results provide the basis for the establishment of a theoretical model.

Modeling of sectionally continuous communication channel with inhomogeneously distributed tissues

BACKGROUND

This study aimed to investigate effects on the transmission channel caused by heterogeneous distribution in tissues and joint characteristics.

METHOD

Human arm section scans were taken using CT technology, and zoned, following which, a circumference measurement experiment was performed to analyze the effect of inhomogeneous distribution of tissues. In order to analyze the arm joint's effect on channel transmission, we proposed a piecewise modeling method in combination with connection conditions.

CONCLUSIONS

It can be seen from the experiment that, in the quasi-static mode, the communication channel error caused by the inhomogeneous distribution of tissues is small enough to be negligible. The error between calculated and experimental results is reduced by 3.93 dB in this experiment relative to models that did not include joint characteristics, and the average error is lowered by 0.73 dB. The variation curve fit to experimental data is also improved in this method. As such, it can be quantitatively determined that a channel model with joint characteristics is superior to models excluding joint characteristics.

Path Loss Measurement and Channel Modeling with Muscular Tissue Characteristics

BACKGROUND

The galvanic coupling intra-body communication has low radiation and strong anti-interference ability, so it has many advantages in the wireless communication.

METHOD

In order to analyze the effect of muscle tissue's characteristics upon the communication channel, we selected the muscle of pig buttock as the experimental sample, and used it to study the attenuation property with the galvanic coupling intra-body communication channel along the parallel direction and the transverse direction relative to the muscular fibre line as well as on the surface of destroyed muscular fibre; the study frequency ranges from 1kHz to 10MHz.In the isotropic experiment, in order to destroy muscle's fibre characteristics, we grinded the muscle four times, at least five minutes for each time. 0dbm sine-wave signal was input to measure the channel attenuation parameter S21 when the transmitter and the receiver were placed at different positions and different distances d1 and d2 (20mm, 40mm, 60mm), so as to analyze channel loss.

CONCLUSION

Within the same frequency range and at the same communication distance, the maximum error of channel attenuation was 10dB; within the same frequency, as the communication distance was increased, the channel attenuation rose gradually, with 4dB increased every 20mm. The conclusion provides the basis for building the theoretical model in the future.