Body Channel Communication Research Articles

PERFORMANCE OF ENERGY DETECTION AND MATCHED FILTER RECEIVERS IN HUMAN BODY COMMUNICATION CHANNEL

This study studies the Bit-Error-Rate (BER) performance of matched filter and energy detection receivers in Human Body Communication (HBC) channel model. HBC, as defined by the IEEE 802.15 Task Group (TG) 6, is a Body Area Network (BAN) at frequency band 5-50 MHz, where communication is from body surface to body surface. The Bit-Error-Rate (BER) performance is investigated for Energy Detection (ED) and Matched Filter (MF) receivers. BER performance is studied and compared for Binary Pulse-Position Modulation (BPPM) and Binary Phase Shift Keying (BPSK). Moreover, the effect of varies channel parameters on the BER of studied receivers is investigated, including ground plate area at Transmit (Tx) and Receive (Rx) antennas and distance between Tx and receive antennas through air and body. Results show that the BER of both receivers is not affected by varying channel parameters.

The Signal Transmission Mechanism on the Surface of Human Body for Body Channel Communication

The signal transmission mechanism on the surface of the human body is studied for the application to body channel communication (BCC). From Maxwell's equations, the complete equation of electrical field on the human body is developed to obtain a general BCC model. The mechanism of BCC consists of three parts according to the operating frequencies and channel distances: the quasi-static near-field coupling part, the reactive induction-field radiation part, and the surface wave far-field propagation part. The general BCC model by means of the near-field and far-field approximation is developed to be valid in the frequency range from 100 kHz to 100 MHz and distance up to 1.3 m based on the measurements of the body channel characteristics. Finally, path loss characteristics of BCC are formulated for the design of BCC systems and many potential applications.

A 0.24-nJ/b Wireless Body-Area-Network Transceiver With Scalable Double-FSK Modulation

An energy-efficient wireless body-area-network (WBAN) transceiver is implemented in 0.18-μm CMOS technology with 1-V supply voltage. For the low energy consumption, the body channel communication (BCC) PHY is utilized with the theoretical results of Maxwell's equation analysis behind the BCC. Based on the channel analysis, the resonance matching (RM) and contact impedance sensing (CIS) techniques are proposed to enhance the quality of the body channel. A double-FSK modulation scheme is adopted with high scalability to fulfill the IEEE 802.15.6 Task Group specifications. In addition, a low-power double-FSK transceiver is implemented by five circuit techniques: 1) a reconfigurable LNA with CIS; 2) a current-reuse wideband demodulator; 3) a divider-based local oscillator (LO) generation with duty-cycle correction in the receiver; 4) a reconfigurable driver with RM; and 5) a divider-based digital double-FSK modulator in the transmitter. As a result, fully WBAN compatible receiver and transmitter consume 2.4 and 2 mW, respectively, at a data rate of 10 Mb/s, corresponding to energy consumption of 0.24 nJ per received bit and 0.2 nJ per transmitted bit.

PERFORMANCE EVALUATION OF UWB ON-BODY COMMUNICATION UNDER WIMAX OFF-BODY EMI EXISTENCE

A study of UWB on-body communication system performance, with the WiMax ofi-body electromagnetic interference (EMI) existence, is presented. Firstly, a compact UWB antenna with good on-body performance is verifled and chosen as our reference antenna. Using this realistic antenna, channel transfer function (CTF) of UWB on-body channel in an indoor room is investigated by measurements. Based on the measured data, the parameters of its pathloss model and its power delay proflle (PDP) model are extracted respectively. Secondly, a new body channel communication system model, composed of the on-body and ofi-body dual-link channel, together with UWB and WiMax signal models are presented. Finally, UWB on-body communication performances under difierent WiMax ofi-body EMI levels are studied by simulation. Simulated results show that this on-body system performance is quite limited and easily afiected by the ofi-body WiMax EMI. It is pointed out that the existing UWB on-body communication abilities should be greatly improved when WiMax ofi-body EMI signals are considered.

A 3.9 mW 25-Electrode Reconfigured Sensor for Wearable Cardiac Monitoring System

A low power highly sensitive Thoracic Impedance Variance (TIV) and Electrocardiogram (ECG) monitoring SoC is designed and implemented into a poultice-like plaster sensor for wearable cardiac monitoring. 0.1 Ω TIV detection is possible with a sensitivity of 3.17 V/Ω and SNR > 40 dB. This is achieved with the help of a high quality (Q-factor > 30) balanced sinusoidal current source and low noise reconfigurable readout electronics. A cm-range 13.56 MHz fabric inductor coupling is adopted to start/stop the SoC remotely. Moreover, a 5% duty-cycled Body Channel Communication (BCC) is exploited for 0.2 nJ/b 1 Mbps energy efficient external data communication. The proposed SoC occupies 5 mm × 5 mm including pads in a standard 0.18 μm 1P6M CMOS technology. It dissipates a peak power of 3.9 mW when operating in body channel receiver mode, and consumes 2.4 mW when operating in TIV and ECG detection mode. The SoC is integrated on a 15 cm × 15 cm fabric circuit board together with a flexible battery to form a compact wearable sensor. With 25 adhesive screen-printed fabric electrodes, detection of TIV and ECG at 16 different sites of the heart is possible, allowing optimal detection sites to be configured to accommodate different user dependencies.

Dual-mode impulse radio ultra-wideband transmission for body area networks

A dual-mode impulse radio ultra-wideband (IR-UWB) system, which combines body channel communication for wearable on-body transmission with conventional UWB communication for in-body to on-body transmission, is proposed. The basic system structure is presented, and the path loss characteristics are derived based on numerical analysis and measurement. Moreover, through a bit error rate performance analysis, the required transmit power against communication distance shows the feasibility for on-body and in-body transmissions at a data rate of at least 10 Mbps.

A 10.8 mW Body Channel Communication/MICS Dual-Band Transceiver for a Unified Body Sensor Network Controller

With the increasing number of portable and implantable personal health care devices, there is a strong demand to control their communication in a single wireless network. Recently, the IEEE 802.15 WBAN task group has discussed the combining of wearable and implantable body sensor networks (BSNs) [1], but no real chip implementation has been reported. In this paper, the implementation of a unified BSN as shown in Fig. 24.9.1 is described.. The unified BSN combines low-power body-channel communication (BCC) [2] and versatile medical implant communication service (MICS) [3] using a network controller located on the human body. This unified BSN has 2 main advantages over the conventional BSNs. First, the MICS band antenna shared with the BCC electrode can be attached directly to human skin to shorten the communication distances among the controller and implanted radios, relaxing their sensitivity and selectivity requirements. Second, due to low path loss of the human body channel, low-power communication is possible among the wearable devices [4]. In addition, the on-body sensors do not need external antennas because the bio-signal sensing electrode functions as the interface for data transmission.

A Planar MICS Band Antenna Combined With a Body Channel Communication Electrode for Body Sensor Network

A 2.5 times 1.8 cm2 medical implant communication service band antenna is combined with an electrode for body channel communication. The proposed design enables a body sensor network controller to communicate with health-care devices located on and inside a patient's body. The spiral microstrip antenna with its radiating body and ground plane placed side-by-side has the thickness of 2 mm and can be attached to human skin conveniently. The propagation loss of the body channel is measured when the proposed antenna is used as the skin interface for BCC in the 10-70-MHz band, and the results are compared with the cases of Ag/AgCl and circular dry electrodes. The equivalent-circuit model of the antenna as the electrode is also derived from the measured impedance characteristics. The LC resonance structure to drive the on-body antenna with its capacitance increased due to the skin contact reduces the power consumption of the TX buffer by >50%. TheS 11-parameter of the on-body antenna, its radiation pattern, and the signal loss inside the human body are investigated.

Diversity performance of body communication channels using switching parasitic disk‐loaded monopole array antenna

AbstractIn the cellular systems diversity reception techniques such as space, time, frequency, polarization, and pattern diversity are widely used to minimize or mitigate the effect of multipath fading due to scattering, diffraction, and reflection of the transmitted signal. Practically, these methods can be applied either at the base station or at the mobile terminal. In the on‐body environment, fading has also been found to be significance. Space diversity has been useful in such channels. In this article, a switching parasitic disk‐loaded monopole array antenna (also called pattern diversity antenna) was used to investigate diversity performance in on‐body channels. There were five body channels that have been investigated that are belt‐to‐chest, belt‐to‐wrist, belt‐to‐ankle, belt‐to‐head, and belt‐to‐back channels. The diversity data was analyzed using a switched diversity combining method. Diversity gain has been measured at outage of 1% and 10% for five on‐body channels. The results show significance gains are achieved for nonline‐of‐sight channels especially the ankle and wrist channels which have involved lots of antenna movement. In contrast, very little gain is obtained for line‐of‐sight channel particularly for the chest channel as only one beam was used for most of the time. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1157–1161, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24274

A 60 kb/s–10 Mb/s Adaptive Frequency Hopping Transceiver for Interference-Resilient Body Channel Communication

An interference-resilient 60 kb/s-10 Mb/s body channel transceiver using the human body as a signal transmission medium is designed for multimedia and medical data transaction in body-area network. The body antenna effect which interferes with signals in the human body channel is examined. The body-induced interferences degrade the SIR of the signal to -22 dB in the worst case. In order to overcome the body antenna effect, a 4-channel adaptive frequency hopping scheme using the 30-120 MHz band is introduced to the body channel transceiver. A direct-switching modulator using dual frequency synthesizers and a DLL-based demodulator are proposed for 10 Mb/s FSK and the 4.2 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mu</i> s hopping time. The transceiver fabricated with 0.18 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mu</i> m CMOS withstands -28 dB SIR and its operating distance is over 1.8 m with - 25 dB SIR. Its energy consumption is 0.37 nJ/b with -65 dBm sensitivity.

The $\kappa-\mu$ Distribution Applied to the Analysis of Fading in Body to Body Communication Channels for Fire and Rescue Personnel

In this letter, we perform a novel characterization of the fading experienced in body to body communications channels for fire and rescue personnel using the recently proposed kappa - mu distribution. A transmitter positioned on the lead fire person and four strategically placed, time-synchronized 2.45-GHz receivers situated on the protective helmet and shoulders of another team member allowed small-scale signal variation to be recorded while a rescue team of four persons performed a building sweep and search type operation. A general kappa - mu model with parameters kappa=2.31 and mu=1.19 was obtained using maximum likelihood estimation and shown to provide a good fit to measured data. Level crossing rates for these channels are also presented.