Zhangyong Li

A Novel Encryption Algorithm Based on DWT and Multichaos Mapping

Encryption of a digital image is very important especially in applications of body area networks (BANs) since the image may include a number of privacy. Past encryption methods have disadvantages of the small key space and low ability of resistance to attack. In this paper, we propose a new encryption algorithm based on discrete wavelet transform (DWT) and multichaos which has characteristics of the deterministic, pseudorandomness, and sensitivity of initial values. The image is first decomposed and spatial reconstructed by two-dimensional DWT and then is performed by multichaos matrices for space encryption. The experimental results indicate that the proposed algorithm has a large key space, high key sensitivity, and excellent ability of resistance to attack.

Capsule Design for Blue Light Therapy against Helicobacter pylori

A photo-medical capsule that emits blue light for Helicobacter pylori treatment was described in this paper. The system consists of modules for pH sensing and measuring, light-emitting diode driver circuit, radio communication and microcontroller, and power management. The system can differentiate locations by monitoring the pH values of the gastrointestinal tract, and turn on and off the blue light according to the preset range of pH values. Our experimental tests show that the capsule can operate in the effective light therapy mode for more than 32 minutes and the wireless communication module can reliably transmit the measured pH value to a receiver located outside the body.

A lightweight method of data encryption in BANs using electrocardiogram signal

Abstract Body area network (BAN) is a key technology of solving telemedicine, where protecting security of vital signs information becomes a very important technique requirement. The traditional encryption methods are not suitable for BANs due to the complex algorithm and the large consumption. This paper proposes a new encryption method based on the QRS complex of the ECG signal, which adopts the vital signs from the BAN system to form the initial key, utilizes the LFSR (Linear Feedback Shift Register) circuit to generate the key stream, and then encrypts the data in the BANs. This new encryption method has the advantages of low energy consumption, simple hardware implementation, and dynamic key updating.

Channel models of body area networks for human motion

The channel characteristics of the body area network are important to transmission rate and transmission robustness. Current explorations mainly concern the channel characteristics in static state of the human body. In this paper, we establish human motion models of sitting to standing, walking and running postures, and calculate the path loss values in 2.4GHz for the models. The experimental results show that the path loss values vary sharply in the process of human movement, which is very helpful to determine the transmission power and design BAN sensor nodes.

A Device Based on Adaptive Filtering Algorithm for detecting ECG Signal in Motion Artifacts

Since the detection of electrocardiogram (ECG) is significant for monitoring the stress and diseases of Policeman and current methods for monitoring ECG in motion have drawback of low accuracy, a system for monitoring ECG signal is presented within this paper. The conductive silica gel is used as the collecting electrode, and a low-power-consumption device for detecting ECG signal have been designed. The movement of human body is sensed by the three-axis acceleration sensor, and variable step-size least mean square adaptive algorithm is proposed by using acceleration signal as reference signal. Through adaptive filter and real-time examining R waves of the ECG signal, heart rate is measured in the movement of human body. The results indicate that detection device can output real-time ECG signal and the maximum error of heart rate is within 4%, thus real-time performance and high accuracy of monitoring ECG signal is implemented.

Ontology-Based Meta-Analysis of Animal and Human Adverse Events Associated With Licensed Brucellosis Vaccines

Brucella abortus strain 19 (S19), Brucella melitensis Rev 1 (Rev1), and B. abortus strain RB51 (RB51) are the three licensed animal brucellosis vaccines, and they have been most commonly and successfully used in prevent brucellosis in animals. However, many adverse events (AEs) have been associated with these three vaccines after their administering to animals or being accidentally exposed to humans. In this study, 27 peer-reviewed publications containing animal and human AE reports associated with these three brucellosis vaccines were manually annotated from the PubMed database. Our meta-analysis identified 20 animal AEs and 46 human AEs associated with the three vaccines. Based on the Ontology of Adverse Events (OAE) hierarchical classification, these animal AEs were enriched in the immune and reproductive systems that might eventually result in the occurrence of abortion or infertility. The human AEs were concentrated in the behavioral and neurological conditions, and these AEs showed flu-like symptoms that are consistent with human brucellosis. Furthermore, an analysis of variance (ANOVA) statistics analysis with linear model fits was used to determine the major variables that might affect the occurrence of abortion AE in animals. The ANOVA results indicated that three variables (P-value < 0.05) are significantly associated with the occurrence of abortion AE: animal species, vaccination dose, and vaccination route. The other two variables (i.e., vaccine type and animal age at vaccination) did not significantly (P-value > 0.05) associated with the occurrence of abortion AE. Overall, this study represents the first ontology-based meta-analysis of adverse events associated with animal vaccines. The results of such a study led to the better understanding of brucellosis vaccine AEs, facilitating rational design of more secure and effective vaccines.

The Dynamic Encryption Method Based on ECG Characteristic Value

Body area network (BAN) is a key technology of solving remote medical, where protecting security of vital signs information is a very important technique requirement. This paper presents a data security scheme based on ECG characteristics, investigating methods of the circuit-level data encryption and dynamic key refreshment due to the obtained ECG signal characteristic value. The proposed scheme is constructed from the inherent features of the BAN system, adopting vital information from security protection, which has advantages of high strength, low cost, and easy implementation. Therefore, the scheme helps to design low-power sensor nodes and provides theoretical support and engineering implementation.

Design of Modulation and Packet Detection in Body Area Networks

In burst communication systems like Body Area Networks (BAN), burst packet should be detected prior to the demodulation of the signal at the receiver. Meanwhile, different modulation and demodulation algorithms may affect the BER performance of the entire system seriously. To satisfy the conditions that BAN nodes or devices have to be small in size and very low in power consumption, algorithm design of modulation and packet detection are very important. Referring to IEEE 802.15.6 BAN standard, theoretical analysis of the modulation and demodulation for π/2-DBPSK and π/4-DQPSK is carried out first. The two modulations are realized by using two different two-step looking up table respectively and then united to be one by combining the two phase increment tables. By use of the special structure of π/2-DBPSK modulated preamble, packet detection algorithm with low complexity is also carefully designed. Simulation results of BER performance are presented at last. In AWGN channel, both modulations achieve good performance, and performance degradation of π/4-DQPSK happens in multipath channel which may not satisfy the requirements. Adaptive modulation is considered to solve this problem by choosing different modulation scheme according to channel quality.

DESIGNING OPTIMIZED IMPRECISE FIXED-POINT ARITHMETIC CIRCUITS SPECIFIED BY POLYNOMIALS WITH VARIOUS CONSTRAINTS

Arithmetic circuits in general do not exactly match specifications, leading to different implementations within allowed imprecision. Starting from real-valued representation, such as Taylor series, we propose a new technique based on arithmetic transform (AT) to analyze simultaneous selection of multiple word lengths and even the function approximation schemes, and then derive a verification algorithm to check whether an implementation fits the error bound. To find optimized implementations which both satisfy a given error bound and constraints included interface input, delay and area. An optimization algorithm is derived to explore multiple precision parameters and get the optimized implementations by various constraints.