Thesis (Ph. D.)--New York University, 1974. / Includes bibliographical references (leaves 57-62).

Thesis (Ph. D.)--New York University, 1974. / Includes bibliographical references (leaves 57-62).

Kommunikation genom att använda människokroppen som  överföringsmedium, med kapacitiv koppling mellan hud och sensor, har varit ett pågående forskningsområde för PAN (Personal Area Network) sedan Thomas Guthrie Zimmerman introducerade tekniken 1995. Anledningen till detta är att undersöka fördelar och användningsområden för en kommunikationsmetod som ej sänder ut RF-signaler och därmed minska risken för obehörig avlyssning. Denna rapport beskriver ett examensarbete som undersöker möjligheten till eliminering av USB- till UART-konverterare på Microchip BodyCom genom mjukvaru-USB-stack och kombinera denna med Body Coupled Communication funktionalitet i en gemensam mikrokontroller. Vidare studeras om programkoden i Body Coupled Communication sändare kan modifieras för att utöka funktionaliteten. Det var givet i förutsättningarna att mikrokontroller från Microchip skulle användas, vidare var lågt pris respektive låg strömförbrukning viktigt, särskilt för sändaren. Metoden för att uppnå detta har varit användning av Microchip BodyCom development kit tillsammans med Microchip USB low pin count development kit och Microchip USB firmwareframework. Resultatet blev att USB- till UART-omvandlare kunde integreras med Microchip BodyCom genom att använda mjukvaru-USB-stack och en modifierad programkod för BodyCom i en gemensam mikrokontroller. Endast fantasin sätter gränsen för vad Body Coupled Communication kan användas till. Det skulle t.ex. vara möjligt att utbyta elektroniska visitkort genom en handskakning eller öppna en låst dörr endast genom att ta i handtaget. / Communication using the human body as a transmission medium, the capacitive coupling between the skin and sensor, has been an active research area for PAN (Personal Area Network) since Thomas Guthrie Zimmerman introduced the technique in 1995. The reason for this is to examine the benefits and uses of a communication method that does not emit RF signals and thus reduce the risk of unauthorized interception. This report describes a thesis that examines the possibility of elimination of USB to UART converter on Microchip BodyCom through software USB-stack and combine this with Body Coupled Communication functionality in a single microcontroller. Furthermore, studies on if the application code in Body Coupled Communication transmitters can be modified to extend functionality. It was given in the conditions that microcontrollers from Microchip should be used, furthermore, low price and low power consumption were important, especially for the transmitter. The method for achieving this has been the use of Microchip BodyCom development kit with USB Microchip low pin count development kit and Microchip USB firmware framework. The result was that the USB- to UART-converter could be integrated with Microchip BodyCom, using software USB-stack and a modified program code for BodyCom in a single microcontroller. Only your imagination sets the limits for Body Coupled Communication can be used for. For example, it would be possible to exchange electronic business cards by a handshake or open a locked door only by using the handle.

The main concept of Body-Coupled Communication (BCC) is to transmit the electrical information through the human body as a communication medium by means of capacitive coupling. Nowadays the current research of wireless body area network are expanding more with the new ideas and topologies for better result in respect to the low power and area, security, reliability and sensitivity since it is first introduced by the Zimmerman in 1995. In contrast with the other existing wireless communication technology such as WiFi, Bluetooth and Zigbee, the BCC is going to increase the number of applications as well as solves the problem with the cell based communication system depending upon the frequency allocation. In addition, this promising technology has been standardized by a task group named IEEE 802.15.6 addressing a reliable and feasible system for low power in-body and on-body nodes that serves a variety of medical and non medical applications. The entire BAN project is divided into three major parts consisting of application layer, digital baseband and analog front end (AFE) transceiver. In the thesis work a strong driver circuit for BCC is implemented as an analog front end transmitter (Tx). The primary purpose of the study is to transmit a strong signal as the signal is attenuated by the body around 60 dB. The Driver circuit is cascaded of two single-stage inverter and an identical inverter with drain resistor. The entire driver circuit is designed with ST65 nm CMOS technology with 1.2 V supply operated at 10 MHz frequency, has a driving capability of 6 mA which is the basic requirement. The performance of the transmitter is compared with the other architecture by integrating different analysis such as corner analysis, noise analysis and eye diagram. The cycle to cycle jitter is 0.87% which is well below to the maximum point and the power supply rejection ratio (PSRR) is 65 dB indicates the good emission of supply noise. In addition, the transmitter does not require a filter to emit the noise because the body acts like a low pass filter. In conclusion the findings of the thesis work is quite healthy compared to the previous work. Finally, there is some point to improve for the driver circuit in respect to the power consumption, propagation delay and leakage power in the future.

Body-channel communication (BCC) is based on the principle of electrical field data transmission attributable to capacitive coupling through the human body. It is gaining importance now a day in the scenario of human centric communication because it truly offers a natural means of interaction with the human body. Traditionally, near field communication (NFC) considers as a magnetic field coupling based on radio frequency identification (RFID) technology. The RFID technology also limits the definition of NFC and thus reduces the scope of a wide range of applications. In recent years BCC, after its first origin in 1995, regain importance with its valuable application in biomedical systems. Primarily, KAIST and Philips research groups demonstrate BCC in the context of biomedical remote patient health monitoring system. BCC transceiver mainly consists of two parts: one is digital baseband and the other is an analog front end (AFE). In this thesis, an analog front end receiver has presented to support the overall BCC. The receiver (Rx) architecture consists of cascaded preamplifier and Schmitt trigger. When the signals are coming from the human body, they are attenuated around 60 dB and gives weak signals in the range of mV. A high gain preamplifier stage needs to amplify these weak signals and make them as strong signals. The preamplifier single stage needs to cascade for the gain requirement. The single stage preamplifier, which is designed with ST65 nm technology, has an open loop gain of 24.01 dB and close loop gain of 19.43 dB. A flipped voltage follower (FVF) topology is used for designing this preamplifier to support the low supply voltage of 1 V because the topology supports low voltage, low noise and also low power consumption. The input-referred noise is 8.69 nV/sqrt(Hz) and the SNR at the input are 73.26 dB. The Schmitt trigger (comparator with hysteresis) is a bistable positive feedback circuit. It builds around two stage OTA with lead frequency compensation. The DC gain for this OTA is 26.94 dB with 1 V supply voltage. The corner analyzes and eye diagram as a performance matrix for the overall receiver are also included in this thesis work.

Body coupled communication (BCC) is a hot topic in personal networking domain. Many works arepublished suggesting different architectures for BCC since its inception in 1995 by Zimmerman. The number ofelectronic gadgets used by a single person increases as time pass by. Its a tedious job to transfer data betweenthen from a user point of view. Many of these gadgets can share their resources and save power and money.The existing wired or wireless networks does not meet the requirements for this network like scalable data rate,security etc. So here comes the novel idea of using human body as communication medium. The aim of thisthesis is to realize a hardware for BCC based on wide band signaling as part of a big project.The human body consists of 70% of water. This property makes the human body a fairly good conductor.By exploiting this basic property makes the BCC possible. A capacitance is formed if we place a metal platenear to the human body with the skin as a dielectric. This capacitance forms the interface between the humanbody and the analog front-end of the BCC transceiver. Any other metal structures near to the human body canattenuate the signal.A first-order communication link is established in software by the human body model and the transceiver inthe loop along with noise and interference. This communication link is used to verify the human body modeland the base band model done as part of the same big project. Based on the results a hardware prototype isimplemented. Measurements are taken in different scenarios using the hardware setup. The trade-off betweendesign parameters are discussed based on the results. At the end, it suggests a road map to take the projectfurther.

A wireless body network with sensors and actuators is a topical subject in current situation, because the healthcare services cannot meet peoples requirements for personal health-care. Such a network can be used to monitor the health status of e.g. elderly people and provide a drug delivery without external human interaction. In this project we will implement a prototype of a distributed system of sensors and actuator using the human body as a transmission line for communication purposes (Capacitive Body-coupled Communication), as a solution for the problem. Similar systems have been implemented earlier, using radio-based wireless communication which consumes more power and have critical security issues, compared to capacitive body-coupled communication. This document describes how the system is implemented with focus on robust gathering of sensor data from several sensors from a single node using capacitive body-coupled communication and an actuator control with user interaction.

The Internet of Bodies (IoB) is a wireless network of on-body or in-body commu- nication formed by wearable, ingestible, injectable, and implantable smart devices. The vast majority of on-body communications, is typically required to be within <5 cm vicinity of the human body. The radiative nature of currently used RF devices leads to wasted energy that is radiated in unneeded off-body directions. Consequently, it degrades energy efficiency, introduces co-existence and interference problems, and imposes security threats on sensitive data. As an alternative, the capacitive body channel communication (BCC) couples the signal (between 10 kHz-100 MHZ) to the human body, which is more conductive than air. Hence, it provides lower loss, bet- ter privacy and confidentiality, and nJ/bit to pJ/bit energy efficiency. Accordingly, our work investigates orthogonal and non-orthogonal capacitive body channel access schemes for ultralow-power IoB networks with or without cooperation. We derive the closed-form optimal power allocation for uplink and downlink transmissions and the maximum number of IoB nodes satisfying a reliable and feasible network for non- cooperative schemes. The cooperative schemes necessitate joint optimization of both power and phase time allocations. We achieve this by using the Golden-Section search algorithm to minimize the power consumption in both phases.

No description available.

<div>Decades of scaling in semiconductor technology has resulted in a drastic reduction in the cost and size of unit computing. This has enabled computing capabilities in small form factor wearable and implantable devices. These devices communicate with each other to form a network around the body, commonly known as the Wireless Body Area Network (WBAN). Radio wave transmission over air is the commonly used method of communication among these devices. However, the human body can be used as the communication medium by utilizing its electrical conductivity property. This has given rise to Human Body Communication (HBC), which provides higher energy efficiency and enhanced security compared to over the air radio wave communication enabling applications like remote health monitoring, secure authentication. In this thesis we characterize the human body channel characteristics at low frequencies, utilize the insight obtained from the channel characterization to build high energy-efficiency, interference-robust circuits and demonstrate the security and selectivity aspect of HBC through a Common Off the Shelf (COTS) component-based system. First, we characterize the response of the human body channel in the 10KHz1MHz frequency range with wearable transmitter/ receiver to study the feasibility of using it as a broadband communication channel. Voltage mode measurements with capacitive termination show almost at-band response in this frequency range, establishing the body as a broadband channel. The body channel response is also measured across different interaction scenario between two wearable devices and a wearable and a computer. A bio-physical model of the HBC channel is developed to explain the measurement results and the wide discrepancies found in previous studies.We analyze the safety aspect of different type of HBC by carrying out theoretical circuit and FEM based simulations. A study is carried out among multiple subjects to assess the effect of HBC on the vital parameters of a subject. A statistical analysis of the results shows no signicant change in the vital parameters before and during HBC transmission, validating the theoretical simulations showing >!000x safety margin compared to the established ICNIRP guidelines. Next, an HBC transceiver is built utilizing the wire-like, broadband human body channel to enable high energy efficiency. The transceiver also provides robustness to ambient interference picked up by the human body through integration followed by periodic sampling. The transceiver achieves 6.3pJ/bit energy effciency while operating at a maximum data rate of 30Mbps, while providing -30dB interference tolerant operation. Finally, a COTS based HBC prototype is developed, which utilizes low frequency operation to enable selective and physically secure communication strictly during touch for Human Computer Interaction (HCI) between two wearable devices for the rst time. A thorough study of the effect of different parameters such as environment, posture, subject variation, on the channel loss has also been characterized to build a robust HBC system working across different use cases. Applications such as secure authentication (e.g. opening a door, pairing a smart device) and information exchange (e.g. payment, image, medical data, personal profile transfer) through touch is demonstrated to show the impact of HBC in enabling new human-machine interaction modalities.</div>