Phase Center Computation of a Corrugated Horn (1).pdf

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 62, NO. 1, JANUARY 2014 183

Experimental Evaluation of Implant UWB-IRTransmission With Living Animal

for Body Area NetworksDaisuke Anzai, Associate Member, IEEE, Kenta Katsu, Raul Chavez-Santiago, Member, IEEE,

Qiong Wang, Member, IEEE, Dirk Plettemeier, Member, IEEE,Jianqing Wang, Member, IEEE, and Ilangko Balasingham, Senior Member, IEEE

AbstractOne of promising transmission technologies in wire-less body area networks (BANs) is ultra-wideband (UWB) com-munication, which can provide high data rate for real-time trans-mission, and extremely low power consumption for increasing de-vice longevity. However, UWB signals suffer from large attenua-tion in a wireless communication link, especially in implant BANs.Although several investigations on channel characterization havebeen far thus conducted for evaluating the UWB transmission per-formance, they have been limited to either computer simulations orexperiments with biological-equivalent phantoms. Experimentalevaluation with a living body has rarely been conducted, i.e., theperformance in real implant BANs has been scarcely discussed. Inthis paper, therefore, we focus on a living animal experimental eval-uation on the UWB transmission performance. To begin with, wedevelop an ultra-wideband impulse radio (UWB-IR) communica-tion system with a multipulse pulse position modulation scheme,and then analyze the fundamental characteristics of the developedUWB-IR communication system by a liquid phantom experiment.Finally, we evaluate the performance of the developed UWB-IRcommunication system via the living animal experiment. From theexperimental results, although we have observed that the path lossis more than 80 dB, the developed system can achieve a bit errorrate of 10 within the communication distance of 120 mm withensuring a high data rate of 1 Mb/s. This result first time givesa quantitative communication performance evaluation for the im-plant UWB transmission in a living body.

Index TermsImplant body area networks (BANs), living an-imal experiment, ultra-wideband impulse-radio (UWB-IR) trans-mission.

I. INTRODUCTION

W IRELESS body area networks (BANs) have attracted alot of attention as a future technology for wireless net-works.TypicalapplicationsofwirelessBANsincludehealthcare,

Manuscript received May 30, 2013; revised October 25, 2013; accepted Oc-tober 30, 2013. Date of publication November 26, 2013; date of current versionJanuary 06, 2014.D. Anzai, K. Katsu, and J. Wang are with the Graduate School of Engi-

neering, Nagoya Institute of Technology, Nagoya 466-8555, Japan (e-mail:[email protected]; [email protected]; [email protected]).R. Chavez-Santiago and I. Balasingham are with the Intervention Center,

Oslo University Hospital, University of Oslo, N-0027 Oslo, Norway(e-mail: [email protected]; [email protected]).Q. Wang and D. Plettemeier are with the Department of Electrical En-

gineering and Information Technology, Dresden University of Technology,D-01069 Dresden, Germany (e-mail: [email protected]; [email protected]).Color versions of one or more of the figures in this paper are available online

at http://ieeexplore.ieee.org.Digital Object Identifier 10.1109/TMTT.2013.2291542

medical treatment, and medical monitoring [1][3]. Generally,wireless BANs are classified into two groups: wearable BANsand implantBANs.WearableBANs aremainly used tomonitor apersons healthy condition in daily life[2], whereas wireless cap-sule endoscopy (WCE) has been one of the most important ap-plications in implant BANs [4], [5].WCE involves swallowing asmall capsule by a patient, which contains a color camera, lightsource, and battery and transmits images to the outside receiverin order to assist in diagnosing gastrointestinal conditions suchas obscure malabsorption, gastrointestinal bleeding, chronic di-arrhoea, and abdominal pain. In this paper, we focus on implantBAN applications. Such amedical application requires a reliablewireless communication channel, and extremely low power con-sumption for increasingdevice longevity.To realize the implant communications, the 400-MHz band

and 2.4-GHz band are usually chosen. For example, a commer-cially available implant communication chip for cardiac pace-maker employs the 400-MHz band for data transmission andthe 2.4-GHz band for waking up and control.1 References [6]and [7] have reported that all of the WCE techniques employ400 MHz, 2.4 GHz, or dozens of megahertz bands with narrow-bandmodulation schemes, such as frequency shift keying (FSK)or binary phase-shift keying (BPSK). The data rate is limited toseveral hundred kilobits per second. However, in view of the im-plant communication application, for instance, WCE requires ahigher data rate for a real-time image and video transmission.In order to fulfill the above requirements, this paper

pays attention to ultra-wideband (UWB) transmission. AsUWB transmission schemes, ultra-wideband impulse radio(UWB-IR), direct sequence ultra-wideband (DS-UWB), andmultiband orthogonal frequency-division multiplexing (multi-band-OFDM) have been proposed [8][10]. Of the all UWBschemes, UWB-IR is a technique that iteratively transmitsextremely short pulses on the nanosecond time duration perbit. Therefore, it has a merit in respect of low power consump-tion. Furthermore, a coherent detection, namely a correlationdetection, claims to be one of the most suitable solutions forthe UWB-IR communication system. Although the coherentdetection needs to generate a template signal in a receiver side,the reliability of the coherent detection is generally superior tothat of a non-coherent detection.However, in implant BANs, the UWB-IR signals suffer from

large attenuation, which may lead to undesired performance1Zarlink Semiconductor Inc. [Online]. Available: www.ZARLINK.com

0018-9480 2013 IEEE

184 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 62, NO. 1, JANUARY 2014

degradation. Therefore, it is important to investigate the trans-mission performance of the implant BANs. Although severalpapers have so far investigated the channel characteristics[11][15], the investigations have been performed by eithercomputer simulations or experiments with biological-equiv-alent phantoms. An experimental investigation with a livingbody has been rarely conducted. In other words, the perfor-mance evaluation in real BANs has been scarcely discussed.This paper aims on experimental evaluation for UWB-IRtransmission performance with a living body. For this purpose,to begin with, we develop a UWB-IR communication systemwith a multipulse pulse position modulation (MPPM) scheme.The reason why we employ the MPPM scheme is to control thetradeoff relationship between the data rate and the reliability,namely, the bit error rate (BER) performance. This paper thenanalyzes the basic characteristics of our developed UWB-IRcommunication system by a liquid phantom experiment andvalidates the experimental results with theoretical ones. Finally,the UWB-IR communication system is evaluated in the livinganimal experiment.The remainder of this paper is organized as follows. Section II

presents the design of the developed UWB-IR communicationsystem. Section III then describes the fundamental performanceof the developed UWB-IR communication system by a bio-logical-equivalent liquid phantom experiment, and Section IVdemonstrates and discusses the results of the living animal ex-periment. Finally, Section V concludes this paper.

II. DESIGN OF UWB COMMUNICATION SYSTEM

A. AntennasIn the developed UWB-IR communication system, we chose

the UWB low band (3.44.8-GHz band) because the highertransmitting frequency has smaller penetration depth in bio-logical tissues. For the transmit and receive antennas, we em-ployed three types of UWB low-band antennas. Fig. 1 shows thetransmit and receive antennas. The transmit antenna in Fig. 1(a)is a trapezoid strip excited broad band hemispherical dielectricresonator antenna (DRA), which was designed for medical cap-sule endoscope [16]. A PVC material with dielectric constant ofaround 3 is chosen to build the hemisphere. A conformal tapercopper strip was mounted on the hemisphere surface, and a cir-cular ground plane with the same diameter was set at the base ofthe hemisphere. This structure allows the whole electric currentto flow on the DRA surface and is able to broaden the impedancebandwidth. The antenna has been experimentally confirmed toexhibit an -parameter smaller than 10 dB within a bio-logical-equivalent liquid phantom, and a broad beam directivityat the excitation side. The total radiation gain of the trapezoidstrip excited hemisphere DRA at 4 GHz in the liquid phantom is24 dB toward the maximum radiation direction. The detailed

radiation pattern can be referred in [16]. On the other hand, weused two kinds of receive antennas, as shown in Fig. 1(b) and(c). One was a Vivaldi antenna [17], which has a linear polariza-tion, and the other was a helical antenna, which has a circular po-larization. The Vivaldi antenna consisted of two exponentiallytapered slot lines arranged on the upper surface of a dielectricsubstrate with a dielectric constant of 10.2. The feeding radial

Fig. 1. Transmit and receive antennas for UWB-IR transceivers. (a) Transmitantenna. (b) Vivaldi receive antenna. (c) Helical receive antenna.

stub microstrip was arranged on the lower surface of the dielec-tric substrate, and the corresponding groundmicrostrip was con-nected to one Vivaldi taper. To achieve expected radiation char-acteristics, a metallic reflector plate is added at the back of theVivaldi side. The helical antenna acted at its axial mode. It had astrong radiation along its axial direction so that a high gain wasobtained in this direction. Fig. 2 shows the measured for thehelical antenna. Both antennas were developed for on-body ap-plications, and the s were less than 10 dB in the range of3.44.8-GHz band. Fig. 1 also shows the sizes of transmit andreceive antennas. As can be seen from this figure, the transmitantenna is much smaller than the receive antennas because thetransmit antenna should be implantable to a human body.

B. Transmitter

The structure of the transmitter is shown in Fig. 3. As aUWB-IR pulse, we employ the first-order Gaussian monocyclepulse, and this transmitter uses an MPPM scheme, which cancontrol the tradeoff relationship between the data rate and thereliability of the transmission. Assuming as the total numberof transmitted bits, the MPPM signal can be expressed as

(1)

ANZAI et al.: EXPERIMENTAL EVALUATION OF IMPLANT UWB-IR TRANSMISSION WITH LIVING ANIMAL FOR BANs 185

Fig. 2. characteristic for helical antenna.

Fig. 3. Transmitter structure.

where is the th transmitted bit information vector, namely,, is the symbol duration,

and the operator represents transpose of . Defining asthe number of chip slots in a symbol, and denote a chipsequence vectors corresponding to transmitted bits of 0 and 1,respectively, which are vectors and the th componentsof the both vectors and represent thepulse existence in the th chip slot of the corresponding symbols,respectively. In (1), is defined as vector

(2)

where denotes the chip duration. Fig. 4 shows an example ofMPPM signals when is set to 4, in which two UWB-IR pulsesare assigned to each transmitted symbol. It is possible to con-trol the data rate by changing the number of chip slots . Wenote that the IR-type transmitter does not need a carrier signaland amplifiers. It employs a clock generator and some CMOSgates to produce pulses and a bandpass filter (BPF) for spectrumforming. Since CMOS gates consume low power and the pas-sive BPF does not consume power, the total power consumptionin the transmitter can be expected at a quite low level.

C. Receiver

Fig. 5 shows the structure of the receiver. In our previousstudy [18], we have found that the power delay profile can bewell represented as a two-path model with a very small meantime interval in the order of nanoseconds. This means that themultipaths are almost indistinguishable in the received signaland the multipath fading effect is not dominative. Thus, in thisstudy, we try to investigate the communication performancewithout channel estimation to confirm whether our proposedUWB transmission system can work well in a real living body

Fig. 4. Example of MPPM signals.

Fig. 5. Receiver structure.

environment. As mentioned previously, we pay attention to thecorrelation detection as the receive detection scheme. In the cor-relation detection, since the binary MPPM chooses one fromtwo location assignments in the th symbol, we calculate twokinds of th energies for the corresponding pulse locations fromthe received signal as follows:

(3)

(4)

where denotes the integration time, and and arethe template signals for each symbol, respectively. Note thatis much smaller than the symbol duration and the chip slotduration in UWB-IR transmission. Comparing and ,the received bit information can be decided as

ifotherwise.

(5)

We note that as can be seen from the above equation, theMPPM requires no threshold. Furthermore, the symbol timingin Fig. 5 is synchronized with pilot signals.

D. Theoretical Analysis of BER PerformanceWhen the transmitter sends a signal , we assume the re-

ceived signal is expressed as . Whereasthe is not a narrowband noise (in other words, it is not aGaussian noise) due to the BPF of the receiver designed forUWR-IR signals, the UWB signal can be decomposed into

narrowband signals [19], where denotes the bandwidthof the UWB-IR signals. Therefore, we take into considerationthat the number of UWB pulses in each symbol is , and we


finally obtain ( is dropped without loss of generality so isreplaced by ) [20]

(6)

where represents an orthogonal function over the pulseinterval. In (6), is a zero mean independent Gaussian randomvariable with variance , and is defined to satisfy

, where represents the energy of the transmittedpulse. As a result, from (6), the detected energy is asum of independent variables with a chi-square distribution. According to the Central Limit Theorem,the probability distribution of can be approximated asGaussian distribution when is getting large. Finally, fromthe Gaussian approximation, defining as the energy per bit,the bit error probability , i.e., BER, is given by [21]

(7)

where

(8)

III. EXPERIMENT FOR FUNDAMENTAL PERFORMANCEEVALUATION WITH LIQUID PHANTOM

Before conducting the living animal experiment, we per-formed a preliminary experiment for evaluation of the funda-mental performance of the UWB-IR communication system.For this purpose, we measured the fundamental characteristicsof the UWB-IR transceivers in a liquid phantom simulating ahuman body. In this experiment, we used the helical antenna asan on-body receive antenna put on the liquid phantom surfacewith a spacing of 1 cm. For the in-body transmit antenna,we employed a modified version of the antenna described inSection II, which has an antenna performance similar to theDRA antenna designed for the living body experiment. Themodification was because of the use of the liquid phantom.We coated a type of glue to the antenna and feeding part forpreventing a direct contact of the antenna to the liquid. Figs. 6and 7 show the measurement setup with the liquid phantom anda picture of the phantom experiment, respectively. The transmitantenna was inserted in the liquid phantom. The liquid phantomwas produced to simulate muscle-like dielectric properties.We have measured its dielectric properties between 35 GHz.The measured results show that the relative permittivity rangesfrom 40 to 35, somewhat smaller than that of muscle, whereasthe conductivity ranges from 2.2 to 4.2 S/m, almost the same asthat of muscle, within this frequency band. We used the vesselmade from a plastic material in the liquid phantom experiment.

Fig. 6. Phantom experiment setup.

Fig. 7. View of phantom experiment.

We have checked the dielectric properties of the vessel andfound that its loss is almost ignorable. The transmit and receiveantennas were connected to a network analyzer with coaxialcables. The two coaxial cables were arranged at right angleto each other for removing possible direct coupling betweenthem. Fig. 8 shows examples of shapes of the transmitted andreceived UWB signals. Moreover, Fig. 9 shows the spectrum ofthe UWB signal. We measured the performance, namely,the path-loss characteristic, as a function of the distance fromthe implant transmit antenna to the phantom surface at the fre-quency band of 4 GHz. The measured path-loss characteristicsare shown in Fig. 10. Furthermore, Fig. 11 shows the frequencycharacteristic of the measured path loss. It is found that at adepth of 70 mm from the body surface, the path loss is around80 dB. Such a path-loss level may be acceptable in presenttransceiver design technology.In addition to the path-loss measurement, we then also eval-

uated the communication performance of the UWB-IR trans-ceivers based on the path-loss measurement results in the liquidphantom experiment. In this experiment, we assumed that thetransmitter and the receiver were connected with an attenuatorin order to accurately control the path loss according to the dis-tance between transceivers. The transmitter sent 10 000 bits, andthen we calculated the BER from comparison between the trans-mitted bit sequence and the received bit sequence. As for thesymbol timing and sampling clock synchronization, we haveconfirmed that it is almost perfectly performed with a properlength of pilot signals. Moreover, we have also determined the


Fig. 8. Examples of shapes of transmitted and received signals. (a) Transmittedsignal. (b) Received signal.

Fig. 9. Spectrum of UWB signal.

optimal integration time before conducting the experiment.The parameters of the UWB-IR transceivers are summarized inTable I.Fig. 12 shows the average BER performances by the exper-

iment and the theoretical analysis against the distance betweentransceivers. The theoretical results were derived from (7) bylinking the to corresponding distance via the measuredpath loss in Fig. 10. From Fig. 12, we observe good agreementsbetween the results of the experiment and the theory. Hence,it can be said that we properly set the parameters of the trans-ceivers and the theoretical analysis given by (7) can reasonably

Fig. 10. Path-loss measurement results.

Fig. 11. Frequency characteristic of path loss in phantom experiment.

TABLE IUWB-IR TRANSCEIVER PARAMETERS

explain the developed UWB-IR communication system. Fur-thermore, as seen from Fig. 12, the BER performance is im-proved as the data rate decreases (namely, increases). This isbecause, from (7), we can accomplish times higherafter demodulation in the receiver. Note that the BER perfor-mance of 10 is accomplished at the distance of around 70 mmwhen (namely, the data rate is 1 Mb/s). The achieve-ment of the BER performance of around 10 10 meansthat it is possible to obtain an error-free BER 10 ifwe adapt an adequate forward error correction code [22]. Thiserror-free BER satisfies the requirement for almost all implantBAN applications. Therefore, the developed UWB-IR commu-nication system can establish a reliable communication link atthe maximum distance of 70 mm in the biological-equivalentliquid phantom.


Fig. 12. Effect of attenuation on BER performance.

Fig. 13. Living animal experimental model.

IV. LIVING ANIMAL EXPERIMENT

A. Experimental Setup

Fig. 13 shows the overview of the living body experimentwith the developed UWB-IR system. In the living body ex-periment, we used a living animal (pig) instead of a humanbody because it is difficult to conduct an experiment with aliving human body in our environment. The transmit antennawas implanted into the pig, and the receive antenna was put onthe pig-bodys surface. The transceivers and each antenna wereconnected with coaxial cables. For the received data capture, alaptop computer was connected to the receiver. The insertionpoints of the transmit antenna and the positions of the transmitantennas are shown in Fig. 14, where Fig. 14(a) and (b) show thetransmit antenna positions when the insertion point was in thecenter of the abdomen and the thorax (chest), respectively. Inthe animal experiment, the transmit antenna was covered with avinyl material for insulation. The receive antenna was just abovethe transmit antenna on the body surface. Moreover, Table IIsummarizes the detailed information of the implanted transmitantenna position [23] and the distance between transmit andreceive antennas, which was measured by a magnetic trackersystem. Fig. 15 shows a photograph of the living animal exper-iment.

B. Experimental Results

Figs. 16 and 17 show the BER performance against the dis-tance between transmit and receive antennas in the case of theVivaldi-type receive antenna and the helical-type receive an-tenna, respectively. In these figures, the antenna position IDsare also indicated. Note that, in the both antenna cases, we ob-served no bit error at the distance of 22 mm (Position ID: A),and moreover, in the helical antenna case, also no bit error was

Fig. 14. Positions of antennas. (a) Center of the abdomen. (b) Thorax (chest).

Fig. 15. View of living animal experiment.

observed at the distance of 33 mm (Position ID: D). As for thereason that there is a sharp drop after 10 at 2 and 1 Mb/s,it is because that the transmitted data number is not sufficientfor giving an average BER in this order. Similarly to the resultof the basic characteristic investigation in the previous section,we can see from these figures that the BER performances areinversely proportional to the data rate. Furthermore, as the dis-tance between the antennas increases, the BER performance isgetting worse due to the corresponding path loss in the biolog-ical tissues. However, as can be seen in Figs. 16 and 17, theBER at a distance of 80 mm exhibited a worse performancecompared to that at 120 mm, which means that the BER per-formances are not always getting worse when the communi-cation distance increases. This is because of the difference inthe types and thickness of tissue between the transceivers. Ahigh water-content tissue such as muscle and peritoneal fluidhas a larger path loss, whereas a low water-content tissue suchas fat and bone has a smaller path loss. The implant communi-cation performance is therefore dependent on not only the dis-tance, but also the types and thickness of tissue between thetransceivers, which explains why the results for the antennasplaced in the five positions exhibit such distance dependence.As also pointed out in [24][26], the transmission path is influ-enced by different tissue types which possess different dielec-tric properties. Therefore, we should consider not only the dis-tance between the transceivers, but also the penetrated tissues.To specify the effect of the penetrated tissues in detail, moreinvestigation is required. In total, the developed UWB-IR com-munication system can achieve the BER performance of around10 at the data rate of 1 Mb/s up to a distance of 120 mm.


TABLE IITRANSMIT ANTENNA POSITION AND DISTANCE BETWEEN TRANSMIT AND RECEIVE ANTENNAS

Fig. 16. Experimental results of BER (Vivaldi antenna).

Fig. 17. Experimental results of BER (helical antenna).

As compared between the results in the case of the Vivaldiantenna and the helical antenna, the BER performance of thehelical antenna is better than that of the Vivaldi antenna. The dif-ference of the BER performance may be attributed to the beampatterns of antennas and the polarization mismatch. Half-powerbeamwidth of the circular polarized helical antenna is smallerthan the beamwidth of the linear polarized Vivaldi antenna. Thisresults in a higher gain and in a lower polarization dependencyof the signal received by the helical antenna.On the other hand, to investigate the polarization of the im-

plantable transmit antenna, we conducted a computer simula-tion. In the computer simulation, the polarization of transmitantenna was aligned along each 3-D axis direction at the centerof a muscle-simulating cylinder phantom, whose relative per-mittivity and conductivity were 51.1 and 3.2 S/m, respectively.We employed the Vivaldi antenna as a receive antenna, which

Fig. 18. Effect of antenna polarization on path-loss characteristics. (a) Com-puter simulation setup. (b) Results.

was put on a side surface of the cylinder phantom. Fig. 18 showsthe effect of the transmit antenna polarization on the path-losscharacteristics. From this result, the transmit antenna needs tobe aligned to ensure a good polarization, but it is not easy to re-alize in reality for the implant applications. In the living animalexperiment, the transmit antenna alignment was limited insidethe animal body, so that the transmit antenna and the receive an-tenna were not aligned on the best polarization condition. Thiscould result in a significant degradation on the path loss andBER. In our experiment, the Vivaldi antenna at the receiver wasalways put along the animal body surface so that its polariza-tion was not optimized. As opposed to this, since the helicalantenna acted at its axial mode, it was easy to adjust its axialdirection to have the polarization be optimized at each receiveantenna position. As a result, even though the transmit antennapolarization was not optimized, better BER performance withthe helical antenna has been obtained than that with the Vivaldi


Fig. 19. Path loss estimated from experimental results of BER.

antenna. This result suggests a possibility to ensure a good po-larization by manually adjusting the receive antenna directivityon the body surface.Furthermore, in our previous study, we measured when

the transmit antenna was inserted in a liquid phantom [16]. Theresult has shown smaller than 10 dB in the UWB lowband. Since the liquid phantom was a high water-content onesimulating the average torso tissue properties, the measuredcharacteristic can be considered as a representative of torso.Since the surrounding tissues were almost high water-contentones in our animal experiment, as shown in Table II, there wasno large degradation on from that designed in the liquidphantom. If the transmit antenna is implanted in a low water-content tissue, a large degradation on may occur and somespecial considerations are necessary.Finally, we also investigate the path loss between the trans-

ceivers. From (7), we can roughly estimate from theBER measured in the experiment as

(9)

Here, means the inverse function of (7). Defining asthe spectral efficiency ratio, can be expressed as

(10)

where , , and denote the path loss, transmitted power,and noise power, respectively. Consequently, substituting (10)into (9), we obtain

(11)

Fig. 19 shows the path loss estimated by the measured BERagainst the distance between the transmit and receive antennas.We note that the estimated path loss includes the gains of thetransmit and receive antennas. Therefore, as can be seen fromFig. 19, the path losses for the case of the Vivaldi antenna andthe helical antenna are different from each other. Although theestimated path loss includes the antenna gain, the path loss isaround 80 dB in the both antenna cases. However, we again

emphasize that despite the large path loss of more than 80 dB,the developed UWB-IR communication system can ensure theBER performance of around 10 at a bit rate of 1 Mb/s in theliving animal experiment.

V. CONCLUSIONS

This paper has aimed on experimental evaluation of theUWB-IR transmission performance in a living animal. For thispurpose, to begin with, we have developed a UWB-IR commu-nication system with an MPPM scheme, and then analyzed thefundamental characteristics by a liquid phantom experiment.Finally, we have conducted the living animal experiment withthe developed system in order to evaluate the UWB transmis-sion performance in a real implant BAN environment. Fromthe experimental result, although it has been observed that thepath loss is more than 80 dB, the developed system can achievethe BER performance of 10 at a depth up to 12 cm withensuring a high data rate of 1 Mb/s. This result is the first timethat the feasibility of a UWB transmission for implant BANapplications in a real living body has been shown.There is still room for further improvement of our prototype

UWB-IR communication system. One of our future subject isto optimize the transmit and receive antennas for the developedUWB-IR transceiver. Another is to incorporate some biologicalsensors into the UWB-IR transceiver for real in-body informa-tion transmission.

ACKNOWLEDGMENT

The authors would like to thank R. Hahnel for his help aboutthe antenna use in the experiment.

REFERENCES[1] H. B. Li and R. Kohno, Body area network and its standardization at

IEEE 802.15. BAN, in Advances in Mobile and Wireless Communi-cations. Berlin, Germany: Springer, 2008, pp. 223238.

[2] E. Monton, J. F. Hernandez, J. M. Blasco, T. Herve, J. Micallef, I.Grech, A. Brincat, and V. Traver, Body area network for wireless pa-tient monitoring, IET Commun., vol. 2, no. 2, pp. 215222, Feb. 2008.

[3] J. Wang and Q. Wang, Body Area Communications. New York, NY,USA: Wiley, 2013.

[4] G. Iddan, G. Meron, A. Glukhovsky, and P. Swain, Wireless capsuleendoscopy, Nature, vol. 405, pp. 417417, May 2000.

[5] G. Costamagna, S. K. Shah, M. E. Riccioni, F. Foschia, M. Mutignani,V. Perri, A. Vecchioli, M. G. Brizi, A. Picciocchi, and P. Marano, Aprospective trial comparing small bowel radiographs and video capsuleendoscopy for suspected small bowel disease, Gastroenterology, vol.123, no. 4, pp. 9991005, Oct. 2002.

[6] M. R. Yuce and T. Dissanayake, Easy-to-swallow wireless telemetry,IEEE Microw. Mag., vol. 13, no. 6, pp. 90101, Sep. 2012.

[7] M. R. Yuce, T. Dissanayake, and H. C. Keong, Wireless telemetry forelectronic pill technology, IEEE Sensors, pp. 14331438, Oct. 2009.

[8] M. Z. Win and R. A. Scholtz, Ultra-wide bandwidth time-hoppingspread spectrum impulse radio for wireless multiple-access commu-nications, IEEE Trans. Commun., vol. 48, no. 4, pp. 679691, Apr.2000.

[9] P. Runkle, J. McCorkle, T. Miller, and M. Welborn, DS-CDMA: Themodulation technology of choice for UWB communications, in Proc.IEEE UWBST03 Conf., Nov. 2003, (CD-ROM).

[10] J. Balakrishnan, A. Batra, and A. Dabak, A multi-band OFDMsystem for UWB communication, in Proc. IEEE UWBST03 Conf.,Nov. 2003, (CD-ROM).

[11] Y. Chen, J. Teo, J. C. Y. Lai, E. Gunawan, K. S. Low, C. B. Soh, and P.B. Rapajic, Cooperative communications in ultra-wideband wirelessbody area networks: Channel modeling and system diversity analysis,IEEE J. Select. Areas Commun., vol. 27, no. 1, pp. 516, Jan. 2009.


[12] J. Shi and J. Wang, Channel characterization and diversity feasibilityfor in-body to on-body communication using low-band UWB signals,in Proc. 3rd Int. Appl. Sci. Biomed. Commun. Technol. Symp., Nov.2010, (CD-ROM).

[13] K. Sayrafian-Pour, W. Yang, J. Hagedorn, J. Terrill, and K. Y. Yazdan-doost, A statistical path loss model for medical implant communica-tion channels, in Proc. IEEE PIMRC, Sep. 2009, pp. 29952999.

[14] A. Khaleghi, R. Chavez-Santiago, and I. Balasingham, Ultra-wide-band statistical propagation channel model for implant sensors in thehuman chest, IET Microw., Antennas, Propag., vol. 5, no. 15, pp.18051812, Dec. 2011.

[15] R. Chavez-Santiago, K. Sayrafian-Pour, A. Khaleghi, K. Takizawa, J.Wang, I. Balasingham, and H.-B. Li, Propagation models for IEEE802.15.6 standardization of implant communication in body area net-works, IEEE Commun. Mag., vol. 51, no. 8, pp. 8087, Aug. 2013.

[16] Q. Wang, K. Wolf, and D. Plettemeier, An UWB capsule endoscopeantenna design for biomedical communications, inProc. 3rd Int. Appl.Sci. Biomed. Commun. Technol. Symp., Nov. 2010, (CD-ROM).

[17] Q. Wang, R. Hahnel, H. Zhang, and D. Plettemeier, On-body direc-tional antenna design for in-body UWB wireless communication, inProc. 6th EUCAP, , Mar. 2012, pp. 10111015.

[18] J. Shi, D. Anzai, and J. Wang, Channel modeling and performanceanalysis of diversity reception for implant UWB wireless link, IEICETrans. Commun., vol. E95-B, no. 10, pp. 31973205, Oct. 2012.

[19] P. A. Humblet and M. Azizoglu, On the bit error rate of lightwavesystems with optical amplifiers, J. Lightw. Technol., vol. 9, no. 11, pp.15761582, Nov. 1991.

[20] S. Dubouloz, B. Denis, S. de Rivaz, and L. Ouvry, Performance anal-ysis of LDR UWB non-coherent receivers in multipath environments,in Proc. IEEE Int. Ultra-Wideband Conf., Sep. 2005, pp. 491496.

[21] J. G. Proakis andM. Salehi, Digital Communications. NewYork, NY,USA: McGraw-Hill, 2008.

[22] R. Mehmood, E. Cerqueira, R. Piesiewicz, and I. Chlamtac, Commu-nications Infrastructure, Systems and Applications. New York, NY,USA: Springer-Verlag, 2010.

[23] M. M. Swindle, Swine in the Laboratory: Surgery, Anesthesia,Imaging, and Experimental Techniques. Boca Raton, FL, USA:CRC, 2007, pp. 2530.

[24] M. Hofmann, J. Edelmann, R. Weigel, G. Fischer, and D. Kissinger,Depth and rate of the save, IEEE Microw. Mag., vol. 13, no. 7, pp.S14S21, Nov./Dec. 2012.

[25] M. Hofmann, J. C. Edelmann, A. Bolz, R. Weigel, G. Fischer, andD. Kissinger, Modeling and experimental investigation of microwavecardiopulmonary resuscitation feedback systems, in IEEE GermanMicrow. Conf., Ilmenau, Germany, Mar. 2012, (CD ROM).

[26] M. Hofmann, J. C. Edelmann, A. Bolz, R. Weigel, G. Fischer, and D.Kissinger, RF based feedback system for cardiopulmonary resuscita-tion, in IEEE Biomed. Wireless Technol. Netw. Sens. Syst. Top. Conf., Santa Clara, CA, USA, Jan. 2012, (CD ROM).

Daisuke Anzai (S06A11) received the B.E.,M.E., and Ph.D. degrees from Osaka City Uni-versity, Osaka, Japan, in 2006, 2008 and 2011,respectively.Since April 2011, he has been an Assistant Pro-

fessor with the Graduate School of Engineering,Nagoya Institute of Technology, Nagoya, Japan. Hehas engaged in the research of biomedical communi-cation systems and localization systems in wirelesscommunication networks.

Kenta Katsu received the B.Eng. degree from theNagoya Institute of Technology, Aichi, Japan, in2012, and is currently working toward the M.Eng.degree at the Nagoya Institute of Technology.His research interest concerns wireless communi-

cation in implant BANs.

Raul Chavez-Santiago (M13) received the Ph.D.degree in electrical and computer engineering fromBen-Gurion University , Negev, Israel, in 2007.He has held several postdoctoral positions with the

University Paris-Sud XI, Paris, France, and Bar-IlanUniversity, Ramat-Gan, Israel. In 2009, he joined theIntervention Centre, Oslo University Hospital, Oslo,Norway. He currently investigates short-range radiocommunication technology for implantable medicalapplications.Dr. Chavez-Santiago is a Management Committee

member of the European COST Actions IC0902, IC0905, and IC1004.

Qiong Wang (S09M11) received the B.E. degreein communication engineering fromYanshanUniver-sity, Qinhuangdao, China, in 2003, and the D.E. de-gree in communication engineering from Nagoya In-stitute of Technology, Nagoya, Japan, in 2010.From 2003 to 2007, she was a Ph.D. candidate with

the Beijing University of Aeronautics and Astronau-tics, Beijing, China, where she was mainly focusedon the behavioral-level modeling of communicationsystems and simulation of interference effects. From2007 to 2008, while studying at the Nagoya Institute

of Technology, she was a Technical Assistant. Since 2008, she has been an As-sociate Assistant with the Department of Electrical Engineering and Informa-tion Technology, Dresden University of Technology, Dresden, Germany. Herresearch interests include biomedical communications, antennas for BANs andelectromagnetic compatibility.

Dirk Plettemeier (S95M04) received theCommunications Engineering diploma from theUniversity of Applied Sciences, Lemgo, Germany,and the Electrical Engineering diploma and Ph.D.degrees from Ruhr-Universitat Bochum, Germany,in 2002.Until 2003, he was with the Institute for High-Fre-

quency Technique/Department of Antennas andWave Propagation, University of Bochum. From2003 to 2007, he was the Head of the ResearchGroup Numerical Calculation of High-Frequency

Electromagnetic Fields and Waves, Electrotechnical Institute/Chair and Labo-ratory for Theory of Electromagnetic Fields and Electromagnetic Compatiblity(EMC), Dresden University of Technology, Germany. From 2007 to 2011, hewas Head of the Research Group High Frequency Engineering-Antennas andWave Propagation, Dresden University of Technology. Since 2011, he hasbeen Head of the Chair for Radio Frequency Engineering, CommunicationsLaboratory, Dresden University of Technology.

Jianqing Wang (M99) received the B.E. degree inelectronic engineering from the Beijing Institute ofTechnology, Beijing, China, in 1984, and the M.E.and D.E. degrees in electrical and communication en-gineering from Tohoku University, Sendai, Japan, in1988 and 1991, respectively.He was a Research Associate with Tohoku Univer-

sity, and a Senior Engineer with the Sophia SystemsCompany Ltd., prior to joining the Nagoya Instituteof Technology, Nagoya, Japan, in 1997, where he iscurrently a Professor. His research interests include

biomedical communications and electromagnetic compatibility.


Ilangko Balasingham (S91M98SM11) re-ceived the M.Sc. and Ph.D. degrees in signalprocessing from the Norwegian University of Sci-ence and Technology (NTNU), Trondheim, Norway,in 1993 and 1998, respectively.He performed his Masters degree thesis at the

Department of Electrical and Computer Engineering,University of California at Santa Barbara, SantaBarbara, CA, USA. From 1998 to 2002, he wasa Research Scientist involved in the developmentof image and video streaming solutions for mobile

handheld devices at Fast Search & Transfer ASA, Oslo, Norway, which iscurrently part of Microsoft Inc. Since 2002, he has been with the Interven-tion Center, Oslo University Hospital, Oslo, Norway, as a Senior Research

Scientist, where he heads the Wireless Sensor Network Research Group. In2006, he became a Professor of signal processing in medical applicationswith NTNU. He has authored or coauthored 151 papers and has been activein organizing special sessions and workshops on wireless medical technologyat major conferences and symposiums. He is an Area Editor for ElseviersNano Communication Networks. His research interests include super-robustshort-range communications for both in-body and on-body sensors, body areasensor networks, microwave short-range sensing of vital signs, short-rangelocalization and tracking mobile sensors, and nano-neural communicationnetworks.Dr. Balasinghamwas the general chair of the 2012 Body Area Networks (BO-

DYNETS) Conference.

Documents

Phase Center Computation of a Corrugated Horn (1).pdf