Mobile Wireless Electrocardiogram by wuyunyi

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									                         Final Report




A Mobile Wireless Electrocardiogram System for Health Care
                         Facilities




                ECE4007 Senior Design Project

                Section L01, J and the Three J’s

                  Joe Richard, Team Leader
                         John Farner
                         Jason Fritts
                        Julian Jaeger




                           Submitted

                        December 5, 2007
                                                    TABLE OF CONTENTS


Executive Summary ...........................................................................................................3

1. Introduction ..................................................................................................................4

     1.1 Objective ..................................................................................................................4
     1.2 Motivation ................................................................................................................5
     1.3 Background ..............................................................................................................5

2. Project Description and Goals ....................................................................................6

3. Technical Specification ................................................................................................7

4. Design Approach and Details

     4.1 Design Approach .....................................................................................................8
     4.2 Codes and Standards ..............................................................................................11
     4.3 Constraints, Alternatives, and Tradeoffs ...............................................................12

5. Schedule, Tasks, and Milestones...............................................................................14

6. Project Demonstration...............................................................................................15

7. Marketing and Cost Analysis ....................................................................................16

     7.1 Marketing Analysis ................................................................................................16
     7.2 Cost Analysis .........................................................................................................16

8. Summary .....................................................................................................................17

9. References ...................................................................................................................19

Appendix A .......................................................................................................................21

Appendix B .......................................................................................................................22




J and the Three Js (ECE4007L01)                                                                                                          2
                                   EXECUTIVE SUMMARY

       The Mobile Wireless Electrocardiogram (EKG) is a medical telemetry instrument used

by medical personnel to monitor a patient’s EKG signal while allowing the patient to remain

fully mobile and comfortable. This EKG measures small electrical signals from the patient’s

chest caused by the heart beating. Using these signals, doctors and other medical staff can

monitor the patient’s well being and predict future problems. While EKGs are commonly used in

hospitals, many patients would benefit from the ability to perform usual tasks while remaining

monitored on an EKG. In environments such as nursing homes and assisted living centers this

technology would allow the elderly to retain their freedom of movement and still allow nursing

staff to monitor important cases and patients. The wireless data relay ability would allow many

patients to be monitored from a single base station with limited staff. This feature would be

valuable to hospital administrators and management. With a small fleet of these devices an entire

nursing home or hospital floor could be well looked after by a small nursing staff.

        This design team has completed a prototype for the mobile wireless EKG unit as well as

developed software for the wireless transmission and base station. The mobile unit can be worn

by the patient, and can measure heart rhythm data, digitize it, and transfer it wirelessly back to

the base station. At the base station the software can store the data and allow medical staff to

view the EKG reading and heartbeats per minute measurement. In further design efforts battery

life could be extended beyond the achieved 3.5 hours, alarms could be added to alert medical

staff of problems, the packaging could be optimized, and a number of other features could be

implemented to increase the unit’s ease of use and appeal to customers.




J and the Three Js (ECE4007L01)                                                                      3
                           Mobile Wireless Electrocardiogram


1.     INTRODUCTION

       Electrocardiograms (EKG) have long been used in the hospital environment to diagnose

cardiac arrhythmias and screen for heart disease. However, until recently patients had to be

tethered to the EKG machine by a few feet of wire [1]. The mobile wireless EKG system is an

electrocardiogram with wireless data transmission capabilities, and a monitoring base station

used to receive and monitor the patient’s condition. With the invention of the mobile EKG,

patients can now move freely around their environment, allowing their caregivers to easily

monitor the patient’s status at any location.


1.1    Objective

       The objective of this project was to provide hospitals with a wireless electrocardiogram

with the ability to operate away from its monitoring station. Hospitals around the country use

electrocardiograms every day to monitor patients’ heart conditions using stationary bedside EKG

units. Our objective was to allow caregivers the ability to move their patients around their

environments without ever having to disconnect and reconnect EKG wires. Using the same EKG

design used in hospitals today, we added wireless capabilities to the unit by adding an IEEE

802.11g Wi-Fi adapter for data transmission. With the addition of a mobile battery pack, the

EKG base unit is able to travel with the patient wherever they go. We also designed software for

a base station that can receive the EKG unit’s Wi-Fi signal using another IEEE 802.11g Wi-Fi

adapter.




J and the Three Js (ECE4007L01)                                                                   4
1.2     Motivation

        Using current electrocardiograms in hospitals can be a time-consuming and unsanitary

task [2]. Connecting and disconnecting EKG leads from hospital room to hospital room takes up

valuable time that nurses could be using to focus on the patient’s ailment. Changing wires also

introduces bacteria to the patient, further increasing the risk of infection.

        By using a mobile EKG, the hospital staff only has to connect wires to the patient once.

This feature will save the caregivers time and decrease the risk of bacteria being introduced to

the patient. The patient will also be “more comfortable in their beds and getting up and around”

since they are free from unnecessary wires [2]. This project was motivated by the realization that

wires are unnecessary given the current state of wireless communication technologies.


1.3     Background

        Currently there are a few wireless electrocardiograms being tested on the market.

LifeSync has a mobile EKG system being tested in thirteen hospitals across the country.

LifeSync’s system uses Bluetooth for its wireless capabilities, giving it a range of thirty to forty

feet [1]. The main goal of this device is to “provide a mobile interface to existing EKG monitors

in the hospital” [3].

        Phillips provides a wireless “IntelliVue Telemetry System” that can be used to monitor a

patients EKG measurement. This system relies on a 2.4 GHz cellular network using fixed

antennas installed throughout the hospital [4].




J and the Three Js (ECE4007L01)                                                                        5
2.       PROJECT DESCRIPTION AND GOALS

         The completed project prototype is a mobile electrocardiogram. A patient will wear the

mobile EKG that gathers heart rhythm data, stores the data, and transmits it wirelessly to a

remote base station for analysis by a health care professional. This EKG monitoring system can

be marketed to hospitals, nursing homes, and other health care facilities based on these goals.

     -   Safe for user
     -   Reliable EKG data under a variety of circumstances
     -   Base station interface
     -   Easy to use mobile system
     -   Lightweight and small size
     -   Wireless data transfer
     -   Sufficient wireless range

         One of the primary goals of the mobile EKG was reliable heart rhythm representation.

The EKG readouts should be comparable to standard EKG units that are currently being used.

The design’s signal digitization was modified to ensure this level of quality, and has exceeded

original design goals. Similarly, the mobile EKG must satisfy the same safety standards as

present systems.

         Since the unit will be worn by a patient for the majority of its functional operation, the

EKG interface must be easy to understand. The unit has been proven during testing to be small

and light enough to allow the patient to move unrestricted.

         Finally, the advantage of this system is its mobility. The wireless capabilities are the

ultimate determining factor for the range of applications for the system. A moderate wireless

range and battery life allow the patient a level of freedom that is impossible with conventional

EKG systems.




J and the Three Js (ECE4007L01)                                                                       6
3.        TECHNICAL SPECIFICATIONS

          The goals stated in the project description lead to the quantifiable specifications of the

mobile EKG. Each of these specifications determines the scope of usefulness of the design. The

technical specifications are given below in Table 1.


 Table 1. Mobile EKG Technical Specifications.

                             Proposed                Final                   Description
                          Specifications        Specifications
                        ≈ 1.25 hours           ≈ 3.5 hours        The eBox 2300 uses 15W of
                                                                  power. Using a 9.6V battery
     Battery Life                                                 pack with approximately
                                                                  2200mAh gives this lifetime.

                        ≈ 38 m                 ≈ 45 m             This is a typical range for
     Wireless range                                               802.11g wireless networks.
                        0.1 W/cm               0.1 W/cm           This is the maximum allowable
     Electrode power                                              power to the EKG electrodes.
                        < 1.3 kg               1.5 kg             This includes the weight/size of
     Weight of unit
                                                                  the eBox, battery pack, EKG
                        150mm x 115mm          241mm x            circuit, and packaging.
     Size of unit       x 80mm                 161mm x
                                               76mm
                        65 Hz                  22050 Hz           A sufficient resolution will
     Resolution                                                   ensure accurate analysis.
                        1000                   831                With heartbeats providing a
                                                                  signal on the order of a
     EKG gain                                                     millivolt, the amplification
                                                                  circuit must have a gain of
                                                                  1000.




          Safety is of primary importance for the mobile EKG. Adequate isolation from the mobile

pack’s electronics and a minimum amount of power applied to the EKG electrodes help ensure

the patient’s safety.



J and the Three Js (ECE4007L01)                                                                        7
       The battery life and range are large enough to ensure that the system can be used in a

variety of locations for a reasonable amount of time. The unit’s relatively small weight and size

cause only small hindrances while moving. Finally, the mobile EKG has proven to be able to

take readings while the patient is moving. With all of these specifications met, the mobile EKG

unit can truly be considered mobile.

       The accuracy of the mobile EKG must be comparable to that of existing telemetric

monitoring equipment. The use of an onboard sound card rather than the Phidgets interface board

improved the specifications of the mobile EKG in two ways. First, the gain of the amplification

circuit was originally required to be high enough to obtain a clear heart rhythm reading: 3 to 5

volts for an analog input of the Phidgets interface board. The sound card requires a lower, more

obtainable signal of 1 volt peak-to-peak for its microphone input. The second improvement in

specifications is that the resolution of the heart rhythm signal was vastly increased. The Phidgets

board sampled the heart rhythm at approximately 65 Hz, while the sound card can sample the

signal at frequencies up to 44100 Hz.


4.     DESIGN APPROACH AND DETAILS


4.1    Design Approach

       The mobile EKG design consists of two major sections as shown in Figure 1. First, the

analog signal input takes the signal reading from the user, amplifies the signal, filters out any

noise, and converts the signal from analog to digital form [16]. The second part wirelessly

transmits the data back to a computer base station, stores the data, and allows for analysis by

physicians or medical personnel.




J and the Three Js (ECE4007L01)                                                                     8
   Figure 1. Design flow chart.


                                              The analog signal input can further be divided into

                                       parts consisting of signal measurement, amplification,

                                       signal filtering, safety isolation, and the A/D conversion.

                                       The signal is measured using two electrode leads attached

                                       to the body with a medical adhesive. Pre-prepared electrode

                                       leads were purchased and used for this function. Figure 2

 Figure 2. EKG lead                 displays the lead placement on the body. The leads are
 .....placement.
named after the appendage to which they are closest (i.e. RA for Right Arm).

       The electrodes are attached through shielded wire to the input amplifier. For this

amplifier an AD624AD high-precision instrumentation amplifier has been chosen. The average

voltage measured from the human body is the in the range of 0.1 mV to 1.0 mV [16]. This

amplifier is able to amplify the signal up to 1000 times. An amplification of 831 times was used

for this design. With the signal strength increased, filtering and the A/D conversion became

easier. Figure 3 displays the circuit diagram of the amplifier. [17]




J and the Three Js (ECE4007L01)                                                                      9
        Measuring the signal from the body and

transferring the signal through wires between the

body and the amplifier creates noise in the signal

that needed to be filtered out. A linear notch filter

was implemented to remove this noise. The average

EKG signal is usually between 3 and 20 Hz [16].

Above these frequencies excess noise is taken in by

the wires from the surrounding environment. Below         Figure 3. Amplifier circuit.

3 Hz the leads will pick up signals from other bodily functions such as breathing and muscle

movement [16]. A passive bandpass filter between 1 and 20 Hz was designed and implemented.

Figure 4 displays the bandpass filter. A

passive filter was designed because of

battery life constraints. As a result the

signal is attenuated by about half, but

because of the amplification this is not a
                                                 Figure 4. Passive Bandpass Filter.
problem. Appendix A contains the bode

plot of the filter.

        One item not yet addressed is the safety precaution within the circuit to prevent short

circuits from redirecting current back through the user’s chest. Since this device is powered by a

small battery, there is not as much danger as an EKG powered by a 120-volt wall receptacle.

However, it is an important issue that must be addressed. There were two main options to deal

with this problem. The first was to use an optical isolation amplifier between the amplification




J and the Three Js (ECE4007L01)                                                                    10
and filtering phase. The second was to use diodes at the input of the signal to disallow any

outbound signals. Due to cost and availability of parts the diode option was chosen.

       After amplification and filtering the signal is passed into an analog to digital converter

using a standard microphone cable. The eBox-2300’s sound card was chosen as the A/D

converter for its excellent sampling rate of 44.1 kHz. This sampling rate provided us with the

resolution needed to sample a heart signal. The fact that the sound card was already included in

the eBox, its ease of use, and its excellent sampling rate contributed to it being our choice for an

A/D converter.

       From here the heart signal will enter the second stage of the design. Once Window CE is

loaded on the eBox, a simple batch program will perform four main tasks. First it will run

wavrec.exe, a C++ program which records a 5 second wave file containing the patient’s heart

signal. Next the batch file will run MobileEKG.exe, a C# program which converts the wave file

to a text file containing only x and y data pairs. The batch program will then copy this text file to

the base station using Windows CE file sharing and an 802.11g Wi-Fi network. Finally the batch

program deletes any files created in order to save space on the eBox and restarts itself for another

heart signal sample. At the base station the data is displayed using a C# graphical user interface.

This interface reads the text files created by MobileEKG.exe, graphically displays the heart

signal, and calculates its beats per minute. All of the code is available in the project

documentation.


4.2 Codes and Standards

       One of the most fundamental electrical standards for medical equipment is the

International Electrotechnical Commission’s standard IEC 60601-1. The first section of this

standard is referred to as the base standard, and provides requirements for the prevention of


J and the Three Js (ECE4007L01)                                                                     11
electrical shock, mechanical, ignition, flammable anesthetics, excessive output and flame hazards

[5].

       The hazard most relevant to the mobile EKG, the electrical shock hazard, is outlined in

section three of IEC 60601-1 [6]. Limiting exposure to 25 VAC, 60 VDC, circuit separation, and

proper grounding are all stated by this standard [5]. Product safety guided design decisions

regarding battery size and amplifier design. The battery voltages and subsequent amplifier rail

voltages, have been made as low as possible. An isolating diode circuit was integrated into the

EKG amplifier design for further patient safety.

       The second type of IEC 60601 sections are referred to as specific standards. The standard

IEC 60601-2-27 specifies safety requirements and essential performance for electrocardiographic

monitoring equipment specifically [5]. This standard is applicable to EKG equipment used

outside of the hospital environment, but does not apply to home or test usage.


       Finally, a standard for wireless LAN connections is the IEEE 802.11g. This standard

provides a mandatory maximum data transfer rate of 54 Mbps [9]. The decision to use a

standardized wireless communication technology ensures the most reliable interface between

different systems within the project.


4.3    Constraints, Alternatives, and Tradeoffs

       The analog to digital conversion of the EKG signal is what ultimately determines the

resolution of the heart rhythm signal. The initial design of the mobile EKG used a Phidgets

interface board as the ADC. The signal digitization, however, proved to be far too slow to give

an accurate representation of the heartbeat. The most robust alternative to the Phidgets interface

board was using a sound card as an ADC. Not only did the use of a sound card increase the




J and the Three Js (ECE4007L01)                                                                   12
resolution the EKG signal, but also provided for a more streamlined design and a lower

production cost.

        Reading the EKG signal from a microphone jack and sound card proved to be a

challenging task from the perspective of software design, and introduced another set of design

tradeoffs. Designing software in the C# language for the embedded Windows CE 6.0 limited our

options for interfacing with the embedded PC’s sound card. Some of the approaches that were

explored but eventually discarded included using DirectX and DirectSound libraries, calling

waveIn APIs, and the use of the dynamic link library, coredll. The simplest solution involved

creating a batch file to execute a pre-made C++ sound recording program. Having access to the

source files of this program allowed for full customization.

        Safety is a primary medical standard, which narrowed the options of the amplification

circuit design. To prevent the EKG patient from potentially lethal shocks from the amplification

circuit, an isolation circuit was needed. Our two choices were a diode based isolator or an optical

isolator. Isolating diode circuits provide excellent safety, are widely available, and cost much

less than optical isolators [10]. The isolating diode circuit was chosen for its safety benefits and

availability.

        One of the wireless EKG’s goals is to allow the patient to move around their environment

freely. For the patient to freely move around their environment, the EKG’s wireless system must

have a large wireless range. We considered three wireless systems for our project: IEEE 802.11g

Wi-Fi, Bluetooth, and a cellular communication system. The IEEE 802.11g Wi-Fi system gave

us the greatest benefit based on range and ease of setup. During testing, the IEEE 802.11g Wi-Fi

provided a range of 45 meters, and can be easily installed in a hospital using Wi-Fi routers

available at any computer retailer [9]. Bluetooth currently has a range of 9 to 12 meters which is




J and the Three Js (ECE4007L01)                                                                    13
not sufficient to cover an entire hospital. A cellular based system would require installing

cellular antennas throughout the hospital and would likely consume the entire budget [4]. For its

wireless range, price, and ease of installation the IEEE 802.11g was chosen as the mobile EKG’s

wireless system.


   5.      SCHEDULE, TASKS, AND MILESTONES
        As shown in the Gantt charts located in Appendix B, there were nine major milestones

that needed to be reached before the unit could begin the final test phase. At least two engineers

were assigned to most of these tasks. This method did not only bring more knowledge to each

task, but it also ensured that separate engineers held each other accountable. All nine tasks were

completed, although some steps took longer than originally planned. Most of the delays were

caused by the late change in hardware.
   Table 2. Degrees of Difficulty.

                          Task Name                           Degree of Difficulty
   1              Build Amplifier Circuit                        Medium
   2                Build Filter Circuit                         Medium
   3     Complete “Hello World” eBox program                       Low
   4         Test Amplifier and Filter Circuits                  Medium
   5    Write program to read from eBox sound card                 High
   6       Combine Circuit with other Hardware                     High
   7          Program Wi-Fi to transmit data                     Medium
   8          Design Packaging for Hardware                        Low
   9            Program Computer Interface                         High


        The degree of difficulty of each task can be seen in Table 2. They are ranked based on the

time it took for completion, the effort it required, and the delay it caused.




J and the Three Js (ECE4007L01)                                                                  14
6.     PROJECT DEMONSTRATION

       Most of our specifications stated in the proposal were achieved or exceeded. The only

specifications that were not met were weight and size. After completing the packaging of the

mobile unit, the package was weighed and measured. Table 3 shows the weight and size, as well

as the other specifications.

     Table 3. Specifications.
                                      Proposed                         Actual
           Range                     38 Meters                        45 Meters
         Battery life               1.25 Hours                        3.5 Hours
          Weight                       1.3 kg                           1.5 kg
            Size                  150x115x80 mm                    241x161x76 mm
         Resolution                    65 Hz                          22050 Hz

       To test the Wi-Fi range of the EKG unit, a test patient walked through the floors of the

Van Leer building in order to see how far the unit could reach, and yet continue its wireless

transmission to a wireless router placed some distance away. After numerous tests the average

range was around 45 meters, which far exceeds our original proposed range.

       To test battery life, the EKG unit was turned on and allowed to run until the unit stopped

sending EKG data back to the base station. After three and a half hours the unit shut down. A

three and a half hour battery life was almost three times longer than expected.

       Finally, because of the switch from the Phidgets board to the eBox sound card ADC, our

resolution jumped from only 65 Hz to 22 kHz. This massive increase allows for very intricate

data point gathering and recording.




J and the Three Js (ECE4007L01)                                                                   15
7.     MARKETING AND COST ANALYSIS


7.1 Marketing Analysis

       Electrocardiograms have been available on the market for many years, but only a few

wireless electrocardiograms have ever been produced. Currently there are three wireless EKG

systems available: the LifeSync Wireless ECG System, Phillip’s IntelliVue Telemetry system,

and Transoma Medical’s Sleuth Wireless Electrocardiogram Monitoring System. The LifeSync

and Phillips systems provide a wireless interface for an already existing electrocardiogram

system, whereas the Transoma system is a standalone EKG system with wireless communication

capabilities. The LifeSync system uses Bluetooth for its wireless transmission giving it a range

of only 10 meters [18]. The Phillips and Transoma systems use a cellular network that requires

cellular antennas to be installed throughout a hospital. The Transoma system also requires an

EKG chip with an antenna to be implanted in the patient’s body [19].


       The mobile EKG system is a stand-alone product, which does not require an existing

EKG system. The mobile EKG system also does not require an intrusive implantable chip for the

patient; instead it uses traditional EKG electrodes attached to the chest of the patient. The

system may also be sold in packages of 5 to 50 units. An existing EKG machine can cost as

much as $4,500, whereas our product’s price is $637 [20]. The mobile EKG also uses IEEE

802.11g for its wireless capabilities giving it a range of up to 45 meters [9].


7.2 Cost Analysis
       Building the prototype cost about $120 in parts and $19,200 in labor as shown in the cost

calculation in Appendix B. This cost assumes four engineers worked for 160 hours each at a pay

rate of $30 per hour. Including fringe benefits and overhead, the developmental cost of the



J and the Three Js (ECE4007L01)                                                                 16
prototype was about $37,386. The cost of parts was relatively low for the prototype because

many of the needed parts are already in stock. The main required parts that were not available

were the AD624AD Precision Instrumentation Amplifier which cost $19.32 [11], and a 5V

Switching Voltage Regulator, which cost $29.95 [13]. Shipping costs, a couple of other smaller

items and packaging made up the rest of the required $120 for building the prototype.

       When mass producing the mobile EKG unit, part costs will be higher due to the fact that

other parts need to be ordered for every single unit. Every unit requires an eBox-2300 which

costs about $133 [14]. This will raise the cost of parts to around $253. With assembly and labor

costs being fairly low, each unit will cost $637 to produce. This is assuming 2,000 units can be

sold every year for five years. At a selling price of $725, around $88 or 12.2% profit would be

made on every single unit. Selling 10,000 units over five years would lead to a total profit of

$883,614.

8.     SUMMARY AND CONCLUSION

       Currently the EKG unit is in a complete prototype form. It can measure EKG data from a

patient and transfer the data wirelessly through a wireless router to software developed for

analyzing and storing the data. The software can store the data of any number of mobile units

and keep track of various records of patients such as date of birth, height and weight, and

medical history.

       Many things could still be optimized or implemented in future work on the device. As

with any mobile unit the battery life should be extended, and the size of the packaging shrunk to

reduce size and weight. A set of alarms could be implemented either to the software or the unit

itself to warn of any medical problems detected by the EKG. The signal could further be filtered

to improve clarity of the signal. It has been suggested that PDA support could be implemented so




J and the Three Js (ECE4007L01)                                                                    17
that medical staff could monitor patients away from the base station. Finally, GPS support or

location tracking could allow medical staff to track the location of patients in case of an

emergency.

       Before real production on this project could be implemented, the packaging would need

to be optimized and the battery life extended. Another round of testing and design would be

needed before any production could begin.




J and the Three Js (ECE4007L01)                                                                 18
9.     REFERENCES

[1]    Life Sync Corp., “Why the LifeSync System ?,” [Sales Literature], [citied 2007 Sep 4]
       Available HTTP: http://www.lifesynccorp.com/healthcareproviders/why-lifesync.html

[2]    D. Wood, RN (2004, August). “Wireless ECGs Make for Flexibility, Freedom.” Nurse
       Spectrum. [Trade magazine]. (pp. 2-3). [cited 2007 Sep 4], Available:
       http://www.lifesynccorp.com/assets/pdfs/press/NurseSpectrum1.pdf

[3]    I. Noorzaie, CSE 574 “Survey Paper: Medical Applications of Wireless Networks,”
       [Survey Paper], Washington University in St. Louis, St. Louis, MO, December 2006.
       Available HTTP: http://www.cse.wustl.edu/~jain/cse574-06/medical_wireless.htm

[4]    Philips Electronics, “IntelliVue Telemetry System,” [Sales Literature], [cited 2007 Sep
       4], Available HTTP:
       http://www.medical.philips.com/main/products/patient_monitoring/products/telemetry/

[5]    L. Eisner, R. Brown, and D. Modi, “A Primer for IEC 60601-1,” [Online document] 2003
       Sep, [cited 2007 Sep 13], Available HTTP:
       http://www.devicelink.com/mddi/archive/03/09/015.html

[6]    International Electrotechnical Commission, International Standard IEC 60601-1-1, 2nd
       Edition, Geneva: International Electrotechnical Commission, 2000

[7]    R. A. Mayes Company, Inc, “IEC 61000-4-2 ESD Test,” [Online document] 2007 Sep 6,
       [cited 2007 Sep 13] , Available HTTP:
       http://www.ramayes.com/EMC_Test_Specifications/ESD_Testing_per_IEC_61000-4-
       2.htm

[8]    DLS, “IEC 61000-4-3 Testing,” [Online document] 2007, [cited 2007 Sep 13], Available
       HTTP:
       http://www.dlsemc.com/index.htm?emc/testing/ec/en61000_4_03/03.htm~mainFrame

[9]    Broadcom, “The New Mainstream Wireless LAN Standard,” White Paper, [Online
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       http://www.dell.com/downloads/global/shared/broadcom_802_11_g.pdf

[10]   Jaycar Electronics, “Optocouplers: When & How To Use Them”, [Company Website],
       [cited 2007 Sep 14], Available HTTP:
       http://www1.jaycar.com.au/images_uploaded/optocoup.pdf

[11]   Digi-Key, “AD624ADZ-ND Order Form”, [Company Website], [cited 2007 Sep 17],
       Available HTTP:
       http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=AD624ADZ-ND


J and the Three Js (ECE4007L01)                                                                  19
[12]   Phidgets Inc., “Analog Sensors”, [Company Website], [cited 2007 Sep 17], Available
       HTTP: http://www.phidgets.com/products.php?category=2

[13]   RoboticsConnection.com, “5V Switching Voltage Regulator”, [Company Website],
       [cited 2007 Sep 17], Available HTTP: http://www.roboticsconnection.com/p-38-5v-
       switching-voltage-regulator.aspx

[14]   WDL Systems, “Online Buyers Guide: eBOX-2300 200MHz VESA PC (Mini PCI,
       2xRS-232)”, [Company Website], [cited 2007 Sep 17], Available HTTP:
       http://www.wdlsystems.com/modperl/view_services.cgi?r=list_aisle.plate&aisle_id=100
       7

[15]   Phidgets Inc., “PhidgetInterfaceKit 8/8/8”, [Company Website], [cited 2007 Sep 17],
       Available HTTP: http://www.phidgets.com/products.php?product_id=1018

[16]   E. Company-Bosch and E. Hartmann, “ECG Front-End Design is Simplified with
       MicroConverter®,” Analog Dialogue, [Online Serial] vol. 37, Nov., 2003, Available
       HTTP: http://www.analog.com/library/analogDialogue/archives/37-11/ecg.html

[17]   S. Carlson, “Amateur Scientist: Home is Where the ECG Is,” Scientific American,
       [Online Serial] June, 2000, Available HTTP:
       http://www.sciam.com/article.cfm?articleID=000C74E4-5172-1C74-
       9B81809EC588EF21

[18]   Commil, “Bluetooth vs. Wi-Fi,” [Company Website], [cited 2007 Sep 4], Available
       HTTP: http://www.commil.com/bluetooth_vs.htm

[19]   EKG Machines, “Interpretive EKG/ECG Machines,” [Company Website], [cited 2007
       Sep 13], Available HTTP: http://www.ekg-machines.com/ekg-machines.html

[19]   Transoma Medical, “Sleuth Implantable ECG Monitoring System” [Company Website],
       [cited 2007 Dec 5], Available HTTP: http://www.transomamedical.com/products.asp

[20]   EKG Machines, “Interpretive EKG/ECG Machines,” [Company Website], [cited 2007
       Sep 13], Available HTTP: http://www.ekg-machines.com/ekg-machines.html




J and the Three Js (ECE4007L01)                                                              20
APPENDIX A. Filter Bode Plot




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APPENDIX B. Gantt Charts (Old and New)



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                   Old Gantt Chart   New Gantt Chart




J and the Three Js (ECE4007L01)                        23

								
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