ECG Implementation on the TMS320C5515 DSP Medical ...

Application ReportSPRAB36B–June 2010

ECG Implementation on the TMS320C5515 DSP MedicalDevelopment Kit (MDK)

Vishal Markandey .............................................................................................................................

ABSTRACT

The medical development kit (MDK) provides a development platform to TI medical customers, thirdparties, and other developers. This application report focuses on the C5515 MDK; however, the analogfront ends that are included can also be used with other platforms.

Please be aware that an important notice concerning availability, standard warranty, and use in criticalapplications of Texas Instruments semiconductor products and disclaimers thereto appears at the end ofthis document.

NOTE: Disclaimer Statement: Do not use this medical development kit for the purpose ofdiagnosing patients.

This application report may not include all of the details necessary to completely develop thedesign. It is provided as a reference and only intended to demonstrate the ECG application.

Contents1 Introduction .................................................................................................................. 22 Front-End Architecture ..................................................................................................... 53 DSP Subsystem ........................................................................................................... 114 PC Application ............................................................................................................. 175 Installation .................................................................................................................. 176 Running the Demo Application .......................................................................................... 207 Options and Selections ................................................................................................... 218 References ................................................................................................................. 22Appendix A Front-End Board Schematics ................................................................................... 23Appendix B Front-End Board BOM ........................................................................................... 30Appendix C Sensors and Accessories ....................................................................................... 33Appendix D MEDICAL DEVELOPMENT KIT (MDK) WARNINGS, RESTRICTIONS AND DISCLAIMER .......... 34

List of Figures

1 MDK Hardware Overview .................................................................................................. 3

2 ECG Board................................................................................................................... 4

3 ECG Front-End Block Diagram ........................................................................................... 6

4 De-Fibrillation Protection Circuit .......................................................................................... 7

5 Right-Leg-Drive Circuit ..................................................................................................... 7

6 Lead-Off Detection Circuit ................................................................................................. 8

7 Lead I Formation ............................................................................................................ 9

8 LPF for Lead II .............................................................................................................. 9

9 Block Diagram of ADS1258 .............................................................................................. 10

10 Interface Between ADS1258 and DSP ................................................................................. 10

11 DSP Software Architecture............................................................................................... 12

12 DC Removal Filter Response ............................................................................................ 13

1SPRAB36B–June 2010 ECG Implementation on the TMS320C5515 DSP Medical Development Kit(MDK)

Copyright © 2010, Texas Instruments Incorporated

Introduction www.ti.com

13 Pole and Zero Location for IIR Filter .................................................................................... 13

14 1Hz Signal Response via DC Removal Filter.......................................................................... 14

15 MBF Frequency Response............................................................................................... 15

16 Buffer-Shifting Convolution Algorithm................................................................................... 15

17 ECG Front-End Mounted on the C5515 EVM ......................................................................... 18

18 Input Dialog Box ........................................................................................................... 20

19 Display on the EVM LCD Screen........................................................................................ 21

20 ECG_I_II .................................................................................................................... 23

21 ECG_LEAD_V1_V2_V3 .................................................................................................. 24

22 ECG_LEAD_V4_V5_V6 .................................................................................................. 25

23 ECG_ADC .................................................................................................................. 26

24 ECG_LEAD_OFF_DET................................................................................................... 27

25 Right Leg Drive ............................................................................................................ 28

26 PWR_CONN_INTRFCE .................................................................................................. 29

27 ECG Cable Details ........................................................................................................ 33

List of Tables

1 J22 Connector Interface .................................................................................................. 11

2 Release CD Contents..................................................................................................... 19

3 Bill of Material .............................................................................................................. 30

1 Introduction

A number of emerging medical applications such as electrocardiography (ECG), digital stethoscope,and pulse oximeters require DSP processing performance at very low power. The TMS320C5515digital signal processor (DSP) is ideally suited for such applications. The C5515 is a member of TI'sC5000™ fixed-point DSP platform. To enable the development of a broad range of medicalapplications on the C5515, Texas Instruments has developed an MDK based on the C5515 DSP. Atypical medical application includes:

• An analog front end, including sensors to pick up signals of interest from the body• Signal processing algorithms for signal conditioning, performing measurements and running analytics

on measurements to determine the health condition• User control and interaction, including graphical display of the signal processing results and

connectivity to enable remote patient monitoring

1.1 Medical Development Kit (MDK) Overview

The MDK is designed to support complete medical applications development. It includes the followingelements:

• Analog front-end boards (FE boards) specific to the key target medical applications of the C5515(ECG, digital stethoscope, pulse oximeter), highlighting the use of the TI analog components formedical applications

• C5515 DSP evaluation module (EVM) main board• Medical applications software including example demonstrations

C5000, Code Composer Studio are trademarks of Texas Instruments.All other trademarks are the property of their respective owners.

2 ECG Implementation on the TMS320C5515 DSP Medical Development Kit SPRAB36B–June 2010(MDK)


ECGFront End

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Color LCD Display

Keypad

C5515 EVM

Front-EndDaughterboards

Common PlatformData process, memory, display, user input, etc.

www.ti.com Introduction

Figure 1 shows an overview of the MDK hardware, consisting of individual analog front-end boards forECG, digital stethoscope, pulse oximeter, and the C5515 DSP EVM. Any of the analog front-end boardscan be connected, one of at a time, to the C5515 EVM using universal connectors on the front-end boardsand the EVM. The analog front-end boards connect to the appropriate sensors for the ECG, digitalstethoscope or the pulse oximeter, and perform analog signal conditioning and analog-to-digital (A/D)conversion of the signals from the sensor. Then, the digital signal is sent to the C5515 EVM where theC5515 DSP performs signal processing algorithms for the application. The DSP is also responsible formanaging user control and interaction including graphical display of the signal processing results. Thesignal processing results can also be transferred from the C5515 EVM to a PC for further display,analysis, and storage using the PC application software that is provided with the MDK.

Figure 1. MDK Hardware Overview

1.2 MDK ECG System

An electrocardiogram (ECG/EKG) is the recording of the electrical activities of the heart and is used in theinvestigation of heart disease. The electrical waves can be measured by selectively placed electrodes(electrical contacts) on the skin.

1.2.1 Key Features

The key features of the MDK ECG system are:

• 12 lead ECG output using 10 electrode input• Defibrillator protection circuitry• Diagnostic quality ECG with bandwidth of 0.05 Hz to 150 Hz• Heartbeat rate display• Leads off detection• Real-time 12 lead ECG waveform display on EVM LCD screen, one lead selectable at a time• Zoom option for the Y-axis (amplitude) on EVM LCD screen• Real-time 12 lead ECG waveform display on PC, three leads at a time• Zoom function on X-axis (time) and Y-axis (amplitude) on PC application• Freeze screen option on PC Application• Recording of ECG data and offline view option of recorded ECG data on PC application



DB-15 Conn.

for Electrode

Connection

Introduction www.ti.com

1.2.2 MDK Hardware

Several elements of the MDK ECG system are:

• C5515 EVM• ECG front-end board• ECG cable

1.2.2.1 C5515 EVM

The EVM comes with a full compliment of on-board devices that suit a wide variety of applicationenvironments.

For further details on the C5515 EVM, see the Medical Devlopment Kit provided with your EVM.

Key components and interfaces of the C5515 EVM used in the MDK ECG system include:

• Texas Instrument's TMS320C5515 operating at 100 MHz• User universal serial bus (USB) port via the C5515• Inter-integrated circuit (I2C) /serial peripheral interface (SPI) electrically erasable programmable

read-only memory (EEPROM)• External memory interface (EMIF), I2C, universal asynchronous receiver/transmitter (UART), SPI

interfaces• SAR• External IEEE Standard 1149.1-1990, IEEE Standard Test Access Port and Boundary-Scan

Architecture (JTAG) emulation interface• Embedded JTAG controller• Color LCD display• Keys (user switches)

The EVM operates from a + 5 V external power supply or battery and is designed to work with TI’s CodeComposer Studio™ integrated development environment (IDE). Code Composer Studio communicateswith the EVM board through the external emulator, or on-board emulator.

1.2.2.2 ECG Front-End Board

Figure 2 shows the ECG front-end board. The potentials captured by the electrodes are passed throughthe defibrillator protection (DP) circuit in the ECG front-end board. Then, the front end board derives 8 outof 12 ECG leads and provides the digital input to the DSP subsystem. The front-end board can beinterfaced with the EVM board through a universal front-end connector. The front-end board is interfacedwith and powered by the C5515 EVM board through the universal front-end connector by using I2C andI2S interfaces.

The 16 channel analog-to-digital converter (ADC) (ADS1258) on the front-end board is configured for 500Hz sampling with 24-bit data resolution. ADC is interfaced with the C5515 using the SPI bus.

Figure 2. ECG Board



www.ti.com Front-End Architecture

1.2.2.3 ECG Cable

The ECG cable consists of four limb and six chest electrodes. This cable is connected to the front-endboard through the DB15 connector. The ECG electrodes pick up ECG signals from the ECGsimulator/patient and send them to the ECG front-end board; an off-the-shelf ECG cable is used. For moredetails regarding ECG cable, see Appendix C.

1.2.3 MDK Software

The software for the MDK application includes:

• C5515 software application• PC application

1.2.3.1 C5515 Software Application

The hardware is initialized by the DSP on the EVM. The DSP reads the digitized signals from the ADCthrough the SPI interface. The DSP subsystem conditions the ECG signals by removing DC offset andnoise using digital filters. Then, the DSP subsystem derives the remaining four ECG electrodes, lead offstatus, and heart rate. The DSP subsystem also displays one channel ECG wave form, lead offinformation and heart rate on the LCD screen and sends the the ECG data to the PC application throughthe UART interface.

1.2.3.2 PC Application

The PC application, which has to be installed on the PC, can be used for viewing the ECG waveform,heart rate, and lead off information. It also provides options to zoom, store and playback the signalstransmitted from the EVM. The PC application can operate in two modes: online and offline.

2 Front-End Architecture

The front-end board has a DB15 connector to allow connection for 10 electrode ECG cables; it can beinterfaced with the EVM board through the universal front-end connector. The C5515 EVM board suppliespower to the front-end board through the universal front-end connector.



Defibrillator

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ProtectionOPA335

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RA,LA,LL signals

Low Pass Filter

150 Hz

Buffer

ADS1258

Crystal 32.768 KHz

Reference Voltage

Powersupply

-5 V TPS60403

-2.5 V TPS72325

+2.5 V TPS73025

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TLV3404

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Front-End Architecture www.ti.com

Figure 3 shows the ECG front-end board architecture.

Figure 3. ECG Front-End Block Diagram

The front-end board contains the following stages:

• Defibrillator protection• Right leg driving circuit• Lead off detection• Derives eight ECG leads using differential amplifier (instrumentation amplifier)• Low-pass filtering (anti-aliasing)• Analog-to-digital conversion (ADC)

2.1 Defibrillator Protection

WARNINGIf defibrillator is used for development purposes, use of medicalgrade EVM input power supply (Accessory Part Number: SL PowerAULT Model MW173KB0503F01) is strongly recommended. Use ofthe Isolator (Accessory Part Number: MOXA Model Name: TCC-82)that isolates the MDK from the PC is also strongly recommended.These accessories provide additional supplemental protection todevelopment users from high voltages that may be present whenintroducing defibrillator voltages during development simulation.There may also be other voltage transients sourced from thedefibrillator to accompanying interface hardware such as apersonal computer when used in conjunction with the ECG/EVMdevelopment hardware.

The defibrillator protection circuit protects the ECG system while the defibrillator is used on the patient.



R1 R2

Electrode

Neon

Lamp

+VCC

-VCC

Vz

To Instrumentaion

Amplifier


The neon lamps and clamping diodes (zener diodes) are connected across the electrode input lines, toprovide protection from the defibrillator pulse. The neon lamps give the first level of protection and theclamping diodes give the second level of protection. These shunting devices are used to bypass largevoltage applied during defibrillation. The neon lamp (NE2 series) shunts voltages above 70 V-80 V. Zenerdiodes, with a breakdown voltage of 9.1 V, are used for shunting the voltage dropped across neon lampsto a safe 11.6 V ( VCC + VZ = 2.5 + 9.1) before it appears across the instrumentation amplifiers. A currentlimiting resistor (R1) of 20K with high energy withstanding capability (~ 2.5J) and power rating (> 1W) isplaced in the series on each input line, which limits the current flow. One more current limiting resistor(R2) of 10K is put in between the neon lamp and the zener diodes to prevent high current from passingthrough the zener diodes. Figure 4 depicts the protection circuitry.

Figure 4. De-Fibrillation Protection Circuit

2.2 Right Leg Drive Circuit

A right-leg-drive circuit (RLD) is used as an alternative to the grounding of a patient with the MDK ECGsystem. In the RLD circuit, an electrode attached to the right leg is driven by the output of an auxiliaryoperational amplifier, where the common-mode voltage is sensed and amplified. The negative feedback ofa common-mode signal in this circuit drives the common-mode voltage low. In turn, the body’sdisplacement current flows to the op-amp output circuit, which reduces the pickup of the ECG system andeffectively grounds the patient. The averaging is done with the electrode signals RA, LA and LL. OPA335is used as the inverting amplifier for the RLD circuit. The gain of the RLD circuit design is -39.

Figure 5. Right-Leg-Drive Circuit

2.3 Lead-Off Detection

The lead-off detection circuit detects the lead status for all the electrodes except RL.The lead-off detectionhas pull up registers, comparator (TLV3404) and an I2C port expander (PCA9535) as shown in Figure 6.

The ECG electrode leads, except RL, are connected to a pull up resistor (10 M); when any one of theleads is disconnected, the voltage for that lead is pulled up to VCC (+ 2.3 V).




The pull up circuit outputs are connected to the negative and positive terminals of the comparator, and setto 500 mV (threshold voltage). When any lead gets disconnected, the output of the comparator for thatlead becomes 0 V. The output of the comparator is connected to the I2C port expander. The portexpander generates an interrupt to the DSP whenever there is any change in the input voltage. Theinterrupt service routine at the DSP reads the output of the port expander using I2C lines and,correspondingly, updates the lead-off status.

Figure 6. Lead-Off Detection Circuit

2.4 Lead Formation Using Instrumentation Amplifier

The following ECG leads are formed using instrumentation amplifier (INA128) and ECG electrodecombinations:

Lead I = LA – RA

Lead II = LL – RA

Lead V1 = V1 - (LA + RA + LL) / 3

Lead V2 = V2 - (LA + RA + LL) / 3

Lead V3 = V3 - (LA + RA + LL) / 3

Lead V4 = V4 - (LA + RA + LL) / 3

Lead V5 = V5 - (LA + RA + LL) / 3

Lead V6 = V6 - (LA + RA + LL) / 3

Where, RA, LL, LA and V1 to V6 are ECG electrodes.

Lead I is formed by connecting LA to the instrumentation amplifier’s non-inverting input, while RA isconnected to the inverting input. Lead II is formed by connecting LL to the instrumentation amplifier’snon-inverting input, while RA is connected to the inverting input.

Uni-polar chest leads (Lead V1 to Lead V6) are formed by applying the corresponding electrodes to thenon-inverting input of the instrumentation amplifier, while the inverting input is connected with the averageof the RA, LA and LL signals. The average is calculated by addition using three equal value resistors.




Figure 7 shows the lead formation for Lead I.

Figure 7. Lead I Formation

The instrumentation amplifier also provides amplification of the weak input signal. The gain of the amplifieris set to 8.35 by using a 6.8K (R4) nominal value precision resistor.

2.5 Low-Pass Filters (Anti-Aliasing)

An active first-order, low-pass filter (LPF) is used for anti-aliasing and for removing frequencies above 150Hz from each of the ECG leads. The LPF has a cutoff at 150 Hz. The instrumentation amplifier output isfed to the LPF filter input. Figure 8 shows the implementation for the LPF.

Figure 8. LPF for Lead II

2.6 Analog-to-Digital Conversion (ADC)

Analog signals are converted to digital before sending them to the DSP sub-system. LPF output isconnected as input to the ADC (ADS1258).



AVDD

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C5505 EVM ECG FE

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ADS1258 is a 16-channel, 24-bit delta-sigma ADC. Figure 9 shows the block diagram of ADS1258.

Figure 9. Block Diagram of ADS1258

The following configuration is used for the ADS1258:

Host to ADC interface SPISampling frequency 500 HzData format 24-bit linearADC mode used Fixed channel modeReference voltage 2.5 V

The eight ECG lead outputs from the LPF are connected to eight channels of the ADS1258. Using SPIinterface, the ADC is connected to the C5515 for 500 sps/channels with 24-bit resolution.

The ADS1258 is interfaced to C5515 DSP as shown in Figure 10.

Figure 10. Interface Between ADS1258 and DSP

2.7 Front-End Connector

The front-end board is connected to the EVM through the universal front-end connector, which consists ofthree connector interfaces with legends on the EVM: J20, J21, and J22.



www.ti.com DSP Subsystem

2.7.1 J20 Connector Interface at C5515 EVM

The mating for this connector is maintained, but no signals are used by the ECG front-end board.


This connector carries the 5 V, 3.3 V and 1.8 V from the C5515 EVM. These voltages act as the primarysource for the ECG front-end board.


This connector carries GPIOs, I2C, SPI and interrupt (INT1) connections from the C5515 EVM to thefront-end board. Pin mapping for the used interfaces are shown in Table 1.

Table 1. J22 Connector Interface

Connector Pin Number Signal Assigned

1 SPI_START

3 SPI_CLK

7 SPI_CS

11 SPI_IN

12 SPI_DRDY

13 SPI_OUT

15 I2C_INT

16 I2C_SCL

20 I2C_SDA

3 DSP Subsystem

The DSP software, running on the C5515 EVM, takes the digitized signal from the front-end board andprocesses it the same. The DSP receives eight ECG lead data from the ADC through the SPI interface.Then, filters are applied to remove DC signal, 50/60 Hz power line noise, and unwanted signals. Thefiltered signal is used to detect the heart rate and to obtain four ECG leads: Lead III, aVR, aVL and aVF.

The software is designed to handle the following activities:

• Data acquisition through ADC• Lead-off detection• DC signal removal• Multi band-pass filtering• ECG leads formation• QRS (HR) detection• Display of ECG data• UART communication



FIRFilters

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X z za

--= =

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DSP Subsystem www.ti.com

Figure 11 shows the high-level architecture of DSP subsystem.

Figure 11. DSP Software Architecture

The various blocks of the DSP subsystem are described in the following sections.

3.1 Data Acquisition

Using the C5515 timer, an interrupt is generated every 250 ms to sequentially acquire 500 sps of eightECG leads. The interrupt service routine (ISR) issues a set channel number and (SOC) command to theADC to acquire 24-bits of ECG data for the selected channel. The acquired data is provided to the infiniteimpulse response (IIR) filter module after downscaling to 20 bits; the data read for the same channelhappens after every 2 ms. The ADC is interfaced with the DSP through the SPI bus.

3.2 Lead-Off Detection

The lead status is read in the IIR for INTR1 of the C5515 (external interrupt 1). This interrupt is generatedin the front ECG board by the I2C port expander as and when the lead status is changed.

3.3 Interrupt Service Routine (IIR) Filter - DC Signal Removal

The DC signals from the eight ECG leads are removed by using the first-order IIR filter. The followingtransfer function is used for the filter:

To provide DC attenuation of 22 dB, the value of alpha is chosen as 0.992. The IIR filter output isdownscaled to 16 bits and then provided to the finite impulse response (FIR) filter.




Figure 12 shows the frequency response for the filter.

Figure 12. DC Removal Filter Response

Figure 13 shows the pole and zero location for the IIR filter. The pole is located at z = 0.992 and zero at 1in the Z plane.

Figure 13. Pole and Zero Location for IIR Filter




Figure 14 shows 1 Hz signal response via the DC removal filter.

Figure 14. 1Hz Signal Response via DC Removal Filter

3.4 FIR Filter

The multi band-pass filter (MBF) is used for removing unwanted signals and power line noise from the DCremoved ECG lead data.

The MBF digital filter being used is the FIR hamming window with the order of 351, which provides cutoffat 150 Hz and notch at 50/60 Hz; the notch frequency is compile-time programmable. This filter alsoprovides a very sharp cutoff at 150 Hz with attenuation of 60 dB at stop-band and notch at 8 dBattenuation. The sampling frequency is 500 samples/second.



x(n) x(n-1) x(n-2) . . . . . x(n-L+2) x(n-L+1)

New Data

x(n) x(n-1) x(n-2) . . . . . x(n-L+1)

Discarded

Next time, n+1

Current time, n


Figure 15 shows simulation results for the MBF.

Figure 15. MBF Frequency Response

Buffer-shifting convolution algorithm is used for the realization of the MBF filter. The filter window is shiftedfor every filtered sample and to insert the new sample into the buffer as depicted in Figure 16.

Figure 16. Buffer-Shifting Convolution Algorithm

3.5 ECG Lead Computation

Eight ECG lead data from the MBF filter is fed to the ECG lead formation module. This module computesthe remaining four ECG lead data using the following formula:

Lead III = Lead II - Lead I

Lead aVR = - Lead II + 0.5 * Lead III

Lead aVL = Lead I - 0.5 * Lead II

Lead aVF = Lead III + 0.5 * Lead I

3.6 QRS (HR) Detection Algorithm

QRS detection is based on the first derivative of the Lead II ECG signal and threshold. Once fiveconsecutive QRS are detected, the heart rate is calculated by taking the average of the five RR intervals.




The following steps are involved for calculating heart rate:

1. Calculate the first derivative of the Lead II ECG signal samples. The first derivative for any sample iscalculated as:y0(n) = |x(n + 1) – x(n - 1)|Where, y0(n) is the first derivative.x(n + 1) is the sample value for (n + 1)th samplex(n – 1) is the sample value for (n – 1)th sampleThe initial 2sec of the first derivatives in a buffer are stored and the maximum value (P) in this bufferare obtained.

2. Calculate the threshold as 0.7 * P.3. Compare each of the first derivative values calculated with the calculated threshold.4. Mark the ECG sample index (S1) of that particular sample, whenever a derivative crosses the

threshold.5. Detect the QRS peak by scanning the next 40 derivatives (MAXIMA_SEARCH_WINDOW = 40) and

obtaining the maxima (M1). This maxima (M1) value is stored in another buffer.

6. Skip the next 50 samples (SKIP_WINDOW = 50) to take care of the minimum RR interval that canoccur in case of maximum detectable heart rate (i.e., 240 BPM), after detecting a QRS peak.

7. Detect the next five QRS peaks by repeating steps 3 to 6.8. Calculate the RR interval as the number of samples between two consecutive QRS peaks.9. Calculate heart rate using the following formula:

HR per Minute = (60 * Sampling Rate)/(Average RR interval for five consecutive RR intervals)10. Recalculate threshold from the QRS peak values detected.

3.7 LCD Display

The LCD display shows the ECG, heart rate, and lead-off status. The display is controlled using the SW7and SW8 keys on the EVM as mentioned in Section 7.1.1. For each of these keys, an interrupt isgenerated and communicated to the DSP through the SAR interrupt. The interrupt service routine for thekey that is pressed takes care of the corresponding action for the interrupt.

3.8 Universal Asynchronous Receiver/Transmitter (UART)

The data sent to the PC through UART has eight ECG lead data; these signals are sent at 250 sps/lead.The PC application derives the remaining four ECG leads using the Lead I and Lead II data. Asynchronization frame (header) of 5 bytes is also sent to the UART interface every 1 s. The packetnumber, heart rate, and lead status values are sent along with the ECG header. The header is followed byinterleaved samples of eight ECG leads. The interval between the two ECG data packets is 500 ms. Thepacket number gets incremented for every new sample sent.

The UART configuration is set as 115200 bps, 8 bits data, 1 stop bit and no parity.



www.ti.com PC Application

ECG Header

Lead LeadPacket00 80 00 80 00 Heart Rate Status StatusNumber (Low) (High)

ECG Data

Current Channel Low 8 Bits Current Channel High 8 Bits

4 PC Application

The PC application is used for viewing the ECG waveform and ECG values. It also provides options tozoom, store and playback the signals.

The PC application has two modes of operation: online and offline.

• Online mode: the ECG data is plotted in real-time as a scrolling display• Offline mode: the recorded ECG data is displayed for analysis

Two timers run on the application for online mode: acquisition and display timer.

The acquisition timer is set for 100 ms intervals and reads the data from the serial port. After fetching thedata from serial port, it parses the stream of bytes to different variables like packet number, heart rate,lead-off status and to the ECG data object containing the digital value of eight leads ECG samples. Thefour non-acquired leads, Lead III, aVR, aVL and aVF data, are derived from Lead I and Lead II as follows:

Lead III = Lead II - Lead I

aVR = - Lead II + 0.5 * Lead III

aVL = Lead I - 0.5 * Lead II

aVF = Lead III + 0.5 * Lead I

The ECG data object for each sample is stored in a queue buffer.

The display timer is set to an interval of 60 ms and is used to plot the ECG wave forms, and update theheart rate and lead-off status information on the screen. This timer is elapsed every 60 ms; in eachelapsed event 15 samples of the leads are plotted on the screen.

5 Installation

5.1 Components and Accessories Required

The following components and accessories are required for the MDK ECG installation.

• C5515 EVM with power supply• ECG front-end board (ECG FE)• Code Composer Studio v3.3• RS232 cable• USB cable• 10 lead ECG patient cable• C5515 DSP application software• PC application software



JTAG Header J4DB9 J14

Power Jack J7 Power Switch SW4

DB15 P1

Installation www.ti.com

5.2 Hardware Installation1. Mount the ECG front-end board on top of the C5515 EVM at connectors J20, J21 and J22. Ensure that

there is a firm connection between the front-end board and the EVM.

Figure 17. ECG Front-End Mounted on the C5515 EVM

2. Connect the USB cable between the PC and the C5515 EVM for the debug mode of operation.3. Connect the C5515 emulator JTAG cable to the C5515 EVM.4. Connect the serial cable (UART) to the DB9 connector (J13) of the C5515 EVM and the other end to

the serial port of the PC, for viewing the signals on the PC application.5. Connect the ECG cables to DB15 connector P1.6. Connect the other end of the ECG cable (there are 10 leads) to an ECG simulator.7. Power on the system using slide switch SW4 on the C5515 EVM.

NOTE: The ECG simulator has 10 connector points that are assigned to different electrodes, i.e.,RA, RL, LA, etc. Ensure that the ECG leads are connected to the corresponding connectorson the simulator.

5.3 Software Installation

5.3.1 System Requirements

The following installations are required to run the software provided with the MDK ECG kit.

• Code Composer Studio v3.3• bios_5_32_01• Spectrum Digital XDS510 USB driver for Code Composer Studio v_3.3• .NET 2.0 frame work



www.ti.com Installation

Table 2 explains the content of the CD provided with the MDK ECG kit.

Table 2. Release CD Contents

S Number Directory/Filename Contains

1 ECGSystem_V_5_0 Project source code

2 Output Contains three files:

ECGSystem.out

c5505evm.gel and

C5515 XDS510USB Emulator.ccs

3 PCApplication Executable for PC application

4 BootImageCreation.zip Folder that contains the following files:

bootImage.exe

convertBind0.bat

convertEnc0.bat

convertInsecure.bat

programmer.out

readme.txt

5 Document Contains the following documents:

ReleaseNote.txt

Quick starter guide V6.0 doc

5.3.2 C5515 DSP Software (debug mode) Installation Steps1. Copy the c5505evm.gel file from the CD to <CCS installation dir>/CC/GEL/.2. Copy the ECGSystem directory from the CD to a local directory on the PC where Code Composer

Studio is installed.

5.3.3 C5515 DSP Software (standalone mode ) Installation Steps1. Copy the BootImageCreation.zip file from the CD to a local directory on the PC where Code Composer

Studio is installed. This path needs to be used later for Flashing; ensure that there are no spaces inthe path name.

2. Copy the ECGSystem.out file from the CD to the < BootImageCreation> folder.3. Execute convertInsecure.bat from the <BootImageCreation> folder to create the new

InsecureBootImage.bin file.4. Open Code Composer Studio.5. Power on the C5515 EVM.6. Select Debug → Connect in Code Composer Studio to connect to the C5515 EVM.7. Load programmer.out C5515 EVM from the < BootImageCreation> folder.8. Select Debug → Run in Code Composer Studio.



Running the Demo Application www.ti.com

9. Enter 241:<BootImageCreation Folder>\InsecureBootImage.bin and press OK in the popup windowshown in Figure 18.

Figure 18. Input Dialog Box

10. Wait until Programming Complete.11. Power off the C5515 EVM and disconnect.

5.3.4 PC Application Installation Steps

Prior to installing the PC application, ensure that .NET 2.0 framework is installed on the system. .NET 2.0redistributable framework can be downloaded from the following URL:http://www.microsoft.com/downloads/details.aspx?familyid=0856eacb-4362-4b0d-8edd-aab15c5e04f5&displaylang=en.

1. Open the PCApplication folder on the CD and double click on C55x ECG Medical DevelopmentKit.msi.

2. Click Next on the welcome screen to continue the installation.3. Browse to the folder where the application is installed. Select the installation mode for Everyone or Self

and click Next.4. Click Next on the Confirmation screen. This installs the application into the specified folder.5. Click Close to complete and exit the installation.

6 Running the Demo Application

The ECG application can be run in two modes: standalone and debug.

• Standalone mode, for running from Flash memory• Debug mode, for loading and debugging using Code Composer Studio

6.1 Running in Standalone Mode1. Complete the installation steps provided in Section 5.3.2. Power on C5515 EVM using slide switch SW4.3. Switch on the ECG simulator to view the ECG signal on the C5515 EVM.

6.2 Running in Debug Mode1. Complete the installation steps provided in Section 5.3.2. Power on the C5515 EVM using slide switch SW4.3. Open Code Composer Studio.4. Click on Debug → Connect in Code Composer Studio to connect to the C5515 EVM.5. Click on Project → Open in Code Composer Studio and select the ECGSystem.pjt file.6. Click on File → Load .out file in Code Composer Studio.7. Execute the application.8. Switch on the ECG simulator to view the ECG signal on the C5515 EVM.



http://www.microsoft.com/downloads/details.aspx?familyid=0856eacb-4362-4b0d-8edd-aab15c5e04f5&displaylang=en

http://www.microsoft.com/downloads/details.aspx?familyid=0856eacb-4362-4b0d-8edd-aab15c5e04f5&displaylang=en

Lead Status

Displaying Lead

www.ti.com Options and Selections

6.3 Running the PC Application

6.3.1 Online Mode

The following steps are required to view signals in online mode using the PC application:

1. Connect the RS232 cable between the PC COM port and the C5515 EVM.2. Complete the installation steps provided in Section 5.3.3. Open the PC application.4. Select online mode and click OK.5. Select the available COM port and click OK.6. Signals transmitted from the C5515 EVM can be viewed on the PC application.

6.3.2 Offline Mode

The following steps are required to view signals in offline mode stored on the PC using the PC application:

1. Open the PC application.2. Select offline mode and click OK.3. Browse and select the previously saved .wav file and click OK.4. View the static ECG waveforms along with the heart rate and lead-off status on the PC application.

7 Options and Selections

7.1 On the C5515 EVM

7.1.1 ECG Display on the C5515 EVM Side

The ECG display on the LCD screen starts by showing the ECG Monitor followed by lead and heart rate;by default, ECG Lead II is displayed.

SW7 switch on the EVM can be pressed to view one channel after the other. Pressing the switch displaysthe next ECG lead in a cyclic manner: II, I, III, aVR, aVL, aVF, V1, V2, V3, V4, V5 and V6.

The SW8 switch on the EVM can be used for the zoom in and zoom out feature for the ECG waveform.Low, Medium (default) and High are the three levels of zooming provided.

If all 10 leads are connected, a green color dot is displayed at the lead status location on the EVM display.In case any one lead fails, the failed lead name is displayed at the lead status location. If more than onelead off is detected, a red color dot is displayed at the lead status location.

Figure 19. Display on the EVM LCD Screen



References www.ti.com

7.1.2 PC Application

By default, three leads are displayed simultaneously. The sequence of the leads are I, II, III, aVR, aVL,aVF, V1, V2, V3, V4, V5 and V6. Lead-off status and heart rates are displayed on the screen and thevalues are refreshed once every second. The serial port connection status (RS232) for the device isdisplayed on the status bar.

The following features are available on the PC application.

• Next (up arrow) - This button can be used to view the next three lead wave forms.• Previous (down arrow) - This button can be used to view the previous three lead wave forms.• Scaling on Amplitude - This button can be used to vertically zoom in and zoom out of the ECG

waveform display on the PC application.• Scaling on Time - This button can be used to horizontally zoom in and zoom out of the ECG

waveform display on the PC application.• Start Recording - This can be used to start the recording of the ECG waveform. During recording, this

same button is used for the Stop Recording operation. Note that after the start recording option isselected, the zoom options get disabled.

• Stop Recording - This can be used to stop recording and save the ECG waveform as an .ECG file. Itcan be played back using the PC application in offline mode.

• Freeze - This button can be used to view a static waveform. Particular portions of the waveform can beviewed by moving the Left and Right cursors during the Freeze option.

• Unfreeze - Pressing this button enables the waveform to be in continuous scrolling mode.• Cancel: This can be used to close the form.

8 References• TMS320VC5505 DSP Medical Development Kit (MDK) Quick Start Guide (SPRUGO1)



http://www.ti.com/lit/pdf/SPRUGO1

LA

LA

RA

RA

RA

LL

LL

LE

AD

_I

LE

AD

_II

-2.5

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CC

+2

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VC

C

+2

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VC

C

-2.5

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CC

-2.5

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CC

+2

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VC

C

-2.5

_V

CC

+2

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VC

C

+2

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VC

C

-2.5

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CC

-2.5

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CC

+2

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VC

C

+2

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VC

C

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CC

+2

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VC

C

-2.5

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CC

+2

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VC

C

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CC

LP

F_

I

LP

F_

II

DB

15

_R

A

DB

15_

LA

DB

15

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LA

RA

LL

DE

FIB

RIL

LA

TO

RP

RO

TE

CT

ION

(D

P1)

DE

FIB

RIL

LA

TO

RP

RO

TE

CT

ION

(D

P2)

DE

FIB

RIL

LA

TO

R P

RO

TE

CT

ION

(D

P3)

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

1)

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

2)

LO

WP

AS

SF

ILT

ER

(LP

F1)

Fc=

159H

z

LO

WP

AS

SF

ILT

ER

(LP

F2)

Fc=

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z

GA

IN8

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GA

IN8

.35

DN

I

DN

I

DN

I

DN

I

DN

I

C2

0.1

uF

C5

0.1

uF

C8

0.1

uF

C1

0.1

uF

J3

CO

N3

123

TP

17

C100

22nF

U1

A

OP

A2

335

In-

2

In+

3

Out

1

V+8 V- 4

U3

INA

12

8

Vin

-2

Vin

+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

C3

0.1

uF

R14

0E

D6

9.1

V

R3

10K

R8

0E

R4

6.8

K

R9

10M

D1

9.1

V

R18

0E

D4

9.1

V

D2

9.1

V

C6

0.1

uF

R19

10M

DS

2M

C0

8010000

R6

0E

D5

9.1

V

D3

9.1

V

U1B

OP

A2

335

In-

6

In+

5

Out

7

V+ V-

R16

22K

C98

22nF

U2

INA

12

8

Vin

-2

Vin

+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

C7

0.1

uF

R12

6.8

K

DS

3M

C0

8010000

R17

10K

TP

9

R2

22K

TP

8

TP

16

R11

10K

R5

10K

R1

310K

R10

22K

C4

0.1

uF

C99

22nF

DS

1M

C0

8010000

J1

CO

N3

123

R1

10M

J2

CO

N3

123

www.ti.com

Appendix A Front-End Board Schematics

A.1 Front-End Board Schematics

The schematics for the ECG front-end board are shown below:

Figure 20. ECG_I_II



V1

V2

V3

LE

AD

_V

1

LE

AD

_V

2

LE

AD

_V

3

-2.5

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CC

+2

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VC

C

-2.5

_V

CC

-2.5

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CC

+2

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VC

C

+2

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VC

C

-2.5

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CC

+2

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VC

C

+2

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VC

C

-2.5

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CC

-2.5

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CC

-2.5

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CC

+2

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VC

C

+2

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VC

C

+2

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VC

C

-2.5

_V

CC

+2

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VC

C

-2.5

_V

CC

+2

.5_

VC

C

-2.5

_V

CC

+2

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VC

C

-2.5

_V

CC

LP

F_

V1

V2

LP

F_

V2

DB

15

_V

2

DB

15

_V

1

V1

AV

G_

LA

_R

A_LL

AV

G_

LA

_R

A_LL

LP

F_

V3

DB

15

_V

3

AV

G_

LA

_R

A_LL

V3

DE

FIB

RIL

LA

TO

RP

RO

TE

CT

ION

(D

P4)

DE

FIB

RIL

LA

TO

R P

RO

TE

CT

ION

(D

P5)

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

3)

LO

WP

AS

SF

ILT

ER

(LP

F3)

Fc=

159H

z

LO

WP

AS

SF

ILT

ER

(LP

F4)

Fc=

159H

z

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

5)

DE

FIB

RIL

LA

TO

RP

RO

TE

CT

ION

(D

P6)

LO

WP

AS

SF

ILT

ER

(LP

F5)

Fc=

159H

z

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

4)

GA

IN8

.35

GA

IN8

.35

GA

IN8

.35

DN

I

DN

I

DN

I

DN

I

DN

I

DN

I

R3

710K

U6

INA

12

8

Vin

-2

Vin

+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

C13

0.1

uF

U4B

OP

A2

335

In-

6

In+

5

Out

7

V+ V-

D8

9.1

V

DS

6M

C0

8010000

U7

A

OP

A2

335

In-

2

In+

3

Out

1

V+8 V- 4

C20

0.1

uF

R35

10M

TP

20

J6

CO

N3

123

DS

4M

C0

8010000

R2

06

.8K

J5

CO

N3

123

C15

0.1

uF

C1

01

22

nF

J4

CO

N3

123

R22

0E

D7

9.1

V

C16

0.1

uF

C1

8

0.1

uF

C9

0.1

uF

C1

0

0.1

uF

R32

22K

R3

66

.8K

TP

19

C1

03

22

nF

R26

0E

R30

0E

TP

12

R27

10M

D12

9.1

V

TP

11

R41

10K

C21

0.1

uF

R25

10K

D10

9.1

V

R2

86

.8K

C19

0.1

uF

R38

0E

DS

5M

C0

8010000

R43

10M

R33

10K

U4

A

OP

A2

335

In-

2

In+

3

Out

1

V+8 V- 4

U8

INA

12

8

Vin

-2

Vin

+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

R34

0E

R2

110K

R42

0E

TP

10

R24

22K

D11

9.1

V

D9

9.1

V

C102

22nF

C12

0.1

uF

R2

910K

C11

0.1

uF

U5

INA

12

8

Vin

-2

Vin

+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

TP

18

C17

0.1

uF

C1

4

0.1

uF

R40

22K

Front-End Board Schematics www.ti.com

Figure 21. ECG_LEAD_V1_V2_V3



V4

V5

V6

LE

AD

_V

4

LE

AD

_V

5

LE

AD

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6

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CC

+2

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VC

C

+2

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VC

C

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CC

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CC

+2

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C-2

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VC

C

+2

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CC

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VC

C

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CC

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VC

C

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CC

+2

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VC

C

-2.5

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CC

+2

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VC

C

-2.5

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CC

LP

F_

V4

LP

F_

V5

DB

15

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6

V6

DB

15

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5

V5

DB

15

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4

V4

LP

F_

V6

AV

G_

LA

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A_LL

AV

G_

LA

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A_LL

AV

G_

LA

_R

A_LL

DE

FIB

RIL

LA

TO

RP

RO

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CT

ION

(D

P7)

DE

FIB

RIL

LA

TO

R P

RO

TE

CT

ION

(D

P8)

DE

FIB

RIL

LA

TO

R P

RO

TE

CT

ION

(D

P9)

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

8)

LO

WP

AS

SF

ILT

ER

(LP

F6)

Fc=

159H

z

LO

WP

AS

SF

ILT

ER

(LP

F7)

Fc=

159H

z

LO

WP

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SF

ILT

ER

(LP

F8)

Fc=

159H

z

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

6)

INS

TR

UM

EN

TA

TIO

NA

MP

LIF

IER

(IA

7)

GA

IN8

.35

GA

IN8

.35

GA

IN8

.35

DN

I

DN

I

DN

I

DN

I

DN

I

DN

I

R4

510K

C2

3

0.1

uF

R6

51

0K

R4

46

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U7B

OP

A2

335

In-

6

In+

5

Out

7

V+ V-

C32

0.1

uF

R57

10K

R6

7

10

M

R5

9

10

M

C2

2

0.1

uF

R51

10M

R5

0

0E

R5

40

E

C2

40

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F

J9

CO

N3

123

D16

9.1

V

R58

0E

TP

14

TP

22

J7

CO

N3

123

R66

0E

C1

05

22

nF

R64

22K

R4

91

0K

U1

0B

OP

A2

335

In-

6

In+

5

Out

7

V+ V-

C29

0.1

uF

R62

0E

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7

0.1

uF

TP

13

U11

INA

12

8

Vin

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+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

U1

0A

OP

A2

335

In-

2

In+

3

Out

1

V+8 V- 4

D15

9.1

V

R46

0E

DS

7M

C0

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C2

6

0.1

uF

C25

0.1

uF

R5

310K

R5

62

2K

D1

4

9.1

V

DS

8M

C0

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C3

1

0.1

uF

C1

04

22

nF

D18

9.1

V

R6

110K

TP

21

DS

9M

C0

8010000

C1

06

22

nF

C28

0.1

uF

R5

26

.8K

C3

0

0.1

uF

U9

INA

12

8

Vin

-2

Vin

+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

TP

15

D13

9.1

V

R6

06

.8K

D17

9.1

V

J8

CO

N3

123

TP

23

R48

22K

U1

2

INA

12

8

Vin

-2

Vin

+3

Vo

6

Rg

11

Rg

28

V+7 V- 4

Re

f

5

www.ti.com Front-End Board Schematics

Figure 22. ECG_LEAD_V4_V5_V6



+2

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VC

C

+2

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VC

C

-2.5

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CC

-2.5

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CC

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VC

C

3.3

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CC

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CC

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V2

LP

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V5

LP

F_

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LP

F_

V3

LP

F_

V1

SP

I_IN

SP

I_D

RD

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AD

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14

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15

GP

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16

GP

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17

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18

GP

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19

GP

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20

GP

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21

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U14

OP

A3

35

In-

4

In+

3

Out

1

V+5 V- 2

C46

0.1

uF

C1

07

10

uF

R70

0E

R7

3

10

K

R11

21

0K

R11

51

0K

U1

5

OP

A335

In-

4

In+

3

Out

1

V+5 V- 2

TP

32

R71

0E

R11

01

0K

C7

9

10

uF

R8

01

K

C5

0

10

uF

C3

6

0.1

uF

C43

10

uF

R123

0E

R11

85

1E

C3

92

2n

F

C41

0.1

uF

R1

21

0E

R7

4

10

K

TP

29

R122

0E

C4

9

0.1

uF

TP

24

R113

10K

R11

61

0K

C4

04

.7p

F

R75

0E

C4

7

10

0u

F

R8

11

00

EC

42

4.7

pF

R72

0E

C3

4

10

uF

C4

4

0.1

uF

C3

72

.2nF

C3

3

0.1

uF

C38

0.1

uF


Figure 23. ECG_ADC



TH

RS

H_V

OL

RA

'

LA

'

LL'

V1

'

V2

'

V5

'

RA

'

V5

'

V6

'

V6

'

V3

'

V3

'

TH

RS

H_V

OL

V4

'

TH

RS

H_V

OL

TH

RS

H_V

OL

V4

'T

HR

SH

_V

OL

TH

RS

H_V

OL

LA

'

TH

RS

H_V

OL

TH

RS

H_V

OL

TH

RS

H_V

OL

TH

RS

H_V

OL

V2

'

V1

'

LL'

-2.5

_V

CC

3.3

_V

CC

+2

.5_

VC

C

3.3

_V

CC

3.3

_V

CC

3.3

_V

CC

3.3

_V

CC

I2C

_IN

T

I2C

_S

CL

I2C

_S

DA

LA

LL

V1

V2

V3

V4

V5

V6

RA

LE

AD

OF

FD

ET

EC

TIO

NC

OM

PA

RAT

OR

S

I2C

I/O

EX

PA

ND

ER

LO

WP

AS

SF

ILT

ER

SF

c=

15.9

Hz

No

te:

IfL

PF

no

tre

qu

ire

dp

ut

a0

ohm

jum

pe

ro

nth

ere

sis

tor

pa

th a

nd

do

not

po

pu

late

ca

pacitors

C5

1

0.1

uF

TP

27

C56

0.1

uF

R90

100K

TP

41

R8

4

100K

R8

5

10

0K

R8

8

10

0K

R9

5

4.7

K

R1

26

0E

R1

32

0E

R1

24

0E

TP

37T

P34

TP

25

TP

44

C55

1uF

R9

1

10

0K

U1

7

TLV

34

01

IN-

4

IN+

3

OU

T1

VC

C5

GN

D

2

TP

38

R131

0E

TP

33

R129

0E

R1

30

0E

TP

35

R86

100K

R9

3

10

K

C9

1

0.1

uF

TP

39

C90

0.1

uF

C9

7

0.1

uF

U1

8

TLV

34

04

IN1

-2

IN1

+3

IN2

-6

IN2

+5

IN3

-9

IN3

+1

0

IN4

-1

3

IN4

+1

2

VCC4

GND11

OU

T1

1

OU

T2

7

OU

T3

8

OU

T4

14

C89

0.1

uF

R1

27

0E

R1

28

0E

TP

26

U20

TLV

3404

IN1

-2

IN1

+3

IN2

-6

IN2

+5

IN3

-9

IN3

+1

0

IN4

-1

3

IN4

+1

2

VCC4

GND11

OU

T1

1

OU

T2

7

OU

T3

8

OU

T4

14

C54

10nF

TP

40

R8

9

100K

R1

25

0E

C9

6

0.1

uF

C9

5

0.1

uF

C9

4

0.1

uF

U1

9

PC

A9

535

A0

21

A1

2

A2

3

PA

04

PA

15

PA

26

PA

37

PA

48

PA

59

PA

61

0

PA

711

PB

01

3

PB

11

4

PB

21

5

PB

31

6

PB

41

7

PB

51

8

PB

61

9

PB

72

0

VCC24

GND12

INT

1

SC

L2

2

SD

A2

3

R83

100K

_P

OT

R8

7

10

0K

R9

2

10

0K

_P

OT

C9

3

0.1

uF

R8

2

10

0K

C9

2

0.1

uF

C5

2

0.1

uF

R9

4

4.7

K

TP

36

C53

0.1

uF


Figure 24. ECG_LEAD_OFF_DET



BU

FF

_L

A

BU

FF

_R

A

BU

FF

_L

L

RL

D_

VO

L

-2.5

_V

CC

+2

.5_

VC

C

-2.5

_V

CC

+2

.5_

VC

C

-2.5

_V

CC

+2

.5_

VC

C

-2.5

_V

CC

+2

.5_

VC

C

+2

.5_

VC

C

-2.5

_V

CC

AV

G_

LA

_R

A_

LL

LA

RA

LL

DB

15

_R

L

RL

D_

VO

L

WIL

SO

NT

ER

MIN

AL

GA

IN-3

9

RL

DR

IVE

CK

T

DE

FIB

RIL

LA

TO

RP

RO

TE

CT

ION

(D

P10)

BU

FF

ER

FO

RL

A,R

A&

LL

sig

nals

R1

04

10K

U2

3

OP

A335

In-

4

In+

3

Out

1

V+5 V- 2

C65

0.1

uF

TP

43

U24

TLV

2221

IN+

1

IN-

3

OU

T4

V+5 V- 2

R96

390K

C5

8

0.1

uF

R9

71

0K

C6

30

.1uF

C6

4

0.1

uF

R1

03

10K

R1

02

22K

TP

42

C57

0.1

uF

D1

9

9.1

VR

99

10K

R1

33

39

0K

C6

2

0.1

uF

U2

2

TLV

22

21

IN+

1

IN-

3

OU

T4

V+5 V- 2

R1

00

10K

C6

1

0.1

uF

R1

05

10K

D2

0

9.1

V

C59

47pF

DS

10

MC

08

010000

C6

0

0.1

uF

R1

01

10K

R9

81

0K

U2

1

TLV

22

21

IN+

1

IN-

3

OU

T4

V+5 V- 2


Figure 25. Right Leg Drive



BR

D_

DE

T1

BR

D_

DE

T0

BR

D_

DE

T0

BR

D_

DE

T1

3.3

_V

CC

1.8

_V

CC

5_

VC

C

5_

VC

C+

2.5

_V

CC

-5_

VC

C

3.3

_V

CC

3.3

_V

CC

5_

VC

C-5

_V

CC

-2.5

_V

CC

+2

.5_

VC

C

-2.5

_V

CC

DB

15

_V

2D

B1

5_

RA

DB

15_

V3

DB

15

_V

4

DB

15

_V

5

DB

15

_V

6

DB

15

_LL

DB

15

_V

1

I2C

_S

CL

I2C

_S

DA

SP

I_C

LK

I2C

_IN

TS

PI_

OU

TS

PI_

IN

RL

D_

VO

L

DB

15

_LA

DB

15

_R

L

SP

I_C

S

SP

I_S

TA

RT

SP

I_D

RD

Y

CO

NN

EC

TO

R IN

TE

RF

AC

EL

DO

+2

.5V

LD

O -

2.5

V

EC

G E

LE

CT

RO

DE

CO

NN

EC

TO

R

FR

ON

TE

ND

BO

AR

D D

ET

EC

TIO

N M

EC

HA

NIS

M

BR

D_

DE

T1

BR

D_

DE

T0

EC

G

ST

ET

H

SP

O2

11

01

10

-5V

INV

ER

TE

R DN

I

EV

MG

ND

-F

EG

ND

ISO

LA

TIO

N

DE

CO

UP

LIN

G+

2.5

V&

-2.5

V

C7

6

10

0uF

C70

1u

F

L1

BE

AD

L5

3.3

uH

C78

10

0uF

TP

6

J10

PO

WE

R_

CO

NN

1 3 5 7 9

2 4 6 81

0

C82

10uF

C7

1

1u

F

R1

08

10

K

C7

5

0.1

uF

TP

2

R1

07

0E

C69 0.0

1uF

C8

7

10

uF

L4

3.3

uH

TP

1

J13

CO

N3

123

C88

0.1

uF

C7

7

0.1

uF

C8

0

10u

F

C8

4

10

uF

C6

8 2.2

uF

C72 2.2

uF

R109

0E

L3

3.3

uH

C8

3

10

uF

C73 0.0

1uF

TP

5

C74 2.2

uF

U26

TP

S6

04

03

IN2

OU

T1

CF

LY

-

3

CF

LY

+

5

GN

D

4

P1

CO

NN

EC

TO

RD

B15

81

5 71

4 61

3 51

2 411 3

10 2 9 1

C66 0.1

uF

C67

1uF

L2

3.3

uH

TP

4

TP

7

U27

TP

S7

23

25

IN2

EN

3

GND1

NR

4

OU

T5

C81

10uF

C8

5

10

uF

R1

06

10K

U25

TP

S7

30

25

IN1

EN

3

GND2

NR

4

OU

T5

J11

DA

TA

_C

ON

N

1 3 5 7 911

13

15

17

19

2 4 6 8 10

12

14

16

18

20

TP

3

C86

10uF

J1

2

DU

MM

Y_

CO

NN

1 3 5 7 9 11

13

15

17

19

2 4 6 81

01

21

41

61

82

0


Figure 26. PWR_CONN_INTRFCE



www.ti.com

Appendix B Front-End Board BOM

B.1 Front-End Board BOM

Table 3 provides the bill of material for the digital stethoscope front-end board.

Table 3. Bill of Material

Ite Quantitm y Value Reference Description Part Number Manufacturer DNI

1 17 0.1 mF C1,C4,C9,C12,C17, CAP CERM 0.10 mF 50 V 5% 08055C104JAT2A AVX DNIC20,C25,C28,C89, 0805 SMD CorporationC90,C91,C92,C93,C94,C95,C96,C97

2 49 0.1 mF C2,C3,C5,C6,C7, CAP CERM 0.10 mF 50 V 5% 08055C104JAT2A AVXC8,C10,C11,C13, 0805 SMD CorporationC14,C15,C16,C18,C19,C21,C22,C23,C24,C26,C35,C36,C38,C41,C44,C46,C27,C29,C30,C31,C32,C33, 48,C49,C51,C52,C53,C56,C64,C65,C66,C75,C77,C88 C57,C58,C60,C61,C62,C63

3 5 10 mF C34,C43,C50,C79, C107 CAP TANT LOESR 10 mF 16 V TPSB106K016R080 AVX10% SMD 0 Corporation

4 1 2.2 nF C37 CAP CERM 2200 pF 5% 50 V 08055A222JAT2A AVXNPO 0805 Corporation

5 1 22 nF C39 CAP CER 22000 pF 50 V X7R 08055C223J4T2A AVX0805 Corporation

6 2 4.7 nF C40,C42 CAP CER 4.7 pF 50 V NPO 0805 08055A4R7BAT2A AVXCorporation

7 5 1 mF C45,C55,C67,C70, C71 CAP CERM 1.0 mF 10% 25 V 08053C105KAZ2A AVXX7R 0805 Corporation

8 3 100 mF C47,C76,C78 CAP ELECT 100 mUF 16 V TK EEE-TK1C101P Panasonic-ECGSMD

9 1 10 nF C54 CAP CER 10000 pF 16 V NPO 0805YA103JAT4A AVX0805 Corporation

10 13 47 pF C59 CAP CERM 47 pF 5% 50 V NPO 08055A470JAT2A AVX0805 Corporation

11 3 2.2 mF C68,C72,C74 CAP CER 2.2 mUF 25 V X7R 08053C225MAT2A AVX0805 Corporation

12 2 0.01 mF C69,C73 CAP CERM 0.01 10% 50 V X7R 08055C103KAT2A AVX0805 Corporation

13 8 10 mF C80,C81,C82,C83,C84, CAP CER 10 mF 16 V X5R 0805 EMK212BJ106KG-T Taiyo YudenC85, C86,C87

14 9 22 nF C98,C99,C100,C101,C1 CAP CER 22000 pF 50 V X7R 08055C223J4T2A AVX02, 0805 CorporationC103,C104,C105,C106

15 10 MC08010000 DS1,DS2,DS3,DS4,DS5, Neon lamp MC08010000 MulticompDS6,DS7,DS8,DS9,DS10

16 20 9.1 V D1,D2,D3,D4,D5,D6,D7, DIODE ZENER 1W 9.1 V PTZTE259.1B ROHMD8, SOD-106D9,D10,D11,D12,D13,D14,D15,D16,D17,D18,D19,D20

17 10 CON3 J1,J2,J3,J4,J5,J6,J7, J8, CONN HEADER 3POS .100 22-28-4030 MolexJ9,J13 VERT TIN

18 1 POWER_CONN J10 Elevated Female Header 5x2 BB02-KD102-T03- Gradconn100000

19 1 DATA_CONN J11 Elevated Female Header 10x2 BB02-KD202-T03- Gradconn100000



www.ti.com Front-End Board BOM

Table 3. Bill of Material (continued)


20 1 DUMMY_CONN J12 Elevated Female Header 10x2 BB02-KD202-T03- Gradconn100000

21 1 BEAD L1 FERRITE BEAD 470 Ω 0805 BK2125HM471-T Taiyo Yuden

22 4 3.3 mH L2,L3,L4,L5 INDUCTOR POWER 3.3 mH 1.3A VLF4012AT- DK CorporationSMD 3R3M1R3

23 1 CONNECTOR P1 CONN D-SUB RCPT R/A 15POS 745782-4 TycoDB15 PCB AU Electronics

24 9 10M R1,R9,R19,R27,R35,R4 RES 10.0MΩ 1/8W 1% 0805 CRCW080510M0FK Vishay3, R51,R59,R67 SMD EA

25 10 22K R2,R10,R16,R24,R32,R RES 22KΩ 1W 5% 2512 SMD CRCW251222K0JN Vishay40,R48,R56,R64,R102 EG

26 10 10K R3,R11,R17,R25, RES 10KΩ 1/2W 5% 2010 SMD CRCW201010K0JN VishayR33,R41, EFR49,R57,R65,R101

27 8 6.8K R4,R12,R20,R28,R36, High Precision Chip Resistor Y162406K8000T9R VishayR44, R52,R60 6.8KΩ

28 15 10K R5,R13,R21,R29,R37, High Precision Chip Resistor Y162410K0000T9R VishayR45,R53,R61,R97, R98, 10KΩR99,R100,R103,R104,R105

29 38 0E R6,R8,R14,R18,R22, RES 0.0 Ω 1/8W 5% 0805 SMD CRCW08050000Z0 VishayR26,R30,R34,R38, EAR42,R46,R50,R54,R58,R62,R66,R68,R69,R70,R71,R72,R75,R77,R78, R79,R119,R120,R121,R122,R124,R125,R126,R127,R128,R129,R130,R131, R132

30 11 10K R73,R74,R93,R110, RES 10.0KΩ 1/8W 1% 0805 SMD CRCW080510K0FK VishayR111,R112,R113, EAR114,R115,R116, R117

31 1 47E R76 High Precision Chip Resistor 47 Y162447R0000T9R VishayΩ

32 1 1K R80 RES 1.00KΩ 1/8 W 1% 0805 CRCW08051K00FK VishaySMD EA

33 1 100E R81 High Precision Chip Resistor 100 Y1624100R000T9R Vishaym

34 9 100K R82,R84,R85,R86, RES 100KΩ 1/8W 1% 0805 SMD CRCW0805100KFK VishayR87,R88,R89,R90, R91 EA

35 2 100K_POT R83,R92 POT 100KΩ 4MM SQ CERMET 3314G-1-104E Bourns IncSMD

36 2 4.7K R95,R94 RES 4.70KΩ 1/8W 1% 0805 SMD CRCW08054K70FK VishayEA

37 2 390K R96,R133 High Precision Chip Resistor TNPW0805390KBY Vishay390KΩ TA

38 2 10K R108,R106 RES 10.0KΩ 1/8W 1% 0805 SMD CRCW080510K0FK Vishay DNIEA

39 3 0E R107,R109,R123 RES 0.0 Ω 1/8W 5% 0805 SMD CRCW08050000Z0 Vishay DNIEA

40 1 51E R118 RES 51 Ω 1/8W 5% 0805 SMD CRCW080551R0JN VishayEA

41 4 OPA2335 U1,U4,U7,U10 IC OP AMP CMOS SGL SPLY OPA2335AIDGKT TI DNI8-MSOP

42 8 INA128 U2,U3,U5,U6,U8,U9,U11 IC LOW PWR INSTR AMP INA128UA TI, U12 8-SOIC

43 1 ADS1258 U13 IC ADC 24 BIT 125 ksps 48-QFN ADS1258IRTCT TI

44 3 OPA335 U14,U15,U23 IC OP AMP CMOS SGL SPLY OPA335AIDBVT TISOT-23-5

45 1 REF5025 U16 IC PREC V-REF 2.5 V LN REF5025AID TI8-SOIC



Front-End Board BOM www.ti.com

Table 3. Bill of Material (continued)


46 1 TLV3401 U17 IC OUT COMPARATOR TLV3401IDBVR TINANOPWR SOT23-5

47 2 TLV3404 U18,U20 COMPARATOR LW POWER R-R TLV3404IDR TI14-SOIC

48 1 PCA9535 U19 IC REMOTE 16-BIT I/O EXP PCA9535PWR TI24-TSSOP

49 3 TLV2221 U21,U22,U24 IC RAIL-TO-RAIL OP AMP TLV2221CDBVR TISOT-23-5

50 1 TPS73025 U25 IC LDO REG HI-PSRR 2.5 V TPS73025DBV TISOT23-5

51 1 TPS60403 U26 IC UNREG CHRG PUMP V INV TPS60403DBVT TISOT23-5

52 1 TPS72325 U27 IC LDO REG 200MA 2.5 V TPS72325DBVT TISOT23-5

53 1 32.768KHz Y1 CRYSTAL 32.7680 KHz 12.5 pF C-001R EpsonCYL 32.7680K- Toyocom

A:PBFREE Corporation



www.ti.com

Appendix C Sensors and Accessories

C.1 ECG Cable Details

Figure 27. ECG Cable Details

Cable details: 10 lead ECG cable for philips/hp -snap, button (Part No: 010302013)http://www.biometriccables.com/index.php?productID=692

Cable details: 10 lead ECG cable for philips/hp -Clip-on type (P/n-010303013A)http://www.biometriccables.com/index.php?productID=693

Other compatible cables for MDK: HP/Philips/Agilent Compatible 10 Lead ECG cable

C.2 ECG Sensor

Sensor details: Disposable Electrodes - Medico Lead - Lok

Vendor name: Medico Electrodes International Link : http://www.medicoleadlok.com/

Other compatible parts: Any Ag/AgCl solid gel ECG electrode on the market.



http://www.biometriccables.com/index.php?productID=692

http://www.biometriccables.com/index.php?productID=693

http://www.medicoleadlok.com/

www.ti.com

Appendix D MEDICAL DEVELOPMENT KIT (MDK) WARNINGS, RESTRICTIONS ANDDISCLAIMER

Not for Diagnostic Use: For Feasibility Evaluation Only in Laboratory/Development Environments.

The MDK may not be used for diagnostic purposes.

This MDK is intended solely for evaluation and development purposes. It is not intended for diagnostic useand may not be used as all or part of an end equipment product.

This MDK should be used solely by qualified engineers and technicians who are familiar with the risksassociated with handling electrical and mechanical components, systems and subsystems.

Your Obligations and Responsibilities.

Please consult the TMS320VC5505 DSP Medical Development Kit (MDK) Quick Start Guide (SPRUGO1)prior to using the MDK. Any use of the MDK outside of the specified operating range may cause danger tothe users and/or produce unintended results, inaccurate operation, and permanent damage to the MDKand associated electronics. You acknowledge and agree that:

• You are responsible for compliance with all applicable Federal, State and local regulatory requirements(including but not limited to Food and Drug Administration regulations, UL, CSA, VDE, CE, RoHS andWEEE,) that relate to your use (and that of your employees, contractors or designees) of the MDK forevaluation, testing and other purposes.

• You are responsible for the safety of you and your employees and contractors when using or handlingthe MDK. Further, you are responsible for ensuring that any contacts or interfaces between the MDKand any human body are designed to be safe and to avoid the risk of electrical shock.

• You will defend, indemnify and hold TI, its licensors and their representatives harmless from andagainst any and all claims, damages, losses, expenses, costs and liabilities (collectively, "Claims")arising out of or in connection with any use of the MDK that is not in accordance with the terms of thisagreement. This obligation shall apply whether Claims arise under the law of tort or contract or anyother legal theory, and even if the MDK fails to perform as described or expected.

WARNINGIf defibrillator is used for development purposes, use of medicalgrade EVM input power supply (Accessory Part Number: SL PowerAULT Model MW173KB0503F01) is strongly recommended. Use ofthe Isolator (Accessory Part Number: MOXA Model Name: TCC-82)that isolates the MDK from the PC is also strongly recommended.These accessories provide additional supplemental protection todevelopment users from high voltages that may be present whenintroducing defibrillator voltages during development simulation.There may also be other voltage transients sourced from thedefibrillator to accompanying interface hardware such as apersonal computer when used in conjunction with the ECG/EVMdevelopment hardware.

WARNINGTo minimize risk of electric shock hazard, use only the followingpower supplies for the EVM module: Medical DevelopmentApplications: SL Power AULT Model MW173KB0503F01.



http://www.ti.com/lit/pdf/SPRUGO1

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