Biomed my presentation

                     Biomedical Engineering

                          Electro Cardiogram




1   ECE Discipline                             1/5/2018
    ECG Signal Generation and Heart Bit
    Calculation:



                       Submitted To:
                 Engr. Dr. Md. Maniruzzan    Submitted By:
                         Professor           Kangkan Bhakta
                      ECE Discipline          ID: 13 09 10
                    Khulna University        4th Year, Tarm:II
                                             ECE Discipline
                                            Khulna University.




2   ECE Discipline                                               1/5/2018
    Outlines:
     What is ECG signal?
     Why we need ECG signal?
     Heart rate calculations.
     How it works?
     MATLAB code of ECG signal.




3   ECE Discipline                 1/5/2018
    What is ECG signal?
     Electrocardiography (ECG or EKG) is the process of
       recording the electrical activity of the heart over a period of
       time using electrodes placed on the skin. These electrodes
       detect the tiny electrical changes on the skin that arise from
       the heart muscle's electro physiologic pattern
       of depolarizing and repolarizing during each heartbeat. It is a
       very commonly performed cardiology test.




4   ECE Discipline                                              1/5/2018
    Why we need ECG signal?
     Suspected myocardial infarction (heart attack) or new chest
        pain
       Suspected pulmonary embolism or new shortness of breath
       A third heart sound, fourth heart sound, a cardiac murmur or
        other findings to suggest structural heart disease
       Perceived cardiac dysrhythmias either by pulse or palpitations
       Monitoring of known cardiac dysrhythmias
       Fainting or collapse.
       Seizures
       Monitoring the effects of a heart medication (e.g. drug-
        induced QT prolongation).
5   ECE Discipline                                              1/5/2018
    Heart Bit Calculations:
     To determine heart bit we will use Karvonen method:
     Calculate your maximum heart rate (Hrmax):
        Multiply your age by 0.7 , then subtract the result from 207.
      Example: If your age is 39 then , 207 – 39*0.7 = 180 bpm
     Checking your resting heart rate ( RHR):
     Watch a clock with a second hand and count the number of heart
      beats in 30 seconds, starting with "zero" on the first heartbeat.[5]
      Multiply the count by 2 to get your resting heart rate in
      beats per minute.




6   ECE Discipline                                                  1/5/2018
    Heart Bit Calculation:
     For greater accuracy, find the average from three different
      mornings. For example, if you measure 62, 65, and
      63 bpm, the average is (62 + 65 + 63) / 3, or about 63 bpm
      RHR.
     Calculate your Heart Rate Reserve (HRR):
      To get your HRR, HRMax - RHR = HRR
                          180 – 63 = 117 bpm
     Calculate your Target Minimum Heart Rate (Target HRMin).
      Multiply your HRR by 0.5
      117*0.5 = 58.5 bpm.


7   ECE Discipline                                            1/5/2018
    How it works?
     Introduction to ECG measurement system
     The ECG system is shown on Figure 1. The ECG system
        comprises four stages, each stage is as following:
       (1) The first stage is a transducer—AgCl electrode, which convert
        ECG into electrical voltage. The voltage is in the range of 1 mV ~
        5 mV.
       (2) The second stage is an instrumentation amplifier (Analog
        Device, AD624), which has a very high CMRR (90dB) and high
        gain (1000), with power supply +9V and -9V.
       (3) We use an opto-coupler (NEC PS2506) to isolate the In-Amp
        and output.
       (4) After the opto-coupler is a bandpass filter of 0.04 Hz to 150
        Hz filter. It’s implemented by cascading a low-pass filter and a
        high pass filter.

8   ECE Discipline                                                  1/5/2018
    How it works?




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     How it works?
      ECG Signal
             The basic structure of the heart is shown on Figure 2.
         Measuring at different region of the heart will retrieve
         different bio potential.




10   ECE Discipline                                              1/5/2018
        The cardiac mechanism of ECG is shown on Figure 4. In
       the top figure, the electrocardiogram (ECG) initiates the
       cardiac cycle. The cardiac sounds are also shown. The
       bottom figure shows that ejection occurs when the pressure
       in the left ventricle exceeds that in the arteries.
      Once the electrodes convert the ECG into electrical voltage,
       these voltage can be fed into an instrumentation amplifier,
       and then be processed.




11   ECE Discipline                                          1/5/2018
      Figure 4 The ECG cardiac cycle.
      We measure the ECG by connecting two electrodes on the right
        and left chest respectively, as shown on Figure 5. The body should
        be connected to ground of the circuits, so that we connect the leg
        to the ground. If the body is not grounded, no signal would be
        obtained.

12   ECE Discipline                                                 1/5/2018
     How it works?




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     MATLAB Code Implementation:
      Now we will investigate the ECG signal through MATLAB
        code, Let’s see!




14   ECE Discipline                                      1/5/2018
     Video tutorials for ECG measurement




15   ECE Discipline                   1/5/2018
     ECG Animation




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