SEE ATTACHED DOCUMENTS MAKE SURE REVIEW IT BEFORE MESSAGING

iLAB OVERVIEW

Introduction

This exercise is assigned to help prepare each team member to contribute satisfactorily in guided team projects assigned later in the semester. Upon completion of these exercises, each student will submit an informal report. Attendance during these sessions will count as part of the student's grade for this lab.

Materials

· Computers

· Labview 2010 or higher

· Multisim

· Student electronic kits

INSTRUCTIONS

iLab 3a: Analog and Digital Filters

This experiment requires simulation and construction of a low-pass filter and a high-pass filter using operational amplifiers. The two filters will be connected in series and form a band-pass filter. The frequency response of the filters based on the values of the resistors and capacitors will be determined through calculation, simulation, and testing. A low-pass and high-pass filter will be constructed based on the provided schematics in the theory discussion below. Use the rules of ideal operational amplifier and RC circuits to estimate the frequency response (i.e., identify the cutoff frequencies of the filter). Draft a protocol to measure the frequency response of the filter using the signal generator.  Objectives

· Low-pass and high-pass filters simulation

· Low-pass and high-pass filters construction

· Testing data acquisition using LabVlEW

Theory  The low-pass and high-pass filters are designed based on the rules of the operational amplifier. When the feedback resistor is paralleled by a capacitor, the amplifier becomes a low-pass filter. When the input resistor to the negative terminal of the operational amplifier is in series with a capacitor, the amplifier becomes a high-pass filter (Refer to Figures 1 and 2, below). The cut-off frequency of the filter is defined as the frequency at which the gain of the filter is 3 dB less than the gain in pass-band. The students are required to derive the equations that determine the cutoff.    Figure 1: High-pass active filter—first order    Figure 2: Low-pass active filter—first order

iLab 3a: Group Work

Back to Top

Procedures

1. Model a band-pass filter using a low-pass and high-pass filter in series with a frequency response of 10–300 Hz.

2. Test the circuit with a 1 V input single and show the band-pass of the circuit with the Bode plotter.

3. Provide a print-out of your circuit. The printout can be made by framing the desired area on your circuit diagram by dragging the cursor, copying it (edit/copy), and pasting it into a Word document. Also provide screens with scope and Bode analyzer.

4. Now construct the filter with op-amps from you circuit kit.

5. Measure the SNR = Vo / Vn. Vn = noise signal coming in without the measurand signal present.

6. Measure the gain as you vary the excitation signals from ± 2.5 V– ± 15 V.

7. Measure the frequency response amplitude of the input and output signal.

Deliverables  Answer the following questions (each group member must submit his or her own answers). To answer questions, use this lab, lecture notes, your textbook, any LabVIEW/Matlab help files, or any other open source. Please reference any sources you use, and please provide print-outs/screenshots and answers for the following calculations/measurements outlined below.

· Print-out of your circuit (Procedure Step 3)

· Screenshot of your circuit with the scope and body analyzer on it (Procedure Step 3)

· SNR (Procedure Step 5)

· Measured gain in 0.5 V increments (Procedure Step 6). Create a table and plot your results.

· Measured frequency response amplitude of the input and output signal (Procedure Step 7)

iLab 3b: Bioamplifiers

Bioamplifiers are used to maximize physiological signal output. The electrical activity of cells in things like our hearts, brains, and muscles can actually be recorded, but there is a lot that happens between the actual cellular activity and the reading on a computer screen. These signals are very small, and sometimes environmental noise or noise inherent to the human body make visualizing the signal challenging. Often, these signals need to be magnified in order to be visualized. However, in magnifying the signals, sometimes noise is magnified as well. The goal of this next part of the lab is to do some research into bioamplifiers—what they are, what they do, why they are necessary, and so on. The lab deliverable for this section will be a small report of your findings, with specific objectives outlined below.  Objectives

· Gain a better understanding of why bioamplifiers are necessary.

· Understand how they are used.

· Learn the magnitude of amplification needed for various physiological signals.

· Make the connection between bioamplifiers and filters.

 

iLab 3b: Individually

Back to Top

Deliverables Answer the following questions (each group member must submit his or her own answers). To answer questions, use this lab, lecture notes, your textbook, and so on. Please reference any sources you use, and please answer the following in your own words. Answers should be well researched, thoughtful, and in complete sentences.

1. Define bioamplifier.

2. What are bioamplifiers used for?

3. Give four examples of different physiological signals in which bioamplifiers are used.

a. For each of these physiological signals, what is the approximate magnitude of the signal (millivolts, microvolts, etc.)?

b. What is the bioamplifier gain needed for each of the above-mentioned physiological signals?

4. Choose one of the physiological signals researched above.

4. List at least three challenges to acquiring a good signal.

4. How does a bioamplifier attempt to rectify these challenges?

1. Bioamplifiers are almost always used in conjunction with some sort of filter(s).

5. Why are filters necessary when acquiring a physiological signal?

5. Are the filters used before or after the signal is acquired?

Submit Your Deliverables

In addition to those below, the deliverables outlined in iLab 3a and iLab 3b should be compiled and handed in at the beginning of class via the Dropbox.

1. Cover page with the following

· Title of lab

· Group member names

· Date lab performed

2. Screenshots with annotations for both iLabs 3a

3. Each member's version of answers to the questions above from iLab 3b

[Company Address]

Telephone: [Company Phone]

Fax: [Company Fax]

Email: [Company E-mail]

Web: [Web address]