BENG 87 Spring

BENG 87 Spring: Freshman Seminar in Bioengineering

“Introduction to Instrumentation”

Instructor

Dr. Jeff Omens (Offices: Room 2004 BSB and Room 232 PFBH) email: jomens@ucsd.edu

Overview

This course will explore biomedical instrument design in a hands-on laboratory setting. The goals of the course are to design, test, and document a biopotential amplifier/recording system, specifically for recording and analyzing the human electrocardiogram (ECG) with a working prototype hardware/software system. 


Spring 2018: Course Information

Office Hours for BE87: Mondays, 2:00 – 3:30 pm, Room 2004 BSB

Lectures/Labs

Classes/labs are from 2:00 – 2:50 pm on Thursday each week. The course will include 2 lectures (April 5 and April 12, Room PFBH 291) followed by 8 Lab sessions in PFBH 108 from April 19-June 7. You should be able to design, construct, test and document your device during these sessions. You will need some outside time to complete the written report, but you should be accumulating sections/figures as you go throughout the quarter, and the last class time is reserved for working on the final report with your partner.

Written Assignment

The ultimate goal of the course is to document the ECG amplifier design process in a written report, to be completed and turned in by Wednesday June 13, 2018, 6 pm. Specific sections of the written report will be described later, but the document will contain a background and engineering design goals section, the instrumentation design including electronic schematic, test results and analysis, and future considerations. This paper will be an accumulation of work done each week, compiled into a single Word document summarizing the project.

Design teams will be 2 members each, and each group of 2 will turn in a single written report. Your P/NP grade in BE87 will be based on this report, and attendance each week. It will be very difficult to create and test a hands-on design instrument without attending the labs! Please do your best to arrive on-time each day, since we have limited time during the 50-minute labs. There are no make-up sessions available.

Weekly Topics/Goals

Week 1 (April 5) Lecture, Room PFBH 291: Course Overview and the ECG: Overall process and project goals. Class requirements. ECGs and recordings. The human ECG.
– Reporting goals: Electrocardiogram instrumentation and design. The physiological basis of the ECG and need for recording instrumentation. Design project goals for this course, including block diagram of the system that will be used in this course.

Week 2 (April 12) Lecture , Room PFBH 291: System Design: Background for ECG recordings, design considerations, existing technology. Noise and patient safety considerations. Review of entire system in our lab for recording ECGs.
– Reporting goals: The engineering design process. Safety considerations in electrical instrumentation for shock hazard. Noise on bio-signals and possible design enhancements to reduce noise on a human ECG.

Week 3 (April 19) Notes Lab, Room PFBH 108: ECG amplifier design: Schematic, parts list. Review electronic circuit for ECG amplifier. Discuss discrete and functional blocks. Create a parts list; verify available components. Create a part list table.
– Reporting goals: Electronic schematic figure of the ECG amplifier. Overall function of the circuit, and overview of amplifier function. Parts list in tabular form, including pictures. List matches schematic.

Week 4 (April 26) Notes Lab, Room PFBH 108: ECG amplifier prototype: Breadboard ECG amp. Use provided parts and schematic to construct a breadboard circuit. Re-check wires and connections to match schematic.
– Reporting goals: Brief description of the bread boarding process. Review and revise amplifier and overall circuit functions from Week 3. Picture of your bread boarded circuit.

Week 5 (May 3) Notes Lab, Room PFBH 108: ECG amplifier interconnects and testing: Add electrode wires, output. Review function of an oscilloscope. Acquire signal on the o-scope.
– Reporting goals: Describe testing setup, including oscilloscope. Brief discussion of function of skin electrodes. Safety issues for human-device connections. Picture of an ECG signal from the oscilloscope screen. Description of specific clinical ECG “lead” being acquired by the system.

Week 6 (May 10) Notes Lab, Room PFBH 108: Data acquisition design: Use Labviewto create a recording/display virtual instrument (VI). LabVIEW is a graphical interface programming environment for creating virtual instruments. LabVIEW software interfaces with data acquisition hardware, including breakout connector box at the lab stations.
Labview VI Instructions
– Reporting goals: Virtual device design with computer software and graphic user interface (GUI). Components of the virtual instrument, including function of the A/D card and external connections. Screen shot of your Labview VI, and brief description of its components and functions.

Week 7 (May 17) Notes Lab, Room PFBH 108: Data acquisition tests: Test Virtual Instrument with signal generator: Run and record data (sine waves) from signal generator. Input sine waves, record and save output. Create and save data plots with Sigmaplot.
– Reporting goals: Describe test setup with known input (sine wave function). Plot results for sine-wave tests. Show sine wave data plot with axis scales for 2 different amplitudes and/or frequencies.

Week 8 (May 24) Notes Lab, Room PFBH 108: Acquire and record a human ECG: Use ECG amplifier and Labview VI to acquire and save human ECG data files. Attach skin electrodes and record several seconds of the electrocardiogram and save data from VI. Try one ECG from each partner. Plot ECG to verify valid results.
– Reporting goals: Description of overall acquisition system. Plots of human ECGs (with axis labels and scaling). Electrode locations. Qualitative description of signal quality and noise.

Week 9 (May 31) Notes Lab, Room PFBH 108: Data analysis: Perform noise/filter analysis on previously acquired ECGs. Running average of raw data, compare to unfiltered signal. Use MatLAB to perform frequency analysis of the data, plot. Quantify signal noise as noise ratio. Measure and report physiologic clinical values from your ECG.
Matlab Fourier Analysis Instructions
– Reporting goals: Summarize sources of noise on a human ECG recording. Quantify “signal to noise ratio” of your original signal. Describe simple averaging filter and show results and plots. Describe frequency analysis (with Matlab) and show results as a plot. Report simple ECG parameters with clinical significance.

Week 10 (June 7) Notes Lab, Room PFBH 108: Final report: Compile final report, including next steps in optimizing system design.
– Reporting goals: Assemble and combine all sections from above, including Figures, in a single Microsoft Word file. Each figure should have some form a legend/caption, describing the main message of the figure (see sample below). Add a final text section (paragraph) on limitations of the current design, future considerations for the next version of the instrument, and which features will be most important for possible clinical use. Comment on novel features that could make a competitive product.

– Sample page in a Word document with Figure and legend: Sample_Page
– Save final document as a single PDF file, and e-mail final report by 6 pm, June 13th, to Dr. Omens, jomens@ucsd.edu.