write introduction about lab Estimating Muscle Force from the Surface EMG

BME 370 - Project #1: Surface EMG and muscle force 2/3/2017

BME-370–Microcomputer Applications in Bioengineering Fall 2014

Estimating Muscle Force from the Surface EMG

OBJECTIVE The objective of this project is to investigate the relationship between the force generated by a muscle

and the muscle’s surface electromyogram (or EMG). The technical tasks are to:

1. Develop LabView VI’s for data acquisition and analysis 2. Develop a signal conditioning circuit for EMG pre-processing 3. Develop a reasonable measure that relates the EMG with muscle force.

The scientific tasks are to design and complete experiments to address the following questions:

1. How does the EMG vary with muscle force? 2. Does EMG vary with fatigue? 3. Is the EMG a consistent and reliable estimate of muscle force? 4. Is “trained” muscle more efficient than an untrained muscle?

MATERIALS • Surface EMG electrodes • Dumbbells • LabView and the DAQ board • Electronic components • Electronic test equipment

PROCEDURES Each team is to develop a full-fledged, computer-based, biomedical instrumentation system to record

and analyze the EMG following the broad guidelines given above. The system will be used to investigate the scientific questions listed above involving the estimation of muscle force from EMG. Each group will design experiments and collect the appropriate data (using class members as subjects) to reach some type of data-based conclusion for each question.

The responsibilities of each team member are described below. While you are responsible for completing your individual tasks, you are also responsible for collaborating with other team members on their tasks. Remember the lab report is a combined grade for all members of the group.

Hardware Engineers • Design and verify circuit designs before prototyping • Design and prototype a “Instrumentation amplifier” (see modules 9 and 10) as your head or 1st

stage for your signal conditioning circuit. • Design and prototype a single-ended amplifier with appropriate gains. • Design and prototype a separate active low-pass filter with unity gain and an appropriate cutoff

frequency (determined by the systems engineer). • Design and prototype a separate active high-pass filter with appropriate gain and cut-off

frequency (determined by the systems engineer).

BME 370 - Project #1: Surface EMG and muscle force 2/3/2017

BME-370–Microcomputer Applications in Bioengineering Spring 2017

• Test the final circuits and document with schematics and test results (use known input signals and present the results obtained).

• Work with systems analyst on running and analyzing the experiments.

Software Engineers • Design a LabView VI to sample the EMG data as required. You will be acquiring “raw” EMG

signals (as delivered by the circuit above when connected to patch electrodes). Determine and implement a sampling frequency (to be determined from the literature by your research on EMG signals) that will not alias the raw EMG signal for durations of 5 to 15 seconds.

• Decide on file structures for any input and output data files • Develop a set of test data for verifying the algorithms and the programs • Design and implement the data analysis functions required for calculating either the rectified

(absolute value) moving average or the root-mean-square muscle activation. • Test your program thoroughly • Document your programs • Work with systems analyst on running and analyzing the experiments.

Systems Analysts • Develop and update the system block diagram • Work with the team to describe the signals and the transformations at each stage of the system. • Design the experimental protocol required to answer the given scientific questions (how many

subjects, how many repetitions of each experiments, what are the appropriate metrics for capturing the changes observed in the EMG signal, what statistics will be used to analyze the data and derived metrics, how will you make a scientifically valid conclusions based on the statistics, etc)

• Document the experiments and the data collection in your group log book. • Design system-level, end-to-end tests of the entire system • Take the lead role in data analysis. • Take the lead role in compiling the project report (see syllabus for guidance before you begin!)

Pre-lab for week #1 of this project (to be completed before your lab on Feb. 8 or 10, 2017):

1. Draw a block diagram of the system you will be building and label the individual blocks (parts) you will need to get it all working together. You should be able to come up with at least 2 or 3 hardware blocks and 2 or 3 software blocks.

2. What will be the gain and cut-off specifications for the amplifier, and filters that you will make? 3. What are some commonly used EMG signal processing techniques? Name at least two. 4. Include a time-line for completion of the project and performing your demo by the week of Mar.

3, 2017. This document should: (i) provide group and individual goals for each lab session, and (ii) outline of activities of each group member for each lab session.

SCHEDULE FOR COMPLETION You have to do a demonstration on the week of Mar. 3, 2017. Your project report is due one week after the demonstration, on March 1 or 3, 2017. There will be a 20% penalty for late lab reports.

BME 370 - Project #1: Surface EMG and muscle force 2/3/2017

BME-370–Microcomputer Applications in Bioengineering Spring 2017

Reference: Commonly used EMG analysis equations

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BME 370 - Project #1: Surface EMG and muscle force 2/3/2017

BME-370–Microcomputer Applications in Bioengineering Spring 2017

APPENDIX A

EMG Basics

BME 370 - Project #1: Surface EMG and muscle force 2/3/2017

BME-370–Microcomputer Applications in Bioengineering Spring 2017

APPENDIX B

EMG Instrumentation Article