KP351 Lecture Notes - Lecture 3: Adipose Tissue, Oscilloscope
20 Mar 2020
School
Department
Course
Professor
Document Summary
Recorded by an oscilloscope or a/d board in computer. Blood ow (1), muscle depth, muscle length, adipose tissue: noise sources. Reference/ground electrode (2) (alot of noise when it should be quite) Use the most dominant middle portion of the muscle body. Ensure electrode site remains on active muscle during shortening. Parallel to muscle bers (can reduce signal by 50%) Keep inter-electrode distance as small as possible (6cm; 2cm is best) Knowledge of frequency characteristics of emg signal is important when choosing a sampling rate. Nyquist minimum limit = 2 x highest frequency. Emg signal 10 - 350 hz (semg) Nyquist min limit = 2 x 350 = 700 hz. Record signal before and after activity for at a least 1 second. Signi cant loss of signal if sampling frequency is too low. What"s the drawback of too high of a sampling frequency. If sampling frequency is too high there is too much data.
