1. By Sundar Singh P ½ M.Tech (BME) Bioelectric Potentials

2. Sources of Bioelectric Potentials Electrochemical activities of certain cells produce ionic voltages known as Bioelectric potentials. Bioelectric potentials are associated with the following activities. Brain activity. Heart beat. Muscle functions. By using transducers generated ionic potentials are converted into electric potentials.

3. Types of Potentials:- Cell s are suspended in body fluids. Chlorine (Cl-) Sodium (Na+) Potassium(K+) Cell membrane Cell

4. Types of Potentials:- Resting potentials. Chlorine (Cl-) Sodium (Na+) Potassium(K+) Cell membrane Cell

5. Types of Potentials:- Resting potentials. V -70mv

6. Action Potentials If any stimuli is applied then the cell membrane changes its properties Sodium(Na+) enters the cells and constitute ionic current. The resulting potentials is known as Action potentials. It is +20mv. Types of Potentials:- Chlorine (Cl-) Sodium (Na+) Potassium(K+) Cell membrane Cell

7. Types of Potentials:- Action potentials. V + 20mv

8. Waveform of Action potentials

9. Concentration of IONS Inside Of cell Outside Of cell Sodium (Na+)60110 Potassium(K+)12020 Chlorine(Cl-)45100

10. Propagation of Action Potentials When stimuli exited a cell action potential is generated. This process can in turn excites neighboring cell.

11. Propagation rate It depends on diameter and type of nerve. In Nerve fibers it is 20 to 140 mts per sec. In Heart muscle it is0.2 to 0.4 mts per sec. Propagation of Action Potentials

12. Types of Bioelectric potentials:- ElectroCardioGram (ECG): Measures the Bioelectric potentials produced in Heart. Bioelectric potentials of heart is due to SA node( Natural Pacemaker).

13. ElectroEncephaloGram (EEG):- Measures the Neural activity of Brain These waveforms are complex than that ECG. These are measured at the scalp. EEG patterns vary wrt to mental condition of person being tested. Types of Bioelectric potentials:-

14. EEG patterns of different stages of sleep o Drowsiness o Alpha (8-13 Hz) o Light Sleep o Theta (3.5-8 Hz) o Deep Sleep o Delta (below 3.5 Hz) o REM Sleep o Beta (above 13 Hz)

15. ElectroMyoGram(EMG):- Measures the bioelectric potentials at certain muscles. Types of Bioelectric potentials:- Time-  Voltage 

16. Electroretinogram (ERG):- It gives the pattern of bio potentials near the eye retina. Electro-Oculogram( EOG):- It gives the variations of corneal-retinal potentials, which are affected by change in position and movement of eye. ElectroGustroGram(EGG):- Measure bio potentials in peristaltic movements of intestines Other Types of Bioelectric potentials:-