1. Biopotential Electrodes II

2. Motion Artifact When the electrode moves with respect to the electrolyte, Motion artifact is minimal for non-polarizable electrodes

3. Equivalent Circuit 1: Electrode-Electrolyte interface

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5. ?

6. equivalent circuit

7. Equivalent Circuit electrode-electrolyte

8. Equivalent Circuit: Skin-Electrolyte-Electrode Interface Skin anatomy Stratum Stratum Stratum corneum granulosum germinativum

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12. Sweat glands and ducts effect

13. Expanded Equivalent Circuit

14. Simplified Equivalent Circuit

15. Frequency Response

16. Electrode Skin Interface Sweat glands and ducts Electrode Epidermis Dermis and subcutaneous layer RuRu E he RsRs RdRd CdCd Gel Stratum Corneum Skin impedance for 1cm 2 patch: 200kΩ @1Hz 200 Ω @ 1MHz Alter skin transport (or deliver drugs) by: Pores produced by laser, ultrasound or by iontophoresis