Analog.com Analog Dialogue Wiki English 简体中文 日本語
$EngineerZone
EngineerZone
  • Log In
  • Site
  • Search
  • User
  • Forums

    Popular Forums

    • RF and Microwave
    • Power Management
    • Video
    • FPGA Reference Designs
    • Precision ADCs
    • Linux Software Drivers
    • SigmaDSP Processors & SigmaStudio Dev. Tool

    Product Forums

    • A2B
    • Amplifiers
    • Analog Microcontrollers
    • Clock and Timing
    • Data Converters
    • Direct Digital Synthesis (DDS)
    • Energy Monitoring and Metering
    • Interface and Isolation
    • MEMS Inertial Sensors
    • Processors and DSP
    • Switches/Multiplexers
    • Temperature Sensors
    • Voltage References
    View All

    Application Forums

    • Audio
    • Automated Test Equipment (ATE)
    • Condition-Based Monitoring
    • Depth, Perception & Ranging Technologies
    • Embedded Vision Sensing Library
    • Motor Control Hardware Platforms
    • Optical Sensing
    • Precision Technology Signal Chains Library
    • Video
    • Wireless Sensor Networks Reference Library

    Design Center Forums

    • ACE Evaluation Software
    • ADEF System Platforms
    • Design Tools and Calculators
    • FPGA Reference Designs
    • Linux Software Drivers
    • Microcontroller no-OS Drivers
    • Reference Designs
    • Signal Chain Power (SCP)
    • Software Interface Tools
    • System Demonstration Platform (SDP) Support
  • Learn

    Highlighted Webinar

    Digital Isolator Working Voltage Considerations for End Application Optimization

    Recent Discussions

    • ADALM-2000 SET A STATIC IP
    • Error in compiling program using libad9361 and libiio
    • Inconsistent receiver power between 2 transmissions of the same signal
    • DMA (from PS to PL) unexpected behavior
    • ADALM-PLUTO firmware upgrade crash

    Places

    • ADI Education Home
    • ADI Webinars
    • StudentZone (Analog Dialogue)
    • Video Annex
    • Virtual Classroom

    Latest Webinars

    • Digital Isolator Working Voltage Considerations for End Application Optimization
    • In-vehicle Networking Simplified with 10BASE-T1S
    • Design of Multi-Band Phased Array Systems for Space Applications
    • Designing Optimized Power Solutions for Precision Signal Chains (2023)
    • One Size Fits All - Power Your Applications with an Integrated Power IC
    View All Webinars
  • Community Hub

    Challenge Yourself!

      KCC's Quizzes AQQ248 about a funny function
    View All

    Places

    • Community Help
    • Logic Lounge
    • The Weekly Brew

    Resources

    • EZ Code of Conduct
    • EZ How To Help Articles
    • Getting Started Guide
    • ADI: Words Matter
    • Community Help Videos
    View All
  • Blogs

    Highlighted Blogs

    Rediscovering Signal Chain µModule®︎

     

    Why AI Assisted/Enabled Buildings Need Intelligent Edge Devices

    Latest Blogs

    • Mastering Precision: A Guide to Setup Your Laboratory for IPn Measurement
    • A Visit to the EMC Lab: Radiated Vs. Conducted Emissions and Immunity
    • Finally, Batteries You Can Believe
    • Powering Your Drive - It's More Than Just Plugging It In
    • How Old Wires Are Bringing New Efficiencies to Building Retrofits
    Read All Blogs

    ADI Blogs

    • EZ Spotlight
    • The Engineering Mind
  • Partners

    Electronic Design Services - PartnerZone

    • Boston Engineering
    • Calian, Advanced Technologies
    • Colorado Engineering Inc. (DBA CAES AT&E)
    • Clockworks Signal Processing
    • Epiq Solutions
    • Fidus
    • PalmSens
    • Richardson RFPD
    • Tri-Star Design, Inc.
    • VadaTech
    • Vanteon
    • X-Microwave
    View All
Amplifiers
Amplifiers
Documents How does the right leg drive technique work?
  • Forums
  • Video/Images
  • Members
  • Tags
  • More
  • Cancel
  • +Documents
  • Tags List Amplifiers
  • +General Information: FAQ
  • +AD59: FAQ
  • +AD202: FAQ
  • +AD203: FAQ
  • +AD210: FAQ
  • +AD215:FAQ
  • +AD22100: FAQ
  • +AD22151: FAQ
  • +AD22151G: FAQ
  • +AD594: FAQ
  • +AD600: FAQ
  • +AD603: FAQ
  • +AD604: FAQ
  • +AD605: FAQ
  • +AD608: FAQ
  • +AD620: FAQ
  • +AD621: FAQ
  • +AD623: FAQ
  • +AD623BRZ: FAQ
  • +AD626: FAQ
  • +AD628: FAQ
  • +AD629: FAQ
  • +AD630: FAQ
  • +AD632: FAQ
  • +AD633: FAQ
  • +AD636: FAQ
  • +AD637: FAQ
  • +AD664: FAQ
  • +AD734: FAQ
  • +AD7357BCPZ: FAQ
  • +AD736: FAQ
  • +AD811: FAQ
  • +AD817: FAQ
  • +AD822: FAQ
  • +AD823: FAQ
  • +AD825: FAQ
  • +AD829: FAQ
  • +AD846: FAQ
  • +AD855: FAQ
  • +AD8002: FAQ
  • +AD8005: FAQ
  • +AD80066: FAQ
  • +AD8009: FAQ
  • +AD8012: FAQ
  • +AD8015: FAQ
  • +AD8016: FAQ
  • +AD8019: FAQ
  • +AD8033: FAQ
  • +AD8036: FAQ
  • +AD8039: FAQ
  • +AD8041: FAQ
  • +AD8041S: FAQ
  • +AD8042: FAQ
  • +AD8045: FAQ
  • +AD8061: FAQ
  • +AD8066: FAQ
  • +AD8074: FAQ
  • +AD8075: FAQ
  • +AD8079: FAQ
  • +AD8105: FAQ
  • +AD8108: FAQ
  • +AD8111: FAQ
  • +AD8112: FAQ
  • +AD8113: FAQ
  • +AD8114: FAQ
  • +AD8128: FAQ
  • +AD8129: FAQ
  • +AD8130: FAQ
  • +AD8131: FAQ
  • +AD8132: FAQ
  • +AD8134: FAQ
  • +AD8137: FAQ
  • +AD8138: FAQ
  • +AD8138S: FAQ
  • +AD8139: FAQ
  • +AD8145: FAQ
  • +AD8174: FAQ
  • +AD8185: FAQ
  • +AD8191: FAQ
  • +AD8195: FAQ
  • +AD8207: FAQ
  • +AD8208: FAQ
  • +AD8210: FAQ
  • +AD8211: FAQ
  • +AD8214: FAQ
  • +AD8217: FAQ
  • +AD8218: FAQ
  • +AD8220: FAQ
  • +AD8221: FAQ
  • +AD8225: FAQ
  • +AD8227: FAQ
  • +AD8230: FAQ
  • +AD8231: FAQ
  • +AD8232: FAQ
  • +AD8237: FAQ
  • +AD8253: FAQ
  • +AD8265: FAQ
  • +AD8283: FAQ
  • +AD8295: FAQ
  • +AD8302: FAQ
  • +AD8304: FAQ
  • +AD8305: FAQ
  • +AD8306: FAQ
  • +AD8307: FAQ
  • +AD8309: FAQ
  • +AD8310: FAQ
  • +AD8314: FAQ
  • +AD8318: FAQ
  • +AD8319: FAQ
  • +AD8321: FAQ
  • +AD8324: FAQ
  • +AD8328: FAQ
  • +AD8330: FAQ
  • +AD8331: FAQ
  • +AD8332: FAQ
  • +AD8333: FAQ
  • +AD8334: FAQ
  • +AD8336: FAQ
  • +AD8337: FAQ
  • +AD8338: FAQ
  • +AD8339: FAQ
  • +AD8397: FAQ
  • +AD8421: FAQ
  • +AD8422: FAQ
  • +AD8428: FAQ
  • +AD8476: FAQ
  • +AD8495: FAQ
  • +AD8500: FAQ
  • +AD8515: FAQ
  • +AD8519: FAQ
  • +AD8532: FAQ
  • +AD8538: FAQ
  • +AD8541: FAQ
  • +AD8551: FAQ
  • +AD8552: FAQ
  • +AD8555: FAQ
  • +AD8556: FAQ
  • +AD8557: FAQ
  • +AD8561: FAQ
  • +AD8564: FAQ
  • +AD8567: FAQ
  • +AD8592: FAQ
  • +AD8597: FAQ
  • +AD8602: FAQ
  • +AD8605: FAQ
  • +AD8606: FAQ
  • +AD8608: FAQ
  • +AD8610: FAQ
  • +AD8611: FAQ
  • +AD8622: FAQ
  • +AD8624ARUZ: FAQ
  • +AD8628: FAQ
  • +AD8629: FAQ
  • +AD8638: FAQ
  • +AD8643ACPZ: FAQ
  • +AD8646: FAQ
  • +AD8648: FAQ
  • +AD8655: FAQ
  • +AD8661: FAQ
  • +AD8662: FAQ
  • +AD8666: FAQ
  • +AD8674: FAQ
  • +AD8675: FAQ
  • +AD8677: FAQ
  • +AD8682: FAQ
  • +AD9101: FAQ
  • +AD9257: FAQ
  • +ADA4000-2: FAQ
  • +ADA4004: FAQ
  • +ADA4077-2: FAQ
  • +ADA4096: FAQ
  • +ADA4096-2: FAQ
  • +ADA4302-4: FAQ
  • +ADA4350: FAQ
  • +ADA4411: FAQ
  • +ADA4500-2: FAQ
  • +ADA4528: FAQ
  • +ADA4528-X: FAQ
  • +ADA4637-1: FAQ
  • +ADA4661-2: FAQ
  • +ADA4666-2: FAQ
  • +ADA4807: FAQ
  • +ADA4807-2: FAQ
  • +ADA4817: FAQ
  • +ADA4895: FAQ
  • +ADA4897: FAQ
  • +ADA4897-1: FAQ
  • +ADA4898-2: FAQ
  • +ADA4899-1: FAQ
  • +ADA4922-1: FAQ
  • +ADA4927: FAQ
  • +ADA4930: FAQ
  • +ADA4938-1: FAQ
  • +ADA4940-1:FAQ
  • +ADA4941-1: FAQ
  • +ADA4950-1: FAQ
  • +ADA4960-1: FAQ
  • +ADCMP341: FAQ
  • +ADCMP343: FAQ
  • +ADCMP552: FAQ
  • +ADCMP553BRM: FAQ
  • +ADCMP566: FAQ
  • +ADCMP572: FAQ
  • +ADCMP573: FAQ
  • +ADCMP580: FAQ
  • +ADCMP600: FAQ
  • +ADCMP602: FAQ
  • +ADCMP609: FAQ
  • +EVAL-FW-BPDF1: FAQ
  • +EVAL-PRAOPAMP: FAQ
  • +MAT01: FAQ
  • +MAT02: FAQ
  • +Mat12: FAQ
  • +MAT14: FAQ
  • +OP07: FAQ
  • +OP1177: FAQ
  • +OP16: FAQ
  • +OP184: FAQ
  • +OP2177: FAQ
  • +OP279: FAQ
  • +OP27AZ: FAQ
  • +OP281: FAQ
  • +OP284: FAQ
  • +OP285: FAQ
  • +OP290: FAQ
  • +OP293: FAQ
  • +OP295GS: FAQ
  • +OP297GSZ: FAQ
  • +OP37: FAQ
  • +OP400S: FAQ
  • +OP4177: FAQ
  • +OP484AM: FAQ
  • +OP484S: FAQ
  • +OP497: FAQ
  • +OP90: FAQ
  • +OP97: FAQ
  • +Opamps: FAQ
  • +OPx177: FAQ
  • +REF01: FAQ
  • +REF02: FAQ
  • +REF02A: FAQ
  • +REF193: FAQ
  • +REF195: FAQ
  • +REF198: FAQ
  • +REF43NBC: FAQ
  • -Right Leg Drive (RLD): FAQ
    • How does the right leg drive technique work?
    • Use of  right leg drive amplifier
  • +SFP-RDK: FAQ
  • +SPICE: FAQ
  • +UG-084: FAQ
  • +VGAs: FAQ
  • +Precision Technology Learning Modules

How does the right leg drive technique work?

Q 

How does the right leg drive technique work?

 

A 

One of the challenges associated with making biopotential measurements is
rejecting the common-mode voltages to which the human body, electrodes, and
cables are exposed. That is the reason why having an instrumentation amplifier
with high CMRR is important.

Capacitive coupling of the 50/60Hz mains voltage is the main source of common
mode interference. You can picture this situation as a patient (so far
electrically floating) connected to a 220Vrms at 50/60Hz voltage source via a
low value capacitor.

This interference intensifies when the user/patient is close to electrical
equipment (a hospital bed with lots of bedside monitors, a surgery room…),
close to a motor (in a treadmill, for instance) or the system uses long cables
(susceptible to higher coupling).

One way of reducing this interference is by actively driving the body back with
a known voltage so that the body is not electrically floating any more. In its
basic implementation a dc voltage could be driven but the results are improved
if the body is driven back dynamically depending on the interfering common
voltage. This is done by constantly monitoring the changing common voltage the
two electrodes are riding on top of. This voltage is mirrored around the
reference voltage (usually half the supply) and driven back to the body.

In summary, as the body is capacitively pulled away from the reference voltage,
the RLD amplifier pulls it back in. It is traditionally named Right Leg Drive
because the driving is done in the part of the body which is furthest from the
heart (the right leg).

  • ad8232
  • Share
  • History
  • More
  • Cancel
Related
Recommended
Social
Quick Links
  • About ADI
  • ADI Signals+
  • Analog Dialogue
  • Careers
  • Contact us
  • Investor Relations
  • News Room
  • Quality & Reliability
  • Sales & Distribution
  • Incubators
Languages
  • English
  • 简体中文
  • 日本語
myAnalog

Interested in the latest news and articles about ADI products, design tools, training and events?

Go to myAnalog
Analog Logo
©1995 - 2023 Analog Devices, Inc. All Rights Reserved
沪ICP备09046653号-1
  • Sitemap
  • Legal
  • Privacy & Security
  • Privacy Settings
  • Cookie Settings