The Cardionics E-Scope electronic stethoscope amplifies heart, breath, bruit, bowel or Korotkoff sounds up to 30 times louder than normal acoustic stethoscopes.  For improved listening, it has controls for volume up-down and heart-breath sounds frequency selection.  The E-Scope automatically shuts off after 90 seconds and restarts with the touch of a button to the same volume setting.  It has a sounds output that allows for connection to a PC or other device for recording.  Under normal use, it operates approximately 4 months on a AAA battery.  Cardionics offers a selection of bells, diaphragms and ear tips.  The E-Scope comes in clinical, hard-of-hearing and EMS models.

Cooper Consulting Service (CCS) designed several generations and all of the offered models of the Cardionics E-Scope. CCS performed the following engineering design functions for the E-Scope.


  • Developed complete FDA design controls documentation package which passed through FDA inspections
  • Wrote operator’s manual
  • Developed device master record (schematics, drawings, component specifications, BOMs, labels, etc.)

Analog Design

  • Designed microphone interface
  • Designed speaker drive amplifier for low power drain and high audio power
  • Designed switching regulator for low power operation
  • Designed power timer and battery monitor with audible and visual indicators
  • Designed volume adjust and filter frequency selection circuitry
  • Designed EMC protection to meet standards

Enclosure Design

  • Worked with plastics designer to develop body and chest piece housing designs
  • Worked with plastics molding vendor to develop and qualify molds for housings.
  • Designed membrane switch on chest piece
  • Designed labels for body housing
  • Developed packaging for shipping and storage


  • Developed test fixture for acoustic input to chest piece
  • Developed test fixture for measuring acoustic output from speaker
  • Performed verification testing
  • Worked with test laboratory to get product to pass medical electrical safety and EMC standards
  • Performed environmental and drop shock tests
  • Performed packaging drop shock test

Design Transfer and Production

  • Wrote assembly procedure for system
  • Developed production test procedure
  • Released DMR and provided support for vendor qualification