Accelerometer-based rate-adaptive cardiac pacing with second generation signal processing

US5649968A · kind A · utility

Assignee

• Intermedics Inc. · US

Inventors

• Eckhard Alt · Ottobrunn, DE
• Lawrence J. Stotts · Lake Jackson, US
• Matthias Schmidt · Munich, DE

Key dates

• Filing date: Nov 14, 1995
• Grant date: Jul 22, 1997
• Expiry date: Nov 14, 2015

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61N1/36542
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A variable rate cardiac pacemaker is adapted to be implanted in a human patient for automatically adapting pacing rate to metabolic need of the patient when the patient is walking in an ascending path, a descending path, or on a level plane. An accelerometer senses the activity of the patient walking, and produces an electrical sensor signal representative of the activity. The accelerometer signal has variable parameters indicative of morphology, including amplitude, of the sensor signal according to status of activity of the patient and to the upward, downward, or horizontal direction of the patient's walking. A pulse generator generates pacing pulses at a variable rate according to an applied control signal to electrically stimulate the patient's heart at a pacing rate which varies according to patient activity. A processing and control circuit of the pacemaker processes the sensor signal for detecting differences in the signal morphology attributable to whether the patient is walking on an ascending path, a descending path, or a level path, irrespective of the presence or absence of disparity in the amplitude of the sensor signal resulting from walking along the respective path.…