Beamformed ultrasonic imager with delta-sigma feedback control

US6208189A · kind A · utility

Assignees

• THE REGENTS OF THE UNIVERSITY OF MICHIGAN · US
• Q-Dot, Inc. · US

Inventors

• Steven Russell Freeman · Ann Arbor, US
• Matthew O'Donnell · Ann Arbor, US
• Thomas E. Linnenbrink · Monument, US
• Marc A. Morin · Woodland Park, US
• Marshall K. Quick · Colorado Springs, US
• Charles S. Desilets · Edmonds, US

Key dates

• Filing date: Jul 20, 1999
• Grant date: Mar 27, 2001
• Expiry date: Jul 20, 2019

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03M3/504
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and apparatus are provided for reducing distortion in a dynamically delayed digital sample stream of an imaging system. The method includes the steps of delta-sigma modulating an input analog signal of the imaging system at a frequency above the Nyquist frequency of the input analog signal to generate a digital sample stream and changing a length of the sample stream to delay a portion of the sample stream while maintaining synchronism between a delta-sigma modulator and a demodulator of the system.