Intracardiac ultrasound scanner using a micromachine (MEMS) actuator.

Journal Article (Journal Article)

Catheter-based intracardiac ultrasound offers the potential for improved guidance of interventional cardiac procedures. The objective of this research is the development of catheter-based mechanical sector scanners incorporating high frequency ultrasound transducers operating at frequencies up to 20 MHz. The authors' current transducer assembly consists of a single 1.75 mm by 1.75 mm, 20 MHz, PZT element mounted on a 2 mm by 2 mm square, 75 mum thick polyimide table that pivots on 3-mum thick gold plated polyimide hinges. The hinges also serve as the electrical connections to the transducer. This table-mounted transducer is tilted using a miniature linear actuator to produce a sector scan. This linear actuator is an integrated force array (IFA), which is an example of a micromachine, i.e., a microelectromechanical system (MEMS). The IFA is a thin (2.2 mum) polyimide membrane, which consists of a network of hundreds of thousands of micron scale deformable capacitors made from pairs of metallized polyimide plates. IFAs contract with an applied voltage of 30-120 V and have been shown to produce strains as large as 20% and forces of up to 8 dynes. The prototype transducer and actuator assembly was fabricated and interfaced with a GagePCI analog to digital conversion board digitizing 12 bit samples at a rate of 100 MSamples/second housed in a personal computer to create a single channel ultrasound scanner. The deflection of the table transducer in a low viscosity insulating fluid (HFE 7100, 3M) is up to +/-10 degrees at scan rates of 10-60 Hz. Software has been developed to produce real-time sector scans on the PC monitor.

Full Text

Duke Authors

Cited Authors

  • Zara, JM; Bobbio, SM; Goodwin-Johansson, S; Smith, SW

Published Date

  • January 2000

Published In

Volume / Issue

  • 47 / 4

Start / End Page

  • 984 - 993

PubMed ID

  • 18238633

Electronic International Standard Serial Number (EISSN)

  • 1525-8955

International Standard Serial Number (ISSN)

  • 0885-3010

Digital Object Identifier (DOI)

  • 10.1109/58.852082


  • eng