Acoustic Doppler velocity measurement system using capacitive micromachined ultrasound transducer array technology.

This paper describes the design, fabrication, modeling, and characterization of a small (1 cm(2) transducer chip) acoustic Doppler velocity measurement system using microelectromechanical systems capacitive micromachined ultrasound transducer (cMUT) array technology. The cMUT sensor has a 185 kHz resonant frequency to achieve a 13° beam width for a 1 cm aperture. A model for the cMUT and the acoustic system which includes electrical, mechanical, and acoustic components is provided. Furthermore, this paper shows characterization of the cMUT sensor with a variety of testing procedures including Laser Doppler Vibrometry (LDV), beampattern measurement, reflection testing, and velocity testing. LDV measurements demonstrate that the membrane displacement at the center point is 0.4 nm/V(2) at 185 kHz. The maximum range of the sensor is 60 cm (30 cm out and 30 cm back). A velocity sled was constructed and used to demonstrate measureable Doppler shifts at velocities from 0.2 to 1.0 m/s. The Doppler shifts agree well with the expected frequency shifts over this range.

Challenges associated with privacy in health care industry: implementation of HIPAA and the security rules.

This paper discusses the challenges associated with privacy in health care in the electronic information age based on the Health Insurance Portability and Accountability Act (HIPAA) and the Security Rules. We examine the storing and transmission of sensitive patient data in the modem health care system and discuss current security practices that health care providers institute to comply with HIPAA Security Rule regulations. Based on our research results, we address current outstanding issues that act as impediments to the successful implementation of security measures and conclude the discussion and offer possible avenues of future research.