Novel Applications of Laser Doppler Vibration Measurements to Medical Imaging

Abstract

Laser Doppler Vibrometry (LDV) has been widely used in engineering applications involving non-contact vibration and sound measurements. This technique has also been used in some biomedical applications including hearing research. The detectable frequencies are in the range of near-DC to 1 GHz or higher. This paper reviews applications of LDV in biomedical engineering and proposes new medical imaging applications based on measuring surface vibrations of tissues and organs. Tests were conducted on human skin using single point and scanning laser vibrometers. These tests suggest that skin vibrations due to the forcing excitation from the heart can be used in imaging of blood flow. The results of these tests illustrate the potential of such vibration measurements in a variety of diagnostic medical imaging applications including blood flow/restrictions, real-time monitoring of blood pressure variations, wound healing, muscle movements, etc. The fact that the measurements can be conducted remotely (non-contact) is an important benefit that adds to the promise of this approach.Electronic supplementary materialThe online version of this article (doi:10.1007/s11220-013-0077-1) contains supplementary material, which is available to authorized users.

Multichannel fiber laser Doppler vibrometer studies of low momentum and hypervelocity impacts

“…The detection of biosignals such as ocular pulse, breathing and heartbeat, among others, are potential applications for MFLDV measuring slow vibrations and impacts. As an example, laser Doppler vibrometry demonstrated that skin vibrations due to the forcing excitation from the heart can be used in imaging blood flow [13]. Moreover, the flexibility of MFLDV to measure vibrations and impacts at inaccessible locations on a target has yet to be explored.…”

Methods and algorithms for video-based multi-point frequency measuring and mapping

“…Although their really good performance, in some occasions the complexity or accessibility of the specimen to be measured increases the installation cost and may be even hazardous for the test crew safety. Because of this, non-contact methods such as laser vibrometers are becoming more popular and are being applied to new fields [1]. Nevertheless, their high cost is still a big drawback that restricts their use to only some particular cases.…”

Heart:valve Sounds Obtained with a Laser Doppler Vibrometer

“…Microphones and accelerometers have been the obvious choices since the beginning of the 20 th century, showing that a wealth of information about cardiac movement is available, also outside the audible frequency range, as well as about the audible valve sounds and murmurs. A relatively new method in cardiac "auscultation" is the use of laser Doppler Vibrometry (LDV), which is a contactless method which can be used to measure skin movement [1][2][3][4].…”