Search

MIT Lincoln Laboratory, the Medical Device Realization Center (MEDRC) at MIT, and the Massachusetts General Hospital (MGH) are collaboratively developing a novel optical system that acquires ultrasound images within the human body without physical contact to the patient. The system is termed, non-contact laser ultrasound (N-CLUS) and yields anatomical images in tissue and bone and can also measure elastographic properties, in-vivo, all from an operational standoff of a few inches to several meters as desired. N-CLUS employs a pulsed laser that converts optical energy into ultrasonic waves at the skin surface via photoacoustic mechanisms, while, a laser Doppler vibrometer measures reflected-emerging ultrasonic waves from tissue at depth at the skin surface. The key of the N-CLUS approach is driven by shallow optical absorptivity that creates an acoustic source that enables ultrasound propagation deeper into the tissue.We discuss the motivation of the non-contact laser concept, its development path involving signal generation, skin and eye safe laser measurement, and system design perspectives. Elastogrphic measurements are then demonstrated with determination of bone elastic moduli for beef rib within tissue. N-CLUS images from soft tissue specimens are also compared with commercial ultrasound, showing that the noncontact optical approach may have potential as a viable method in medical ultrasound.

A new method of non-contact vibration control of the technical condition of support-rod insulators, which are in operation under operating voltage, is developed. Theoretical studies were carried out in the ANSYS software complex to determine the information frequencies of natural oscillations of support-rod insulators associated with certain types of defects. A new measurement and diagnostic complex and software for implementing a new method for contactless monitoring of the technical condition of the support-rod insulators using laser vibrometry methods have been developed and created. Experimental studies of the parameters of natural oscillations of the of support-rod insulators on the operating substation under operating voltage have been carried out, and the operability of a new method for contactless monitoring of the technical condition of the support-rod insulators has been tested.

In the work the scheme of the differential sensor for non-invasive distant anemometry of microcirculatory bloodstream is described. The sensor is designed on base of the laser speckle theory. Some important parameters like maximal distance and time of measurement are calculated. Experimental results on blood speed determination are presented.

Ultrasound (US) is an ideal imaging modality used in medical practice: it is portable, has no known bio-effects and produces images with excellent resolution. Despite these advantages, MRI and CT are dominant modalities used for most medical imaging, while accepting much higher cost and health risks. US is acquired with hand held transducers dependent on operator applied pressure and angle plane selection with no fixed acquisition frame. This leads to inter-operator variability — significant image distortion with limited feature accuracy/confidence, especially upon repeat measurement and is the primary reason US is unable to compete with MRI and CT. For example, the standard criteria for determining tumor progression in cancer trials do not permit tumor measurements made with US.

Rail track geometric parameters, such as gage, level, longitudinal and alignment etc, have much influence on the operation safety of train vehicles. In this paper, a new measurement system for track geometric parameters is described. The measurement system is based on the three-point method for the straightness measurement, it uses laser sensor of displacement to collect data, uses notebook to process data, the whole measurement system is integrated in a portable measurement car.

The present approaches to the laser treatment can be divided into transurethral sidefiring application, either under visual or ultrasound control, transurethral contact laser fibers, a combination of these two techniques, and transurethral or transperineal interstitial laser application.