University of Southern California

University of California

California Institute of Technology

Tzung Hsiai

Yu-Chong Tai

Hongyu Yu

Mahsa Rouhanizadeh

Eun Sok Kim

Fei Yu

Yu Zhao

Xiaoxiao Zhang

Christina Tiantian Lin

Parinaz Abiri

Gopkrishnani Soundararajan

E S Kim

Tiantian Lin

Gopikrishnan Soundararajan

Jianguo Ma

Rene R Sevag Packard

Yuan Luo

The present invention provides devices for characterizing regions of tissue and methods for using the same. The devices are capable of locating, identifying, and characterizing tissue regions of interest in vivo. In one embodiment, the devices are ultrasound-guided. In one embodiment, the devices use characterize regions of tissue using electrical impedance spectroscopy (EIS) sensors. In one aspect, the devices are useful in predicting plaque rupture, such as by determining the level of oxidized low density lipoprotein (oxLDL) and macrophage/foam cells present in an atheroma. In one aspect, the devices are useful in identifying metabolically active atherosclerotic lesions that are angiographically invisible.

Electrochemical impedance spectroscopy

A portion of a concentric bipolar microelectrode sensor is attached to an inflatable balloon of a catheter. Another portion of the concentric bipolar microelectrode sensor is also attached to a body of the catheter. The inflatable balloon is guided to become in proximity of a tissue. The inflatable balloon is then inflated. The inflation increases the likelihood of contact between microelectrodes of the concentric bipolar microelectrode sensor with the tissue. A voltage is supplied to the microelectrodes. The tissue's impedance is accordingly measured over a frequency range. A disease of the tissue, such as a lesion, is diagnosed based on the measured impedance.

Electrical impedance spectroscopy measurement based on concentric bipolar microelectrode sensor

A micromachined sensor for measuring vascular parameters, such as fluid shear stress, includes a substrate having a front-side surface, and a backside surface opposite the front-side surface. The sensor includes a diaphragm overlying a cavity etched within the substrate, and a heat sensing element disposed on the front-side surface of the substrate and on top of the cavity and the diaphragm. The heat sensing element is electrically couplable to electrode leads formed on the backside surface of the substrate. The sensor includes an electronic system connected to the backside surface and configured to measure a change in heat convection from the sensing element to surrounding fluid when the sensing element is heated by applying an electric current thereto, and further configured to derive from the change in heat convection vascular parameters such as the shear stress of fluid flowing past the sensing element.

MEMS vascular sensor

Growing community of inventors

Santa Monica, CA, United States of America

Tzung Hsiai