Other

University Health Network

Michael C Kolios

Eric M Strohm

Michael D Sherar

Gregory J Czarnota

John Hunt

Scott Tsai

Raffi Karshafian

Darren Ross Morofke

Byeong-Ui Moon

Victor Xiao Dong Tang

Vaskar Gnyawali

Muhannad N Fadhel

Michael J Moore

Various embodiments are described herein for an imaging device and associated method for performing fluence compensation on a photoacoustic (PA) image of at least a portion of an object for sets of RF acoustic response signals that are obtained using different illumination wavelengths. A first set of RF acoustic response signals is fluence matched to a second set of RF acoustic response signals by determining relative frequency data for first set of RF acoustic response signals relative to the second set of RF acoustic response signals and using the relative frequency data to filter the first set of RF acoustic response signals.

Method and system for fluence matching in photoacoustic imaging

Methods and apparatuses for controlling the size of microbubbles are provided herein. The methods include forming a microbubble in a liquid at an inlet end of a liquid microchannel, the liquid microchannel having an outlet end spaced from the inlet end and a liquid microchannel conduit extending therebetween. As the liquid is propelled along a length of the liquid microchannel, the liquid carry the microbubble, a negative pressure is applied to a first very low pressure microchannel having a first end, a second end spaced from the first end and a first very low pressure microchannel conduit extending between the first end and the second end and having a portion thereof being laterally spaced from and adjacent to a portion of the liquid microchannel conduit. The negative pressure withdraws air from the microbubble in the liquid microchannel to shrink the microbubble as the microbubble travels along the portion of the liquid microchannel conduit.

Apparatus, systems and methods for microfluidic vacuum shrinkage of microbubbles

There is provided a method for sensing a sample. The method includes the following steps: first a light beam is directed onto the sample. The sample transmits at least a portion of the light beam to form a transmitted light beam. Next, the transmitted light beam is received at an acoustic transducer. The acoustic transducer absorbs at least a portion of the transmitted light beam and in response generated an acoustic wave. Subsequently, an electrical signal is generated at the acoustic transducer. The electrical signal is generated based on at least a portion of the acoustic wave.

Method and apparatus for sensing a sample

Provided herein is a method to detect, characterize and classify a particle. A light source and an ultrasound transducer are controlled to irradiate the particle with light and an ultrasound pulse. A feature associated with the particle is determined by processing ultrasound data resulting from the particle being irradiated. The feature is compared to a reference to determine at least one property of the particle. According to some non-limiting implementations, the feature comprises a power spectrum of the particle. According to some non-limiting implementations, the ultrasound data is processed to determine characteristics in a range of about 100 MHz to about 1000 MHz of the power spectrum. According to some non-limiting implementations, the ultrasound pulse is in a range of about 100 MHz to about 1000 MHz. A computing device to detect, characterize and classify a particle is also provided.

Method, system and apparatus for the detection, characterization and classification of particles using photoacoustic and ultrasound techniques

Optical Coherence Tomography (OCT) is a high-resolution, non-invasive technique to image subsurface tissue and tissue functions. A broadband light source illuminates an object and the reflected photons are processed using an interferometer, demodulated into inphase and quadrature components and then digitized. The captured data contains information about the velocity of the moving scatterers but current Doppler estimation algorithms have a limited velocity detection range. Using a two dimensional velocity estimation, Doppler OCT (DOCT) can be used for the detection of in vivo aortic blood flow rates of over 1 m/s peak velocity through an esophageal DOCT probe. Previous methods have used a transverse Kasai (TK) autocorrelation estimation to estimate the velocity which is good for slow velocities, such as in the microvasculature. By calculating the Kasai autocorrelation with a lag in the depth or axial direction, backscattered frequency information is obtained which yields high velocity rate information. Through subtraction with stationary backscattered information, the Doppler shift is obtained by the axial Kasai (AK) technique. Through utilizing information from two dimensions, velocities can be resolved which spans rates from the microcirculation to cardiac blood flow velocities.

Two-dimensional estimation technique for doppler optical coherence tomography (OCT)

A non-invasive method of monitoring apoptosis in cell culture, ex-vivo tissues and in-vivo tissues using high frequency ultrasound imaging is provided. The method includes the steps of: 1) imaging a selected site of the cell culture or tissues using high frequency (above 20 MHz) ultrasound imaging (before image); 2) exposing the selected site to an apoptosis-inducing stress; 3) imaging the selected site or a portion thereof, using ultrasound imaging at subsequent timed intervals (after image(s)); 4) measuring the signal amplitude of a region of interest of the selected site in the before and after images; 5) comparing the signal amplitude measurements for the regions of interest in the before and after images and determining whether the after image regions exhibit an increase in amplitude as compared to the before image regions which is an indication that apoptosis has begun; and 6) measuring the change in the frequency spectrum of the radiofrequency ultrasound backscatter signal in the region of interest in the before and after images and confirming that apoptosis has begun when the slope of the frequency spectrum has increased.

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Toronto, Canada

Michael C Kolios