Abstract: A catheter-based imaging apparatus comprises a catheter having a proximal end and a distal end. An optical emitter is configured to emit optical excitation signals from a distal portion of the catheter. One or more ultrasound transducers are configured for: (a) transmission of acoustic excitation signals from the distal portion of the catheter; and (b) detection of ultrasound response signals from an object of interest at or near to the distal portion of the catheter at frequencies which include a lower receive frequency at least as low as 10 MHz and a higher receive frequency at least as high as 35 MHz. The one or more ultrasound transducers are thereby configured to detect response signals comprising photoacoustic response signals from the object of interest at the lower receive frequency and high resolution imaging signals from the object of interest at the higher receive frequency.

Abstract: A catheter-based optical imaging system for imaging a patient includes a catheter-based imaging device configured to direct optical radiation towards a vessel wall and to receive reflected radiation therefrom. A displacement mechanism is configured to vary the position of the imaging device relative to the catheter as a function of time during an imaging scan. An input is configured to receive cardiac event timing data, such as ECG data, from the patient. A trigger module is configured to initiate an imaging scan based on the cardiac event timing obtained from the cardiac event timing data. By triggering the optical imaging scans between cardiac events, artifacts in the image data can be reduced or eliminated.

Abstract: A catheter-based imaging apparatus comprises a catheter having a proximal end and a distal end. An optical emitter is configured to emit optical excitation signals from a distal portion of the catheter. One or more ultrasound transducers are configured for: (a) transmission of acoustic excitation signals from the distal portion of the catheter; and (b) detection of ultrasound response signals from an object of interest at or near to the distal portion of the catheter at frequencies which include a lower receive frequency at least as low as 10 MHz and a higher receive frequency at least as high as 35 MHz. The one or more ultrasound transducers are thereby configured to detect response signals comprising photoacoustic response signals from the object of interest at the lower receive frequency and high resolution imaging signals from the object of interest at the higher receive frequency.

Abstract: A method of obtaining an image of buried structures in an object, comprising: providing a camera for imaging visual and infrared-images; providing a bounded light source; partly irradiating said object by said bounded light source; imaging a non-irradiated area of said object by said camera to image said buried structure; and combining said buried structure image with a visual image of said object. Accordingly an image can be obtained while discarding specular reflections of the object. Additionally there is disclosed a method of enhancing imaging of buried structures in an object, comprising: aligning said infrared light source with a visual light source; providing a first edge analysis of said infrared image; providing a second edge analysis of said visual image; comparing said first and second edge analysis; and discarding edges in said infrared image that are also detected in said second image.

Abstract: A method for generating hardness information of tissue subject to a varying pressure. The method comprises receiving signals from the tissue from a sensor for measuring the deformation of the tissue in a measuring plane defined by the sensor, which sensor, during a varying pressure exerted on the tissue, is moved along the tissue in a direction transverse to the measuring plane; identifying strain of the tissue from the resulting signals; and relating the strain to elasticity and/or hardness parameters of the tissue. The method may comprise the step of displaying elasticity and/or hardness parameters of a tissue surface or tissue volume part extending practically parallel to the direction of motion of the sensor.

Abstract: Provided herein are Pulse-Inversion (PI) sequences that provide for fundamental frequency suppression in nonlinear imaging applications. In an embodiment, a weighting scheme is applied to the received echo pulses resulting from transmit pulses of alternating polarity to reduce the effect of transducer motion. In an embodiment, a three-pulse weighting scheme is applied to a PI sequence. In other embodiments, different combinations of the three-pulse weighting scheme are applied to a PI sequence.

Abstract: A method of obtaining an image of buried structures in an object, comprising partially irradiating said object by light of a wavelength that images said buried structure; and obtaining a complementary partial image of said buried structure by light diffused from a non-irradiated image area. According to the method, an image can be obtained while discarding specular reflections of the object. Thus, deeper structures will be better visible. In a further aspect, the invention offers a method of enhancing imaging of buried structures in an object, comprising: analysing said image as a first image in order to detect the edges of said buried structure; obtaining a second image by irradiating said object with a second light that visually images said object; and combining said first and second images for defining edges of said buried structure in said visual image.

Abstract: Intravascular ultrasound techniques provide for intravascular imaging using contrast agents and nonlinear techniques. An ultrasound imaging device for detecting internal properties of a target body comprises an ultrasound transducer positioned at a distal end portion of a catheter, for transmitting excitation pulses and for receiving echo signals. A signal processor analyses echo signals at harmonics and/or subharmonics of the transmit frequency. The catheter may include a contrast agent delivery conduit extending along the catheter, the delivery conduit having an exit orifice proximal to the ultrasound transducer. The device may discriminate between echo signals respectively arising from interaction with tissue and from the interaction with contrast agent. The device may generate an image of the site of interest using non-linear components of the received ultrasound echo signals.

Abstract: A method to measure spatial fluid flow components and their velocity profiles in a number of locations in a cross-sectional area of a lumen or other body cavity by using ultrasound in which the cross-sectional area is interrogated by a plurality of ultrasonic beams; the estimation of the spatial flow components is obtained from a combination of estimations of axial, lateral and total flow; the estimation of one or more flow components is obtained through any combination of time-shift and decorrelation analysis of two or more beam-signals of the interrogating ultrasound transducer; and the estimation accuracy is further improved by the use of a reference decorrelation curve obtained from experiments or beam-theory or both.

Abstract: A method to measure spatial fluid flow components and their velocity profiles in a number of locations in a cross-sectional area of a lumen or other body cavity by using ultrasound in which the cross-sectional area is interrogated by a plurality of ultrasonic beams; the estimation of the spatial flow components is obtained from a combination of estimations of axial, lateral and total flow; the estimation of one or more flow components is obtained through any combination of time-shift and decorrelation analysis of two or more beam-signals of the interrogating ultrasound transducer, and the estimation accuracy is further improved by the use of a reference decorrelation curve.