A system for visualizing a tissue region of interest comprises a deployment catheter defining a lumen and a hood coupled to and extending distally from the deployment catheter. The hood has a low-profile configuration within a delivery sheath and a deployed configuration when extended distally of the delivery sheath. The hood in the deployed configuration defines an open area in fluid communication with the lumen. A distal portion of the deployment catheter extends into the open area. An imaging element is coupled to an imager support member. When in the deployed configuration, the imaging element is configured to extend distally of the distal portion while the imager support member extends within the deployment catheter. The imaging element comprises a tapered surface and the deployment catheter comprises a complementary tapered surface. Retraction of the imaging element causes the imaging element to shift radially outward from a longitudinal axis.

In part, the disclosure relates to computer-based methods, devices, and systems suitable for performing intravascular data analysis and measurement of various types of data such as pressure and flow data. The disclosure relates to probes and methods suitable for determining an event in a cardiac cycle such as flow threshold such as a peak flow, a fraction thereof, other intravascular parameters or a point in time during which peak flow or a change in one of the parameters occurs. An exemplary probe includes one or more of a pressure sensor, a resistor, a flow sensor and can be used to generate diagnostic data based upon measured intravascular and other parameters. In part, the disclosure relates to methods and systems suitable for determining a coronary flow reserve value in response to one or more of intravascular pressure and flow data or data otherwise correlated therewith.

The invention relates to a method for determining the microvascular resistance reserve, MRR, in the myocardium perfused by a normal or a stenotic coronary artery of a human patient, which method comprises the step of during rest condition of the patient: measuring the blood flow, Q.sub.rest, through the coronary artery; and further comprising the step of during rest condition or during maximum hyperemia of the patient: measuring the blood pressure, P.sub.a, at a position proximal in the coronary artery or proximally of any stenosis, if present; and further comprising the steps of during maximum hyperemia of the patient: measuring the blood flow, Q.sub.max, through the coronary artery; and measuring the blood pressure, P.sub.d, at a position distal in the coronary artery or distally of any stenosis, if present, and wherein the microvascular resistance reserve, MRR, is determined by the additional step of calculating the microvascular resistance reserve as

[00001]$MRR=\frac{Q_{\max }}{Q_{\mathrm{rest}}}\frac{P_a}{P_{d,hyper}}.$

Imaging devices, systems, and methods are provided. Some embodiments of the present disclosure are particularly directed to imaging a region of interest in tissue with photoacoustic and ultrasound modalities. In some embodiments, a medical sensing system (100) includes a measurement apparatus (102) configured to be placed within a vascular pathway. The measurement apparatus may include a sensor array (106) comprising two or more sensor modalities. The sensor array may be configured to receive sound waves created by the interaction between emitted optical pulses and tissue, transmit and receive ultrasound signals, and rotate around a longitudinal axis of the measurement device. The medical sensing system may also include a processing engine operable to produce images of the region of interest and a display configured to visually display the image of the region of interest.

A catheter system for optical coherence tomography includes an elongate catheter body, an optical fiber in the elongate catheter body, and an anamorphic lens assembly coupled with a distal end of the optical fiber. The optical fiber and the lens assembly are together configured to provide a common path for optical radiation reflected from a target and from a reference interface between the distal end of the optical fiber and the lens assembly.

A system for determining peripheral artery disease and method of use for determining the presence or absence of peripheral vascular disease and the severity of the disease in particular vascular segments. The System for determining peripheral artery disease and method of use includes a continuous wave Doppler transceiver which generates a digitized version of quadrature detected stereo audio and is coupleable to a waveform converter and processor. The waveform converter and processor provides filtering, time domain to frequency domain conversion, gain control, and statistical processing of the converted Doppler Stereo audio and is operationally coupled to a display for presenting results to a technician.

A digital topographic model of the luminal surface is generated by projecting an optical pattern on the luminal surface from the first location within the lumen. At least a portion of the projected pattern is detected from a second location within the lumen which is based apart from the first location. The dimensions of the luminal wall can be measured by triangulation in order to produce the digital topographic model of the body lumen.

A catheter, such as a fractional flow reserve catheter, includes an elongate shaft having a pressure sensing wire extending to the distal portion of the elongate shaft. The wire has a pressure sensor mounted on the distal end for measuring a pressure of a fluid within lumen of vessel. The pressure sensor wire is disposed within a pocket formed adjacent to the pressure sensor thereby minimizing the profile of the catheter. Bending stresses experienced by a pressure sensor mounted to a fractional flow reserve catheter when tracking the catheter through the vasculature creates a distortion of the sensor resulting in an incorrect pressure reading or bend error. In order to isolate the sensor from bending stresses, the sensor is spaced apart from the pressure sensor wire to allow the pressure sensor and the pressure sensor wire to move independently from one another.

An automatic clipping technique capable of satisfactorily extracting blood vessels to be extracted is provided. A specific tissue extraction mask image which is created by extracting a specific tissue (for example, a brain) from a three-dimensional image acquired by magnetic resonance angiography and a blood vessel extraction mask image which is created by extracting a blood vessel from an area (a blood vessel search area) which is determined using a preset landmark position and the specific tissue extraction mask image are integrated to create an integrated mask. By applying the integrated mask to the three-dimensional image, a blood vessel is clipped from the three-dimensional image.

An apparatus for measuring bio-information may include: a pulse wave sensor comprising at least one pair of light emitters which are disposed apart from each other and a light receiver disposed between the at least one pair of light emitters, and configured to measure a plurality of pulse wave signals from an object by using the light receiver and the at least one pair of light emitters; a force sensor configured to measure a contact force that is applied to the pulse wave sensor by the object; and a processor configured to generate an integrated pulse wave signal by integrating the plurality of pulse wave signals based on the contact force and an area of a contact surface of the pulse wave sensor, and estimate bio-information of the object based on the integrated pulse wave signal.