Abstract: A lens assembly comprising one or more lenses is provided. The one or more lenses together comprise a first surface and a second surface. An optical axis of the lens assembly extends in the z-direction. The first surface comprises a first cross-section in a y-z plane, wherein the first cross-section comprises an aspheric first curve that varies in the y-z plane, wherein the first aspheric curve is non-circular, non-elliptical, and non-conical. One surface selected from the first surface and the second surface comprises a second cross-section in a x-z plane, wherein the second cross-section comprises an aspheric second curve in the x-z plane, wherein the second first aspheric curve is non-circular, non-elliptical, and non-conical.

Abstract: Techniques for fluorescence imaging are provided. A tissue region comprising a target fluorophore is illuminated with an excitation light in a wavelength range of 380-490 nm. First image data of the tissue is captured at an image sensor, wherein the first image comprises an autofluorescence contribution from the tissue and a fluorescence emission contribution from the target fluorophore, wherein the first image data comprises red channel data and green channel data. A corrected fluorescence image is generated, based on the first image data, wherein generating the fluorescence image comprises subtracting a second component based on one of the green channel data or the red channel data from a first component based on the other of the green channel data or the red channel data.

Abstract: Methods and systems for facilitating assessment of blood flow in a tissue volume of a subject are disclosed. In some variations, the method may include: after a predetermined amount of a fluorescence agent has been administered to the subject, exciting the fluorescence agent in the tissue volume such that the excited fluorescence agent emits fluorescent light, acquiring fluorescence data based on the fluorescent light emitted during blood flow through the tissue volume, estimating a molar concentration of the fluorescence agent in the blood flowing through the tissue volume, and generating an assessment of blood flow in the tissue volume based at least in part on the fluorescence data and the estimated molar concentration of the fluorescence agent. The estimated molar concentration may be based on the predetermined amount of the fluorescence agent and an estimated circulating blood volume of the subject.

Abstract: A first light source with a first etendue generates a first light beam to travel along a first optical path having an expanded portion formed by a collector optical system. A second light source having a second etendue less than one tenth of the first etendue forms second light, which is conducted by a light guide having a distal section with an end face. The second light is emitted from the end face as a second light beam that travels over a second optical path that resides within the expanded portion of the first optical path due to the light guide being disposed relative to the first optical path from an off-axis direction. An optical condenser receives and directs the first and second light beams to a common exit plane to form the combined light beam.

Abstract: The present disclosure relates generally to medical imaging, and more specifically to devices and systems for simulating a time-varying fluorescence response. An exemplary device for simulating a fluorescence response of a tissue comprises: a simulated tissue layer; one or more optical detectors to detect a fluorescence excitation light incident on the simulated tissue layer; a plurality of illumination sources underneath the simulated tissue layer; and a controller configured to control the plurality of illumination sources to emit light based on the detected fluorescence excitation light and at least one time-varying pattern.

Abstract: A first light source with a first etendue generates a first light beam to travel along a first optical path having an expanded portion formed by a collector optical system. A second light source having a second etendue less than one tenth of the first etendue forms second light, which is conducted by a light guide having a distal section with an end face. The second light is emitted from the end face as a second light beam that travels over a second optical path that resides within the expanded portion of the first optical path due to the light guide being disposed relative to the first optical path from an off-axis direction. An optical condenser receives and directs the first and second light beams to a common exit plane to form the combined light beam.

Abstract: Provided herein are systems for fluorescence imaging of an object and methods of use thereof, the systems comprising: an image sensor assembly comprising at least one image sensor; and an optical assembly configured to transmit light emitted from the object to the image sensor assembly, the optical assembly comprising at least one notch filter configured to block light in a plurality of fluorescence excitation wavebands while transmitting fluorescence light that is emitted from the object, wherein the optical assembly is configured to project the emitted fluorescence light as one or more fluorescence images onto the at least one image sensor of the image sensor assembly.

Abstract: A method, an apparatus, and a kit including the apparatus and a fluorescence agent are provided for measuring a time-varying change in an amount of blood in a tissue volume, and include exciting a fluorescence agent in the blood, acquiring a time-varying light intensity signal during a pulsatile flow of the blood through the tissue volume, the pulsatile flow having a systolic and a diastolic phase resembling a conventional photoplethysmogram, and processing the acquired signal by applying a modified Beer-Lambert law to obtain a measurement of the time-varying change in the amount of blood in the tissue volume. The instantaneous molar concentration of the fluorescence agent is determined by utilizing a concentration-mediated change in a fluorescence emission spectrum of the fluorescence agent. There is further provided a fluorescence agent for use in the method.

Abstract: An image sensor assembly includes at least one upconverter configured to detect light in a NIR waveband that is received from an object to be imaged and generate, based on the detected light, upconverted light that is outside of the NIR waveband; and at least one image sensor configured to detect the upconverted light.

Abstract: An adjustable aperture for an imager includes a mechanical aperture having an opening for permitting light to pass through the mechanical aperture; and an electro-optic shutter having a hole in at least one linearly polarizing layer such that at least a portion of light incident on the electro-optic shutter can pass through the electro-optic shutter regardless of an operating state of the electro-optic shutter, wherein an aperture size of the adjustable aperture is defined by the mechanical aperture when the electro-optic shutter is controlled for light transmission and by the electro-optic shutter when the electro-optic shutter is controlled for light blocking.

Abstract: Methods and systems for facilitating assessment of blood flow in a tissue volume of a subject are disclosed. In some variations, the method may include: after a predetermined amount of a fluorescence agent has been administered to the subject, exciting the fluorescence agent in the tissue volume such that the excited fluorescence agent emits fluorescent light, acquiring fluorescence data based on the fluorescent light emitted during blood flow through the tissue volume, estimating a molar concentration of the fluorescence agent in the blood flowing through the tissue volume, and generating an assessment of blood flow in the tissue volume based at least in part on the fluorescence data and the estimated molar concentration of the fluorescence agent. The estimated molar concentration may be based on the predetermined amount of the fluorescence agent and an estimated circulating blood volume of the subject.

Abstract: Methods and systems for facilitating assessment of blood flow in a tissue volume of a subject are disclosed. In some variations, the method may include: after a predetermined amount of a fluorescence agent has been administered to the subject, exciting the fluorescence agent in the tissue volume such that the excited fluorescence agent emits fluorescent light, acquiring fluorescence data based on the fluorescent light emitted during blood flow through the tissue volume, estimating a molar concentration of the fluorescence agent in the blood flowing through the tissue volume, and generating an assessment of blood flow in the tissue volume based at least in part on the fluorescence data and the estimated molar concentration of the fluorescence agent. The estimated molar concentration may be based on the predetermined amount of the fluorescence agent and an estimated circulating blood volume of the subject.

Abstract: A method and an apparatus for measuring a time-varying change in an amount of blood in a tissue include exciting a fluorescence agent in the blood, acquiring a time-varying light intensity signal during a pulsatile flow of the blood through the tissue volume, the pulsatile flow having a systolic and a diastolic phase resembling a conventional photoplethysmogram, and processing the acquired signal by applying a modified Beer-Lambert law to obtain the measurement of the time-varying change in the amount of blood in the tissue volume. The instantaneous molar concentration of the fluorescence agent is determined by utilizing a concentration-mediated change in a fluorescence emission spectrum of the fluorescence agent.

Abstract: An image sensor assembly includes at least one upconverter configured to detect light in a NIR waveband that is received from an object to be imaged and generate, based on the detected light, upconverted light that is outside of the NIR waveband; and at least one image sensor configured to detect the upconverted light.

Abstract: A fluorescence imaging system for imaging an object, the system includes a white light provider that emits white light, an excitation light provider that emits excitation light in a plurality of excitation wavebands for causing the object to emit fluorescent light, a component that directs the white light and excitation light to the object and collects reflected white light and emitted fluorescent light from the object, a filter that blocks light in the excitation wavebands and transmits at least a portion of the reflected white light and fluorescent light, and an image sensor assembly that receives the transmitted reflected white light and the fluorescent light.

Abstract: A first light source with a first etendue generates a first light beam to travel along a first optical path having an expanded portion formed by a collector optical system. A second light source having a second etendue less than one tenth of the first etendue forms second light, which is conducted by a light guide having a distal section with an end face. The second light is emitted from the end face as a second light beam that travels over a second optical path that resides within the expanded portion of the first optical path due to the light guide being disposed relative to the first optical path from an off-axis direction. An optical condenser receives and directs the first and second light beams to a common exit plane to form the combined light beam.

Abstract: A fluorescence imaging system for imaging an object, the system includes a white light provider that emits white light, an excitation light provider that emits excitation light in a plurality of excitation wavebands for causing the object to emit fluorescent light, a component that directs the white light and excitation light to the object and collects reflected white light and emitted fluorescent light from the object, a filter that blocks light in the excitation wavebands and transmits at least a portion of the reflected white light and fluorescent light, and an image sensor assembly that receives the transmitted reflected white light and the fluorescent light.

Abstract: A fluorescence imaging system for imaging an object, the system includes a white light provider that emits white light, an excitation light provider that emits excitation light in a plurality of excitation wavebands for causing the object to emit fluorescent light, a component that directs the white light and excitation light to the object and collects reflected white light and emitted fluorescent light from the object, a filter that blocks light in the excitation wavebands and transmits at least a portion of the reflected white light and fluorescent light, and an image sensor assembly that receives the transmitted reflected white light and the fluorescent light.

Abstract: Methods and systems for facilitating assessment of blood flow in a tissue volume of a subject are disclosed. In some variations, the method may include: after a predetermined amount of a fluorescence agent has been administered to the subject, exciting the fluorescence agent in the tissue volume such that the excited fluorescence agent emits fluorescent light, acquiring fluorescence data based on the fluorescent light emitted during blood flow through the tissue volume, estimating a molar concentration of the fluorescence agent in the blood flowing through the tissue volume, and generating an assessment of blood flow in the tissue volume based at least in part on the fluorescence data and the estimated molar concentration of the fluorescence agent. The estimated molar concentration may be based on the predetermined amount of the fluorescence agent and an estimated circulating blood volume of the subject.

Abstract: A method, an apparatus, and a kit including the apparatus and a fluorescence agent are provided for measuring a time-varying change in an amount of blood in a tissue volume, and include exciting a fluorescence agent in the blood, acquiring a time-varying light intensity signal during a pulsatile flow of the blood through the tissue volume, the pulsatile flow having a systolic and a diastolic phase resembling a conventional photoplethysmogram, and processing the acquired signal by applying a modified Beer-Lambert law to obtain a measurement of the time-varying change in the amount of blood in the tissue volume. The instantaneous molar concentration of the fluorescence agent is determined by utilizing a concentration-mediated change in a fluorescence emission spectrum of the fluorescence agent. There is further provided a fluorescence agent for use in the method.