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:
There is provided a method and a system for quantification of absolute blood flow in tissue using near-infrared fluorescence angiography in conjunction with photoplethysmography (fluorescence-mediated photoplethysmography). The method and system of the present invention provide absolute, real-time measurements of flow in terms of volume/time/area based upon measurement of fluorescence intensity.
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:
Disclosed herein is a composition for imaging nerve cells. The composition includes a fluorescent dye; and a viral component including a neurotropic herpes varicellae unable to replicate in nerve cells, a viral protein of a neurotropic herpes varicellae unable to replicate in nerve cells, a capsid of a neurotropic herpes varicellae unable to replicate in nerve cells, or a combination thereof. The fluorescent dye is bound to the viral component to form a dye/viral component complex that is capable of penetrating nerve cells.