Vital signs fiber optic sensor systems and methods
An intensity-based, micro-bending optical fiber sensor is disclosed herein, which is configured to acquire clean, stable, and reliable vital sign signals. Related systems and methods for vital sign monitoring are also provided herein. The sensor of various embodiments includes a multi-mode optical fiber, an LED light source, an LED driver, a receiver, and a single layer deformer structure. In various embodiments, the optical fiber and single layer deformer structure of the sensor are selected to meet specific parameters necessary to achieve a level of reliability and sensitivity needed to successfully monitor vital signs. In some embodiments, a specific sizing relationship exists between the optical fiber and the single layer deformer structure. In sonic embodiments, the sensor is configured to acquire ballistocardiograph waveforms.
1. A sensor for detecting a physiological parameter, the sensor comprising:
a multi-mode optical fiber comprising an inner core, a cladding layer, and an outer coating, wherein a core diameter is greater than 50% of a cladding diameter;
an LED (light emitting diode) light source coupled to a first end of the optical fiber;
an LED driver electrically coupled to the LED light source and configured to regulate a power level of the LED light source;
a receiver coupled to a second end of the optical fiber, the receiver configured to sense changes in an intensity of light traveling through the optical fiber; and
a deformer structure is a single mesh layer formed of mesh having openings disposed therein, wherein a surface area of the openings is between 30% and 60% of a total surface area of the mesh layer;
wherein the optical fiber is arranged in a plane in contact with a surface of the deformer structure such that an application of force onto the sensor results in a first portion of the optical fiber bending into an opening of the mesh layer and a second portion of the optical fiber flexing against the mesh;
a total diameter of the optical fiber consists of a diameter across the inner core, the cladding layer, and the outer coating;
the mesh layer is formed of interwoven fibers;
wherein a diameter of each interwoven fiber is ±25% of the total diameter of the optical fiber.
2. A sensor for detecting a physiological parameter, the sensor comprising:
a multi-mode optical fiber comprising an inner core, a cladding layer, and an outer coating, wherein a core diameter is greater than 50% of a cladding diameter;
an LED (light emitting diode) light source coupled to a first end of the optical fiber;
an LED driver electrically coupled to the LED light source and configured to regulate a power level of the LED light source;
a receiver coupled to a second end of the optical fiber, the receiver configured to sense changes in an intensity of light traveling through the optical fiber; and
a deformer structure is a single mesh layer formed of mesh having openings disposed therein, wherein a surface area of the openings is between 30% and 60% of a total surface area of the mesh layer;
wherein the optical fiber is arranged in a plane in contact with a surface of the deformer structure such that an application of force onto the sensor results in a first portion of the optical fiber bending into an opening of the mesh layer and a second portion of the optical fiber flexing against the mesh;
a total diameter of the optical fiber consists of a diameter across the inner core, the cladding layer, and the outer coating;
wherein each opening of the single mesh layer is 100% to 300% of the total diameter of the optical fiber.