Systems and methods for measuring capillary refill time
Inventors
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-12226198-B2
Publication Date
2025-02-18
Expiration Date
Abstract
An example device for measuring a digital capillary refill time (CRT) can include a wearable component, a processor, and an output. The wearable component includes a touch pressure element and an optical sensor capable of transmitting and detecting optical energy. The detector converts the received optical energy into an electrical signal that represents the optical energy incident on the optical detector. The processor is programmed to receive the electrical signal from the detector, determine the CRT based on the optical sensor data, and output the electrical signal or the determined CRT.
Core Innovation
The invention relates to digital capillary refill time (CRT) measurement using an objective capillary refill time measurement component. The component includes an optical sensor with an optical source and an optical detector that generates an electrical signal representative of optical energy received by the optical detector, producing optical sensor data. The system detects an application of and a release of a blanching pressure on patient tissue based on one or more characteristics of the optical sensor data and determines a specific and objective CRT measurement based on the optical sensor data and the detected release of the blanching pressure.
The invention further uses the specific and objective CRT measurement in closed-loop feedback for infusion pump control. A processor receives the optical sensor data, detects application and release of blanching pressure, determines the CRT measurement, and adjusts an infusion pump infusion parameter so the adjustment correlates to an adjustment to a patient fluid state. This closed-loop feedback connects objectively measured CRT to infusion pump operating parameter changes to reflect patient fluid state changes.
In disclosed embodiments, CRT measurement quality and validity are assessed using characteristics of force and optical signal, including force stability and residual force, and optical trace characteristics such as amplitude/noise/monotonicity and baseline/return criteria. Optional temperature sensing and motion sensing are included for temperature compensation and artifact rejection, and perfusion index (PI) and pulse/SpO2 considerations are used as part of the measurement context. The system may provide repeated measurement and retry prompts when measurement quality criteria are not met, and it supports integration with patient monitors and storage/communication such as EHR/EMR, HL7, and wireless communication.
Claims Coverage
The partial content provides two independent claims, both directed to closed-loop feedback for infusion pump control using an objective CRT measurement derived from optical sensor data. One independent claim additionally requires detecting blanching pressure application and release, while the other focuses on determining CRT and adjusting the infusion parameter based on optical sensor data.
Closed-loop infusion pump feedback using objective CRT from optical sensing
An infusion pump delivers a fluid to a patient having a patient fluid state, and a processor receives optical sensor data from an optical sensor, determines a specific and objective CRT measurement based on the optical sensor data, and adjusts the infusion pump infusion parameter so the adjustment correlates to an adjustment to the patient fluid state.
Objective CRT measurement based on detected blanching pressure application and release
An objective capillary refill time measurement component includes an optical sensor with an optical source and an optical detector configured to generate an electrical signal representative of optical energy received, such that the optical sensor generates optical sensor data including the electrical signal; a processor detects an application of and a release of a blanching pressure on patient tissue based on one or more characteristics of the optical sensor data, determines a specific and objective CRT measurement based on the optical sensor data and the detected release of the blanching pressure, and adjusts an infusion pump infusion parameter so the adjustment correlates to an adjustment to the patient fluid state.
Across the two independent claims, the inventive coverage centers on generating optical sensor data to determine a specific and objective CRT measurement and using that CRT measurement in closed-loop feedback to adjust an infusion pump infusion parameter that correlates with changes in patient fluid state. The additional distinguishing element in one independent claim is detecting blanching pressure application and release based on optical sensor data before determining the CRT measurement.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?