Thumb-Worn Oximetry Probe with Wrist Transceiver for Motion Artifact Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pulse oximeters are prone to inaccuracies and false alarms due to motion-related artifacts, and they are uncomfortable and impractical for continuous monitoring of ambulatory patients, especially when measuring vital signs like blood pressure.
Innovation Solution
A body-worn monitor system that includes a pulse oximetry probe comfortably clipped to the patient's thumb, connected to a wrist-worn transceiver with motion-detecting sensors and a wireless communication system, which processes signals from accelerometers and an electrocardiogram to accurately measure SpO2, blood pressure, and other vital signs while accounting for patient motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pulse oximeters are used for continuous monitoring, then vital signs can be measured, but motion-related artifacts cause inaccuracies and false alarms
Solution Approach 1:
The patent introduces motion-detecting sensors (accelerometers) as intermediary devices that detect patient motion and provide signals to the processing unit. These motion signals serve as mediators that allow the system to distinguish between signal changes caused by motion artifacts and those caused by actual physiological changes, thereby improving measurement accuracy during ambulatory monitoring
Solution Approach 2:
The system implements feedback by continuously monitoring motion through accelerometers and using this information to adjust the interpretation of pulse oximetry signals. The processing unit receives feedback from motion sensors and automatically compensates for motion-induced artifacts in real-time, reducing false alarms and improving reliability of vital sign measurements
2Productivity
If conventional pulse oximeter probes are worn on patients, then vital signs can be monitored, but they are uncomfortable and impractical for ambulatory patients
Solution Approach 1:
The monitoring system is segmented into separate functional components: a comfortable thumb-worn probe that captures only optical signals, and a wrist-worn transceiver that houses the motion sensors, processing unit, and power source. This segmentation allows the probe to be lightweight and comfortable for ambulatory patients while distributing the bulk of the equipment to the wrist, enabling continuous monitoring without compromising patient mobility or comfort
Solution Approach 2:
The patent replaces traditional cumbersome pulse oximeter probes with a streamlined thumb-worn design that uses optical fibers and miniaturized components. The mechanical complexity is reduced by substituting traditional probe structures with flexible, lightweight materials and integrating electronics into a wrist-worn unit, making the system practical for ambulatory patients while maintaining continuous monitoring capability
3Measurement precision
If motion-detecting sensors are added to the monitor system, then motion-related artifacts can be filtered out, but device complexity increases
Solution Approach 1:
The wrist-worn transceiver is designed as a multi-functional device that integrates motion detection, signal processing, wireless communication, and power management into a single unit. This universal design consolidates multiple functions into one device, reducing overall system complexity while maintaining high measurement precision through integrated motion artifact filtering
Solution Approach 2:
The patent merges the motion-detecting sensors, processing unit, wireless transmitter, and power source into a single wrist-worn transceiver unit. This consolidation combines multiple complex components into one integrated device, simplifying the overall system architecture while enabling accurate motion artifact filtering and continuous vital sign monitoring
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides clinically accurate, continuous monitoring of vital signs, reducing false alarms and enhancing patient comfort by effectively filtering out motion-related noise and allowing ambulatory patients to move freely.
Implementation Method 1
Conventional pulse oximeters feature algorithms that assume only HbO2 and Hb are present in the blood, and measure SpO2 from the ratio of oxygenated hemoglobin to the total amount of hemoglobin... HbO2 and Hb feature different absorption spectra in the visible and infrared regions
Implementation Method 2
A body-worn monitor system that includes a pulse oximetry probe comfortably clipped to the patient's thumb, connected to a wrist-worn transceiver with motion-detecting sensors... processes signals from accelerometers
Implementation Method 3
processed: i) the first and second signals to determine AC signals; ii) at least one of the AC signals and the motion signal to determine selected AC signals; and iii) the selected AC signals, or signals derived therefrom, to determine the physiological property of the patient's blood
Data Source
AI summary
The invention provides a body-worn system that continuously measures pulse oximetry and blood pressure, along with motion, posture, and activity level, from an ambulatory patient. The system features an oximetry probe that comfortably clips to the base of the patient's thumb, thereby freeing up their fingers for conventional activities in a hospital, such as reading and eating. The probe secures to the thumb and measures time-dependent signals corresponding to LEDs operating near 660 and 905 nm. Analog versions of these signals pass through a low-profile cable to a wrist-worn transceiver that encloses a processing unit. Also within the wrist-worn transceiver is an accelerometer, a wireless system that sends information through a network to a remote receiver, e.g. a computer located in a central nursing station.