RFID Moisture Sensing in Patient Support Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for detecting moisture, such as incontinence or other abnormal moisture on patient support surfaces, lack accuracy and efficiency in distinguishing between moisture presence and sensor displacement, particularly in environments where contamination is a factor.
Innovation Solution
The use of RFID sensors tuned to specific frequencies, combined with protective and exposed sensor configurations, and multiplexed sensor arrays, allows for precise detection of moisture events by comparing center and test frequency responses, and analyzing rate of change in signal strength to differentiate between moisture presence and sensor displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional moisture sensors are used in patient support surfaces, then moisture detection capability is provided, but the system cannot reliably distinguish between moisture presence and sensor displacement, leading to false positives and negatives
Solution Approach 1:
The sensor system is divided into multiple independent sensor elements distributed across the patient support surface. Each sensor element can be independently monitored for both moisture response and displacement, allowing the system to distinguish between localized moisture events and generalized sensor displacement patterns.
Solution Approach 2:
The system monitors changes in electrical parameters (such as impedance, capacitance, or resistance) of the sensor elements in response to moisture. By analyzing the magnitude and pattern of these parameter changes across multiple sensors, the system can differentiate between moisture-induced changes (which affect specific localized sensors) and displacement-induced changes (which affect multiple sensors in a spatial pattern consistent with movement).
2Area of stationary object
If sensor arrays are deployed to improve detection coverage, then detection capability is enhanced, but system complexity increases making it harder to distinguish moisture from displacement
Solution Approach 1:
The patient support surface is segmented into multiple detection zones with distributed sensor elements. This segmentation allows the system to analyze spatial patterns of sensor responses, where moisture events produce localized changes in specific zones while displacement produces coordinated changes across multiple zones, simplifying the discrimination task despite the distributed architecture.
Solution Approach 2:
The system continuously monitors the electrical parameters of all sensor elements and compares the pattern of changes against expected patterns for moisture events versus displacement events. This feedback mechanism allows real-time differentiation without requiring complex hardware, as the discrimination is achieved through algorithmic analysis of the sensor array responses.
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
This approach enhances the accuracy and reliability of moisture detection, reducing false positives and negatives by accounting for environmental factors that affect sensor tuning, thereby improving the system's responsiveness to actual moisture events.
Implementation Method 1
the sensor has a center frequency that may be affected by the presence of moisture
Implementation Method 2
exciting the sensors with an electromagnetic signal; monitoring for a response from the sensors
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A moisture management apparatus monitors an area for moisture events and wirelessly transmits moisture-related information to one or more notification devices. An embodiment of the moisture management apparatus includes a substrate and one or more sensors supported by the substrate. The sensor(s) emit wireless signals indicative of the moisture-related information. A sensor event communication system forwards the sensor signals to another device, such as a notification device. The sensor event communication system may monitor other types of patient events. Portions of the moisture management apparatus and/or the moisture event communication system may be embodied in a patient support apparatus, such as a bed.