Pressure Pad Presence Circuit for Disconnection-Aware Patient Detection
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Solution Overview
Problem
Existing bed pad presence sensing systems fail to accurately detect the presence of a patient when the pad is disconnected during operation, leading to erroneous alerts or missed detections.
Innovation Solution
A system with a pressure detection circuit and a presence detection circuit is introduced, utilizing a shorting connection within the pad to ensure accurate detection of pad connection status, including a tamper sensor circuit and a connector device for removably joining the pad and monitor, ensuring reliable voltage measurements across pins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard pressure pad circuit with pull-up resistor is used, then the circuit is simple and成本低, but the system cannot distinguish between pad disconnection and actual pressure release, leading to erroneous alerts
Solution Approach 1:
The patent divides the detection function into two separate circuits: a pressure detection circuit that measures pressure conditions and a presence detection circuit that verifies pad connection status. This segmentation allows each circuit to specialize in one function, improving reliability while keeping individual circuits relatively simple.
Solution Approach 2:
The patent introduces an intermediary shorting connection within the pad that actively participates in the presence detection circuit. This intermediary element serves as a reliable indicator of pad connection status, enabling the system to distinguish between disconnection and pressure release events.
2Reliability
If the pad is disconnected during operation, then the circuit opens, but the system cannot determine whether this is intentional removal or wiring damage, causing false alarms or missed detections
Solution Approach 1:
The presence detection circuit continuously monitors the integrity of the pad connection before pressure detection is performed. By checking connection status in advance and continuously, the system is prepared to recognize disconnection events immediately, preventing false alarms and missed detections.
Solution Approach 2:
The system implements feedback through the presence detection circuit that continuously reports pad connection status to the monitoring system. This feedback mechanism enables real-time detection of disconnection events and allows the system to respond appropriately by generating alerts or adjusting operation mode.
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 effectively detects both pressure on the pad and disconnection, preventing false alarms and ensuring consistent patient detection, even in the presence of wiring harness damage.
Implementation Method 1
a pressure sensitive zone configured to act as an open switch when a pressure on the pressure pad is below a threshold pressure and to act as a closed switch when the pressure on the pressure pad is above the threshold pressure
Implementation Method 2
The detection line is connected to a (weak) pull-up resistor R1 connected to a power source having a predetermined input voltage VIN higher than ground (e.g., +5V), to establish a default high voltage condition at pin 6 when the switch is open
Implementation Method 3
The presence detection circuit comprises a shorting connection on the first pathway before reaching the pressure sensitive zone
Data Source
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AI summary
An aspect of some embodiments of the present invention relates to a system configured for detecting connection between a pressure pad and a monitor. The system includes a pressure detection circuit and a presence detection circuit. The pressure detection circuit is configured for sensing whether the pressure on the pad is above or below the threshold pressure. The presence detection circuit is configured for determining whether a connection between the monitor and the pad is intact. The presence detection circuit is configured to establish a high voltage condition that occurs when connection is broken along the presence detection circuit and a low voltage condition when the presence detection circuit is intact.