Patient support surface having a pneumatic control assembly
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Solution Overview
Problem
Inflatable mattresses for patient support surfaces, such as hospital beds, face challenges with pneumatic control assemblies that generate excessive heat and noise, and require improved heat management and noise reduction.
Innovation Solution
A pneumatic control assembly with dual-stage compression mode and direct feed mode for inflatable sections, utilizing a first air supply device for high flow rate and low pressure, and a second air supply device for low flow rate and high pressure, along with solenoid valves and diaphragm valves, to manage air flow efficiently and reduce noise and heat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single air supply device is used to control multiple inflatable bladders, then the device complexity is reduced, but the heat generation and noise level increase
Solution Approach 1:
The patent divides the air supply system into two separate devices: a first air supply device (blower) for high flow rate applications and a second air supply device (compressor) for high pressure applications. This segmentation allows each device to be optimized for its specific function, reducing overall heat generation and noise levels compared to a single device handling all requirements.
Solution Approach 2:
The patent introduces a pneumatic control assembly as an intermediary system that coordinates between the two air supply devices and multiple valves. This intermediary structure manages air flow distribution, allowing the system to leverage the advantages of both blowers and compressors while isolating their harmful effects (heat and noise) through proper routing and control.
2Adaptability or versatility
If multiple valves are used to control air flow to different inflatable bladders, then the adaptability of the mattress is improved, but the heat generated by valves increases
Solution Approach 1:
The patent segments the valve control into two distinct systems: one controlled by the first air supply device and another by the second air supply device. This segmentation allows independent control of air flow to different inflatable bladders while distributing the heat generation across two separate valve assemblies rather than concentrating it in one location.
Solution Approach 2:
The patent applies different control characteristics to different valve assemblies based on local requirements. The first valve assembly (controlled by the blower) is optimized for high flow rate applications, while the second valve assembly (controlled by the compressor) is optimized for high pressure applications. This local optimization reduces overall heat generation by matching each valve's operating conditions to its specific function.
3Speed
If a blower is used for high flow rate air supply, then the inflation speed is improved, but the pressure capacity is limited
Solution Approach 1:
The patent segments the air supply function into two devices with complementary characteristics: a blower for high flow rate (speed) and a compressor for high pressure capacity. This segmentation allows the system to achieve both fast inflation and high pressure requirements by selecting the appropriate device for each specific task.
Solution Approach 2:
The patent implements dynamic switching between the blower and compressor based on real-time operational requirements. The system can dynamically select which device to activate depending on whether high flow rate or high pressure is needed, allowing the mattress system to adapt its inflation characteristics dynamically rather than being fixed to a single device's limitations.
4Stress or pressure
If a compressor is used for high pressure air supply, then the pressure capacity is improved, but the flow rate is reduced
Solution Approach 1:
The patent segments the air supply function to assign the compressor specifically for high pressure applications where flow rate is less critical, and the blower for high flow rate applications where pressure requirements are lower. This segmentation allows each device to operate in its optimal performance range, maximizing overall system efficiency.
Solution Approach 2:
The system dynamically selects between compressor and blower based on the specific operational requirement. When high pressure is needed (e.g., for firmness adjustment), the compressor is activated. When high flow rate is needed (e.g., for rapid inflation), the blower is activated. This dynamic adaptation ensures optimal performance for each task while avoiding the flow rate limitation of the compressor during high-speed operations.
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 solution effectively manages air flow and pressure to inflatable sections, reducing noise and heat, enhancing the performance and comfort of patient support surfaces.
Implementation Method 1
a first air supply device providing air at a high flow rate and a low pressure
Implementation Method 2
a second air supply device providing air at a low flow rate and a high pressure
Implementation Method 3
the at least one solenoid valve is selectively actuated to control air flow from the second air supply device to the pilot port of the at least one first valve to thereby actuate the at least one first valve
Implementation Method 4
Each of the at least one first valve is a diaphragm valve
Data Source
AI summary
A pneumatic control assembly for a patient support surface includes a first air supply device providing air at a high flow rate and a low pressure, and a second air supply device providing air at a low flow rate and a high pressure. At least one first valve is configured to be fluidly connected to at least one inflatable section of the patient support surface, the at least one first valve being selectively actuated to fluidly connect the first air supply device with a corresponding one of the at least one inflatable section. The at least one first valve is piloted by the second air supply device. Other aspects of the pneumatic control assembly are also disclosed.