Infusion Pump Independent Valve Control for Flow Reliability
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Solution Overview
Problem
Existing infusion pumps face challenges in maintaining low flow rates and controlling fluid flow accurately, particularly due to mechanical failures such as bearing failure, which can lead to uncontrolled fluid delivery and hazardous dosage issues, and manual gravity-feed methods are prone to human error.
Innovation Solution
An infusion pump equipped with a specially programmed microprocessor, flow sensor, and independent control of inlet and outlet valves using actuators, allowing for precise control of fluid flow rates and redundancy in flow shut-off, even in the event of mechanical failure, and the ability to switch between gravity-feed and active pumping modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single cam shaft is used to control both upstream and downstream valves and peristaltic fingers, then the device complexity is reduced, but the reliability deteriorates because bearing failure leads to loss of flow control
Solution Approach 1:
The patent divides the single cam shaft system into separate drive mechanisms: one cam shaft for controlling the upstream and downstream valves, and a separate drive mechanism for the peristaltic fingers. This segmentation ensures that failure of one mechanism does not compromise the other, maintaining flow control reliability even when mechanical components fail.
Solution Approach 2:
The patent implements a safety feature where the downstream valve can be closed independently of the peristaltic pumping action. This beforehand cushioning ensures that even if the peristaltic drive fails, the system can prevent uncontrolled fluid delivery by closing the downstream valve, thereby maintaining reliability without requiring complex redundant systems.
2Productivity
If the upstream valve is fully opened to maximize fluid intake, then the productivity is improved, but the manufacturing precision deteriorates because the amount of fluid entering the tubing cannot be precisely controlled
Solution Approach 1:
The patent employs a feedback mechanism where a sensor detects the actual fluid flow or volume delivered, and this information is fed back to the control system. The control system then adjusts the timing and duration of the upstream valve opening and peristaltic finger compression to achieve precise fluid volume control, allowing the valve to be fully opened for maximum productivity while maintaining precision through active control.
Solution Approach 2:
The patent makes the valve opening duration and peristaltic compression timing dynamic rather than fixed. The control system can adjust these parameters in real-time based on the required fluid volume, allowing the upstream valve to be fully opened when high productivity is needed while precisely controlling the intake volume through variable timing, thus resolving the contradiction between productivity and precision.
3Ease of operation
If manual gravity-feed operation is used, then the ease of operation is improved, but the reliability deteriorates due to human error in controlling flow rates
Solution Approach 1:
The patent implements an automated control system that monitors fluid flow, detects abnormalities such as occlusions or disconnections, and automatically responds by adjusting valve positions or alarming. This self-service capability maintains the simplicity of operation for the user while eliminating human error in flow rate control, as the system autonomously manages the critical control functions.
Solution Approach 2:
The patent replaces manual mechanical control of flow rates with an automated electronic control system that uses sensors and actuators to precisely regulate fluid delivery. This substitution maintains ease of operation through simple interface controls while dramatically improving reliability by eliminating human error in flow rate management through automated monitoring and adjustment.
Data Source
AI summary
An infusion pump is provided, including a specially programmed microprocessor, a flow sensor for measuring flow from a source of fluid through an output tubing, a pumping section including a plurality of fingers in operational relationship to the output tubing, an outlet valve associated with the output tubing, and a first actuator configured for sequentially displacing the plurality of fingers to displace fluid through the output tubing. An inlet valve is disposed between the pumping section and the source of fluid; and a second actuator is also included. For detection, by the flow sensor, of flow above a predetermined level, the microprocessor is configured for one of: closing the outlet valve independently of the inlet valve using the first actuator; and closing the inlet valve independently of the outlet valve using the second actuator.