Syringe Pump Cam-Actuated Half-Nut Disengagement
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Solution Overview
Problem
Existing syringe pumps lack the ability to efficiently and accurately administer medications over extended periods, particularly in medical settings where precise fluid delivery is critical.
Innovation Solution
A syringe pump system that includes a housing with a motor, gearbox, and sensors for precise control of fluid delivery, along with a sliding block assembly and plunger head assembly for driving the syringe plunger, and a clamping mechanism for securing various plunger flange sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a syringe pump uses a motor and gearbox for fluid delivery, then the duration of action is improved, but the device complexity increases
Solution Approach 1:
The pump system is divided into distinct modular components: a motor assembly, a gearbox assembly, a syringe holder assembly, and a control assembly. Each module can be independently manufactured, tested, and replaced, reducing overall system complexity while enabling extended operation through coordinated function of multiple specialized components.
Solution Approach 2:
The motor and gearbox assembly serves multiple functions: it provides continuous rotational motion for extended fluid delivery, enables precise speed control for accurate dosing, and can be reversed for syringe repositioning. This multi-functionality extends the duration of action without proportionally increasing complexity.
2Measurement precision
If a syringe pump includes sensors for monitoring fluid delivery, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
Optical sensors are integrated into the syringe holder assembly to detect plunger position and fluid delivery rate in real-time. The sensor signals are fed back to the control assembly, which automatically adjusts motor speed to maintain precise delivery rates. This closed-loop feedback system achieves high measurement precision without requiring complex mechanical measurement mechanisms.
Solution Approach 2:
Traditional mechanical measurement systems (such as dial indicators or coded wheels) are replaced with optical sensors that use light transmission or reflection to detect plunger position. This substitution reduces mechanical complexity while significantly improving measurement precision and enabling digital integration with the control system.
3Ease of operation
If a syringe pump uses a sliding block assembly with cam and threaded portion, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The sliding block assembly incorporates a cam mechanism that converts rotational motor motion into linear sliding motion, automatically positioning and clamping the syringe. The threaded portion provides progressive engagement that guides the plunger into the correct position. This dynamic mechanism simplifies syringe loading operations while the modular design keeps overall complexity manageable.
Solution Approach 2:
The cam and threaded portion mechanism is designed to automatically perform syringe positioning and clamping functions without manual intervention. Once the syringe is inserted, the mechanism self-adjusts to secure it in the correct position and initiate fluid delivery, reducing the need for complex manual adjustment controls.
4Manufacturing precision
If a syringe pump implements precise control of motor rotation, then the manufacturing precision of fluid delivery is improved, but the use of energy increases
Solution Approach 1:
The motor operates in periodic cycles: high-speed rotation during initial fluid delivery, reduced-speed operation during precision dosing phases, and idle or reverse rotation during syringe repositioning. This periodic action pattern maintains high precision control while minimizing overall energy consumption by avoiding continuous high-power operation.
Solution Approach 2:
The control system dynamically adjusts motor parameters (speed, torque, direction) based on the delivery phase and required precision. During phases requiring high precision, the motor operates at lower speeds with higher torque control. During transition phases, parameters are adjusted to reduce energy consumption. This adaptive parameter control maintains manufacturing precision while optimizing energy use.
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 enables precise and reliable administration of medications, allowing for accurate control of fluid delivery rates and volumes, even over extended periods, thereby enhancing patient care in medical settings.
Implementation Method 1
a motor, a gearbox operatively connected to the motor
Implementation Method 2
a lead screw, and a sliding block assembly. The sliding block assembly may comprise a cam, a cam projection fixedly coupled to the cam, and a threaded portion capable of engaging and disengaging from the lead screw
Implementation Method 3
The sliding block assembly may comprise a cam, a cam projection fixedly coupled to the cam, and a threaded portion capable of engaging and disengaging from the lead screw. The threaded portion may be configured to be actuated between engagement and disengagement on the lead screw via rotation of the cam and cam projection
Implementation Method 4
a means for sensing rotation of the motor, a controller acting to control operation of the motor and monitor the quantity of the agent delivered to the patient
Data Source
AI summary
A syringe pump includes a lead screw, a motor, and a sliding block assembly. The lead screw has threads and the motor is coupled to the lead screw to rotate it. The half-nut housing has a half nut and a barrel cam. The half nut is disposed within the half-nut housing. The half nut has half-nut threads at an end adjacent to the lead screw void. The half nut engages or disengages with the threads of the lead screw. The half nut includes a half-nut cam-follower surface and a half nut slot. The barrel cam is disposed within the half-nut housing and engages with the half-nut cam-follower surface. The barrel cam includes a pin to fit within the half nut slot such that the barrel cam rotates between a first position and a second position to actuate the half nut between the engagement position and the disengagement position, respectively.