Radioactive Liquid Dispensing via Stepper Motor Pipette
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Solution Overview
Problem
Existing methods for transferring radioactive liquids lack accuracy and precision, and expose operators to nuclear radiation during the handling of hazardous substances in radiopharmaceutical production.
Innovation Solution
A liquid handling system with a radiation containment chamber and a pipette assembly mounted on a rotatable support arm, controlled by stepper motors, which allows for precise aspiration and dispensing of radioactive liquids while minimizing operator exposure through the use of radiation shielding and the absence of radiation-sensitive electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual methods are used to transfer radioactive liquids, then operator flexibility is maintained, but accuracy and precision of dispensing are insufficient and operator radiation exposure increases
Solution Approach 1:
The patent introduces a robotic arm as an intermediary between the operator and the radioactive liquid handling. The robotic arm performs the aspiration and dispensing operations within a radiation shielded enclosure, while the operator controls the system remotely through a user interface. This intermediary mechanism enables precise dispensing control while protecting the operator from direct radiation exposure.
Solution Approach 2:
The patent replaces manual mechanical pipetting operations with an automated robotic system. The robotic arm, controlled by stepper motors and position sensors, performs the liquid transfer operations with higher precision and consistency than manual methods, while the entire operation is conducted within radiation shielding to protect the operator.
2Object-affected harmful factors
If radiation shielding is added to protect operators, then operator radiation exposure is reduced, but device complexity and space requirements increase
Solution Approach 1:
The patent implements a nested structure where the robotic arm and liquid handling components are positioned inside a radiation shielded enclosure. The enclosure itself is nested within a larger support structure that includes the user interface and control systems. This nested arrangement provides effective radiation shielding while organizing components efficiently to minimize overall complexity.
Solution Approach 2:
The radiation shielded enclosure acts as an intermediary barrier between the radioactive materials and the operator. This enclosure is integrated with the robotic arm system, allowing the operator to control the robotic operations remotely without direct exposure to radiation, thus managing the complexity through functional integration rather than separate components.
3Manufacturing precision
If stepper motors are used to control piston displacement, then dispensing precision is improved, but the system becomes more sensitive to radiation damage
Solution Approach 1:
The patent positions the stepper motors and electronic control components outside the radiation shielded enclosure, using the enclosure as an intermediary protective barrier. The robotic arm transmits motion commands through the shielding, allowing high-precision volume control via stepper motors while protecting the electronics from radiation damage. This spatial separation maintains both precision and reliability.
Solution Approach 2:
The patent uses stepper motors with high-resolution position feedback to replace less precise control mechanisms. The stepper motors provide exact control of piston displacement for precise volume dispensing, while their placement outside the radiation field ensures long-term reliability and durability in the radiation environment.
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 accurate and precise transfer of small volumes of radioactive liquids between vials, reducing operator radiation exposure and maintaining high operational reliability in high-radiation environments.
Implementation Method 1
a radiation containment chamber including an enclosure constructed of a radiation shielding material
Implementation Method 2
a stepper motor operatively connected to the piston to control linear displacement of the piston
Data Source
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AI summary
Systems and methods for dispensing radioactive liquids using a liquid dispensing apparatus are described. The apparatus includes a support arm rotatable about a rotation axis, an actuator operatively connected to the support arm and configured to at least one of rotate the support arm about the rotation axis and displace the support arm in a direction parallel to the rotation axis, and a pipette assembly mounted to the support arm. The pipette assembly includes a pipette tip defining an opening through which liquids are aspirated and dispensed, a piston, and a stepper motor operatively connected to the piston to control linear displacement of the piston.