Automated Drop Deposition for Microorganism Counting
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Solution Overview
Problem
The existing colony counting methods, such as CFU, are laborious, prone to errors, and cause damage to bacteria during the manual spreading process, especially in high-volume applications, and require expensive and cumbersome robotic setups for automation.
Innovation Solution
A method using standard syringes to deposit specimen samples as drops on a non-wetting solid substrate, allowing for contactless deposition and precise control, with the concentration determined by counting empty drops, and an apparatus to synchronize drop deposition and substrate movement for accurate pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If manual spreading is used to deposit liquid sample on agar surface, then the method is simple and requires basic equipment, but the spreading quality is sub-optimal with colonies aggregating and high error rates
Solution Approach 1:
The patent replaces the manual mechanical spreading operation with an automated robotic system that uses precision motors and control algorithms to deposit liquid samples in systematic patterns (e.g., spiral, concentric circles). This substitution eliminates human variability and achieves uniform colony distribution while maintaining operational simplicity through automated control.
Solution Approach 2:
The robotic spreading system dynamically adjusts its motion parameters (speed, trajectory, deposition rate) during the spreading process to optimize colony distribution. The system can adapt its path in real-time based on feedback sensors, ensuring uniform coverage across the agar surface regardless of variations in liquid sample volume or viscosity.
2Manufacturing precision
If manual spreading is performed to achieve good distribution, then spreading quality improves, but the time required increases and bacteria are damaged
Solution Approach 1:
The robotic system performs spreading operations at optimized speeds that are faster than manual operations while maintaining or improving distribution quality. The automated control enables continuous motion without the pauses and adjustments required in manual spreading, reducing total time while preventing bacterial damage through controlled, gentle deposition forces.
Solution Approach 2:
The robotic spreading system operates continuously without interruption, moving the liquid sample across the agar surface in a seamless motion. This eliminates the start-stop nature of manual spreading, reducing the total time required while ensuring continuous, uniform distribution that prevents colony aggregation and minimizes bacterial stress from repeated handling.
3Productivity
If robotic automation is implemented for high-volume plating, then productivity increases, but device complexity and cost increase significantly
Solution Approach 1:
The robotic spreading system is designed with multi-functionality to justify its complexity: it can perform not only spreading but also automated liquid sample dispensing, plate handling, and even colony counting. This consolidation of multiple functions into a single platform increases productivity across the entire workflow while amortizing the complexity and cost across multiple operations.
Solution Approach 2:
The robotic system is modular, with separate components for liquid handling, spreading motion, and control. This segmentation allows for easier maintenance, calibration, and scaling. Individual modules can be optimized independently, and the system can be configured for different throughput levels, making the complexity manageable and the investment justified by the productivity gains.
4Object-affected harmful factors
If specific equipment is used for contactless deposition, then disinfection requirements are reduced, but device complexity and cost increase
Solution Approach 1:
The system uses a non-contact liquid deposition mechanism where the liquid sample is transferred through an intermediary field (e.g., electrostatic field, acoustic field, or controlled gravity flow) rather than direct contact between the container and agar surface. This intermediary approach eliminates the need for sterilization of contact surfaces while maintaining precise control over deposition, reducing complexity compared to full contactless technologies.
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
This method achieves nearly perfect spread and accurate counting with lower disinfection requirements, reducing errors and preserving microorganisms for potential revival, while being more cost-effective and efficient than existing automated systems.
Implementation Method 1
pushing the specimen sample out of the container to produce drops of a predetermined volume that detach by gravity and fall on said at least first substrate
Implementation Method 2
said at least first substrate is a non-wetting solid substrate so that the drops of said first plurality of drops produce a pattern of at least a first plurality of isolated drops on said at least first substrate
Data Source
AI summary
According to an aspect, the present description is related to an apparatus for depositing on a substrate drops of a specimen sample including a liquid medium and living microorganisms. The apparatus includes a tray for supporting the substrate, a container, e.g. a syringe, configured to receive a volume of the specimen sample and a drop deposition motor configured to push the specimen sample out of the container to form drops of a predetermined volume that detach by gravity and fall on the substrate. The apparatus further includes guiding motors configured for changing a relative position of the tray and the container and a control unit configured to synchronize the drop deposition motor and the guiding motors in order to deposit drops on the substrate according to a pattern.