The MicroScan WalkAway System is an automated instrument used in clinical microbiology laboratories for the identification (ID) of microorganisms and the determination of their antimicrobial susceptibility (AST). This system streamlines workflow and provides accurate results for guiding patient treatment decisions. It utilizes microbroth dilution technology, considered a gold standard for obtaining Minimum Inhibitory Concentration (MIC) results. This automation allows laboratories to handle mid- to high-volume testing efficiently while maintaining high standards of accuracy, particularly in detecting emerging resistance mechanisms like MRSA or CRE. Reliable operation depends on precise initial setup, consistent calibration, and adherence to a strict maintenance schedule.
Initial System Setup and Configuration
The MicroScan WalkAway System implementation begins with careful site preparation, ensuring the environment meets the instrument’s operational requirements. The laboratory space must accommodate the physical footprint of the reader and incubator modules, while adhering to environmental conditions: typically 15°C to 27°C with 30% to 80% relative humidity. Power requires a stable, grounded electrical supply, and the instrument is engineered for power loss protection during interruptions.
Once the site is prepared, the physical components, including the main instrument, computer interface, and peripherals, are connected according to the manufacturer’s checklist. The system accommodates different panel capacities (e.g., 40 or 96 panels) depending on the model. Following installation, the LabPro Information Manager software is loaded and configured.
Software configuration involves defining user profiles and establishing connectivity to the Laboratory Information System (LIS). Integration with the LIS is critical for automatically transferring test orders and results, streamlining workflow and reducing manual transcription errors. The initial software setup also incorporates customized institutional procedures and expert rules, such as LabPro Alert\(_{EX}\), which automatically flags atypical results for immediate review by laboratory staff.
Calibration and Quality Control Protocols
Ensuring the accuracy of results requires calibration and quality control (QC). Calibration involves adjusting the instrument’s internal components, such as the optical reading system, to correctly measure growth and colorimetric changes within the microbroth dilution panels. While the system performs internal checks, full recalibration is typically a reactive procedure, performed when QC results fall outside acceptable limits or during a scheduled preventative service visit.
QC is a proactive testing process that uses known, characterized microbial strains to verify the system’s performance. Laboratories use specific reference organisms, most commonly sourced from the American Type Culture Collection (ATCC), which have known identification and antimicrobial susceptibility profiles. The frequency of these QC runs is standardized, often requiring daily or weekly testing, depending on the specific panel type and laboratory accreditation standards.
The procedure involves inoculating the QC panels with the reference strains and processing them through the WalkAway system, just like patient samples. The resulting ID and AST profiles must fall within the established acceptable ranges for the specific ATCC strain. If QC results are out of range, the laboratory must take immediate corrective action, which can include instrument troubleshooting, panel retesting, or initiating a full instrument recalibration procedure.
Routine Maintenance Schedule
Preventative care maintains the MicroScan WalkAway System’s reliability and minimizes operational downtime. Maintenance tasks are systematically organized by frequency, starting with daily checks to ensure the immediate readiness of the instrument.
Daily Maintenance
Daily tasks include checking and managing the waste fluid container, which holds spent reagents and wash solutions. Staff must also verify that all reagent levels, including oil and water reservoirs, are sufficient for the day’s testing.
Weekly and Monthly Maintenance
Weekly maintenance focuses on cleaning the reading chamber and the exterior surfaces of the instrument to prevent contamination and maintain optical clarity. The movement mechanisms, such as the robotic arm, are visually inspected for obstructions or buildup that could impede smooth operation. Monthly tasks include a more thorough cleaning of internal components and an inventory check of disposables and reagents.
Quarterly Maintenance
Quarterly maintenance, often performed by a trained service technician, involves scheduled optical checks and adjustments to the internal light source (typically a tungsten-halogen lamp) to ensure consistent photometric readings. This service also includes a comprehensive check of the temperature stability within the incubator, which is maintained at 35°C \(\pm\)1°C for optimal microbial growth. Adherence to this structured schedule helps prolong the lifespan of the components and ensures the system meets its performance specifications.
Troubleshooting Common Operational Issues
Even with maintenance, automated systems occasionally present operational issues. One of the most frequent mechanical issues involves a panel or tower jam within the incubator or reader arm mechanism. The fix involves safely accessing the instrument through the interlocked panel doors, carefully removing the jammed component, and initiating a system reset to clear the mechanical error flags.
Fluid level warnings indicate the waste container is full or reservoirs are low. The system is equipped with level sensors that notify staff, and the solution is simply to empty the waste or refill the appropriate reservoir. Communication errors between the WalkAway instrument and the LabPro software or LIS often require verifying the network connection and restarting the software modules to re-establish the data link.
The system communicates problems through specific error codes displayed on the screen, which serve as a practical guide for the operator. While deep technical repairs are reserved for certified service personnel, most common alerts are designed to be resolved quickly by laboratory staff following the instructions provided in the system’s operational guide.