Chemdye CDWU Ultrasonic Cleaning Indicator

Introduction

Control of the cleaning and washing process of medical instruments and materials is critical for the success of subsequent disinfection and sterilization processes. Ultrasonic washers are key in this process, removing soils from difficult-to-access areas like joints, crevices, and lumens of medical instruments. Their cleaning power stems from cavitation, where high-temperature vacuum bubbles collapse, creating high-pressure liquid flows that impact instruments and remove residues.

Product Description

The Chemdye® CDWU indicator is designed to monitor the cavitation process. It allows testing the operation of ultrasonic washing machines with different configurations by measuring the generated cavitation energy. The CDWU indicator consists of a clear vial containing a reactive blue solution and immersed glass beads. When cavitation energy is adequate, the vibration of the glass beads triggers a color change in the solution from blue to yellow, passing through intermediate green shades.

Characteristics

The CDWU indicator does not require a special holder. Simply place one vial in the ultrasonic machine zone you wish to monitor and start the ultrasonic washer cycle. It can be used for monitoring ultrasonic cleaning processes in machines operating between 18°C to 70°C, with detergent or washing solution, and at frequencies of 35 kHz or higher.

Instructions for Use

Ultrasonic washers should be checked at least once per week, and results recorded. The CDWU indicator can be used for two types of tests:

Periodic Functional Test

For initial setup of the washing machine, and at regular intervals of three months or after a repair. Its purpose is to verify the uniform distribution of the cavitation process within the washer tank.

Routine Test

Performed weekly or daily to verify correct cavitation function, allowing detection of potential failures in the ultrasonic washing machine's performance.

Procedure

1. Prepare the tank with cleaning solution according to the ultrasonic washing machine manufacturer's and detergent manufacturer's instructions.
2. Degas the tank as per the detergent manufacturer's instructions.
3. Adjust the temperature according to the detergent manufacturer's instructions.
4. Take the necessary number of indicators based on the test type (Periodic Functional Test or Routine Test) and the washer tank size.
5. Place them in the basket without load, according to the distribution plan for the test.
6. Place the basket in the tank and run the desired ultrasonic cleaning program.
7. After the program is completed, remove the indicators from the machine.
8. Analyze the results according to the table and record the obtained data.

Interpretation of Results

The color change from blue to yellow is an accepted result, indicating adequate cavitation energy for washing. The time taken for this change reflects the strength of the cavitation energy. An intermediate green color indicates a failure to reach the necessary cavitation energy for good cleaning.

In both tests, a slower color change in an indicator suggests an area with less cavitation energy or a "weak point" in the tank. A failure result points to a "cold spot" or an area lacking sufficient cavitation energy for proper washing.

The cavitation process is influenced by variables such as dissolved gases in water, water hardness, temperature, and detergent use. If results are unfavorable, check:

• Working Frequency: CDWU indicators are usable with frequencies ≥ 35 kHz. Frequencies > 40 kHz result in faster color changes.
• Presence of Bubbles: Bubbles in the washing solution indicate dissolved gases, which can weaken cavitation. Degassing the cleaning solution is crucial and may take minutes to hours depending on temperature and tank size. Follow manufacturer instructions for degassing.
• Time and Temperature: The CDWU indicator is designed for ultrasonic washing with a minimum duration of 3 minutes (180 seconds) and temperatures between 18-70°C.
• General Machine Condition: Visible deterioration or unusual sounds from the ultrasonic machine may indicate malfunction.

Repeat the test after checking these factors. Report any unsatisfactory results for corrective action according to institutional policies. For operational questions or fault verification, contact technical service.

Precautions

• Do not reuse CDWU indicators.
• Do not open the indicator before use, as this will cause deterioration.
• Do not use CDWU indicators for monitoring non-ultrasonic cleaners.
• Indicator color may vary after 24 hours; read and record results during the test.

Storage

Store CDWU indicators at temperatures between 10-30°C, protected from light and moisture, in their original packaging. Shelf life is 18 months under these conditions.

Disposal

Dispose of indicators after use according to your country's healthcare and safety regulations.

Results Reference Guide

This section describes the visual outcomes of the test:

• Unprocessed: The indicator solution is blue.
• Failures: The indicator solution shows intermediate green colors, indicating insufficient cavitation energy.
• Processed and Correct: The indicator solution has turned yellow, indicating adequate cavitation energy.

Test Distribution: The document includes diagrams illustrating the placement of indicators in small, medium, and large ultrasonic cleaners for both Periodic Functional Tests and Routine Tests. These diagrams show the recommended distribution pattern to ensure comprehensive coverage of the tank's cavitation performance.

Symbols Explanation

• [CE mark]: Conforms to European Union standards.
• [EU Representative]: Authorized representative in the European Community.
• [Medical Device symbol]: Indicates the product is a medical device.
• [Batch Number]: Batch number.
• [Manufacture Date]: Date of manufacture.
• [Expiration Date]: Date of expiry.