Nonin Onyx II 9590

Asset Type

Pulse Oximeter

Manufacturer

Nonin

Model

Onyx II 9590

Manual Reference

Nonin Onyx Vantage 9590 Finger Pulse Oximeter Instructions for Use, document 113634-001-01; current Nonin Onyx Vantage 9590 product-support documentation.

Manufacturer Recommendation / AEM Status

The manufacturer states that the device's digital circuitry requires no calibration or periodic maintenance other than battery replacement. The reviewed manual lists an expected service life of five years.

• Replace both 1.5 V AAA batteries when the numeric displays flash once per second or as needed.
• Remove the batteries if the device will be stored for more than 30 days.
• Clean the device before applying it to a patient.
• Verify that every LED illuminates during startup. If any LED does not illuminate, do not use the device; contact Nonin Technical Service.
• Do not open the case or attempt electronics repair; field repair is not possible.
• A Datrend OxitestPlus7 can verify operation, but a functional tester cannot assess pulse-oximeter accuracy.

If the facility schedules inspection or functional verification, manage the interval under its approved AEM program, risk assessment, maintenance history, and applicable requirements. Do not represent a simulator check as manufacturer calibration or clinical SpO₂ accuracy verification.

What This PM Procedure Covers

• Identification and service-life review.
• Physical, spring, flexible-circuit, optical-path, display, and battery inspection.
• Manufacturer-approved cleaning.
• Battery and automatic power operation.
• Startup LED, pulse-quality, display, and shutdown verification.
• Optional functional-tester operation check.
• Return-to-service determination.

Required Tools and Equipment

• Soft cloth.
• Mild detergent or a 10% bleach solution made using household bleach containing 5.25% sodium hypochlorite.
• Two new 1.5 V AAA alkaline batteries if replacement is needed.
• Compatible pulse-oximeter functional tester, such as the Datrend OxitestPlus7 identified by Nonin, when required by facility policy.
• Facility-required personal protective equipment.

Do not use isopropyl alcohol, ammonium-chloride cleaners, caustic or abrasive cleaners, undiluted bleach, or cleaning solutions other than those recommended by Nonin.

Step-by-Step PM Procedure

1. Confirm Device Identification and Maintenance Basis

Action: Verify the asset tag, serial number, manufacturer, model, acquisition date when available, accessories, and CMMS record. Review whether the device has reached the manufacturer's five-year expected service life.

Expected outcome: The device matches the CMMS record, and age-related disposition is handled according to facility policy. Reaching five years does not establish a field-repair method or an invented tolerance.

2. Remove the Device From Clinical Use

Action: Confirm the oximeter is not applied to a patient. Ensure it is off before opening the battery tray.

Expected outcome: The device is ready for safe inspection and maintenance.

3. Perform a Physical Inspection

Action: Inspect the housing, upper and lower halves, hinge/spring, flexible circuit, finger stop, optical surfaces and light path, displays, pulse-quality indicator, battery tray and contacts, lanyard, and attachment for cracks, contamination, corrosion, leakage, loose parts, wear, liquid intrusion, or impact. Do not open the oximeter more than 90 degrees, twist or pull the flexible circuit, overextend the spring, or hang the lanyard from the flexible circuit.

Expected outcome: All accessible components are intact, the spring moves normally, and the optical path is unobstructed.

Remove from service if: A safety- or performance-related component is damaged.

4. Inspect the Batteries and Battery Compartment

Action: Check polarity, battery type and charge-state matching, leakage, corrosion, swelling, contamination, and contacts. Replace both batteries together when low or questionable using two new 1.5 V AAA alkaline batteries.

Expected outcome: The compartment is clean and undamaged, and a matched battery set is correctly installed.

Remove from service if: Leakage or corrosion has damaged the device, or correct battery replacement does not restore stable operation.

5. Clean the Device

Action: Wipe surfaces with a soft cloth dampened with mild detergent or the manufacturer-listed 10% bleach solution. Dry with a soft cloth or air dry. Do not sterilize, autoclave, immerse, pour or spray liquid onto the device, or twist or pull it while cleaning.

Expected outcome: The device is visibly clean and completely dry without damage.

6. Verify Automatic Startup and All LEDs

Action: Insert an appropriate test finger, nail side up, flat and centered, until it reaches the stop guide. Do not squeeze the device or press it against a surface. Observe the startup sequence.

Expected outcome: The device turns on automatically and every numeric-display LED and the pulse-quality indicator illuminate.

Remove from service if: Any LED does not illuminate; contact Nonin Technical Service.

7. Verify Pulse Detection, Display, and Signal Quality

Action: Allow the reading to stabilize and observe approximately four seconds of continuous green pulse-quality indication. Verify that SpO₂ and pulse-rate values display and the indicator flashes with the pulse. If signal quality is marginal, reposition or try another appropriate digit.

Expected outcome: The displays are complete and readable, a stable pulse is detected, and the pulse-quality indicator behaves normally.

8. Verify Finger-Removal and Automatic Shutdown Behavior

Action: Remove the test finger and observe the left-most SpO₂ digit and displayed values through shutdown.

Expected outcome: A minus sign appears; the last values remain for approximately ten seconds; the device then turns off automatically.

9. Perform an Optional Functional-Tester Operation Check

Action: When required by facility policy, use a compatible tester according to its manufacturer's instructions. Record simulator settings and displayed results, applying only supported facility-approved operational criteria.

Important limitation: A functional tester cannot assess clinical pulse-oximeter accuracy. Do not apply Nonin's clinical accuracy specifications as bench-simulator tolerances or document this check as calibration.

Expected outcome: The oximeter responds consistently to simulated input and displays plausible SpO₂ and pulse-rate values under the approved test method.

10. Complete the Return-to-Service Review

Action: Confirm inspection, cleaning, batteries, startup, all LEDs, pulse detection, displays, automatic shutdown, and optional functional testing all pass. Confirm no unresolved performance or accuracy complaint remains.

Expected outcome: The oximeter is ready to return to service according to facility policy.

Electrical Safety Testing

The Onyx II 9590 uses two AAA batteries and has no mains connection. The reviewed manual does not list protective-earth resistance or touch/chassis leakage testing as periodic maintenance. Do not add inapplicable electrical-safety limits. Evaluate an externally powered tester under its own documentation and facility policy.

Pass / Fail Criteria

PM Pass Criteria

• Housing, hinge/spring, flexible circuit, optical path, displays, battery tray, contacts, and accessories are intact.
• The device is clean and completely dry.
• Matched batteries are installed without leakage or corrosion.
• The device powers on automatically and every LED illuminates.
• SpO₂, pulse rate, and pulse-quality indication display and stabilize.
• Finger removal and automatic shutdown behave as described.
• Optional functional testing passes facility-approved operational criteria when performed.
• No unresolved performance or accuracy complaint remains.

Remove From Service Criteria

• Physical, flexible-circuit, spring, optical, battery-compartment, or liquid damage could affect operation.
• The device cannot be cleaned and dried using the approved method.
• Power remains intermittent after replacing both batteries.
• Any LED fails to illuminate during startup.
• Pulse detection, display, signal-quality indication, or shutdown remains abnormal.
• Optional operational testing fails approved criteria.
• An accuracy concern remains unresolved; a functional tester must not be used to claim clinical accuracy verification.
• Opening the case or internal repair would be required; refer to Nonin Technical Service.

Use the manufacturer service manual, facility policy, and approved AEM program to determine the final PM interval and return-to-service requirements.

Sources Used

• Nonin Onyx Vantage 9590 product support
• Nonin Onyx Vantage 9590 Instructions for Use
• Nonin Onyx Vantage 9590 product page