SpO2 Sensor Most Durable Compared to Envitec, Unimed, and Cables & Sensors Brands

By Jason Sims October 24, 2018

Nonin Medical SpO2 Sensor Most Durable Compared to Envitec, Unimed, and Cables & Sensors Brands
Greater Durability Can Contribute to Lower Overall SpO2 Costs

An independent laboratory test comparing Nonin Medical’s 8000AA Adult Pulse Oximetry Sensor with three competitive finger clip pulse oximeter sensors (labeled and promoted as “Nonin Compatible”) was performed in order to compare aspects of durability. The tested brands included Nonin Medical, Envitec, Unimed, and Cables & Sensors. Specifically, the test sought to quantify and compare the maximum amount of force which can be applied to the sensor-end of the SpO2 finger clip sensors before signal transmission from the sensor to the oximeter failed.

As Figure 1 shows, the Nonin 8000AA sensor displayed the greatest durability among the sensors tested. Even more significantly, the structural integrity of the Nonin sensor was never compromised until the sensor reached its average failure point of 50.2 lbs of force. In comparison, other sensor brands became structurally compromised and permanently weakened at less than half of the strength of force exerted on the Nonin sensor before signal transmission failure.

Nonin sensors displayed the greatest durability among sensors tested. Unlike other sensor brands, Nonin sensors remained uncompromised until their breaking point.

Four brands of pulse oximeter clip sensors underwent a mechanical pull test at The Specialty Lab, Inc. in Minneapolis, Minnesota. Using a mechanical pull fixture, gradual force was applied to the sensors’ cables. The objective of this testing was to measure the tensile force on the sensor cable until the point where pulse oximeter signal transmission failure occurred, as verified by loss of reading on the pulse oximeter monitor. Testing was performed on three samples from four different manufacturers.

The four sensor brands included:
• Nonin Medical adult SpO2 reusable sensor, model 8000AA
• Envitec reusable SpO2 adult finger sensor, model F-3012
• Unimed reusable adult finger SpO2 sensor, model/catalogue number U410-08L
• Cables & Sensors reusable adult finger SpO2 sensor, model/catalogue number S403-080

Test equipment included:
• Instron TTC Automated Material Tester
• Instron TTC Weights
• Nonin Model 7500

The testing session began by connecting each manufacturer’s sensor to the Nonin Model 7500 pulse oximeter. A finger simulator was then inserted into the sensor to verify functionality. Next, the sensor was inserted into the bottom restraint fixture of the mechanical pull tester and the cable was secured to a cable restraint fixture. For testing consistency, the same amount of cable length was left between each restraint fixture at the beginning of each test. The gauge was then zeroed out while no tension was applied to the sensor. Finally, the mechanical pull tester was started, pulling at a rate of 2.0 in/min. The pull test was halted the instant readings were lost on the oximeter monitor. The maximum tension was recorded, and a plot of load versus displacement was generated for the report. The entire procedure was repeated for an additional two samples of each brand under test.

As Figure 2 shows, the Nonin Medical 8000AA SpO2 sensor endured the most amount of force and continued to perform with over 50 lbs of force applied. Other sensors that were tested in this session market and label themselves as “Nonin Compatible.” When tested with Nonin oximeters, competitive sensor performance was compromised well before the point of complete breakage and failure.

FIGURE 2. Test results showed the Nonin sensor was
the most durable over Envitec, Unimed, and Cables & Sensors brands.

Sensor Force at First Compromise (lb) Force at Failure (lb)
Nonin 50.2 50.2
Envitec 23.2 41.6
Unimed 21.1 21.2
Cables & Sensors 17.6 20.6

n=3; numerical averages displayed

• The Nonin sensor was strongest and never failed or broke with up to 50.2 lbs. of force.
• The Nonin sensor showed no compromise up to 50.2 lbs. of force.

Sensor replacement is often the most significant expense in the cost of ownership of pulse oximetry patient monitoring. Sensors must be able to withstand the rigors of a fast-paced healthcare environment. They get pulled, caught, dropped and damaged on a regular basis. In addition, testing shows that sensors start to break even though damage to them may not be readily visible. The shortened lifespan due to compromise and breakage leads to increased sensor replacement costs.

Nonin’s Durable SpO2 Sensors are Designed for a Wide Range of Patient Sizes, Ages and Conditions

* Requires adapter for use with WristOx2®, Model 3150