Board 553 - Technology Innovations Abstract Low Cost Pulse Oximeter Probe Repair (Submission #546)

Abstract

Introduction/Background Replacing the pulse oximeter probe on any of the high fidelity Laerdal® manikins can be expensive (∼$500). The simulation specialists at the Medical University of South Carolina (MUSC) found they could fix the majority of probes for less than $2.00 with readily available replacement parts. Methods There are two electronic parts to the pulse oximeter, an emitter (LED) and a detector. Figure 1. Most of the time the problem with the probe is due to a faulty plug, wiring or emitter. Steps to troubleshoot and repair the probe: Faulty Connector or Wire 1. Check the connector that plugs in to the simulator link box. 2. If the connector has a broken plug, replace it as follows. These connectors are readily available and cost ∼$1.50. 3. Check the wiring of the suspect probe near the hinge. If no problem, proceed to the Faulty Emitter section. Faulty Emitter 4. If the problem is not the connector or the wires, replace the emitter according the follow steps. a. Disassemble the probe using a paperclip to press the retaining pin completely through the clip. Figure 2 b. Separate the two pieces; use a flat bladed screwdriver to “scrape” the boot off the emitter piece of the clip. Figure 3 c. Peel the emitter off the boot from the back side. Figure 4 d. Cut the wires and strip off 1/8 inch of insulation; tin the wires with a soldering iron. e. Replace the LED, which costs ∼$0.25. The new LED has four leads. Figure 5 i. Bend the connected leads over on top of each other so they are flat with the body of the LED. ii. Place the new emitter in a vise with the leads facing you while soldering the wire to the leads. Make sure to observe proper polarity when connecting the leads. Notice the notch in the upper right corner of the LED make sure the reference or ground lead is connected here and the + voltage is connected to the lower lead. iii. Plug the probe in to a link box and turn it on. Use a voltmeter to determine polarity before attaching the new LED. An unmodified Laerdal SpO2 probe has a blue wire for the reference line. iv. After the polarity is confirmed, tin the LED leads and the wires before soldering them. v. Plug the probe back into a linkbox and turn it on to confirm that the LED lights. f. Peel off the silicon diffuser from the LED window on the rear of the boot. Figures 6a (before) & 6b (after) g. Place the new LED in the boot; apply a couple drops of super glue along each. NOTE: Use the super glue sparingly. Figure 7 h. Place a bead of super glue in the area shown by the red rectangle in Figure 8. i. Replace the emitter and boot; apply firm pressure for 30 seconds. j. After the glue has cured, put the probe back together. HINT: Insert the pin about half way through the clip after orienting the two pieces; put the spring in place. Use a small awl to hold the spring while pulling the two legs together and holding them with needle nose pliers. Figures 9 and 10. k. Place the spring on the pin and insert the pin completely. Results: Conclusion MUSC Healthcare Simulation center has replaced a dozen pulse oximeter probes over the last six years. The total cost savings is over $5000. Disclosures None.