Knee CPM Troubleshooting
Since we have stocked facilities like yours with thousands of CPM machines and we have rented CPM machines to patients for more than 30 years, we have figured out just about every issue that can happen to almost every make and model of Knee CPM machine. We have included a few of the easy problems below. If you still have questions, please call one of our experienced technicians at 1 (877) 301-4276.
Problem – no power: It may sound silly, but make sure the machine is plugged in to a working outlet and the power switch is on. Check your circuit breakers and try the machine in a different outlet. If you still do not have power, you most likely will need a new power supply (if external) or you may just have a bad hand control cable. These items are usually easily replaced. Call us today for your CPM parts and service needs at (877) 301-4276.
Problem – squeaky machine: Most machines run very quietly and smoothly. Always be sure to place the knee CPM on a flat surface. Machines are more likely to make noise it they are on an uneven surface. If your machine begins to squeak, check to make sure the patient’s leg is not internally or externally rotating. A rotated leg can put uneven pressure on the track, causing the components to grind. If the CPM is noisy without a patient leg in the machine, apply white lithium grease or a similar agent on the drive screw inside the rubber track. Often times, you will need to apply grease on the inside of the rubber track seals. Adjust the CPM’s range of motion limits to run at full extension and full flexion and allow ample time (usually 20 minutes) for the lubricant to take effect. Be careful not to use WD-40 on your drive screw. It may reduce the noise initially but it will cause more long term issues like component failures and even louder squeaking. You may also find that the squeaking is coming from the proximal (closest to the groin) hinges. Try applying lubricant to this area also. If your machine continues to squeak, it may need to have its track components or belts thoroughly cleaned. This is a major operation that requires your CPM machine to be sent to Medcom for service.
Problem – not running proper range of motion: Many CPM machines have a lock function which prevents patients from changing the range of motion beyond certain set parameters. Always heed the directions given by the physician and DO NOT exceed any range of motion limits which were prescribed. Check your owner’s manual or call the medcom group if you are unable to unlock the range of motion on your hand control because all machine lock functions are different. If your machine appears to be calibrated wrong, it is recommended that a professional Biomedical Technician re-calibrate your machine to the proper angles. Do not use a machine which appears to be out of calibration for fear that the patient may be exceeding the prescribed range of motion. You may also have a bad Potentiometer Cable. This is the cable that connects at the knee hinge and is a common area for intermittent failures.
Problem – machine is migrating: If you feel or see the machine migrating away from the patient with his or her leg is in the CPM, it may not be fit properly. Many times the migration comes from an improper adjustment of the femur length. Try elongating this length to reduce migration. Also, look on the bottom of your CPM machine. It may be missing the rubber strips that help prevent migration. Some patient CPM pads or soft goods kits come with a longer proximal pad which is designed to rest under the patient’s upper leg/hamstring area (including those provided by the medcom group). If comfortable, have this piece of the pad kit rest underneath the patient to prevent the machine from migrating. Finally, check to make sure the surface upon which the CPM is resting does not slant downward. Patients who place their CPM on a firmer, more level surface will have fewer migration concerns to deal with.
Call us today to help troubleshoot your CPM issues at 1 (877) 301-4276.
We repair all types of CPM machines. Our hourly rate is $75/hour.
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