Windows Troubleshooting Tips

General Windows Issues Cardiocomp for Windows Flexicomp for Windows Physiogrip for Windows Spirocomp for Windows

General Windows Issues

Data Plot Falls Behind Your McADDAM II system has a large internal buffer (128k). This means that if your computer falls behind (can not draw data to the screen as fast as it's being acquired), no data will be lost nor will the data acquisition rate be compromised. The slower your computer is, the more pronounced this problem will be, however. If the plot is falling behind and you find it confusing or annoying: Try a slower data acquisition rate (if appropriate). Make sure that your computer is doing NOTHING else in the background. Set your video display to 256 colors if it is currently set to more colors.   McADDAM II Interface Fails to Initialize Is the serial port cable connected properly? Does the serial port to which McADDAM II is connected match the one selected in the software preferences/settings? Is the McADDAM II powered on? The power indicator (light) on the front panel should be lit. Occasionally things can just get so badly out of sync that the best thing to do is quit the program, turn the McADDAM II interface off, wait a few seconds, then turn the McADDAM II interface back on and restart the software.

Cardiocomp for Windows

Noisy Signal The Cardiocomp hardware is very sensitive due to the small voltages being measured. As a result, noise can be easily introduced into the signal from a number of sources. To ensure a clean signal, pay special attention to the following points. First, make sure that you do a good job "prepping" the subject and positioning the electrodes. Abrade the skin well with an alcohol pad, and use the appropriate amount of electrode gel in order to enhance conductivity. Try to position the electrodes over an area of the skin that has little or no hair and which overlies as little muscle as possible. Securing the ends of the electrode cables to the subject with tape (so as to prevent movement at the attachment of the cable to the electrode) can help as well. Try to get the subject to relax as much as possible, since electrical impulses generated by background muscle tension can appear as noise in the signal. Having the subject lie down is ideal, with a relaxed seated position being the next best choice. Make sure all of the electrodes and electrode jacks are firmly connected. Finally, electromagnetic noise from other electrical equipment in the room - especially 60 cycle interference from florescent lighting, electric motors and the like - can also introduce noise into the ECG signal.

Flexicomp for Windows

Software Doesn't Wait for Hammer Application Make sure that the hammer is connected to the external trigger connector, the one on the far left labeled "Transducer," and that the external trigger adjustment knob is in the correct position. Consult the Flexicomp Lab Manual for details. If the hammer is connected and the external trigger adjustment is correct, then the problem is likely a short circuit in the hammer switch or cable. Repair or replacement of the hammer is required. Transducer Rotation Not Reflected on Graph Make sure the thumbscrew on the transducer is tight. You may need to re-calibrate Hammer Stimulus Application not Detected Check the hammer setup as shown in the section on hammer setup or press the "Hammer Setup" button on the "Settings/Calibrate" window. To test the hammer setup, press in the hammer button. When the hammer button is in, the "True" light on the McADDAM II interface should be lit. When the hammer button switch is not pressed the "True" light should not be lit.

Physiogrip for Windows

Motor Point Pointers Obtaining a good set of data with Physiogrip can require patience and persistence in locating the subject's motor point. There is also a great deal of individual variation in the quality of the twitch response you will obtain from electrical stimulation. Following are some pointers which should increase your chances of acquiring good data. Try warming the muscles up a bit first by squeezing a ball or hand grip or just repeatedly making a tight fist and relaxing. Stretching the muscles by pulling the fingers toward the back of the forearm and massaging the forearm can also aid in the warm-up. Prep skin surface just as you would for an ECG - both the back of the hand where the negative electrode is attached as well as the volar surface of the forearm where you will be stimulating. Make sure you are using the lightest weight spring on the Physiogrip transducer and that the tension is backed off as much as possible by turning the wing nut in a counter-clockwise direction. Sometimes, replacing the spring with a lightweight rubberband will reduce the dampening even further. Often, just the act of rotating the forearm into position on the transducer can lead to a loss of the motor point under the probe. Therefore, instead of grasping the transducer like a pistol, keep the hand palm-up, and position it under the transducer so that the 3rd or 4th finger is pulling the trigger from underneath. Use books, rags, or other items to prop up the arm so that the hand (and finger) rests in the most favorable position under the trigger. Females frequently have a little more trouble than males. This is probably due to differences in subcutaneous conductivity. With females in particular, often the best results can be achieved by using the fourth finger rather than the third finger. Try using a stimulator probe other than the one supplied. Some people have achieved good results using a large electrode such as an ECG electrode. You may find that with the large electrode you will stimulate too many muscle fibers. Be carefull, however. With a large electrode it will be easier to slip up and apply a voltage to the left hand. If you are still having trouble, and you are sure that you have followed the directions carefully, try a different subject. Data Seems Noisy or Jumpy An ungrounded computer can cause the data to be jumpy. Plug the computer, stimulator, and McADDAM II interface into a grounded electrical outlet. Also, if the transducer has been stored and not used for a long period of time, the potentiometer (POT) inside can become slightly corroded and dirty - particularly in humid environments. Try turning the large pulley back and forth through its full range several times to "clean" the contact wiper. If you feel comfortable enough doing so, you can even disassemble the transducer and spray some television tuner cleaner into the POT and then rotate the knob back and forth. To access the POT, simply remove the four screws from the metal back plate of the transducer box (the plate on which the connector is mounted).

Spirocomp for Windows

Tidal Cycles Not Detected During TV & ERV Measurements How the spirometer responds to different breaths can be adjusted by changing the tidal sensitivity setting in the software preferences. Consult the Spirocomp User Manual for details. Calibration Difficulty If you are using the Phipps & Bird 6 liter spirometer, make sure that there is a friction band (rubberband) inside the groove of the white pulley over which the chain rides. A dry rotted or missing rubberband will cause the chain to slide over the pulley without turning it, resulting in an inability to calibrate. If you are using the Phipps & Bird 6 liter spirometer, make sure that the white pulley has not separated from the black knob. They should turn together as one unit. If the white pulley is loose and sloppy and turns independently of the black knob, the bond between the pulley and knob has failed and the unit needs to be repaired. You can perform the repair yourself. All you need is a small allen (hex) wrench and some super glue or other strong adhesive. Use the hex wrench to loosen the small inset hex screw on the side of the black knob, and then remove the knob and pulley. Glue the two back together with the adhesive, making sure that the holes are centered, and then reassemble. Chain Jumps Off Pulley During Inflation If you are using the Phipps & Bird 6 liter spirometer and the chain tends to jump off the pulley during volume measurements, check that nothing has become lodged under the friction band in the groove of the pulley, thereby causing a high spot and a tendency for the chain to slip off the pulley. Remove the rubberband and then reseat it. Also, if the bell float is not remaining level throughout its travel, that could also contribute to the chain's tendency to jump off the pulley. See the next tech tip for help with that problem. Bell Float Tips to One Side (Does Not Remain Level) This may happen with some Phipps & Bird 6 liter spirometers. At its worst, it could cause the chain to jump off the pulley during volume measurements. Sight the vertical portion of the chain as it descends from the pulley to the bell float and make sure that it is perpendicular to the top of the bell from all angles. In particular, the chain should be absolutely vertical when viewed in line with the long axis of the float (i.e. parallel with the scale arm). If it is not, gently twist the support post on which the scale arm is mounted. This should improve alignment and will tend to straighten out a leaning bell float. Another thing to try is turning the bell float around so that it is oriented 180 degrees from the way it was originally. This is accomplished by removing the bell float from the tub, spinning it 180 degrees, and reinserting it. You might have to compress the sides of the bell float slightly in order to get it past the retaining pins which protrude from the inside top of the tub. If all else fails, you may have to resort to using one or more counterweights to level the bell float. Simply place coins, microscope slides, or any other handy lightweight small items on the high side of the float to even things out. Readings Seem Unrealistically High Check that the BTPS factor was not inadvertently set to some unreasonably high value. The BTPS factor can be changed in the Preferences section of the software and is accessed under the Edit menu. Readings Seem Unrealistically Low Make sure that the transducer is properly calibrated. Recalibrate it if in doubt. Check that the BTPS factor is not set to some unreasonably low value. The BTPS factor can be changed in the Preferences section of the software and is accessed under the Edit menu. The chain may be "slipping" over the transducer pulley because of a missing, poorly seated, or old (dry rotted) friction band. The friction band is a special size rubberband which sits in the groove of the large pulley. If the chain is slipping, then the pulley isn't turning as much as it should, thereby resulting in low readings. This problem is likely to be most noticeable during rapid movement of the bell float such as VC measurements. Try reseating or, if necessary, replacing the friction band. Data Seems Noisy or Jumpy An ungrounded computer can cause the data to be jumpy. If at all possible, plug the computer and McADDAM II interface into a grounded electrical outlet. Also, if the transducer has been stored and not used for a long period of time, the potentiometer (POT) inside can become slightly corroded and dirty - particularly in humid environments. Try turning the large pulley back and forth through its full range several times to "clean" the contact wiper. If you feel comfortable enough doing so, you can even disassemble the transducer and spray some television tuner cleaner into the POT and then rotate the knob back and forth. To access the POT, simply remove the four screws from the metal back plate of the transducer box (the plate on which the connector is mounted). Capacity of Spirometer Insufficient Unfortunately, there's not much you can do if individuals exceed the capacity of the 6 liter Phipps & Bird spirometer. You can try "overfilling" the tub slightly, but that's about it. If you own the Phipps & Bird 9 liter spirometer, this should not be an issue. Valves Leaking Air If there is air escaping from the valves, make sure you follow the disinfecting procedure outlined in the Spirocomp Lab Manual. Immersing the valve assembly in the alcohol solution and then rinsing between subjects not only disinfects, but the wetting of the valves helps the rubber diaphragm to seal better. If the rubber diaphragm is warped and doesn't seal properly even when wet, then replacing the valve(s) is the only option.