Balancing the Books (July 20)

We first tried to fix the pesky scale by using a variable-voltage power supply we bought from the supermarket yesterday. Needing 9 Volts and 500 milliamps of power, the device we had purchased provided the 500 milliamps at 0, 3.5, 6, 9, or 12 Volts. However, the adaptor heads for the various voltages had ambiguous + and – labels, located to the sides and not specifying which way was correct. Sliding the switch to the 9V setting and guessing the polarity, we plugged in the scale with no results. “I hope we didn’t just fry everything,” Tom said. Disconnecting the adapter from the scale, we measured the voltage of the 9V plug—a staggering 16V from a device rated 0-12V! When we moved the selector switch to the ‘off’ position, the voltage only dropped to 10V—still above the 9V we needed!

Opening up the scale once again, we smelled something like burning metal and plastic. Examining the circuitry, we found that several electrical components had exploded or melted, permanently rendering the scale useless—as the Chinese-built power supply we had purchased (“The Egg”, as the product was called) was. All was not lost, however, for when the bodega (equipment closet) was opened, we found a suitable replacement part for a broken sphygmomanometer, which we were then able to repair, test, and return to the pediatric ward for service.

Our next task was to resume work on the patient monitors (pulse-oximeter, blood-pressure machine, and ECG all-in-one), each of which costs about $2,000. One of the units would not hold power, while the other gave errors for air leaks in the blood pressure tubing, though the tubes did not have any leaks. Opening up the machine which would not hold power, Tom removed a small watch-battery which gave the chip power for keeping time and holding memory. Now having reset the on-board computer, he reinserted the battery, and then absolutely nothing more was wrong with the unit. For the other unit not functioning correctly, we found a setting in “neonatal” mode, though the machine was trying to take adult blood pressures. When we switched this parameter to adult, the errors disappeared and this machine also functioned normally.

In conclusion, although we fried a $50 scale ‘por siempre’, we netted the hospital $3,950 dollars by returning the patient monitors to service. Chah-ching.