"Intuitive" is the word. Running Crono is straightforward and simple. Crono is designed to work with either a 10 or 20 ml syringe. (If you decide to use a 10 ml syringe, the infusion of that volume can be over anywhere from 2 to 99 hours. If you choose the 20 ml syringe, that volume can be infused from 4 to 99 hours.) When you first get the pump, the screen should show a large "OFF" signal, and a small "20" in the bottom left corner. (If the pump shows a small"10" in the top left corner instead, this is not a cause for concern; this simply means that it has been manipulated for some reason since it left the factory, but it does not indicate that the pump is pre-programmed incorrectly.) Before we even want to think about filling up the syringe and attaching it to the pump, here are some basic Crono features. First of all, you will see that the pump has three buttons: The function of some of these buttons is obvious. For instance, if you press "ON" or "+" the pump will turn on. If you are holding a Crono pump in your hand right now, try it! The other two buttons are the "d" button and the "-" button. If you press the "+" and "-" simultaneously, the pump will turn off. When the pump is turned on for the very first time, it will show a large number on the screen, probably "10.00." You will also see that or "20" is still displayed in the bottom left corner. (If this is not the very first time the pump has been handled and it shows another number, don't worry, it isn't important at this particular time.) The pump is giving you a message: "I am programmed for a 20 ml syringe and I am being asked to deliver that volume over 10 hours." You will see that, just by pressing either the - or + buttons, you can change the infusion time. Unless you want to use a syringe volume less than the standard 10 or 20 ml syringes, that is really all that is involved in day-to-day programming. (If you want to use a volume less than the standard 10 ml or 20 ml, look on page 26 of the manual.) If you happen to be happy with the default settings that are preprogrammed into the pump, you could start pumping right now. However there are two basic set-up subjects you need to know about. Basically, the pump needs to have two questions answered: 1) Do you want to change the syringe size from what is already programmed into it? 2) Do you want the End of Infusion alarm activated or not? The syringe size choice will probably already be answered for you. Either by previous experience with pumps or communication between you and your health care professional team, you will have concluded that your medication will come from either a 10 ml or 20 ml syringe. The decision to employ the End of Infusion alarm may be more a matter of your own personal needs. Do you think it is beneficial for the pump to tell you when the medication has been delivered...or not? There is no particular medical benefit to being notified that the infusion is finished, but sometimes pump users are waiting for the infusion to be finished so they can disconnect from the pump. Others aren't that concerned about being notified. You may want to think about this and consult with your health care professional team and perhaps other family members before making a final decision. The way we get to the point of changing the syringe size and telling the pump whether you want the End of Infusion Alarm on or not is to take the battery out of the pump and put it back in again. One of Crono's features is that the battery only has to be changed about every six months, so getting to the battery involves finding a tool to assist in opening the battery compartment door. A paper clip is perfect for this. Just insert the paper clip into the door opening and lever the door open. Take the battery out, wait for a few seconds and put the battery back in again. Replace the door. The screen will show that the pump is going through a brief self check and then show you "20" flashing. This is your opportunity to change the syringe size to 10 ml if that is what you want. You change it just by pressing, and keeping pressed, the "-" button for a few seconds. Once "10" is flashing on the screen, just leave the pump alone for a few more seconds. The screen with then show "AL.0" flashing. This is your opportunity to activate the End of Infusion Alarm if that is what you want. You activate that feature by an extended press on the "+" button. "AL.1" will show on the screen, confirming that the End of Infusion Alarm is activated. Once you have finished with the two steps described above, you know really all you need to know about programming Crono. (Unless you want to start with a volume size less than either the standard 10 or 20 ml, for which the instructions are on page 26 of the manual.)