1.  Field of the Invention
This invention relates to a liquid medicine-prescribing apparatus for blood vessel injection.  The present invention provides a fixed quantity of liquid medicine which can be prescribed without a bottle or a pack being placed at an upper position.  The present invention also presents a constant quantity of liquid medicine to be prescribed at the time of blood vessel injection.  The present invention is also directed to a control system for prescribing liquid medicine and a liquid medicine-prescribing system which can be used for a disposable purpose such as a small portable system which has replaceable parts. 
2.  Discussion of Related Art
Generally speaking, in the case of a liquid medicine, prescribing apparatus for blood vessel injection, a liquid medicine bottle is hung at an upper position and a liquid medicine is input into a blood vessel through a liquid medicine hose.  However, using such a system, when a patient moves, a liquid medicine bottle also is required to move simultaneously.  Also, when the liquid medicine bottle is hung on the upper position, portability is comprised.  Also, using such a system causes inconvenience because the liquid medicine can be used only in a fixed place. 
Accordingly, recently a device, which is designed for easily carrying as well as for being injected without placing a liquid medicine bottle at an upper position, has been developed.  However, most of these devices use a method which uses a silicon tube, through which a liquid medicine is supplied by expansion pressure while a tube is being expanded, so a liquid medicine is input into the tube.  These devices may also use a method which uses electric power using an adapter and a battery.  In these latter devices a liquid medicine can be input into a liquid medicine hose while a multiple axis, which circulates a curved surface and moves sequentially along a curved surface, pressurizes sequentially a liquid medicine hose and inputs a liquid medicine.  However, the disadvantage of the method which uses a tube is that there is some difference in prescribing a liquid medicine, since the beginning pressure of a tube which swelled differs from the last pressure of that tube.  In the case of the method where a multiple axis moves sequentially by a curved surface, there are disadvantages in that it is impossible to repair the device due to the complexity of manufacturing process, and because of high cost it is impossible to use it for a disposable purpose.