Patent ID: 9714886
Date: 2017-07-25
CPC Classifications: G01N

Claim:
1. A sample injection device for biochemical analysis configured to inject a sample into a carrier-liquid channel, the device comprising: a septum on a lower wall side at a sample injection position of the carrier-liquid channel; a septum on an upper wall side at the sample injection position of the carrier-liquid channel; a vessel which is arranged below the septum on the lower wall side and configured to store the sample; a cylindrical needle which is configured to penetrate through the septum on the upper wall side in a vertical direction and penetrate through the septum on the lower wall side; a cylindrical guide provided below the septum on the lower wall side and configured to guide the cylindrical needle; a needle moving unit configured to induce the cylindrical needle to move in a vertical direction and to induce the cylindrical needle to move at least to a sample drawing position, at which a tip of the cylindrical needle faces an inside of the vessel after having penetrated through the septum on the lower wall side, to a sample injection position, at which the tip of the cylindrical needle faces an inside of the carrier-liquid channel after having exited through the septum on the lower wall side, and to a washing position, which is set between the sample drawing position and the sample injection position and at which the tip of the cylindrical needle faces an inside of the cylindrical guide; a measurement pump connected with the cylindrical needle on a side of a base end section thereof and configured to carry out drawing when the cylindrical needle is positioned at the sample drawing position and carry out discharge when the cylindrical needle is positioned at the sample injection position; a pretreatment-, dilution-, or washing-liquid tank; a switching valve which is a three-way valve disposed between the base end section of the cylindrical needle, the measurement pump and the pretreatment-, dilution-, or washing-liquid tank and which connects the measurement pump with the pretreatment-, dilution-, or washing-liquid tank at a first position of the switching valve and connects the measurement pump with the base end section of the cylindrical needle at a second position of the switching valve; and a discharge pump connected to a space surrounding a tip of the cylindrical guide and configured to carry out drawing, wherein the measurement pump can draw liquid from the pretreatment-, dilution-, or washing-liquid tank at the first position of the switching valve and discharge the drawn liquid to the inside of the cylindrical needle at the second position of the switching valve, and wherein at the washing position, washing liquid having been discharged to the inside of the cylindrical needle by the measurement pump is discharged from the tip of the cylindrical needle and the washing liquid is drained by using the discharge pump.