Injection head for injecting a fluid substance and permitting monitoring of the injection site before injection of the fluid substance, and syringe comprising such a head

A syringe for injecting a fluid substance through a skin barrier into an injection site on a body, comprising:

• a reservoir for containing the fluid substance to be injected, pressure of which can be controlled;
• and
• an injection head, the injection head comprising:
• a connection body connected to the reservoir, the connection body comprising a guide channel and an injection channel, each of the guide channel and the injection channel extending from a front part of the connection body to a rear part of the connection body, the injection channel comprising one end emerged into the guide channel and another end configured to communicate with an outlet of the reservoir;
• a hollow tube extending from the guide channel of the connection body to an outlet of the front part of the connection body, the hollow tube configured to communicate with the outlet of the reservoir via the injection channel when the connection body is connected to the reservoir, the hollow tube having a distal end, the hollow tube or the connection body comprising at least one region for monitoring and characterizing a liquid originating from the injection site prior to injection of the fluid substance;
• a solid needle having a pointed distal end, the solid needle slidably mounted in the guide channel and extending from the connection body;
• and
• a control mechanism configured to control movement of the solid needle relative to the hollow tube between a pricking position and a position for monitoring and characterizing the fluid originating from the injection site via the region for monitoring and characterizing, wherein the control mechanism comprises a shuttle mounted to the connection body, the shuttle being movable relative to the connection body in order to place the solid needle into the pricking position or in the position for monitoring and characterizing the liquid originating from the injection site, wherein the solid needle is rigidly connected to the shuttle, and the hollow tube is rigidly connected to the connection body,
• wherein, in the pricking position, the solid needle extends through the hollow tube, the pointed distal end of the solid needle extends beyond the distal end of the hollow tube, and the pointed distal end of the solid needle and the distal end of the hollow tube form a penetrating assembly configured to penetrate into the injection site on the body, and
• wherein, in the position for monitoring and characterizing the fluid originating from the injection site, the solid needle remains extending through the hollow tube but the pointed distal end of the solid needle is retracted from the distal end of the hollow tube, the control mechanism operable to return the shuttle into a position in which the solid needle is in the pricking position after the solid needle has been retracted from the distal end of the hollow tube.

A method of injecting a fluid substance through a skin barrier into an injection site on a body, comprising:

• providing a syringe including:
• a reservoir for containing the fluid substance to be injected, pressure of which can be controlled;
• and
• an injection head comprising:
• a connection body connected to the reservoir, the connection body comprising a guide channel and an injection channel, each of the guide channel and the injection channel extending from a front part of the connection body to a rear part of the connection body, the injection channel comprising one end emerged into the guide channel and another end configured to communicate with an outlet of the reservoir;
• a hollow tube extending from the guide channel of the connection body to an outlet of the front part of the connection body, the hollow tube configured to communicate with the outlet of the reservoir via the injection channel, the hollow tube having a distal end, the hollow tube or the connection body comprising at least one region for monitoring and characterizing a liquid originating from the injection site prior to injection of the fluid substance;
• a solid needle having a pointed distal end, the solid needle slidably mounted in the guide channel and extending from the connection body;
• and
• a control mechanism configured to control movement of the solid needle relative to the hollow tube between a pricking position and a position for monitoring and characterizing the fluid originating from the injection site via the region for monitoring and characterizing, wherein the control mechanism comprises a shuttle mounted to the connection body, the shuttle being movable relative to the connection body in order to place the solid needle into the pricking position or in the position for monitoring and characterizing the liquid originating from the injection site, wherein the solid needle is rigidly connected to the shuttle, and the hollow tube is rigidly connected to the connection body,
• wherein, in the pricking position, the solid needle extends through the hollow tube, the pointed distal end of the solid needle extends beyond the distal end of the hollow tube, and the pointed distal end of the solid needle and the distal end of the hollow tube form a penetrating assembly configured to penetrate into the injection site on the body, and
• wherein, in the position for monitoring and characterizing the fluid originating from the injection site, the solid needle remains extending through the hollow tube but the pointed distal end of the solid needle is retracted from the distal end of the hollow tube, the control mechanism operable to return the shuttle into a position in which the solid needle is in the pricking position after the solid needle has been retracted from the distal end of the hollow tube;
• placing the solid needle in the pricking position;
• penetrating the penetrating assembly into the injection site of the body through the skin barrier;
• after penetrating, moving the solid needle from the pricking position to the position for monitoring and characterizing the fluid originating from the injection site;
• observing whether or not any fluid originates from the injection side;
• and
• injecting the fluid substance into the injection site of the body responsive to detecting that no fluid has originated from the injection site.