Insertion device for a biosensor and insertion method thereof

An insertion device comprising:

• an upper casing including an outer shell, and a cover body that is disposed in said outer shell, said cover body having an accommodating space;
• an insertion module disposed in said accommodating space, forming movement relationship with said outer shell and said cover body of said upper casing, and including a main body assembly, an insertion seat, a first elastic member, a retraction seat, a second elastic member, a base and a sensor assembly, said main body assembly including an upper portion, and a lower portion that cooperates with said upper portion to define a displacement space therebetween, said insertion seat being removably positioned in said upper portion, and being able to move in said displacement space between said lower portion and said upper portion, said first elastic member having two opposite ends that respectively abut against said insertion seat and said upper portion of said main body assembly, said retraction seat being removably positioned relative to said insertion seat, said second elastic member having two opposite ends that respectively abut against said insertion seat and said retraction seat, said base being separably positioned relative to said main body assembly, said sensor assembly being separably mounted to said base;
• and
• a lower casing separably connected to said upper casing;
• wherein the insertion device is configured such that, when said upper casing is depressed to move relative to said main body assembly, the insertion seat is driven by a restoring force of said first elastic member to perform an automatic-insertion operation and to collapse a first limiting structure between said insertion seat and said lower portion of said main body assembly,
• wherein the insertion device is configured such that, after the automatic-insertion operation is completed, said upper casing is positioned relative to said main body assembly without rebounding, and a second limiting structure between said insertion seat and said retraction seat collapses upon the collapse of said first limiting structure between said insertion seat and said lower portion of said main body assembly, so that said retraction seat is driven by a restoring force of said second elastic member to move upwardly to perform an automatic-retraction operation, and
• wherein said upper casing has at least one casing engaging structure, said main body assembly having at least one body engaging structure, said at least one casing engaging structure engaging said at least one body engaging structure when said first limiting structure collapses, so that said upper casing is prevented from rebounding relative to said main body assembly.