Portable interstitial fluid monitoring system

A fluid sampling apparatus, comprising:

• (a) a plurality of microneedles accessible on a first surface of said fluid sampling apparatus;
• (b) a manually-operated pumping apparatus accessible on a second surface of said fluid sampling apparatus;
• and
• (c) a reservoir that is in hydraulic communication with both said plurality of microneedles and said pumping apparatus;
• wherein said reservoir receives fluid that flows through said plurality of microneedles upon manual actuation of said pumping apparatus,
• wherein said first surface is located on a first side of said fluid sampling apparatus, and said second surface is located on a second side of said fluid sampling apparatus, in which said first side is opposite from said second side,
• wherein said fluid sampling apparatus further comprises (a) a member having a first end proximal to said reservoir and extending to a second end distal from said reservoir, (b) at least one electrode positioned on said extending member, and (c) a sensor pad that is in hydraulic communication with said reservoir;
• and wherein said at least one electrode is in communication with said sensor pad, and
• wherein said fluid sampling apparatus further comprises an electrical interface that converts an output of said sensor pad into an electrical signal;
• a processing circuit that detects a value of said electrical signal and generates an output signal;
• and a display device that indicates a value representative of said output signal.

A fluid sensing apparatus, comprising:

• (a) a plurality of solid microneedles accessible on a first surface of said fluid sensing apparatus, said solid microneedles being coated on an exterior surface;
• whereupon said solid microneedles making contact with a biological barrier, said coating on said microneedles acting as an transducer responsive to a property of a fluid of said biological barrier, and thereby generating an electrical signal in response to said fluid property;
• (b) a member having a first end proximal to said coated microneedles and extending to a second end distal from said coated microneedles;
• and
• (c) at least one electrode positioned on said extending member, wherein said at least one electrode is in communication with said coated microneedles,
• wherein said fluid sensing apparatus further comprises an electrical interface that converts an output of said at least one electrode into an electrical signal;
• a processing circuit that detects a value of said electrical signal and generates an output signal;
• and a display device that indicates a value of said output signal.

A fluid sampling apparatus, comprising:

• (a) an attachable/detachable portion that includes a plurality of microneedles, a reservoir, an optical sensor pad, and an optical window;
• and
• (b) a main body portion that includes a receptacle to receive said attachable/detachable portion such that, when in position, the optical window faces said main body portion and the plurality of microneedles are accessible;
• a light source and light detector;
• and a manually-operated control actuator mounted on a surface of said main body portion that causes fluid to flow proximal to said plurality of microneedles;
• wherein said reservoir receives fluid that flows through said plurality of microneedles upon manual operation of said control actuator, and said optical sensor pad exhibits a change in a physical property that is detected by said light detector as said light source shines light upon said optical sensor pad.

A fluid sampling apparatus, comprising:

• (a) an attachable/detachable portion that includes a plurality of microneedles, a reservoir, an electrochemical sensor pad, and at least one electrode in communication with said sensor pad;
• and
• (b) a main body portion that includes a receptacle to receive said attachable/detachable portion such that, when in position, the at least one electrode faces said main body portion and the plurality of microneedles are accessible;
• an electrical sensor;
• and a manually-operated pumping apparatus accessible on a surface of said main body portion;
• wherein said reservoir receives fluid that flows through said plurality of microneedles upon manual actuation of said pumping apparatus, and said electrochemical sensor pad exhibits a change in a physical property that is detected by said at least one electrode which outputs an electrical signal, and said electrical sensor is in communication with said at least one electrode and generates an output signal in response to said electrical signal, and
• wherein said fluid sampling apparatus further comprises a display device that indicates a value representative of said output signal produced by said electrical sensor, or which displays a message to the user.

A fluid sampling apparatus, comprising:

• a plurality of microneedles and an associated substrate that is in mechanical communication with a plunger, said plunger being manually operable;
• a housing that contains a variable volume chamber and which contains a flexible membrane that deflects upon movement of said plunger, said membrane's deflection causing a variation in the volume of said chamber;
• and an output port that is in hydraulic communication with said variable volume chamber;
• wherein upon actuation of said plunger in one direction, said microneedles being pushed into and piercing a biological barrier;
• and upon actuation of said plunger in a second, opposite direction, fluid from said biological barrier is withdrawn into said variable volume chamber and thereby directed to said output port,
• wherein said fluid sampling apparatus further comprises a sensor that generates an electrical signal in response to a change in a property of said fluid after said fluid travels through a tube that is in hydraulic communication with said output port, and a display device that indicates a value of said electrical signal produced by said sensor, or which displays a message to the user.

A single-use microneedle system, comprising:

• an array of microneedle members that protrude from a base member, said microneedle members being of a size, shape, and material so as to penetrate through a stratum corneum of skin when placed against said skin;
• and
• a self-destruct mechanism that renders said microneedle members incapable of penetrating said stratum corneum after being operative upon said microneedle members, said self-destruct mechanism comprising one of:
• (a) a heat source, (b) an electrical energy source, (c) a optical energy source, (d) a chemical reaction, (e) a mechanical member that exerts a force, or (f) a material that permanently encapsulates the microneedle members.