Devices are provided to automatically access blood from beneath or within skin. These devices include an injector configured to drive a needle into the skin and subsequently to retract the needle from the skin. These devices additionally include a seal to which suction is applied. To drive the needle into the skin, the needle is first driven through the seal, creating at least one hole in the seal. The suction applied to the seal acts to draw blood from the puncture formed in the skin by the needle, through the at least one hole in the seal, and to a sensor, blood storage element, or other payload. These devices can be wearable and configured to automatically access blood from skin, for example, to access blood from the skin at one or more points in time while a wearer of a device is sleeping.

A segmented safety cover may include: a) a proximal segment combined with a needle hub; b) a needle cannula that extends from the proximal needle hub to a distal sharpened end; c) a distal end cap with a hollow bore through which the cannula shaft passes; d) a centrally mounted toggle locking mechanism, separating the proximal needle hub from the distal end cap; e) the toggle locking mechanism is torsion spring assisted; f) a proximal cover segment is connected to the hub via a proximal hinge and a distal cover segment is connected to the end cap via a distal hinge; g) said proximal cover segment and said distal cover segment of said toggle locking mechanism being configured with abutting faces when the segmented safety cover is in a safety mode; and h) wherein the proximal hinge, abutting faces and distal hinge are in line in the safe mode.

A segmented safety cover may include: a) a proximal segment combined with a needle hub; b) a needle cannula that extends from the proximal needle hub to a distal sharpened end; c) a distal end cap with a hollow bore through which the cannula shaft passes; d) a centrally mounted toggle locking mechanism, separating the proximal needle hub from the distal end cap; e) the toggle locking mechanism is torsion spring assisted; f) a proximal cover segment is connected to the hub via a proximal hinge and a distal cover segment is connected to the end cap via a distal hinge; g) said proximal cover segment and said distal cover segment of said toggle locking mechanism being configured with abutting faces when the segmented safety cover is in a safety mode; and h) wherein the proximal hinge, abutting faces and distal hinge are in line in the safe mode.

Provided is a non-invasive blood measuring device comprising: a fixture which in part or in whole is buried in bone tissue of a patient; an abutment provided in a space inside the fixture; a sensing unit including biosensors for measuring a substance in the blood; a filter through which the substance in the blood to be measured is passed through; and an outcall unit.