Needle-free blood draw

A hand-portable device comprising:

• an evacuated negative-pressure barrel with an aperture membrane sealing an aperture at a distal end of the evacuated negative-pressure barrel, and a housing affixed to, and sealing, a proximal end of the evacuated negative-pressure barrel;
• an accelerator barrel positioned lengthwise within the evacuated negative-pressure barrel with an open proximal end fixed to the housing and opening into a chamber within the housing, and having an open distal end proximate to, and aligned with, the aperture;
• a high-pressure gas source configured for filling the chamber with pressurized gas;
• a trigger valve situated between, and forming a hydrostatic boundary between, the chamber and the open proximal end of the accelerator barrel;
• a single micro-particle positioned within the accelerator barrel at a launch point proximate to the trigger valve;
• and
• a trigger-valve release actuator configured for abruptly opening of the trigger valve to abruptly release the pressurized gas from the chamber and into the open proximal end of the accelerator barrel,
• wherein, the abruptly released pressurized gas is configured to accelerate the single micro-particle from the launch point to the open distal end of the accelerator barrel and through the aperture with sufficient momentum to pierce through the aperture membrane and penetrate a sufficient depth of dermal tissue proximate to the distal end of the evacuated negative-pressure barrel to induce a micro-emergence of blood at the dermal tissue surface,
• wherein, residual negative pressure within the evacuated negative-pressure barrel is configured to draw at least a portion of blood from the micro-emergence into the evacuated negative-pressure barrel through the pierced aperture membrane,
• wherein the accelerator barrel comprises an inner cylindrical channel having a constant interior cross-sectional shape between the launch point and the open distal end,
• and wherein the single micro-particle has an exterior cross-sectional shape configured to be a flush fit to the constant interior cross-sectional shape of the channel and at the same time not impede free longitudinal motion of the single micro-particle through the channel.