Tissue penetration device
View Patent ↗A tissue penetration device and method of using same. The tissue penetration device may optionally include sampling and analyzing functions, which may be integrated. An embodiment provides control of a lancet used for sampling blood. Electric field coils or solenoids may drive the lancet using electromagnetic force. Advancement and retraction of a lancet may be controlled by a feedback loop monitoring the position and velocity of the lancet embodiments of the lancet driver can be configured to follow a predetermined tissue lancing profile. Embodiments of the invention include a lancet and method for using a lancet to maintain the patency of the wound tract once the lancet has cut into the skin.
1. A method of measuring penetration depth of a lancet during a lancing cycle comprising:
(a) driving the lancet toward the patient's target tissue;
(b) using a processor to determine if the lancet has made contact with a patient's skin by measuring for a sudden reduction in velocity of the lancet due to friction or resistance imposed on the lancet by the patient's skin and determine a contact point of the lancet with the target tissue;
(c) after determining the contact point, advancing the lancet out of a housing into the target tissue to a position of maximum penetration and removing substantially all force imparted from a lancet driver to the lancet at the position of maximum penetration;
(d) reading position of the lancet relative to the contact point during rearward displacement of the lancet due to elastic recoil of target tissue after the force from the lancet driver is removed wherein the lancet remains at the position of maximum penetration; measuring an amount of elastic tenting of the tissue; and further comprising measuring a magnitude of inelastic tenting of the tissue.
2. The method of claim 1 wherein the value of the magnitude of the inelastic tenting is about 100 to about 200 microns.
3. The method of claim 1 wherein the contact point of the lancet with the target tissue comprises measuring the deceleration of the lancet.