METHOD AND APPARATUS FOR LANCET LAUNCHING DEVICE INTERGRATED ONTO A BLOOD-SAMPLING CARTRIDGE
TECHNICAL FIELD 5
Lancing devices are well known in the medical health-care products industry for piercing the skin to produce blood for analysis. Biochemical analysis of blood samples is a diagnostic tool for determining clinical information. Many point-of- 1° care tests are performed using capillary whole blood, the most common being monitoring blood glucose level in diabetics. Typically, a drop of blood is obtained by making a small incision in the fingertip, creating a small wound, which generates a small blood droplet on the surface of the skin. 15
Early methods of lancing included piercing or slicing the skin with a needle or razor. Current methods utilize lancet 20 drivers that contain a multitude of spring, cam and mass actuators to drive the lancet. These include cantilever springs, diaphragms, coil springs, as well as gravity plumbs to actuate the lancet. Typically, the device is pre-cocked, or the user cocks the device. The device is held against the skin and the 25 user mechanically triggers the ballistic launch of the lancet.
The problem with current devices is that they require two hands to operate, one to hold the device and push a button which activates the device, and the other hand to provide a 3Q finger for lacing. After, lancing, the finger needs to be free to move to another device for collection of the blood droplet and subsequent analysis.
Generally, known methods of blood sampling require several steps. First, a measurement session is set up by gathering 35 various paraphernalia such as lancets, launchers, test strips, instrument, etc. Second, the patient must assemble the paraphernalia by loading a sterile lancet, loading a test strip, and arming the launcher. Third, the patient must place their finger against the lancet launcher and using the other hand activate 4Q the launcher. Fourth, the patient must put down the launcher and place the bleeding finger against a test strip, which may or may not have been loaded into the instrument. The patient must insure blood has been loaded onto the test strip and the instrument has been calibrated prior to such loading. Finally, 45 the patient must dispose of all the blood contaminated paraphernalia including the lancet. What has been needed is a blood sampling device and method that simplifies the blood sampling procedure.
Embodiments of the present invention are related to medical health-care products and to methods for obtaining blood for chemical analysis. More particularly, embodiments of the 55 invention relate to devices and methods for piercing the skin (lancing) with a sensor to detect the presence of a patient's finger and activate the lancet automatically. In some embodiments, the cartridge and lancet are disposable.
In accordance with embodiments of the invention, a patient 60 will be able to obtain a sample of blood in an ergonomic, convenient way using a method and apparatus which integrates lancing, sample collection, and analysis. The presence of patients finger on the ergonomic sampling area is sensed by monitoring the pressure applied by the finger on the cartridge 65 which houses the lancet. The application of a predetermined pressure is measured by a piezoelectric or electrical circuit.
Advantages can be achieved in a blood sampling device by integrating the lancing and blood sample collection procedure so that the device can capture and transport the capillary blood from the wound created by the lancet to a desired active area, such as a strip for analyzing glucose. This can be done in embodiments of the invention by integrating the lancet, conduit and reservoir into a disposable cartridge which can be inserted into a hand-held sampling device with instrumentation for analyzing the blood sample.
In the use of an embodiment of the invention, a finger is placed over an ergonomically contoured sampling area and pressure is applied with the finger so that a sensor will activate the lancet, which will, in turn, lance the finger and allow the blood sample to be collected in the conduit and transported to the reservoir for analysis in a single step from the patient's perspective.
BRIEF DESCRIPTION OF DRAWING
The objects, advantages and features of this invention will be more readily appreciated from the following detailed description, when read in conjunction with the accompanying drawing, in which:
FIG. 1 is a drawing of the cartridge which houses the lancet.
FIG. 2 is a drawing of the chamber in the sampling device where the cartridge is loaded.
FIG. 3 is a drawing of the cartridge loaded into the sampling device.
FIG. 4 is a drawing of an alternate lancet configuration. FIG. 5 is a drawing of the orifice and ergonomically contoured sampling area.
FIG. 6 is a drawing of the lancing event.
BEST MODE FOR CARRYING OUT THE
Reference will now be made to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 1 shows the disposable cartridge (10) which houses the lancet (12). Disposable means that the cartridge is used for one lancing cycle and is then discarded. The lancet (12) has a distal end (16) which connects to the driver (40) and a proximal end (14) which lances the skin. The proximal end (14) is embedded within the conduit (18). Embedded means completely shielded by the cartridge when it is not lancing. The distal end (16) extends, into the cavity (20). The reservoir (22) has a narrow opening (24) on the ergonomically contoured surface (26) which is adjacent to the proximal end (14) of the lancet (12). The term ergonomically contoured is generally defined to mean shaped to snugly fit a finger placed on the surface. The term reservoir is generally defined to mean an area which allows pooling of the blood sample. The term narrow is generally defined to mean a reduction in diameter of the reservoir so as to exploit capillary forces to better channel the blood into the rest of the reservoir. The term adjacent, as used in the context of the proximity of the proximal end (16) and narrow opening (24), is generally defined to mean that the proximal end (16) and the narrow opening (24) are located in the same general area. The cartridge (10) is capable of channeling the blood sample, which means transporting through small passages (not shown), to an active area (28) which corresponds to the device's system for analyzing the blood. This system can consist of a chemical, physical, optical,