This patent relates to devices and methods for blood sample collection.
Blood used for diagnostic testing is usually extracted from a patient with a hypodermic needle and collected in a test tube. The collected blood is then packaged for shipment to a remote lab where various diagnostic tests are performed. However, many diagnostic tests require significantly less volume than the actual collected sample. Separation of cellular components from the sample is also needed for some tests.
Many tests only require small blood samples, where a finger stick rather than a hypodermic needle can produce enough blood. But this small amount of blood cannot be easily transported to a remote lab. If the testing method cannot be immediately used at the same time the blood is extracted, convenient and reliable methods of collecting, prepping, and preserving small amounts of blood are still needed.
US Patent Publication US2014/0050620A1, assigned to Boston Microfluidics, Inc., describes several ways to implement a portable, user-friendly device for collecting a biological fluid sample and stabilizing it for transport to a remote lab. The devices may include a housing that provides a chamber for collecting a fluid sample. The housing itself, and/or mechanisms located within the housing, initiate collection of a predetermined, metered volume of a fluid sample. The devices may also stabilize the sample and/or seal the sample in the chamber. Other mechanisms in the device may mix the sample with a reagent.
What is needed is a way for a user, such as patient or health care professional, to more easily introduce blood into a sample port of a blood sample collection device.
In one configuration, a locking, funnel-shaped attachment is provided for a blood collection device. The attachment provides a larger area for collecting a finger tip blood sample from a patient than the collection device itself would otherwise provide. In one embodiment, the funnel incorporates a tubular extension. The tubular extension provides assistance with collecting blood droplets from a fingertip via capillary action.
Optional trenches running down one or more corners of the funnel attachment may be used to further encourage pulling blood drops from the well.
The funnel is preferably easily removable from the collection device after the blood sample is taken.
The attachment may have flexible fingers extending away from the body of the funnel to grab or lock the well in position adjacent the sample port of the collection device. The fingers may then be spread away from the device to remove the funnel after the sample is taken.
The funnel attachment may be mated with the collection device at a point of manufacture, or separately shipped and installed over the collection device at a point of use.
The device 100 is typically used as follows. The housing is presented in its open position, to provide access to the sample port 102. The funnel attachment 103 is clipped onto the housing, over the sample port. Installation of the funnel attachment 103 to the housing 101 may occur at time of assembly in a factory, or in the field at the time the sample is to be taken.
A user, such as a patient herself or a health care professional, then uses a lancet to produce a blood sample such as from a finger tip. Drops of whole blood are then taken with the finger positioned near to, above, adjacent to, or even in contact with the funnel 103 to minimize blood spillage. Blood flows from the funnel 103 down to the sample port 102, introducing whole blood into the rest of the device 101. As will be explained in more detail below for one embodiment, capillary action causes blood to flow from the sample port 102 into one or more collection capillaries 105 adjacent the sample port. The capillaries 105 can optionally be pre-coated with reagents such as heparin and/or EDTA for subsequent stabilization and preservation of the sample. The collection capillaries 105 can have a known and predetermined volume, in which case the incoming sample is precisely metered. The collection capillaries 105 then directed the metered sample to a collection media inside the device housing 101, as shown and described in more detail below.
The user, who can be the patient himself/herself or a healthcare professional, then manually removes (that is, unclips) the funnel 103 from the sample port 102. She then closes the device 100 by pushing the two housing pieces 101-A, 101-B together. The motion associated with closing the housing may then optionally enact one or more mechanisms that further process the sample now securely stored inside the device 100.
A window 300 in the housing may provide an indication of an amount of blood stored in the device, to permit the user to confirm status of the blood collection, such as whether the capillaries are drawing in blood, or whether a sufficient sample of blood is being drawn into (when the housing is in the open position) or was drawn into the device (when the housing is in the closed position).
As seen in the exploded view of
Metering capillaries 204 engage the sample collection port 102 which may be further defined by a silicone inlay structure shaped to fit a hole 221 in backbone 203. The capillaries 204 can optionally be pre-coated with reagents, heparin, EDTA, or other substances.
A base 206 provides mechanical support for a blood collection membrane which may consist of a sample media 209. The sample media may be further supported and/or held in place by a top frame 208, mylar support 210, and bottom frame 211. The top 208 and bottom 211 frames may have extensions or tabs 222 on an outboard end. The tabs 222 assist with handling the media once it is removed from the housing 101.
The sample media 209 may be a pall membrane, an LF1 glass fiber membrane (sold by General Electric Company) or some other filter media designed to receive serum or whole blood which it then separates into a blood portion and a plasma portion. An LF1 paper's structure causes differential migration of the sample, with a slower rate for red cells, resulting in a gradual separation of plasma sample as it migrates down the paper.
The membrane 209 can optionally be previously impregnated with heparin, EDTA, sugars, or other stabilization agents.
In one arrangement, the plunger rack 202 firmly engages with the capillaries 204, creating a shutoff that blocks off any excess sample while also pushing the metered sample volume to the subsequent downstream steps.
It can now be appreciated that the action of closing the housing pieces together causes the sample to exit the capillaries and be deposited onto the sample media 209. In particular, each of the plungers 202 is aligned with a corresponding one of the capillary tubes 204. The capillary tubes 204 are in turn held in place within the silicone rubber inlay 102 through which the capillary tubes 105, 204 are visible in
If a silicone inlay is used to define the sample port 102 it should have an elasticity that is sufficient to hold the capillary tubes 204 in place while the plungers 202 are forced into them. The elasticity of a silicone inlay 102 may also be chosen to seal the space around the capillary tubes and the inlay to prevent blood from flowing around the capillary tubes.
The closed housing also creates a small and isolated internal air space above the sample media 209. The sample can be further encouraged to dry quickly with the aid of one or more desiccant tablets supported by the backbone 203 adjacent where the sample media 209 sits when the housing is in the closed position.
During or after the closing action by the user, a ratcheting mechanism provided by tines 240 on the end of the backbone 203 encourage the housing to remain shut. For example, the tines 240 may act as a ratcheting pall and engage small holes 245 in the end of housing piece 101-A when the housing is pushed shut. The tines 240 may be shape to permit opening of the housing only with a special pinching tool that accesses small holes 245 in the side of the housing to releases the ratchet pawl. Thus, once the device 100 is closed, the blood sample remains enclosed within, largely cut off from the external environment, and ready for transport to a remote lab.
More details of the internal components of one example device 100, including the plunger, capillary tubes, silicone inlay, ratcheting pall and other features are found in our co-pending U.S. Provisional Patent Application Ser. No. 63/577,761 filed Oct. 27, 2017 entitled “Blood Metering and Storage Device”, the entire contents of which are hereby incorporated by reference.
The body of funnel 103 is generally rectangular, with four sides defining a bowl 501 into which blood from the patient is introduced. Two of the sides have downwardly extending, deformable fingers or clips 505 that are shaped to hold the funnel in place against the housing 101. Nibs 510, also located on the funnel adjacent where the funnel engages the port 102, may further assist with holding the funnel 103 in place.
Tabs 508 on the other two sides provide a place to assist with unclipping the funnel 103 from the housing 101.
The bowl 501, open on the bottom to permit blood to flow into the sample port 102, preferably has inwardly sloping walls at an angle of approximately 45 degrees from the vertical. However other bowl shapes, sizes, and slope angles are possible.
Optional trenches 520 extend down from one or more upper portions of the bowl 501. The user may swipe the finger tip against the trenches, to encourage pulling blood drops from the finger tip through capillary action. In one configuration, the trenches 520 are a 1 mm or 2 mm half-diameter pipe cut out of the sloping corners. The trenches 520 thus provide a way for the user to in effect cause trailing blood drops to be wicked away from the finger. They can thus help avoid blood spillage during the collection process.
The locking funnel 103 may be attached to or locked to the collection device 100 during manufacture and then removed after a blood sample is taken.
In some embodiments, a pouch containing an additional fluid may be attached or welded to portions of the device and/or the funnel near the collection well. One example is shown in
For example, when the funnel is attached to the device at the point of use, the pouch 604 may have been placed, during manufacture, in a location where attaching the funnel ruptures the pouch.
When the funnel is pre-installed on the device at the factory, the pouch 604 can be attached to both the device and the funnel, such that the pouch is ruptured when the funnel is removed from the device.
Either configuration permits the additional fluid to be added to the sample as it is drawn into the sample port and/or capillaries.
It should be understood that in light of the above, various modifications and additions may be made to the device without departing from the true scope of the inventions made.
This application claims priority to a co-pending U.S. Provisional application entitled “Funnel with Extension Tube to Augment Blood Collection Device”, Ser. No. 62/810,416, filed Feb. 26, 2019, and to a co-pending U.S. Provisional Application Ser. No. 62/749,163 filed Oct. 23, 2018 entitled “Locking Funnel to Extend a Sample Port in a Blood Collection Device”, the entire contents of each of which are hereby incorporated by reference.
Number | Date | Country | |
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62810416 | Feb 2019 | US | |
62749163 | Oct 2018 | US |