Patent Application
20060167382
1. Technical Field
The technical field relates to analyte sampling devices, and more specifically, methods and devices for storing analyte sampling and measurement devices in a safe, usable condition.
2. Background Art
Lancing devices are known in the medical health-care products industry for piercing the skin to produce blood for analysis. Typically, a drop of blood for this type of analysis 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.
Early methods of lancing included piercing or slicing the skin with a needle or razor. Current methods utilize lancing devices 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 used to drive the lancet. The device may be held against the skin and mechanically triggered to ballistically launch the lancet. Unfortunately, the pain associated with each lancing event using known technology discourages patients from testing. In addition to vibratory stimulation of the skin as the driver impacts the end of a launcher stop, known spring based devices have the possibility of firing lancets that harmonically oscillate against the patient tissue, causing multiple strikes due to recoil. This recoil and multiple strikes of the lancet is one major impediment to patient compliance with a structured glucose monitoring regime.
Success rate generally encompasses the probability of producing a blood sample with one lancing action, which is sufficient in volume to perform the desired analytical test. The blood may appear spontaneously at the surface of the skin, or may be “milked” from the wound. Milking generally involves pressing the side of the digit, or in proximity of the wound to express the blood to the surface. In traditional methods, the blood droplet produced by the lancing action must reach the surface of the skin to be viable for testing.
When using existing methods, blood often flows from the cut blood vessels but is then trapped below the surface of the skin, forming a hematoma. In other instances, a wound is created, but no blood flows from the wound. In either case, the lancing process cannot be combined with the sample acquisition and testing step. Spontaneous blood droplet generation with current mechanical launching system varies between launcher types but on average it is about 50% of lancet strikes, which would be spontaneous. Otherwise milking is required to yield blood. Mechanical launchers are unlikely to provide the means for integrated sample acquisition and testing if one out of every two strikes does not yield a spontaneous blood sample.
Many diabetic patients (insulin dependent) are required to self-test for blood glucose levels five to six times daily. The large number of steps required in traditional methods of glucose testing ranging from lancing, to milking of blood, applying blood to the test strip, and getting the measurements from the test strip discourages many diabetic patients from testing their blood glucose levels as often as recommended. Tight control of plasma glucose through frequent testing is therefore mandatory for disease management. The pain associated with each lancing event further discourages patients from testing. Additionally, the wound channel left on the patient by known systems may also be of a size that discourages those who are active with their hands or who are worried about healing of those wound channels from testing their glucose levels.
Another problem frequently encountered by patients who must use lancing equipment to obtain and analyze blood samples is the amount of manual dexterity and hand-eye coordination required to properly operate the lancing and sample testing equipment due to retinopathies and neuropathies particularly, severe in elderly diabetic patients. For those patients, operating existing lancet and sample testing equipment can be a challenge. Once a blood droplet is created, that droplet must then be guided into a receiving channel of a small test strip or the like. If the sample placement on the strip is unsuccessful, repetition of the entire procedure including re-lancing the skin to obtain a new blood droplet is necessary.
Early methods of using test strips required a relatively substantial volume of blood to obtain an accurate glucose measurement. This large blood requirement made the monitoring experience a painful one for the user since the user may need to lance deeper than comfortable to obtain sufficient blood generation. Alternatively, if insufficient blood is spontaneously generated, the user may need to “milk” the wound to squeeze enough blood to the skin surface. Neither method is desirable as they take additional user effort and may be painful. The discomfort and inconvenience associated with such lancing events may deter a user from testing their blood glucose levels in a rigorous manner sufficient to control their diabetes.
A further impediment to patient compliance is the technique for storing these analyte sampling and analyte detecting devices. The devices used to measure analyte levels are typically stored in a humidity controlled or other safe environment to maintain the device shelf life. This often involves using a variety of containers, some for the test strips and some for the lancets. The introduction of multiple storage devices and the cumbersome design may discourage users from keeping their equipment in a usable condition, further degrading user test compliance and measurement accuracy.
There is a need for a device to measure analyte levels with improved humidity control. There is a further need for a device to measure analyte levels that includes desiccant that is external to penetrating members.
Accordingly, an object of the present invention is to provide an improved fluid sampling device.
Another object of the present invention is to provide a fluid sampling device, and its methods of use, that provides a desiccated case for the entire instrument housing.
Yet another object of the present invention is to provide a fluid sampling device, and its methods of use, that includes a plurality of analyte detection members, a plurality of penetrating members, and a desiccant that is external to the plurality of penetrating members.
A further object of the present invention is to provide a fluid sampling device, and its methods of use, that includes a plurality of analyte detection members, a plurality of penetrating members, a desiccant that is external to the plurality of penetrating members and holds the desiccant.
These and other objects of the present invention are achieved in a fluid sampling device with an instrument housing. A plurality of penetrating members are in the instrument housing. A plurality of analyte detecting members are also included. Each of an analyte detecting member is coupled to a penetrating member. A desiccant material is inside the instrument housing and positioned external to the plurality of penetrating members.
In another embodiment of the present invention, a fluid sampling device has an instrument housing. A plurality of penetrating members are in the instrument housing. A plurality of analyte detecting members are also included. Each of an analyte detecting member is coupled to a penetrating member. A case is sized to contain the instrument housing. A desiccant material is inside the instrument housing or the case. The desiccant material is positioned external to the plurality of penetrating members.
In another embodiment of the present invention, a method determines an amount on an analyte in a body fluid sample by a user. An analyte measuring device is provided that has, a instrument housing, a plurality of penetrating members in the instrument housing, a plurality of analyte detecting members, a sterility barrier configured to provide sterile environments for the penetrating members and a desiccant material inside the instrument housing and positioned external to the plurality of penetrating members. The plurality of analyte detecting members are desiccated with the desiccant that is external to the plurality of penetrating members. A penetrating member and unused analyte detecting member of the analyte measurement device are presented into an active position. The penetrating member is fired to prick the skin and bring a fluid sample to the analyte detecting member. The analyte level is measured.
FIGS. 7(a) and 7(b) illustrate embodiments of displacement and velocity profiles, respectively, of a harmonic spring/mass powered driver that can be used with the
The present invention provides a solution for body fluid sampling. Specifically, some embodiments of the present invention provide improved devices and methods for storing a sampling device. The invention may use a high density penetrating member design. It may use penetrating members of smaller size, such as but not limited to diameter or length, than those of conventional penetrating members known in the art. The device may be used for multiple lancing events without having to remove a disposable from the device. The invention may provide improved sensing capabilities. At least some of these and other objectives described herein will be met by embodiments of the present invention.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. It may be noted that, as used in the specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a material” may include mixtures of materials, reference to “a chamber” may include multiple chambers, and the like. References cited herein are hereby incorporated by reference in their entirety, except to the extent that they conflict with teachings explicitly set forth in this specification.
In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined to have the following meanings:
“Optional” or “optionally” means that the subsequently described circumstance may or may not occur, so that the description includes instances where the circumstance occurs and instances where it does not. For example, if a device optionally contains a feature for analyzing a blood sample, this means that the analysis feature may or may not be present, and, thus, the description includes structures wherein a device possesses the analysis feature and structures wherein the analysis feature is not present.
Referring to
As shown in
The plurality of analyte detecting members 16 and the plurality of penetrating members 14 can form a disposable device 22. The sterility barrier 20 can be a planar material that is adhered to a surface of the disposable device 22. Depending on the orientation of the disposable device 22, the sterility barrier 20 can be on the top surface, side surface, bottom surface, or other positioned surface of the disposable device 20. The desiccant material 18 can be configured to be replaced when the disposable device 22 is replaced from the instrument housing 12.
In various embodiments, the desiccant 18 is present in an amount of no more than, 50 mm3, 10-20 mm3, 10-15 mm3, at least 1 mm3 per each of an analyte detecting member 16 and the like. The desiccant 18 can be a variety of materials, including but not limited to, a molecular sieve, a silica gel, a clay, and the like. The molecular sieve can be mixed with a polymeric binder.
The plurality of analyte detecting members 16 can be supported on a scaffolding 24 (
In one embodiment, many analyte detecting members 16 can be printed onto a single scaffolding 22 which is then adhered to the disposable device 22 to facilitate manufacturing and simplify assembly. The analyte detecting members 16 can be electrochemical in nature. The analyte detecting members 16 can further contain enzymes, dyes, or other detectors which react when exposed to the desired analyte. Additionally, the analyte detecting members 16 can comprise of clear optical windows that allow light to pass into the body fluid for analyte analysis. The number, location, and type of analyte detecting member 16 can be varied as desired, based in part on the design of the disposable device 22, number of analytes to be measured, the need for analyte detecting member calibration, and the sensitivity of the analyte detecting members 16. Wicking elements, capillary tube or other devices on the disposable device 22 can be provided to allow body fluid to flow from the disposable device 22 to the analyte detecting members 16 for analysis. In other configurations, the analyte detecting members 16 can be printed, formed, or otherwise located directly in the disposable device 22.
In one embodiment, the desiccant material 18 is external to the analyte detecting members 16. The desiccant 18 can be on at least a portion of the analyte detecting members 16. In one embodiment, the scaffolding 24 holds the desiccant 18. In another embodiment, the scaffolding 24 includes a desiccant 18 for each of an analyte detecting member 16. Each of analyte detecting member 16 can be stored in an air tight desiccated environment.
The desiccant 18 can be molded and inserted into the scaffolding 24. In one embodiment, the desiccant 18 and the scaffolding 24 are co-molded simultaneously. In another embodiment, the scaffolding 24 and the desiccant 18 are co-molded sequentially. The desiccant 18 can be present as a desiccant block inside of the instrument housing 12.
As shown in
The use of the sterility barrier 20 can facilitate the manufacture of disposable device 22. For example, a single sterility barrier 20 can be adhered, attached, or otherwise coupled to the disposable device 22 to seal many of the cavities 26 at one time. A sheet of analyte detecting members 16 can also be adhered, attached, or otherwise coupled to the disposable device 22 to provide many analyte detecting members 16 on or in the disposable device 22 at one time. During manufacturing of one embodiment of the present invention, the disposable device 22 can be loaded with penetrating members 14, sealed with sterility barrier 20 and a temporary layer (not shown) on the bottom where scaffolding 24 would later go, to provide a sealed environment for the penetrating members 14. This assembly with the temporary bottom layer is then taken to be sterilized. After sterilization, the assembly is taken to a clean room (or it can already be in a clear room or equivalent environment) where the temporary bottom layer is removed and the scaffolding 24 with analyte detecting members 16 is coupled to the disposable device 22. This process allows for the sterile assembly of the disposable device 22 with the penetrating members 14 using processes and/or temperatures that can degrade the accuracy or functionality of the analyte detecting members 16 on the scaffolding 24.
In some embodiments, more than one sterility barrier 20 can be used to seal the cavities 26. As examples of some embodiments, multiple layers can be placed over each cavity 26, half or some selected portion of the cavities 26 can be sealed with one layer with the other half or selected portion of the cavities sealed with another sheet or layer, different shaped cavities 26 can use different seal layer, or the like. The sterility barrier 20 can have different physical properties, such as those covering the penetrating members 14 near the end of the disposable device 22 can have a different color such as red to indicate to the user (if visually inspectable) that the user is down to say 10, 5, or other number of penetrating members before the cartridge should be changed out.
After actuation, the penetrating member 14 is returned into the disposable device 22 and is held therein in a manner so that it is not able to be used again. By way of example and not limitation, a used penetrating member 14 may be returned into the disposable member 22 and held by a launcher in position until the next lancing event. At the time of the next lancing, the launcher may disengage the used penetrating member with the disposable device 22 turned or indexed to the next clean penetrating member 14 such that the cavity 26 holding the used penetrating member is positioned so that it is not accessible to the user (i.e. turn away from a penetrating member exit opening). In some embodiments, the tip of a used penetrating member 14 may be driven into a protective stop that hold the penetrating member in place after use. The disposable device 22 is replaceable with a new disposable device 22 once all the penetrating members 14 have been used or at such other time or condition as deemed desirable by the user.
As shown in
The disposable device 22 can provide sterile environments for penetrating members 14 via the sterility barrier 20, seals, foils, covers, polymeric, or similar materials used to seal the cavities 26 and provide enclosed areas for the penetrating members 14 to rest in. In one embodiment, sterility barrier 20 is applied to one surface of the disposable device 20. Each cavity 26 may be individually sealed in a manner such that the opening of one cavity 26 does not interfere with the sterility in an adjacent or other cavity 26. Additionally, the disposable device 22 can include a moisture barrier 29.
The plurality of penetrating members 14 can be at least partially contained in the cavities 26 of the disposable device 22. The penetrating members 14 are slidably movable to extend outward from the disposable device 22 to penetrate tissue. The cavities 26 can each have a longitudinal opening that provides access to an elongate portion of the penetrating member 14. The sterility barrier 20 can cover the longitudinal openings. The sterility barrier 20 can be configured to be moved so that the elongate portion can be accessed by a gripper without touching the sterility barrier 20.
Referring again to
Once a new disposable device 22 is inserted, the entire inside of the device 10 is sealed from the outside environment. The disposable device 22 can be packaged to come with a large block or other sufficient size of desiccant 18 to desiccate the entire interior volume of the device 10. The desiccant 18 can assume a variety of forms including but not limited to a disc of desiccant 18 that can be placed under the disposable device 22. In other embodiments, the disposable device 22 can be part of the cassette 27 that can house the desiccant 18 and the cassette 27 can have a block of desiccant 18 in the cassette 27. By way of example and not limitation, the desiccant can be molded to the wall of the cassette or can simply be housed in the cassette 27. These applications will work because the interior of the instrument will be sealed from the outside environment when the device is not in use or configured in a mode that is ready for use.
In one embodiment, the desiccant 18 can be designed to keep the analyte detecting members sufficiently dry for 90 days in a normal climate condition. Additionally, since every time the device is used is that a drop of blood is left inside the desiccated environment (on the analyte detecting member). An amount of desiccant sufficient to reduce the spike in humidity after each test is desired. In one embodiment, about 5 cc of desiccant is used. Other embodiments can use greater volumes to more quickly absorb the spike in humidity the occurs after blood is introduced into the desiccated environment.
In one embodiment of the present invention, a device, generally denoted as 34, is included to provide controlled velocity and depth of penetration of the penetrating members 14, as shown in Figure. Device 34 can be any variety of different penetrating member drivers. It is contemplated that the device 34 can be spring based, solenoid based, magnetic driver based, nanomuscle based, or based on any other mechanism useful in moving a penetrating member along a path into tissue. It should be noted that the present invention is not limited by the type of driver used with a penetrating member feed mechanism. One suitable penetrating member driver for use with the present invention is shown in
Referring to the embodiment of
As discussed above, tissue penetration devices 14 which employ spring or cam driving methods have a symmetrical or nearly symmetrical actuation displacement and velocity profiles on the advancement and retraction of the penetrating member as shown in FIGS. 7(a) through 7(d). In most of the available lancet devices, once the launch is initiated, the stored energy determines the velocity profile until the energy is dissipated. Controlling impact, retraction velocity, and dwell time of the penetrating member within the tissue can be useful in order to achieve a high success rate while accommodating variations in skin properties and minimize pain. Advantages can be achieved by taking into account of the fact that tissue dwell time is related to the amount of skin deformation as the penetrating member tries to puncture the surface of the skin and variance in skin deformation from patient to patient based on skin hydration.
In this embodiment, the ability to control velocity and depth of penetration can be achieved by use of a controllable force driver where feedback is an integral part of driver control. Such drivers can control either metal or polymeric penetrating members or any other type of tissue penetration element. The dynamic control of such a driver is illustrated in
After the lancing event, the processor 160 can allow the user to rank the results of the lancing event. The processor 160 stores these results and constructs a database 180 for the individual user. Using the database 179, the processor 160 calculates the profile traits such as degree of painlessness, success rate, and blood volume for various profiles 162 depending on user input information 164 to optimize the profile to the individual user for subsequent lancing cycles. These profile traits depend on the characteristic phases of penetrating member advancement and retraction. The processor 160 uses these calculations to optimize profiles 162 for each user. In addition to user input information 64, an internal clock allows storage in the database 179 of information such as the time of day to generate a time stamp for the lancing event and the time between lancing events to anticipate the user's diurnal needs. The database 179 stores information and statistics for each user and each profile that particular user uses.
In addition to varying the profiles, the processor 160 can be used to calculate the appropriate penetrating member diameter and geometry suitable to realize the blood volume required by the user. For example, if the user requires about 1-5 microliter volume of blood, the processor 160 can select a 200 micron diameter penetrating member to achieve these results. For each class of lancet, both diameter and lancet tip geometry, is stored in the processor 160 to correspond with upper and lower limits of attainable blood volume based on the predetermined displacement and velocity profiles.
The lancing device is capable of prompting the user for information at the beginning and the end of the lancing event to more adequately suit the user. The goal is to either change to a different profile or modify an existing profile. Once the profile is set, the force driving the penetrating member is varied during advancement and retraction to follow the profile. The method of lancing using the lancing device comprises selecting a profile, lancing according to the selected profile, determining lancing profile traits for each characteristic phase of the lancing cycle, and optimizing profile traits for subsequent lancing events.
Referring to
A magnetic member 202 is secured to the elongate coupler shaft 184 proximal of the drive coupler 185 on a distal portion of the elongate coupler shaft 184. The magnetic member 202 is a substantially cylindrical piece of magnetic material having an axial lumen 304 extending the length of the magnetic member 202. The magnetic member 202 has an outer transverse dimension that allows the magnetic member 202 to slide easily within an axial lumen 205 of a low friction, possibly lubricious, polymer guide tube 205′ disposed within the driver coil pack 188. The magnetic member 202 can have an outer transverse dimension of about 1.0 to about 5.0 mm, specifically, about 2.3 to about 2.5 mm. The magnetic member 202 can have a length of about 3.0 to about 5.0 mm, specifically, about 4.7 to about 4.9 mm. The magnetic member 202 can be made from a variety of magnetic materials including ferrous metals such as ferrous steel, iron, ferrite, or the like. The magnetic member 202 can be secured to the distal portion 303 of the elongate coupler shaft 184 by a variety of methods including adhesive or epoxy bonding, welding, crimping or any other suitable method.
Proximal of the magnetic member 202, an optical encoder flag 306 is secured to the elongate coupler shaft 184. The optical encoder flag 306 is configured to move within a slot in the position sensor 191. The slot can have separation width of about 1.5 to about 2.0 mm. The optical encoder flag 306 can have a length of about 14 to about 18 mm, a width of about 3 to about 5 mm and a thickness of about 0.04 to about 0.06 mm.
The optical encoder flag 306 interacts with various optical beams generated by LEDs disposed on or in the position sensor body portions in a predetermined manner. The interaction of the optical beams generated by the LEDs of the position sensor 191 generates a signal that indicates the longitudinal position of the optical flag 306 relative to the position sensor 191 with a substantially high degree of resolution. The resolution of the position sensor 191 can be about 200 to about 400 cycles per inch, specifically, about 350 to about 370 cycles per inch. The position sensor 191 can have a speed response time (position/time resolution) of 0 to about 120,000 Hz, where one dark and light stripe of the flag constitutes one Hertz, or cycle per second. The position of the optical encoder flag 306 relative to the magnetic member 202, driver coil pack 188 and position sensor 191 is such that the optical encoder 191 can provide precise positional information about the penetrating member 183 over the entire length of the penetrating member's power stroke.
An optical encoder that is suitable for the position sensor 191 is a linear optical incremental encoder, model HEDS 9200, manufactured by Agilent Technologies. The model HEDS 9200 can have a length of about 20 to about 30 mm, a width of about 8 to about 12 mm, and a height of about 9 to about 11 mm. Although the position sensor 191 illustrated is a linear optical incremental encoder, other suitable position sensor embodiments could be used, provided they posses the requisite positional resolution and time response. The HEDS 9200 is a two channel device where the channels are 90 degrees out of phase with each other. This results in a resolution of four times the basic cycle of the flag. These quadrature outputs make it possible for the processor to determine the direction of penetrating member travel. Other suitable position sensors include capacitive encoders, analog reflective sensors, such as the reflective position sensor discussed above, and the like.
While the invention has been described and illustrated with reference to certain particular embodiments thereof, those skilled in the art will appreciate that various adaptations, changes, modifications, substitutions, deletions, or additions of procedures and protocols can be made without departing from the spirit and scope of the invention. For example, with any of the above embodiments, the shield or other punch can be adapted for use with other cartridges disclosed herein or in related applications. With any of the above embodiments, the methods for storage can be used with analyte sampling devices, analyte sampling and measurement devices, and/or analyte measurement devices. The use is not restricted. With any of the above embodiments, the lids can be flip up or slide. They can be motorized or user actuated. With any of the above embodiments, the gasket can also be designed for compression. The sliding lids are designed to compress the O-ring to provide a seal.
The publications discussed or cited herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided can be different from the actual publication dates which can need to be independently confirmed. All publications mentioned herein are incorporated herein by reference to disclose and describe the structures and/or methods in connection with which the publications are cited.
Expected variations or differences in the results are contemplated in accordance with the objects and practices of the present invention. It is intended, therefore, that the invention be defined by the scope of the claims which follow and that such claims be interpreted as broadly as is reasonable.
This application claims the benefit of U.S. Ser. No. 60/640,839, filed Dec. 30, 2004, which application is fully incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60640839 | Dec 2004 | US |
