WO2021262061A1

WO2021262061A1 - Collection device for bodily fluid samples

Info

Publication number: WO2021262061A1
Application number: PCT/SE2021/050385
Authority: WO
Inventors: Björn Eriksson; Eva-Lotta PALM
Original assignee: Hemcheck Sweden Aktiebolag
Priority date: 2020-06-24
Filing date: 2021-04-28
Publication date: 2021-12-30
Also published as: SE2050749A1

Abstract

The present invention relates to a collection device for collection and analysis of a bodily fluid, said collection device comprising a sample receiving member and an excess fluid removal member. The sample receiving member and the excess fluid removal member are arranged such that sample fluid received by the excess fluid removal member essentially is prevented from travelling back to the sample receiving member.

Description

Title

Collection device for bodily fluid samples

Field of the invention

The present invention relates to a collection device, and in particular to a collection device for collection and analysis of a bodily fluid.

Background of the invention

Collection and analysis of various bodily fluids such as blood, urine and cerebral spinal fluid is widely performed within medical care. Blood tests are a common tool to diagnose and understand the medical health of a patient. Accurate and useful results of any testing of a bodily fluid relies on proper handling and execution of multiple steps, such as drawing the sample from a patient, handling the sample, transport to a testing laboratory, handling and analysis in the laboratory, documentation and reporting results back to the primary medical personnel.

Globally, one of the most common reason for failure and clinically significant bias during analysis of blood samples is hemolysis, i.e. rupture of the erythrocytes. If hemolysis has occurred in the sample, it may affect the results of multiple blood tests, and in many cases causes a failed result, necessitating retaking the sample. However, the presence of hemolysis can normally not be detected at the point of care. For blood sample vacuum tubes, hemolysis is normally not tested until the sample reaches the testing laboratory, often remote in time and distance from the location where the sample was taken. In many health care settings, blood samples are drawn from the patient in a syringe intended for blood gas analysis in a dedicated blood gas analysis instrument. After drawing the sample, excess air is removed from the syringe, usually by expressing any air bubbles onto a blotting paper or the like. This risks contamination of the sample, and/or contamination of the user or surroundings. After transport to a testing laboratory, the sample in the syringe is thereafter directly injected into a sample port in a blood gas analysis instrument. Traditionally there is no testing of hemolysis when performing blood gas analysis.

To detect hemolysis a separation of the blood plasma in at least a portion of the sample has to be performed. In a laboratory this may be done by centrifugation. However, to accurately and effectively perform sample separation for hemolysis analysis in connection with the taking of a blood sample has proven challenging. In such a setting it is essential to minimally affect the volume and the integrity of the blood sample taken from the patient, while still ensuring safe handling of the sample and getting quick and accurate results.

Various manners of obtaining a small sample for any type of rapid analysis of a larger fluid sample are known. Test strips are commonly used for initial and rapid analysis of a sample, where the test strip is either dipped in the larger fluid sample, or a small drop of fluid is applied to the test strip. One challenge is controlling the amount of sample applied to a rapid analysis test.

In DE2655977A1 a test strip is disclosed for colorimetric analysis of liquids. After the strip is submerged in a liquid, excess fluid is absorbed by an absorbent material placed next to indicator spots for the test to be analyzed.

EP0212634B1 describes another test strip where a sample is applied in a depression, and an absorbent material is arranged at the edge of the depression to absorb any excess liquid overflowing from the depression.

WO2017/133953A1 describes an arrangement for collection and separation of a body fluid comprising a set of filters defining a sample zone, an excess fluid zone and a separation zone for separation of the plasma in the sample to allow color detection in a detection zone. A sample is applied directly from e.g. a blood sample syringe into the sample zone, and the excess fluid zone absorbs any excess fluid after allowing sample to be separated in the separation filter. As it is difficult to apply an exact volume of sample in the small volume required, the excess fluid zone assists in removing any excess amount applied.

The inventors of the present invention have identified a need for an improved collection device for collection and analysis of a bodily fluid, which provides for more effective controlling of the amount of blood provided to an analysis.

Summary of the invention

It is therefore an object of the present invention is to provide a collection device which allows for a quick and efficient application of a sample.

A further object of the present invention is to provide a collection device which effectively handles varying amounts of sample applied. Another object is to provide rapid handling of a sample taken from a patient, such that quick and reliable testing can be performed immediately upon drawing a sample from the patient, providing better quality care for the patient.

A further object is to provide a device and method allowing a more safe, effective and less time-consuming procedure from obtaining a blood sample from a patient and the various steps leading to final analysis of the sample.

Further, an object is to provide a collection device which is easy to manufacture and is disposable after use.

The above-mentioned objects are achieved by the present invention according to the independent claims. Preferred embodiments are set forth in the dependent claims.

In accordance with the present invention a collection device for collection and analysis of a bodily fluid comprises a sample receiving member adapted to receive a fluid sample applied to the collection device, and an excess fluid removal member adapted to remove excess sample fluid applied to the collection device. The sample receiving member and the excess fluid removal member are spatially separated from each other such that excess sample fluid in the sample receiving member is allowed to travel to the excess fluid removal member and sample fluid received by the excess fluid removal member essentially is prevented from travelling back to the sample receiving member.

Further, a method is disclosed, comprising the steps of

- attaching a sample syringe with fluid sample to a sample application opening of a collection device, said sample application opening being provided in a housing of a collection device and arranged in communication with a sample receiving member,

- expelling any air present in the sample syringe into the interior of the collection device,

- essentially simultaneously applying fluid sample from the sample syringe to the collection device, such that sample fluid is received by the sample receiving member, said sample receiving member being spatially separated from an excess fluid removal member, wherein when the sample receiving member is saturated, any excess sample fluid is absorbed by the excess fluid removal member.

Short description of the appended drawings

Figure 1 shows a schematic side view of a collection device for collection and analysis of a bodily fluid and illustrates the function over time. Figure 2a is an exploded perspective view of a collection device.

Figure 2b is a top view of the bottom part of a housing for a collection device and showing selected members of the device.

Figure 2c shows a perspective view of an assembled device.

Figure 2d is a cross-sectional view of a collection device and its housing along a vertical plane indicated by A-A’ in Figure 2c.

Figure 2e is a cross-sectional view of a collection device and its housing along a vertical plane indicated by B-B’ in Figure 2c.

Figure 3a schematically illustrates another aspect of a collection device.

Figure 3b schematically illustrates a further aspect of a collection device.

Detailed description of preferred embodiments of the invention

Within health care, handling and testing of blood samples taken from a patient is performed in a multitude of manners and entails multiple steps. The below disclosures are described in the context of testing whole blood from a blood sample syringe, but may be applicable to other body fluids and collection manners. In addition to whole blood, bodily fluids such as cerebral spinal fluid, urine or fractions of blood may be applicable. Other blood collection containers may be vacuum sample tubes, other types of collection tubes, blood bags, hypodermic needles etc.

Figure 1 shows a schematic drawing of a collection device 10, for collection and analysis of a bodily fluid 12 and illustrates the general concept of the disclosed invention. The sample may be any bodily fluid or equivalent fluid intended for analysis of any kind. In a first aspect, the collection device may be intended for collection of a bodily fluid or equivalent fluid intended for any type of fluid analysis. One of the advantages of the collection device is the ability to adapt to varying amounts of applied sample volume, such that a defined sample volume may be collected, e.g. for use in a following analysis step. This is especially relevant when collecting and analysing small fluid volumes, and in settings where the applied volume may be greatly influenced by variations due to different users, different sampling protocols and varying handling routines. For example, when applying small volumes to a test device, a user will normally tend to inadvertently apply an excess of sample to the device, e.g. via a syringe or dropping a droplet into a sample application opening or site. In the following, examples are shown related to blood samples and hemolysis analysis; however, it is within the scope of the invention to use the collection device for various types of diagnostic tests. For example, in hemolysis analysis using plasma separation, an excess or uncontrolled amount of applied sample can greatly affect or disrupt analysis results.

Figure 1 shows five different steps, a) to e), in chronological order over time, when a sample 12 is applied to a collection device 10. The collection device 10 comprises a sample receiving member 11 adapted to receive a fluid sample 12 applied to the collection device, and an excess fluid removal member 13 adapted to remove excess sample fluid applied to the collection device. The collection device may further be provided with a sample analysis member (not shown in Figure 1) adapted to receive sample from the sample receiving member 11 , for analysis, further handling or manipulation of the sample fluid. In examples below, such a sample analysis member is adapted to analyse hemolysis of the fluid.

A sample receiving member 11 may be configured to receive a sample 12, by absorbing the sample in an absorbent material and/or capillary action, and/or enclosing the sample within a sample chamber or enclosure, or any other manner to receive and hold a predetermined amount of a fluid sample, such as a bodily fluid. Measures may be taken to make sure all sample applied to the collection device is primarily first directed to the sample receiving member 11. This will be further detailed in connection to other figures. The amount of sample

12 applied to a collection device may vary, but is in the general range of a drop to several drops of fluid, i.e. generally in the range of 50 pi to 1000 mI. However, the amount of sample that can or should be applied is also subject to the overall size and configuration of the entire collection device.

As shown in Figure 1, a sample receiving member 11 and an excess fluid removal member

13 may be arranged on a common connecting surface, e.g. of an underlying substrate or support member 14. The sample receiving member 11 and the excess fluid removal member 13 are arranged spatially separated fom each other on the common connecting surface, such as by a gap 15. In such an arrangement, when sample 12 is applied to the sample receiving member 11, as seen in Figure 1a), it will first be absorbed or contained within the sample receiving member 11, as seen in Figure 1b) and c). When the sample receiving member 11 is filled, if present, excess sample 12 will overflow into the gap 15, as shown in Figure 1d) and may travel on the common connecting surface from the sample receiving member 11 to the excess fluid removal member 13 where it will be absorbed. A common feature of the disclosures herein is that the sample receiving member 11 and the excess fluid removal member 13 are spatially arranged such that any portion of the sample fluid 12 absorbed or received by the excess fluid removal member 13, essentially is prevented from travelling to, or back to, the sample receiving member 11. In other words, the spatial separation allows fluid to travel from the sample receiving member to the excess fluid removal member, but not in the opposite direction. This effect may be achieved in several different manners.

The excess fluid removal member 13 is preferably highly absorbent, .ie. quickly absorbes fluid and preferably has the capacity to hold a large volume of fluid, at least compared to the sample receiving member 11. Due to these characteristics of the excess fluid removal member 13, and the spatial distance between the sample receiving member 11 and the excess fluid removal member 13, once the flow of sample from the sample receiving member 11 towards the excess fluid removal member 13 lessens or stops, fluid will not be able to flow in the opposite direction, i.e. back to the sample receiving member 11. This would apply at least as long as the excess fluid removal member 13 is not fully saturated. The arrangement essentially functions as a one-way valve or flow channel. In this manner, a controlled and predetermined volume, i.e. the volume of the sample receiving member 11 , of sample may be obtained, for further analysis, and any excess is contained in the excess fluid removal member 13. Thus, the fluid volume capacity of the sample receiving member 11 may be chosen based on a volume needed for a following analysis step. Thus, an advantage of the present disclosure is that, regardless of the amount of sample applied to the collection device 10, usually being in excess of the amount needed, the present arrangement ensures that a limited or preset amount of sample is contained in the sample receiving member 11 , and thus available for any following analysis. The volume capacity of a sample receiving member 11 may be configured by e.g. size, thickness and material properties, as will be detailed further below.

Other manners of arranging a sample receiving member 11 and an excess fluid removal member 13 such that sample fluid 12 absorbed or received by the excess fluid removal member 13 essentially is prevented from travelling to, or back to, the sample receiving member 11 are also considered. As an alternative to, or in addition to gap 15, a sample receiving member 11 and an excess fluid removal member 13 may be arranged in other manners preventing backflow from the excess fluid removal member 13 to the sample receiving member 11. Such arrangments could include connecting channels, one-way valves, hydrophobic coatings of connecting surfaces and other arrangments regulating flow. Furthermore, a gap may be arranged in different manners, as will be detailed in further aspects below.

The arrangement show in Figure 1 may apply to e.g. a test strip, where the sample receiving member and excess fluid removal member, as well as the direction of the sample flow between the two, are arranged essentially in a linear path, or may be arranged over a larger two- or three-dimensional space. Further examples will be described below.

A sample receiving member, an excess fluid removal member and any sample analysis member may be filters of different types, such as filters with specific absorbancy, filters with specific porosity and/or other types of filters. Examples will be detailed below.

In one aspect, sample may be manually applied to the receiving member by dropping onto the sample receiving member from a pipette, syringe or other means. In some aspects, the collection device is intended to be used with a blood sample syringe, and thus a sample of the whole blood may be applied by attaching the tip of the syringe to the collection member, e.g. by attachment to a housing or holder of the collection device, and a small amount is injected directly to the sample receiving member. Examples of such arrangements are further detailed below.

Figure 2a shows an exploded perspective view of a further aspect of a collection device 30. The collection device comprises a housing, here shown in two parts, 34a and 34b, adapted to be pressed or interlocked together when the device is assembled. Housing parts may be adapted to attach to each other in a number of different manners. The housing is preferably made of plastic or similar material, and is preferably at least partly transparent.

The bottom housing element 34a, is adapted to support a number of filter members, and is, together with the top housing member 34b, adapted to house the filter members.

Furthermore, the filter members are held in place by the two housing elements 34a and 34b when assembled. A top view of a partially assembled collection device 30 is seen in Figure 2b, showing the bottom housing element 34a and filter members. The assembled collection device is shown in Figure 2c in a perspective view . A cross-sectional view of the assembled collection device 30, in the plane A-A’ shown in Figure 2c, is illustrated in Figure 2d, and a cross-sectional view of the assembled collection device 30, in the plane B-B’ shown in Figure 2c, is illustrated in Figure 2e. These figures show how the filters 31 , 33, 36 and 37, are stacked on each other in a particular order as well as sandwiched between the two housing parts 34a, 34b.

In this aspect of a collection device 30, the housing functions to contain and hold the filter members in place, and further to provide a directed application of a fluid sample in a closed and safe system. Thus, in some aspects, the housing makes the collection device largely air tight or fluid-tight, or at least able to contain any sample applied. The top housing 34a is provided with inner walls 38, which when assembled with the lower housing 34b, together with part of filter 31 , form a sample chamber 39. The housing is preferably adapted such that a sample application opening is arranged in communication with a sample chamber comprising the sample receiving member. In the illustrated collection device, sample may be applied from a syringe which may be attached to the sample injection port or opening 40. As is best seen in the cross-sectional view of Figures 2d and 2e, such a sample injection port 40 may be adapted to receive the tip of a standard syringe. Similarly to the device described in connection to Figure 1, as this device is intended for small volumes, a user will normally tend to inadvertently apply an excess of sample to the device, even when only pressing a plunger of the syringe slightly.

Notably, in the illustrated collection device, as best seen in Figure 2a, the receiving filter 31, comprises a sample receiving zone 31a and two extended side zones 31b. The sample receiving zone 31a is defined by the sample chamber walls 38, as will be detailed below. However, it is also conceivable to provide a recieiving filter 31 that only has a sample receiving zone 31a (not shown). In the illustrated aspect of Figure 2a, the extended side zones 31b function as an extra excess sample volume. This will be further described below in connection with Figure 2e.

As may be understood from Figures 2d and 2e, sample is thus injected into the sample chamber 39 and immediately reaches and wets the sample receiving zone 31a of the receiving filter 31 , within the sample chamber. Directly adjacent and under the sample receiving zone 31a a vertical separation filter 36 is arranged, and directly adjacent the vertical separation filter 36, a lateral separation filter 37 is arranged. Thus, in this aspect the vertical and lateral separation filters 36, 37 form, separately or together, the sample analysis member referenced above.

Due to the immediate wetting of the sample receiving zone 31a, on application of sample in the sample chamber 39, the vertical and following lateral separation will occur quickly after application of sample. In this aspect, the vertical separation filter 36, with a porous structure, allows a first rough filtration of the sample before reaching the lateral separation filter 37, where e.g. plasma from a whole blood sample is separated, through capillary action, from blood cells, such that the color of the plasma can be visualized at a detection zone 41. A detection zone may be a transparent part of the housing such that a part of the lateral separation filter is visible through the housing. Detection may be performed by visual inspection and/or using a device capable of detecting color, such as a spectrophotometer.

Together with the housing, the walls 38 form the sample chamber 39, and thus define the sample receiving zone 31a of receiving filter 31. The sample receiving zone 31a is a sample receiving member, as referred to above. The walls 38 may function to control the flow of fluid between the sample receiving zone 31a and extended side zones 31b by mechanical pressure on the filter, as seen in Figure 2e.

As may be understood from e.g. Figures 2a, 2b, 2d and 2e, one or several excess filters 33, forming the excess removal member, may be arranged outside the sample chamber 39. As shown in the figures, such an excess filter may be configured to be provided over a large part of the surface area of a collection device outside the sample chamber 39. The figures shown only one conceivable shape of the excess filter(s) 33. In accordance with the present disclosure, the excess filter 33 is arranged such that a gap 35 is present between the sample receiving filter 31a and the excess filter 33, as seen in Figure 2d. As is understood from this figure, when the sample receiving zone 31 a is saturated, sample fluid will flow from the sample receiving filter 31a out into the remaining part of the collection device, and specifically along the inner surface of the bottom housing 34b, across the gap 35 towards the excess filter 33. Thus, a part of the inner surface of the bottom housing 34b is a common connecting surface between the sample receiving filter 31a and the excess filter 33.

Notably, it should be understood that the illustrated collection device may be held in any orientation during use, and that the flow of sample fluid is due to the characteristics of the different filters and the spatial arrangement of the filters and the gap 35, enabled by the configuration of the housing parts, such as the inner shape of the housing, including the placement of the walls 38. Thus, the flow from the sample receiving zone 31a to the excess filter 33 is not dependent on gravity, but rather the arrangement of the filters within the housing and characteristics of the filters in relation to each other.

As long as sample recieiving filter 31a is over-saturated, fluid will continue to fill gap 35 and continue to flow towards the excess filter 33 and be absorbed. Once flow lessens, the absorbent excess filter 33 will retain the excess fluid, and drain the gap 35, such that fluid cannot flow back to the sample recieiving filter 31a.

The excess filter volume is adapted to be larger than the volume of the sample zone 31 a of the recieiving filter 31 such as twice the volume, three times the volume, or four times the volume of the sample zone 31 a of the recieiving filter 31. As long as there is dry, unsaturated filter volume outside the sample chamber, such as in the excess removal filter 33, fluid will not flow back into the sample chamber volume. Notably, it should be mentioned that the collection device is thus adapted to handle a wide range of applied sample volumes.

As mentioned above, In the collection device illustrated in Figures 2a to 2e, the receiving filter 31, comprises a sample receiving zone 31a and two extended side zones 31b, and the extended side zones 31b function as an extra excess sample volume. Referring to Figure 2e, it may be understood that due to the compression by the walls 38, any sample fluid in the sample receiving zone 31a is to a large degree prevented from flowing to the extended side zones 31b, at least initially. However, over time, the extended side zones 31b may gradually function as excess removal zones, as the fluid will eventually seep across the border defined by the walls 38. Furthermore, as the extended side zones 31b are placed adjacent the excess removal filter 33 in the regions of the collection device outside the sample chamber 39, when the excess fluid filter 33 is saturated, the extended side zones 31b may absorb sample fluid from the excess fluid filter 33.

The collection device shown in Figures 2a to 2e may be any suitable size depending on the volume to be applied and the volume to be collected, for example having a diameter along the line B-B’ within the range of 10 mm to 50 mm, more preferably within the range of 15 mm to 25 mm. In the figures, the collection device is drop-shaped as viewed from above or below. However, any suitable overall shape may be provided, such as round, oval, square etc.

The distance of the gap 35 must be adapted to the overall size of the collection device. For example, the distance of the gap 35 may be within the range of 0,1 mm to 10 mm, more preferably within the range of 0,5 mm to 5 mm, or most preferably within the range of 1 ,0 to 3,0 mm. As an example, in the collection device described in Figures 2a-2e, if a diameter along line B-B’ is approximately 20 mm, the distance of the gap 35 may be within the range of 1,0 to 3,0 mm.

Providing a spatial separation or gap 35, or any other arrangement where sample fluid received by the excess fluid removal member essentially is prevented from travelling back to the sample receiving member, provides the device with a low sensitivity for sample volume variations. Further, also for this collecton device, the spatial separation thus allows fluid to travel from the sample receiving member 31a to the excess fluid removal member 33, but not in the opposite direction.

After obtaining a blood sample in a syringe, it is common practice to remove any excess air and air bubbles by holding the tip upwards and depressing the plunger to expel air and air bubbles until all bubbles are removed. Naturally, a small amount of blood sample will be expelled during this procedure. Typically, the excess blood is discarded, and may pose a contamination risk. In addition, if the user forgets to remove air, this will affect following analysis negatively.

The presently disclosed collection device may be used after or during the air removal procedure. Thus, in some aspects, the collection device may be adapted to be a cap for a syringe, such that it may directly be applied at the tip of a sample syringe, and may thus double as a cap and a collection device. This eliminates the need for a separate cap for the syringe, and eliminates the need to change cap when collection for analysis is performed, hence saving time and effort for the user.

In some aspects, the collection device may be adapted to be used for removal of excess air prior to and/or during application of sample to the collection device. Thus, after the collection device is attached to the syringe, excess air and air bubbles in the syringe tip may be pressed out of the syringe. Once air is removed, sample will flow into the sample chamber. Even though it is normally difficult to gauge the amount of sample applied is such an air removal procedure, especially as the expelled sample from the syringe tip is a mixture of air and blood, the presently disclosed collection device provides advantageous handling of varying sample volumes through the herein described arrangement. Hence, the device may be used as a combined cap, air removal device and collection device, or any combination thereof. If used as an air removal device, the air removal may be performed at the same time, or in the same step, as sample application to the collection device. This provides the advantages of both saving time and effort, as the two steps are combined, and making use of the expelled initial sample from the syringe, such that no excess blood needs to be handled or disposed of. Thus, the sample is essentially contained within a closed system and the risk of contamination of the sample or surrounding environment is minimized. Notably, the collection device is preferably adapted such that sample fluid is contained, unless the device is completely over-filled, but air is allowed to escape.

A method of collecting sample fluid is thus disclosed, comprising the steps of

Notably, as mentioned above, the two steps of expelling air from the blood sample and applying sample fluid to the the sample receiving member are preferably performed in one single motion. Typically, there will be a small amount of excess air in the sample syringe, including a foam mixture of blood and air, and by expelling this foam and a small amount of blood, air will be removed from the syringe. If the syringe is connected to the present collection device when expelling air, the expelled sample is directly applied to the sample receiving member.

Preferably, the sample receiving member and the excess fluid removal member are spatially separated from each other by a gap, as disclosed above, such that sample fluid received and absorbed by the excess fluid removal member essentially is prevented from travelling back to the sample receiving member.

Further, if a hemolysis test is to be performed, as decribed above for the device of Figures 2a-2e, the fluid retained in the sample receiving member may immediately flow into the separation filter and plasma can be visualized after separation as described above. As an alternative, the method above may be applied in a collection device intended for following analysis of any suitable kind, especially those diagnostic tests where it is preferable to use a predetermined volume of sample, such as a blood sample, for analysis. As indicated, the method of combining air removal, sample collection for a following analysis, and sample volume regulation for a following analysis saves time and effort for the user, as well as reduces contamination risk and/or mishandling of a sample. In other words, in the case of collecting a sample for a subsequent hemolysis analysis, or any other analysis, the collection device and the method of collecting a fluid sample for analysis provides a manner of adjusting the variable volume of applied sample to a predetermined volume for following analysis, while at the same time providing means for simultaneous air and air bubble removal in a sample. In addition, if the collection device is adapted for and applied as a cap directly after drawing the sample from a patient, even more time is saved, as the collection device is then used as a cap, which is kept on the syringe throughout air removal, collection and analysis of the sample, eliminating any steps of removing a cap between the drawing if sample and detection of hemolysis. Furthermore, this lessesn the risk of contamination of the sample.

In some aspects, following a separation of plasma in the collection device, detection may be performed by visual inspection, and/or by a detecting instrument, such as a dedicated spectrophotometer or other suitable instrument. In some further aspects, the detecting instrument may be the same instrument as a a blood analysis instrument or combined with a blood analysis instrument, such as a blood gas analysis instrument. In other words, hemolysis detection may be performed directly in a blood analysis instrument.

The collection device and method of the present disclosure allows excess sample to be removed directly on application to the sample receiving member. For many types of blood analysis, it is either essential or preferable to collect a known volume of fluid for analysis. In the present disclosures, this is achieved by removing any excess sample applied. The volume, or fluid capacity, of a sample receiving member, e.g. the sample receiving zone of the receiving filter, may be defined by properties such as choice of material, dimensions of the filter etc. The same applies to the excess removal member.

The predetermined fluid volume capacity of the sample receiving member determines the volume of fluid allowed to be used in the following sample analysis step. Flow to the separation filter starts immediately when the sample receiving member is saturated. If, or when, the receiving member is oversaturated, the excess volume is irreversably absorbed by the excess removal member. Further, the spatial separation between the sample receiving member and the excess removal member prevents backflow from excess removal member back to sample receiving member.

Two further alternative aspects of arranging a collection device for collection and analysis of a bodily fluid are shown in Figures 3a and 3b. The sample receiving members and excess fluid removal members may be formed by suitable filters or absorbing material. Figure 3a illustrates two types of collection devices 50, e.g. in the form of test strips. A sample receiving member 51 is arranged on a support 54, and one or two excess fluid removal members 53 are provided with a gap 55 between the sample receiving member 51 and the excess removal member(s) 53. Similarly, in Figure 3b, an exemplary collection device 50, such as a test patch or similar arrangement. .A circular sample receiving member 51 is arranged on a support 54, and a ring-shaped excess fluid removal member 53 is provided with a gap 55 between the sample receiving member 51 and the excess removal member 53. The gap 55 provides the effect, as previously discussed, that sample fluid received by the excess fluid removal member 53 essentially is prevented from travelling back to the sample receiving member. Thus a controlled volume of fluid may be retained in the sample receiving member 51, and applied to a following analysis (not shown).

The present invention is not limited to the above-described preferred embodiments. Various alternatives, modifications and equivalents may be used. Therefore, the above embodiments should not be taken as limiting the scope of the invention, which is defined by the appending claims.

Claims

1. A collection device (10, 30, 50), for collection and analysis of a bodily fluid, said collection device comprising a sample receiving member (11, 31, 51) adapted to receive a fluid sample (12) applied to the collection device, an excess fluid removal member (13, 33, 53) adapted to remove excess sample fluid applied to the collection device, wherein the sample receiving member (11, 31, 51) and the excess fluid removal member (13, 33, 53) are spatially separated from each other such that excess sample fluid in the sample receiving member (11, 31, 51) is allowed to travel to the excess fluid removal member (13, 33, 53) and sample fluid received by the excess fluid removal member essentially is prevented from travelling back to the sample receiving member (11, 31 , 51).

2. A collection device (10, 30, 50) according to claim 1, wherein the sample receiving member (11, 31, 51) and the excess fluid removal member (13, 33, 53) are spatially separated from each other by a gap (15, 35, 55).

3. A collection device (10, 30, 50) according to any preceding claim, wherein the sample receiving member (11, 31, 51) and the excess fluid removal member (13,

33, 53) are adjacent to a common connecting surface.

4. A collection device (10, 30, 50) according to any preceding claim, wherein the excess fluid removal member (13, 33, 53) is adapted to receive a larger volume than a volume capacity of the sample receiving member (11, 31, 51)

5. A collection device (10, 30, 50) according to any preceding claim, further comprising a sample analysis member (36, 37) adapted to receive sample fluid from the sample receiving member (11, 31 , 51).

6. A collection device (10, 30, 50) according to claim 5, further comprising a detection zone (41) in or in connection with said sample analysis member (36, 37).

7. A collection device (10, 30, 50) according to any preceding claim, further comprising a housing (34a, 34b) adapted to house and contain the sample receiving member (11, 31, 51) and the excess fluid removal member (13, 33, 53).

8. A collection device (10, 30, 50) according to claim 7, further comprising a sample chamber (39) comprising the sample receiving member (11, 31 , 51).

9. A collection device (10, 30, 50) according to claim 8, further comprising walls (38) adapted to form the sample chamber (39).

10. A collection device (10, 30, 50) according to claim 8 or 9, wherein the housing is adapted such that a sample application opening (40) is arranged in communication with the sample chamber (39) comprising the sample receiving member (11, 31, 51).

11. A collection device (10, 30, 50) according to any preceding claim, wherein the collection device is further adapted to be used as a cap for a sample syringe.

12. A collection device (10, 30, 50) according to any preceding claim, wherein the collection device is adapted to be used for removal of excess air from a sample in a syringe prior to and/or during application of sample to the collection device.

13. A method of collecting sample fluid in a collection device, comprising the steps of

14. A method according to claim 13, wherein the sample receiving member and the excess fluid removal member are spatially separated from each other by a gap, such that sample fluid received and absorbed by the excess fluid removal member essentially is prevented from travelling back to the sample receiving member.

15. A method according to claim 13 or 14, further comprising the steps of

- separating the sample fluid in a sample analysis member provided in the collection device,

- detecting the color of the separated plasma at a detection zone of the collection device using a detection instrument.

16. A method according to claim 15, wherein the detection is performed by the same instrument that subsequently performs blood analysis.