TESTING DEVICE FOR LATERAL FLOW ASSAY

Abstract

The invention relates to a testing device with a testing assembly for lateral flow assay. The testing assembly comprises liquid sample receiving interface arranged on a support structure defining a plane. The liquid sample receiving interface is configured to receive a liquid sample. The testing assembly comprises at least one testing strip fluidly connected to the liquid sample receiving interface. The testing strip comprises a capillary wick fluidly connected to the liquid sample receiving interface and including at least one test portion, the test portion comprising at least one respective reacting material configured for reacting in a predetermined manner to at least one specific analyte. The testing device comprises an optical sensor, arranged and configured for detecting light reflected from the at least one test portion and for converting the detected light into an electrical signal representing an intensity and/or a color of the detected light. The testing device further comprises a conversion unit for converting the electrical signal into digital data representing the intensity and/or the color of the detected light, and a transmitter unit for wirelessly transmitting digital data.

Claims

1. A testing device comprising a testing assembly for lateral flow assay, the testing assembly comprising: a liquid sample receiving interface arranged on a support structure defining a plane (XY), the liquid sample receiving interface being configured to receive a liquid sample, at least one testing strip fluidly connected to the liquid sample receiving interface, the testing strip comprising a capillary wick fluidly connected to the liquid sample receiving interface and including at least one test portion the test portion comprising at least one reacting material configured for reacting in a predetermined manner to at least one specific analyte, wherein the testing device further comprises an optical sensor, arranged and configured for detecting light reflected from the at least one test portion and for converting the detected light into an electrical signal representing an intensity and/or a color of the detected light, a conversion unit for converting the electrical signal into digital data representing the intensity and/or the color of the detected light, and a transmitter unit for wirelessly transmitting digital data.

2. The testing device of claim 1, wherein the transmitter unit is configured for transmitting the digital data via a near-field communication link.

3. The testing device of claim 1, comprising at least one optical element (107) that is arranged and configured for directing light reflected from the at least one test portion to the optical sensor.

4. The testing device of claim 1, comprising at least one light source that is arranged and configured to illuminate the at least one test portion.

5. The testing device of claim 4, comprising a further optical element that is arranged and configured for directing illuminating light emitted by the at least one light source to the at least one test portion.

6. The testing device of claim 1, wherein the testing assembly further comprising at least one solution chamber containing a respective buffer solution, and flow control means configured to control a transfer of the buffer solution to the liquid sample receiving interface or to the at least one testing strip.

7. The testing device of claim 6, wherein the flow control means is configured to control a transfer of the buffer solution from the solution chamber to the liquid sample receiving interface either: before the liquid sample is received via the liquid sample receiving interface; or while the liquid sample is being received via the liquid sample receiving interface; or after the liquid sample has been received via the liquid sample receiving interface; or any combination thereof.

8. The testing device of claim 6, wherein the flow control means is configured to control a transfer of the buffer solution from the solution chamber to the at least one testing strip either: before the liquid sample is transferred from the liquid sample receiving interface to the at least one testing strip; or while the liquid sample is being transferred from the liquid sample receiving interface to the at least one testing strip; or after the liquid sample has been transferred from the liquid sample receiving interface to the at least one testing strip; or any combination thereof.

9. The testing device of claim 6, wherein the flow control means comprises microelectromechanical flow control means which are connected to the power management unit for controlling the transfer of the buffer solution.

10. A testing device of claim 1, wherein testing device further comprises a cover unit attachable to the support structure.

11. The testing device claim 10, wherein the testing assembly is non-releasably connected to the cover unit.

12. The testing device of claim 1, comprising a liquid sample providing module, the liquid sample providing module comprising at least one piercing element or a cannula having a tip and a base end, wherein the base end is configured to interface with the liquid sample receiving interface.

13. A testing system for testing a liquid sample for the presence of a specific analyte, the testing system comprising a testing device according to at least one of the preceding claims, and an external device that is configured for receiving digital data provided by the testing device.

14. The testing system claim 13, further comprising a server that is operatively connected to the external device for transmitting digital data received by the external device to the server.

15. The testing system of claim 13, wherein the testing device is configured to provide a raw signal to the external device, said raw signal representing a digital signal that represents an electric sign that in turn represents the optical signal as converted by means of an optical sensor of the testing device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0156] In the following, preferred embodiments of the invention are described with reference to the figure. In the figures:

[0157] FIG. 1A: shows a sectional view of a testing device comprising a piercing element, a testing assembly and a cover unit;

[0158] FIG. 1B: shows a plan view (top view) of an embodiment of a testing assembly for lateral flow assay;

[0159] FIG. 2A: shows a schematic representation of a top view and a cross sectional view of a set of four testing strips of a testing assembly for lateral flow assay, the testing strips being in a planar state;

[0160] FIG. 2B: shows a schematic representation of a top view and a cross sectional view of a set of four testing strips of a testing assembly for lateral flow assay, the testing strips being in a curved state;

[0161] FIG. 3: shows a schematic representation of an embodiment of a testing assembly for lateral flow assay;

[0162] FIG. 4: shows a schematic representation of another embodiment of a testing assembly for lateral flow assay that includes a solution chamber and flow control means;

[0163] FIG. 5: shows a schematic representation of an embodiment of a testing device;

[0164] FIG. 6A: shows a top view of a testing strip having curved longitudinal edges in planar state;

[0165] FIG. 6B: shows a lateral view of a testing strip having curved longitudinal edges in a planar state;

[0166] FIG. 7A: shows an exemplary detaching mechanism in a biased state; and

[0167] FIG. 7B: shows the detaching mechanism of FIG. 7A in an unstressed state.

[0168] FIG. 8A: shows a diagram of an exemplary support structure with a microfluidic system arranged thereon.

[0169] FIG. 8B: shows an enlarged view of a portion of the microfluidic system shown in FIG. 8A.

[0170] FIG. 9: shows a diagram of an exemplary support structure with a microfluidic system carved thereon.

[0171] FIG. 10: is a schematic representation of a testing system according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0172] FIG. 1A shows a sectional view of an embodiment of a testing device 160. The testing device 160 comprises a lancet 128. The testing device includes a testing assembly 170 and a cover unit 103. The lancet is a particular and non-limiting example of piercing element of a liquid sample providing module, and is connected to a liquid sample receiving interface 106 of the testing assembly 170. Other suitable liquid sample providing modules include, but are not limited to, needles, hollow needles or cannulas The testing assembly further comprises a support structure 104, a liquid sample receiving unit 102 and two testing strips 108.1 and 108.2, each comprising a respective test portion 112.1 and 112.2.

[0173] The testing device 160 also comprises a power management unit 105 comprising voltage stabilizing circuitry. The testing device further comprises an optical sensor 111 that is configured for detecting impeding light that is reflected by the test portions 112.1 and 112.2, and for converting the detected light into an electrical signal representing the intensity and/or the color of the impeding light. The optical sensor 111 is connected to a conversion unit 116. The conversion unit is configured for converting an electrical signal into digital data representing an intensity and/or a color of the detected light. The conversion unit 116 is an analog-to-digital converter and is comprised by the optical sensor 111. Alternatively, the conversion unit can be a separate component that is arranged on the support structure 104 and operatively connected to the optical sensor 111. For example, the optical sensor 111, the power management unit 105 and the transmitter unit having an RF-interface can be arranged on the support structure 104. Light reflected from the test portions 112.1 and 112.2 can be directed to the optical sensor using one or more mirrors also arranged on the support structure 104. Using mirrors, a light path can be created linking the test portions 112.1 and 112.2 and the optical sensor 111. It is also possible that the optical sensor 111, the power management unit 105 and the transmitter unit having an RF-interface are arranged on a circuit board, e.g., a flexible PCB. The circuit board can be arranged on the support structure 104. Using optical elements such as mirrors a light path can be created from the test portions 112.1 and 112.2 to the optical sensor 111 that is arranged on the circuit board. The circuit board can also be attached to the inner surface of the cover unit 103, the inner surface facing the support structure. Preferably, the optical sensor is arranged such that if the circuit board is attached to the inner surface of the cover unit 104, the optical sensor likewise faces the support structure. Since the test portions 112.1 and 112.2 face the sidewalls of the testing device, preferably, an optical element is arranged and configured to redirect light reflected from test portions 112.1 and 112.2 about 90° towards the optical sensor 111. Further comprised can be one or more light sources, e.g., LEDs, that are arranged and configured for illuminating test portions 112.1 and 112.2. The one or more light sources can be arranged on the support structure 104, or on a circuit board, or directly to the inner surface of the cover unit 103.

[0174] The testing device 160 also comprises a transmitter unit 113 connected to a power management unit 105 and to the conversion unit 116. The transmitter unit 113 is configured to wirelessly transmit digital data representing the intensity and/or color of the detected light, e.g., in accordance with a predetermined wireless communication protocol.

[0175] FIG. 1B shows a cross plan view (top view) of an exemplary embodiment of a testing device 101 having a testing assembly 100 for lateral flow assay. In the following discussion, those features being shared by the testing device 160 of FIG. 1A and 101 of FIG. 1B, are referred to using the same numerals.

[0176] The testing device 101 of FIG. 1B comprises a liquid sample receiving unit 102 that is arranged on a support structure 104. In alternative and preferred testing devices, the liquid sample receiving unit is arranged on a central position of the support. In other testing devices (not shown), the liquid sample receiving interface can be arranged directly on the testing strip, and thus, these alternative testing devices do not have a dedicated liquid sample receiving unit, as testing device 101 does. The support structure 104 is a flat structure that defines a plane XY as defined by the axes shown in FIGS. 1A, and 1B. The support structure 104 has a largest linear extension L.sub.Max that is shorter than 5 cm, preferably shorter than 3 cm, and more preferably 2.5 cm. The liquid sample receiving unit 102 comprises a liquid-sample receiving interface 106 in the form of an opening on the support structure 104. The liquid sample receiving unit 102 is configured to receive a liquid sample via the liquid sample receiving interface 106. The liquid sample receiving unit includes an absorbent material (not shown), preferably a porous hydrophilic material, preferably comprising nitrocellulose or a similar material.

[0177] The testing assembly 100 also includes two testing strips 108.1 and 108.2. Each testing strip 108.1, 108.2 is fluidly connected to the liquid sample receiving unit 102 and each comprises a capillary wick (110.1, 110.2) connected to the liquid sample receiving unit 102. Preferably, the capillary wick also comprises a porous hydrophilic material such as nitrocellulose or a similar material. Each testing strip 108.1, 108.2 includes a respective test portion 112.1, 112.2 as part of the capillary wicks 110.1 and 110.2. The test portions include a respective reacting material (not shown) configured to react in a predetermined manner to at least one respective analyte. In some testing assemblies, the test portions 112.1 and 112.2 may contain different reacting materials configured to react to different analytes. In other testing assemblies, the test portions comprise a single reacting material configured to react to a given analyte, with a same or a respective different sensitivity, in order to either improve the accuracy of testing assembly or in order to enable a semi-quantitative evaluation of the given analyte. Other alternative testing assemblies may comprise a plurality of test portions having a given material and additionally at least one test portion having a different reacting material.

[0178] In this particular testing assembly 100, the two testing strips 108.1 and 108.2 are arranged so that an angle formed between a width direction of the testing strip (Z, in the particular embodiment of FIGS. 1A, and 1B and the normal N of the plane (XY) at each longitudinal position along the longitudinal direction of the testing strip is substantially constant with an angle value of substantially 0°, within the practical limits of fabrication and angle determination. This means that the width direction of the testing strip is perpendicular to the support structure 104.

[0179] Additionally, a testing assembly can further comprise a first window section 114 (dashed line) arranged around the liquid sample receiving unit 102. The first window section 114 is at least partially transparent in a visible wavelength range and is arranged to allow a control of a positioning of the liquid sample receiving unit onto an external surface. By enabling a user to partially see an external surface onto which the testing assembly is to be positioned, the exact position of the liquid sample receiving unit can be advantageously controlled.

[0180] The testing device 101 also comprises a power management unit 105 having an energy storage unit for storing electric energy and for providing electrical power, and an optical sensor 111. The optical sensor 111 is configured and arranged for detecting impeding light that is reflected from the test portions 112.1 and 112.2. The optical sensor 111 is configured to convert the detected light into an electrical signal representing the intensity or color of the impeding light.

[0181] The testing device 101 of FIG. 1B also includes a light source 109 that is arranged and configured to illuminate the test portion 112.1. Further, an optical element 107 is arranged and configured for directing light provided by the light source 109 and reflected from the test portion 112.1, to the optical sensor 111. Preferably, the optical sensor 111, the conversion unit 116 and the transmitter unit 113 are arranged on an inner side of a cover unit of the testing device (not shown). Also, the light source 109 and the optical member are preferably arranged on the inner side of the cover unit. Alternatively, the optical sensor 111, the conversion unit 116 and the transmitter unit 113 can be arranged on the support structure 104 or on a circuit board that is arranged on the support structure 104. It is also possible to arrange at least one of the optical sensor 111, the conversion unit 116 and the transmitter unit 113 on an outer side of a cover unit of the testing device.

[0182] The optical sensor 111 is operatively connected to the conversion unit 116 that is configured for converting an electrical signal into digital data. The transmitter unit 113 is part of a transceiver unit 117 connected to the power management unit 105 and to the conversion unit 116.

[0183] Via a data bus, the conversion unit 116 is connected to the transceiver unit 117 for providing digital data to the transceiver unit's transmitter unit 113.

[0184] The transceiver unit 117 is configured to receive control commands and to transmit digital data in accordance with a predetermined wireless communication protocol. The transceiver unit 117 is configured for drawing energy from an external device. The transceiver unit 117 thus has energy harvesting capabilities and is configured for drawing energy from an external device via electromagnetic induction. To this end, the transceiver unit's transmitter unit comprises a NFC-coil and an NFC-chip for near-field-communication with the external device. The power management unit 105 comprises a capacitor, preferably, a supercapacitor, for storing harvested energy. In alternative embodiments no energy storage unit is present and the harvested energy is directly used for powering components of the testing device 101.

[0185] Alternatively, or additionally, the testing device 101 can comprise one or more solution chambers 124.1, 124.2 (dashed lines) that contain a respective buffer solution. The testing devices 101 can also include an optional flow control means (not shown in FIG. 1, see description of FIG. 4) that is advantageously configured to control a transfer of the buffer solution to the testing strips 108.1, 108.2. In some testing assemblies each solution chamber is connected to every testing strip. In alternative testing assemblies, however, some solution chambers are only connected to only one or to a sub-set of the testing strips.

[0186] In some embodiments of the testing device (not shown), the flow control means may be configured to control a transfer of the solution buffer to the liquid sample receiving interface or to the liquid sample receiving unit. In some testing devices comprising two or more solution chambers, at least one of the solution chambers is connected to the liquid sample receiving interface and at least one of the solution chambers is connected at least one of the testing strips.

[0187] In any of the previously described testing devices, the capillary wick of the testing strip may be arranged on a testing-strip carrier that is configured to confine at least a part of incoming light inside a light-guiding layer of the carrier by total internal reflection achieved, for instance, by a proper choice of materials with a suitable respective refractive index or position-dependent refractive index profile. The testing-strip carriers also comprise a light output section onto which the test portion of the testing strip is suitably arranged. The light output section is configured to enable confined light to exit the testing-strip carrier. Therefore, these particular testing-strip carriers are suitably configured to illuminate the test portion arranged thereon from its rear part. Advantageously, in some embodiments, the capillary wick has a thickness that is thin enough to let at least part of the light impinging on the rear part of the test portion to travel to the front part.

[0188] The geometry of an exemplary set of testing strips 208 is described with reference to FIGS. 2A and 2B. In FIG. 2A, four testing strips form a set of testing strips. Each individual testing strip has a respective test portion 212. Each testing strip is presented in an planar state and has a testing strip center line length L in a longitudinal direction, a testing strip width W in a width direction perpendicular to the longitudinal direction and a testing strip thickness d, in a thickness direction perpendicular to both the longitudinal direction and the width direction, that is shorter, i.e., has a smaller extension than the testing strip center line length L and the testing strip width W. FIG. 2B shows the same set of testing strips 208 in a curved state in which a shortest distance between two opposite longitudinal ends of the testing strip center line, or in other words, an effective extension R is shorter than the testing strip center line length L in the planar state shown in FIG. 2A. In this particular example, the shortest distance between the two opposite longitudinal ends of the testing strip corresponds to the effective extension R. In another exemplary configuration (not shown) wherein the testing strip is bent in e.g. a circular shape, the shortest distance between the two opposite longitudinal ends vanishes, whereas the effective extension corresponds to the diameter of the formed circle, which is π/L. In any case, the shortest distance and the effective extension are shorter than the testing strip center line length.

[0189] FIG. 3 shows a schematic representation of another embodiment of a testing device 301 having a testing assembly 300. The testing assembly 300 shares many features with the testing assembly 100 described with respect to FIG. 1B. Those features shared will be referred to by using the same reference numbers, only altering the first digit, which is “1” when referring to FIGS. 1 and “3” when referring to FIG. 3.

[0190] The testing assembly 300 comprises a support structure 304 that has an opening 306 which, in this particular testing assembly is in connection with a liquid sample receiving unit 302. In alternative embodiments of the testing assembly, the opening is directly connected to a section of the testing strip acting as a liquid sample receiving interface. The liquid sample receiving interface is advantageously configured to interface with an external liquid sample providing module (not shown). Liquid sample providing modules that can be connected to the liquid sample receiving interface 306 may include, for example, lancets, needles, cannulas or liquid containers with means to transfer a liquid sample contained therein to the liquid sample receiving unit 302 via the liquid sample receiving interface 306. Alternatively, the liquid sample can be directly supplied to the liquid sample receiving interface without the need of a liquid sample providing module.

[0191] The testing assembly 300 includes one testing strip 308 in a curved state (nor shown) that is fluidly connected to the liquid sample receiving unit 320. The testing strip 308 comprises a capillary wick 310. The testing strip also includes conjugate pad 320 that comprises an immobilized conjugate material. The conjugate pad 320 is configured to release the immobilized conjugate material upon contact with the liquid sample. The conjugate material is contained in the conjugate pads, i.e. as colloidal gold, or colored, fluorescent or paramagnetic monodisperse latex particles that have been conjugated to one specific biological component expected to be identified in the liquid sample. This biological component is in some testing devices an antigen and in other testing devices an antibody. The testing strip 308 also comprises test portion 312 that includes a test line 312.1 and a control line 312.2 forming a so-called reaction matrix.

[0192] The liquid sample, received through the liquid sample receiving interface 306 is transported by capillary action from the liquid sample receiving unit 302 along the capillary wick 310. At the conjugated pad 320, the liquid sample releases the conjugate material and a combination of both is further transported towards an absorbent pad 322 located at a distal end of the testing strip 308, opposite to a proximal end whereto the liquid sample receiving unit 302 is connected. The absorbent pad 322 of this (and similar) testing strips is configured to act as a sink for the liquid sample, maintaining a flow of the liquid over the capillary wick and preventing a flow of the liquid sample back to or towards the liquid sample receiving unit 302.

[0193] The testing device 301 also comprises an optical sensor (not shown) that is arranged and configured for detecting light reflected from the test portion 312 of test strip 308. The optical sensor is further configured for converting impeding light into an electrical signal representing the intensity and/or the color of the detected light. The testing device 301 comprises a conversion unit for converting an electrical signal into digital data and a transmitter unit for wirelessly transmitting digital data upon initiating by an external initiator device 1020.

[0194] The features distinguishing the testing assembly 300 from testing assembly 100 can be advantageously used in combination with any of the alternatives to the testing device 100 that have been previously discussed. For instance, some testing devices may include, in addition to the features discussed with reference to FIG. 3, a reflector element or at least one solution chamber with respective flow control means, or, preferably, both a reflector element and at least one solution chamber with respective flow control means. Some of these testing assemblies also comprise a testing-strip carrier onto which the capillary wick is arranged.

[0195] FIG. 4 shows a schematic representation of another embodiment of a testing device 401 testing assembly 400. Here again, the testing assembly 400 shares some features with the testing assemblies 100 and 300 described with respect to FIGS. 1B, and 3. Those features shared are referred to by using the same reference numbers, only altering the first digit, which is “1” when referring to FIG. 1, “3” when referring to FIG. 3 and “4” when referring to FIG. 4.

[0196] The testing device 401 comprises a solution chamber 424 containing a buffer solution, and flow control means 426.1 configured to control a transfer of the buffer solution to the liquid sample receiving unit 402. Alternatively, or additionally, some testing devices include flow control means 426.2 that control a transfer of the buffer solution directly to the testing strip 408 (as indicated by the dashed-line). Some testing devices include a plurality of solution chambers and control flow means that control a respective transfer of the respective solution (which can be identical or different or a combination thereof) to the liquid sample receiving interface or to one or more testing strips. Buffer solutions are advantageously chosen to enhance a transport of the liquid sample along the capillary wick of the testing strips.

[0197] The flow control means 426.1 and 426.2 preferably comprise microelectromechanical (MEMS) flow control means for controlling the transfer of the buffer solution. The microelectromechanical flow control means preferably is connected via a data bus to a microcontroller. Via a transceiver unit control commands can be received for controlling the microelectromechanical flow control means by way of the microcontroller. The microelectromechanical flow control means include, in different testing assemblies, micro-sensors and/or micro actuators, such as micro pumps. In a particular testing device, the micro sensors and/or micro actuators are also integrated to a microprocessor for controlling micro sensors and/or micro actuators.

[0198] The testing device 401 comprises an optical sensor (not shown) for detecting light that was reflected from the test portion 412 of test strip 408, and for converting the light into an electrical signal representing the light intensity and/or color. The testing device 401 comprises a conversion unit (not shown) for converting an electrical signal into digital data and a transmitter unit (not shown) operatively connected to the conversion unit for transmitting digital data to an external receiving device, e.g., via a near-field communication (NFC) link. The transmitter unit can comprise an NFC-chip or a RFID-tag. Alternatively, the transmitter unit can be configured for transmitting the digital data via Bluetooth or Wi-Fi.

[0199] With energy drawn from the external device, electronic and/or electro-mechanical components of the testing device can be powered.

[0200] In particular, energy supply for such micro-pumps or micro actuators preferably is wireless, for instance when reading out the transmitter unit via NFC link.

[0201] The capillary wick of some of the testing assemblies is arranged on a testing-strip carrier configured to confine by internal total refection at least a part of incoming light inside a light-guiding layer of the carrier. The test portion of the testing strip is arranged onto a light output section of the testing carrier, so that light confined inside the light-guiding layer can exit it and thereby illuminate the test portion.

[0202] Any of the testing assemblies described in the previous discussion can form part of a testing device as described with reference to FIG. 5.

[0203] FIG. 5 shows a schematic representation of an embodiment of a testing device 500 for lateral flow assay. The testing device 500 comprises a liquid sample providing module in the form of a lancet 528 that is configured to be connected to the liquid sample receiving interface 506 of the liquid sample receiving unit 502. Here again, the testing device 500 comprises a testing assembly that shares features with the testing assemblies 100 and 400 described with reference to FIGS. 1 and 4. These features share the same reference numbers except for the first digit, which is “1” when referring to FIG. 1, “4” when referring to FIG. 4 and “8” when referring to FIG. 5.

[0204] The testing device 500 comprises three distinct solution chambers 524.1, 524.2 and 524.3. It also comprises flow control means that include microelectromechanical flow means 526.1, 526.2, 526.3 configured control flow of the buffer solution to the testing strips 510.1, 510.2 or to the liquid-sample receiving unit 502.

[0205] In some embodiments of the testing device, the testing device includes flow control means that are alternatively or additionally configured to control the transfer of the buffer solution while the liquid sample is being transferred to the liquid sample receiving interface via the liquid sample providing module.

[0206] Yet other testing devices can include flow control means that are alternatively or additionally configured to control the transfer of the buffer solution after the liquid sample has been transferred to the liquid sample receiving interface via piercing element.

[0207] FIG. 6A shows a top view of a testing strip 601 in an alternative geometrical configuration that is used in some embodiments of the testing assemblies described with reference to FIGS. 1A, 1B, 3 and 4. FIG. 6A shows top views of a testing strip 601 of width W, with curved longitudinal edges and a testing strip center line length L given by the length measure of the center line (dashed lined) and a testing strip 602 with straight longitudinal edges, that has the same width W and the same testing strip center line length L as the testing strip 601). FIG. 6B shows a corresponding lateral view of the testing strips 601 and 602. The thickness of the testing width is given by d.

[0208] The testing strip 601 has already in the planar state an effective extension R that is shorter than the maximal longitudinal extension L of the testing strip in the planar state. The effective extension of the testing strip length in the planar state is in the case depicted in FIG. 6A equivalent to the testing strip center line length (dashed line). In order to achieve, for testing strip 602, an effective extension shorter than L, the testing strip 602 has to be arranged in a curved state, e.g. by folding, curving, wrapping, etc. the testing strip 602.

[0209] FIGS. 7A and 7B show an exemplary detaching mechanism 700 that can be used in combination with any of the testing devices described hereinabove. FIG. 7A shows the detaching mechanism 700 having a spring 702 in a biased state, wherein FIG. 7B shows the same detaching mechanism 700 having the spring 702 in an unstressed or unbiased state. A distal end of the spring 702 is connected to a lancet 704 that forms in this particular case the liquid sample providing module of the testing device. Other detaching mechanisms in accordance with this invention can be alternatively attached to other liquid sample providing modules such as flexible catheters or other fluidic systems. A proximal end of the spring 702 is connected to the support structure 706 of a testing device at an anchor point. The lancet 704 is also in fluid communication with a soluble material 708 that is configured to remain attached to the support structure as long as a predetermined fraction of the soluble material remains in a solid state. When liquid enters in contact with the soluble material, it causes a dissolution thereof that enables a detachment of the spring 702 from the support structure 706. The spring is thus allowed to adopt an unbiased state as shown in FIG. 7B, forcing a movement of the lancet 704 in a Z direction. This detaching movement drives the lancet from the container or the living being from which it was extracting the liquid sample into an inner volume of the testing device. This detaching movement is configured to end an ongoing liquid sample extraction process. Other detaching mechanisms that can be used alternatively may comprise a bi-stable snap dome, connected to the liquid sample providing unit and wherein a transition from a first stable state to a second stable state is driven by a dissolution of at least a fraction of the soluble material.

[0210] FIG. 8A shows a diagram of a support structure 800 with a passive microfluidic system 802 arranged thereon FIG. 8B shows an enlarged view of a portion 802.1 of the microfluidic system shown in FIG. 8A. The microfluidic system comprises 802 an inlet 804 connected to the liquid sample receiving interface for receiving the liquid sample. The microfluidic system also comprises an outlet connected to the testing strip 808, of which only a section is shown in FIG. 8. The inlet 804 is connected to an air vent 805 via a waste channel 818. Further, the inlet 805 and waste channel are fluidly connected to the outlet 806 via a passive valve 812 and a separation chamber 810. An air reservoir 814 is connected via a dedicated connection 820 to an air inlet 816 arranged between the passive valve 812 and the separation chamber. The passive microfluidic system 802 with geometric passive valves can be produced separately from the support structure 800 and then arranged onto it. It can also be connected to a container containing a buffer solution (nor shown). Suitable fabrication methods for the microfluidic system 802 include 3D printing, in particular digital light projector 3D printing (DLP 3D printing).

[0211] FIG. 9: shows a diagram of an exemplary support structure 900 with a microfluidic system 902 carved thereon. The features corresponding to those features of FIGS. 8A and 8B are referred to using the same numerals except for the first digit, which is “8” for the microfluidic system of FIGS. 8A and 8B and “9” for the microfluidic system of FIG. 9. The passive valve 912 is, in a particular exemplary microfluidic system, not a geometric passive valve as valve 812, but a hydrophobic valve, i.e. a portion of the microfluidic system coated with a hydrophobic surface, particularly a nano-coating, to limit the flow of a liquid. A similar hydrophobic surface is also located in the immediate vicinity of the outlet 908, as indicated by the white box in FIG. 9. Also, the dedicated connection 920 between the air reservoir 914 and the air inlet 916 is optionally coated with a hydrophobic surface. Preferably, the remaining surfaces, including the waste channel 918, the connection linking the waste channel with the inlet 916, and the separation chamber are coated with a hydrophilic material forming hydrophilic surfaces suitable for enhancing capillary flow in the respective sections of the microfluidic system 902.

[0212] In summary, the invention relates to a device having a testing assembly for lateral flow assay. The testing assembly comprises liquid sample receiving interface arranged on a support structure defining a plane. The liquid sample receiving interface is configured to receive a liquid sample. The testing assembly comprises at least one testing strip fluidly connected to the liquid sample receiving interface. The testing strip comprises a capillary wick fluidly connected to the liquid sample receiving interface and including at least one test portion, the test portion comprising at least one respective reacting material configured for reacting in a predetermined manner to at least one respective analyte. The testing device further comprises an optical sensor that is arranged and configured for detecting impeding light that was reflected from the at least one test portion, and for converting the detected light into an electrical signal representing the light intensity or the color. The testing device also comprises a conversion unit for converting an electrical signal into digital data. The testing device also comprises a transmitter unit for wirelessly transmitting digital data representing the intensity and/or the color of the detected light to an external device.

[0213] A testing system 1000 according to the invention comprises a testing device 1010 and an external device 1020; see FIG. 10.

[0214] The testing device 160 comprises (see FIG. 1A) [0215] a testing assembly 170, [0216] an optical sensor 111, [0217] a conversion unit 116, and [0218] a transmitter unit 113.

[0219] The testing assembly 170 is a part of the testing device and comprises [0220] a support structure 104, [0221] a sample receiving interface 106, and [0222] at least one testing strip 108, wherein the testing strip 108 comprises [0223] a capillary wick 110, and wherein the capillary wick 110 includes [0224] at least one test portion 112.

[0225] The optical sensor 111, the conversion unit 116 and the transmitter unit 113 preferably are arranged on the testing assembly's support structure 104. Alternatively, the optical sensor 111, the conversion unit 116 and the transmitter unit 113 can be attached to the testing device's cover unit 103.

[0226] The testing device's optical sensor 111 is arranged and configured for detecting light reflected from the at least one test portion 112, and for providing an electrical signal representing an intensity and/or a color of the detected light. The optical sensor 111 can be, e.g., a single-pixel photodiode or a CMOS-sensor or a CCD-sensor.

[0227] After converting detected light into an electrical signal, the electrical signal is provided to the conversion unit 116.

[0228] The conversion 116 unit is configured for converting the electrical signal into digital data representing the intensity and/or the color of the detected light. The conversion unit 116 can be part of the optical sensor 111. The conversion unit 116 can also be a separate component of the testing device 160. Alternatively, the conversion unit 116 can be part of the transmitter unit 113. Preferably, the conversion unit 116 is or comprises an analog-to-digital converter (ADC) for converting the electrical signal into digital data representing the intensity and/or the color of the detected light. The conversion unit can be configured for converting the electrical signal with 8-bit.

[0229] The conversion unit 116 is operatively connected to the transmitter unit 113, e.g., via a data bus, for providing digital data to the transmitter unit 113.

[0230] The transmitter unit 113 is configured for wirelessly transmitting the digital data representing the electrical signal that in turn represents the detected light, preferably, to an external receiving device 1020 (see FIG. 10) using a predetermined wireless communication protocol such as Bluetooth, near-field communication (NFC) or Wi-Fi or RFID. In particular, the transmitter unit 113 can be or can comprise a NFC-chip and a NFC-coil, or a radiofrequency identification (RFID)-tag or transponder, or a Wi-Fi-integrated circuit chip, or a Bluetooth integrated circuit chip.

[0231] A transmitter unit 113 based on a technology such as NFC or RFID not requiring a permanent energy supply is preferred. The energy needed for powering such a transmitter unit is provided by a so-called initiator.

[0232] A transmitter unit 113 that is configured for transmitting data via NFC or RFID, preferably, comprises one or more antennas functioning as a radio-frequency (RF) interface for transmitting electromagnetic signals representing digital data by means of electromagnetic induction to one or more further antennas of an external device. Antennas typically comprise one or more coils each having 4 or 5 windings.

[0233] The initiator can be the external device 1020 providing a carrier field that is modulated by the transmitter unit 113 for transmitting digital data. Preferably, for powering the transmitter unit 113, the transmitter unit 113 draws energy from the external device 1020 via the NFC or RFID link. Thus, in particular, in case the transmitter unit is NFC- or RFID-enabled, it is not necessary that the testing device 160 itself comprises an energy storage unit, e.g., a battery, for powering the transmitter unit 113.

[0234] The testing device 160 is a single device allowing receiving a liquid sample, e.g., a body fluid such as blood, from a patient, processing the received liquid sample with a microfluidic system comprising a capillary wick with at least one test portion and analyzing the received body fluid with respect to the presence of a specific analyte. The evaluation whether or not a specific analyte is present in the liquid sample is performed externally, e.g., directly on the external device 1020 that receives the digital data. The external device can be a smartphone, or a tablet, preferably, having NFC or RFID capabilities and being configured to function as an initiator device. The external device 1020 can also be used to transmit the digital data further, e.g., to a personal computer or a server for evaluation purposes.

[0235] The optical sensor 111, the conversion unit 116 and the transmitter unit 113 can be arranged as separate components on the support structure 104 together with the microfluidic components. It is also possible that the optical sensor 111, the conversion unit 116 and the transmitter unit 113 are be fabricated using electronic packaging, e.g., 3D-packaging. Using 3D-packaging, thus, by stacking the components on top of each other, a compact three-dimensional integrated circuit can be designed. After 3D-packaging the integrated circuit comprising the optical sensor, the conversion unit and the transmitter unit can be mounted onto the support structure or attached to a cover unit. Alternatively, a chip comprising the optical sensor, the conversion unit and the transmitter can be fabricated using wafer-level packaging (WLP). The optical sensor, the conversion unit and the transmitter unit can also be put into a protective package for integration into the testing device.

[0236] In some embodiments, the optical sensor, the conversion unit and the transmitter unit are mounted on a circuit board that is attached as a module onto the support structure or to a cover unit. The circuit board can be flexible, e.g., a flexible substrate made of polyimide, e.g., Kapton, polyether ether ketone (PEEK), liquid-crystal polymer (LCP), or FR4. Also a rigid or semi-flex circuit board can be used as an alternative. In particular, the optical sensor, the conversion unit and the transmitter can be integrated onto a thin FR4 substrate. The circuit board can be a printed circuit board (PCB) which, preferably, is flexible, e.g., a FR4 PCB. Alternatively, the printed circuit board can be a rigid or semi-rigid printed circuit board.

[0237] Attaching at least of the optical sensor, the conversion unit and the transmitter unit to a testing device's cover unit is of advantage since more space is left on the support structure, e.g., for arranging the components of the microfluidic system.

[0238] In particular, an antenna of the transmitter unit can be integrated in the testing device using in-mold manufacturing. In case the testing device has a cover unit attached to the support structure, thus, forming a closed housing, an antenna of the transmitter can be integrated into the housing, e.g., attached on the inside to the lid part of the cover unit by means of in-mold manufacturing. Alternatively, an antenna of the transmitter unit can be integrated into the same chip or in the same circuit as the remaining transmitter electronics, the optical sensor and the conversion unit. For instance, the antenna can be integrated in the PCB.

[0239] Since processing the data representing the light signal acquired by the testing device 1010 is not carried out on the testing device 1010 but on the external device 1020, the testing device can be small and does not need a battery for storing electrical energy for a longer period of time. Rather, energy can be supplied to the testing device 1010 by the external device 1020 as described herein above. The optical sensor 111, the conversion unit 116 and the transmitter unit are simply converting the optical signal into an electrical signal and a digital raw signal, respectively, without further processing the signals and in particular without analysing and evaluating the signal since this is done on the external device or for instance a server operatively connected to the external device 1020. The digital raw signal as provided by the testing device 1010 is analysed and evaluated by the external device 1020 and/or a server 1030 that is at least temporarily connected to external device 1020.

REFERENCE NUMERALS

[0240] 100 testing assembly [0241] 101 testing device [0242] 102 liquid sample receiving unit [0243] 103 cover unit [0244] 104 support structure [0245] 105 power management unit [0246] 106 sample receiving interface [0247] 107 optical element [0248] 108.1, 108.2 testing strip [0249] 109 light source [0250] 110.1, 110.2 capillary wick [0251] 111 optical sensor [0252] 112.1, 112.2 test portion [0253] 113 transmitter unit [0254] 114 window section [0255] 116 conversion unit [0256] 117 transceiver unit [0257] 124.1, 124.2 solution chambers [0258] 128 lancet [0259] 160 testing device [0260] 170 testing assembly [0261] 208 testing strips [0262] 212 test portion [0263] 300 testing assembly [0264] 301 testing device [0265] 302 liquid sample receiving unit [0266] 304 support structure [0267] 306 liquid sample receiving interface [0268] 308 testing strip [0269] 310 capillary wick [0270] 312 test portion [0271] 312.1 test line [0272] 312.2 control line [0273] 320 conjugate pad [0274] 322 absorbent pad [0275] 400 testing assembly [0276] 401 testing device [0277] 402 liquid sample receiving unit [0278] 408 testing strip [0279] 412 test portion [0280] 424 solution chamber [0281] 426, 426.1, 426.2 flow control means [0282] 500 testing device [0283] 502 liquid sample receiving unit [0284] 506 liquid sample receiving interface [0285] 510.1, 510.2 testing strips [0286] 524.1, 524.2, 524.3 distinct solution chambers [0287] 526.1, 526.2, 526.3 microelectromechanical flow means [0288] 528 lancet as part of a liquid sample providing module [0289] 601, 602 testing strip [0290] 700 detaching mechanism [0291] 702 spring [0292] 704 lancet [0293] 706 support structure [0294] 708 soluble material [0295] 800 support structure [0296] 802 microfluidic system [0297] 802.1 portion of the microfluidic system [0298] 804 inlet [0299] 805 air vent [0300] 806 outlet [0301] 808 testing strip [0302] 810 separation chamber [0303] 812 passive valve [0304] 814 air reservoir [0305] 816 air inlet [0306] 818 waste channel [0307] 820 dedicated connection [0308] 900 support structure [0309] 902 microfluidic system [0310] 908 outlet [0311] 912 passive valve [0312] 914 air reservoir [0313] 916 air inlet [0314] 918 waste channel [0315] 920 connection [0316] 1000 testing system [0317] 1010 testing device [0318] 1020 external device [0319] 1030 server