Patent Application
20080081002
The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Embodiments of the diagnostic assay reader to be described below will be described in the context of optically reading a diagnostic assay result. However, the diagnostic assay reader can be used in implementations that read a diagnostic assay result using technology other than an optical reader.
The diagnostic assay reader to be described below is generally intended to be operated by a medical caregiver and used at a point-of-care location. However, other implementations are possible.
The external host device and power source 116 also includes an external power and data interface 120 that couples via connection 122 to the external power and data interface 110. In this embodiment, the external power and data interface 120 also complies with the USB standard and allows the transfer of power and data between the diagnostic assay reader 100 and the external host device and power source 116. However, the diagnostic assay reader 100 can include data and power interfaces other than USB. For example, the diagnostic assay reader 100 can be powered by a serial interface. The external host device and power source 116 also includes reader software 118. The reader software 118 provides a user interface on the external host device and power source 116 for the diagnostic assay reader 100.
The diagnostic assay reader 100 optionally includes a display 134 and a power switch 136. In some applications, it is not desirable for the results of the diagnostic assay to be readily evident on the diagnostic assay reader 100. In such implementations, the display 134 is omitted. Further, instead of a communications and power bus 114, the detector 106, processor 108, memory element 112 and the external power and data interface 110 can be connected using discrete connections.
In an embodiment, the detector 106 is an image sensor, such as a silicon complementary metal oxide semiconductor (CMOS) image sensor capable of electronically reading a diagnostic assay result 102 that is placed or otherwise located in a field of view of the detector 106 or connected to the detector 106. The diagnostic assay result 102 can be, for example, a chemically activated visual indicator of a diagnostic assay or can be an electrochemical reaction. The diagnostic assay result 102 is machine-readable to minimize the occurrence of errors when interpreting the result. For example, the diagnostic assay result 102 may include one or more indicator bars 104, the presence or absence, location, color, intensity, etc., of which convey the result of a diagnostic assay. In an embodiment, the detector 106 is placed in proximity to the diagnostic assay result 102 so that the detector 106 can electronically read and image the bars 104. In an embodiment in which the detector 106 is an image detector, the detector 106 generates an image of the diagnostic assay result. A signal indicative of an electronic representation of the image is then transferred from the detector 106 to the processor 108 via the communication and power bus 114. In an alternative embodiment, the detector 106 can be implemented using a PIN diode, or an array of PIN diodes, to sense the state of the diagnostic assay result. The PIN diode senses the optical intensity of a signal and converts the optical intensity signal to an electrical signal. The output of the PIN diode can be transferred to the processor 108, which can be implemented using an operational amplifier configured as a comparator. The signal from the PIN diode is compared against a threshold value supplied to the comparator to determine the state of the diagnostic assay result 102. The output of the comparator is provided to the memory 112 and to the external power and data interface 110 via the communication and power bus 114. This embodiment will be described below. When the detector is implemented as an imaging device or a PIN diode, a light emitting diode (LED) or laser can be used to illuminate the diagnostic assay result.
Alternatively, the detector 106 can be an electrical sensor if the diagnostic assay result 102 is provided using an electrochemical reaction. In another alternative embodiment in which the diagnostic assay result 102 is provided using an electrochemical reaction, the detector 106 can be implemented using a detector and electrical probes that contact fluid-covered electrical contacts associated with the diagnostic assay result. The electrical signal detected by the electrical probes is representative of the result of the diagnostic assay. The result signal is communicated to the processor 108, which can be implemented using an operational amplifier configured as a comparator. The signal from the electrical probes is compared against a threshold value supplied to the comparator to determine the state of the diagnostic assay result 102. The output of the comparator is provided to the memory 112 and to the external power and data interface 110 via the communication and power bus 114. This embodiment will be described below. If the detector 106 is implemented using one or more PIN diodes or electrical probes, multiple lines, also referred to as detection zones, on the diagnostic assay result can be detected using multiple channels. In such an implementation, the PIN diode or electrical probe will typically be an array of PIN diodes or electrical probes. Alternatively if a single channel is implemented, the diagnostic assay result can be mechanically moved or, in the case of a PIN diode, the field of view of the PIN diode can be optically steered to read the diagnostic assay result.
The processor 108 analyzes the electronic representation of the image and develops a result signal that is indicative of the diagnostic assay result. The result signal can be transferred to the external power and data interface 110 for transmission via power and data connection 122 to the external host device 116.
The result signal can also be stored in the memory element 112 and optionally displayed on the display 134.
The external host device and power source 116 can be coupled to a database 132 via a network 126 and connections 124 and 128. The network 126 can be a local area network or a wide area network, or can be collection of networks such as the World Wide Web (WWW). The connections 124 and 128 can be any connections used to couple devices to a network. Alternatively, the external host device and power source 116 can be coupled directly to the database 132.
The diagnostic assay reader 150 includes a detector implemented using a PIN diode 156. However, an array of PIN diodes may be implemented. The PIN diode 156 senses the state of the diagnostic assay result 102. The PIN diode 156 senses the optical intensity of the diagnostic assay result 102 and converts the optical intensity signal to an electrical signal. The output of the PIN diode 156 is transferred to the processor 158 via connection 164. However, in an alternative implementation, the output of the PIN diode 156 can be transferred to the processor 158 over the communication and power bus 114.
In this embodiment, the processor 158 is implemented using an operational amplifier configured as a comparator 162. The signal from the PIN diode 156 is compared against a threshold value 166 supplied to the comparator 162 via connection 168 to determine the state of the diagnostic assay result 102. Although shown as residing within the processor 158, the threshold element 166 may reside elsewhere. The output of the comparator 162 is provided via connection 172 to the memory 112 and to the external power and data interface 110 via the communication and power bus 114.
The diagnostic assay reader 180 includes a detector implemented using an electrochemical detector 190. In this embodiment, a diagnostic assay result 182 is an electrochemical device in which a test area 184 includes electrical contacts 186 that are covered by a fluid 192. The fluid has electrical impedance. The fluid 192 is electrically stimulated and detected using the probes 188 associated with the electrochemical detector 190. The impedance is proportional to the concentration of analyte in the fluid 192.
The electrical probes 188 are electrically connected to the electrical contacts 186 through the fluid 192 and can sense electrical fluctuations in the fluid 192 in the test area 184. The electrical fluctuations are sensed by the electrical probes 188 and converted to an electrical signal by the electrochemical detector 190. The electrical signal is indicative of the state of the diagnostic assay result 182. The signal is transferred from the electrochemical detector 190 to the processor 158 via connection 164. However, in an alternative implementation, the signal supplied by the electrochemical detector 190 is transferred to the processor 158 over the communication and power bus 114.
In this embodiment, the processor 158 is implemented using an operational amplifier configured as a comparator 162. The signal from the electrochemical detector 190 is compared against a threshold value 166 supplied to the comparator 162 via connection 168 to determine the state of the diagnostic assay result 182. Although shown as residing within the processor 158, the threshold element 166 may reside elsewhere. The output of the comparator 162 is provided via connection 172 to the memory 112 and to the external power and data interface 110 via the communication and power bus 114.
The internal power source 310 provides power to the diagnostic assay reader 300 using one of a number of different technologies. For example, in addition to the power sources mentioned above, the internal power source 310 can be formed as part of a hinge or spring if the diagnostic assay reader 300 is formed as a so called “clamshell” shaped device. In such an embodiment, opening or closing the clamshell device generates energy to power the diagnostic assay reader 300.
The diagnostic assay reader 300 includes a display 334 and an optional power switch 336. Alternatively, instead of a communications and power bus 314, the detector 306, processor 308, memory element 312 and the internal power source 310 can be connected using discrete connections.
The detector 306 can be an image sensor that is similar to the detector 106 described above. The detector 306 reads a diagnostic assay result 102 that is placed in a field of view of the detector 306 or that is otherwise connected to the detector 306. Alternatively, the detector 306 can be an electrochemical detector if the diagnostic assay result is provided using an electrochemical reaction, as described above. An electronic representation of the image is then transferred from the detector 306 to the processor 308 via the communication and power bus 314. The processor 308 analyzes the electronic representation of the image and develops a result signal that is indicative of the diagnostic assay result. The result signal can be stored in the memory element 312 and displayed to a user on the display 334. Alternatively, the diagnostic assay reader 300 is part of a self contained diagnostic assay test kit that includes a diagnostic assay 330. In such an implementation, the diagnostic assay 330 can be internally connected to and read by the detector 306. Alternatively, the detector 306 can be any sensor device capable of interpreting the result of the diagnostic assay 330.
This disclosure describes the invention in detail using illustrative embodiments. However, it is to be understood that the invention defined by the appended claims is not limited to the precise embodiments described.
