Diagnostic measuring system
View Patent ↗The invention concerns a diagnostic tape unit with a test tape that can be wound onto a spool which comprises a transport tape and a plurality of test elements mounted thereon, where the test elements have an analytical reagent layer, a carrier foil supporting the reagent layer and a piece of adhesive tape connecting the carrier foil with the transport tape, and where the front side of the reagent layer facing away from the carrier foil is designed for the application of a sample substance. According to the invention it is proposed that the test elements in combination with the light transmitting transport tape in each case form an optical multi-layer system for a rear-side reflection-photometric measurement of the reagent layer.
1. A diagnostic measuring system comprising:
a diagnostic tape unit comprising a tape cassette for blood sugar tests, the tape cassette having a test tape that is wound onto or can be wound onto a spool as a tape reel, the test tape comprising a light-transmitting transport tape and a plurality of spaced apart test elements mounted thereon, the test elements each comprising an analytical reagent layer supported on a carrier foil layer, and further including an adhesive tape layer connecting the carrier foil layer adhered on one side with the transport tape adhered on an opposite side, wherein a front side of the reagent layer faces away from the carrier foil layer and is configured for the application of a sample substance, the test elements in combination with the transport tape in each case foaming an optical multi-layer system for a rear-side reflection-photometric measurement of the reagent layer, wherein the transport tape, the adhesive tape layer and the carrier foil layer of each test element each have optical properties comprising refractive index, transmission and haze, and wherein at least one optical property of the transport tape, adhesive tape layer and carrier foil layer are matched within predetermined tolerances; and
a reflection photometric arrangement oriented towards the rear side of the reagent layer of the test element located in a measuring position, the reflection photometric arrangement comprising a light source and a photodetector where the photodetector is arranged outside the direct reflection path of the measuring light radiated by the light source through the multi-layer system onto the reagent layer.
2. The diagnostic measuring system according to claim 1 , wherein the light source generates a light spot of less than about 1 mm 2 on the rear side of the reagent layer, wherein a granularity of the reagent layer serves as a scattering body.
3. The diagnostic measuring system according to claim 1 , wherein the refractive index of the transport tape, the carrier tape and the adhesive tape is in each case between about 1.4 and 1.7.
4. The diagnostic measuring system according to claim 3 , wherein the refractive index of the transport tape, the carrier tape and the adhesive tape is in each case between about 1.5 and 1.6.
5. The diagnostic measuring system according to claim 1 , wherein the individual layers of the multi-layer system have a maximum refractive index difference of about 0.2.
6. The diagnostic measuring system according to claim 5 , wherein the individual layers of the multi-layer system have a refractive index difference of less than about 0.1.
7. The diagnostic measuring system according to claim 1 , wherein the total refractive index of the multi-layer system is about 1.5.
8. The diagnostic measuring system according to claim 1 , wherein the transport tape, the adhesive tape and the carrier foil layer each have a transmission in the visible wavelength range of more than 80%.
9. The diagnostic measuring system according to claim 8 , wherein the transport tape, the adhesive tape and the carrier foil layer each have a transmission in the visible wavelength range of between about 85% and 92%.
10. The diagnostic measuring system according to claim 1 , wherein the total transmission of the multi-layer system in the visible wavelength range is at least about 80%.
11. The diagnostic measuring system according to claim 1 , wherein the transmission tolerance is less than about 5% for the entirety of the test elements of a test tape.
12. The diagnostic measuring system according to claim 1 , wherein the optical haze of the carrier foil layer and of the piece of adhesive tape in the visible wavelength range is less than about 10%.
13. The diagnostic measuring system according to claim 12 , wherein the optical haze of the carrier foil layer and of the adhesive tape in the visible wavelength range is less than about 8%.
14. The diagnostic measuring system according to claim 1 , wherein the optical haze of the transport tape in the visible wavelength range is less than about 3%.
15. The diagnostic measuring system according to claim 14 , wherein the optical haze of the transport tape in the visible wavelength range is less than about 2.5%.
16. The diagnostic measuring system according to claim 1 , wherein the total optical haze of the multi-layer system in the visible wavelength range is less than about 20%.
17. The diagnostic measuring system according to claim 16 , wherein the total optical hazeof the multi-layer system in the visible wavelength range is less than about 15%.
18. The diagnostic measuring system according to claim 1 , wherein the adhesive tape comprises a transparent foil substrate furnished on both sides with an adhesive layer.
19. The diagnostic measuring system according to claim 1 , wherein the transport tape and the carrier foil each comprise a PET film.
20. The diagnostic measuring system according to claim 1 , wherein an analyte contained in a sample substance in the form of a body fluid can be determined by a relative reflectance measurement, wherein calibration data are assigned to the test elements which define the concentration of the analyte as a function of the measured reflectance.