1. A process for controlling the composition of a solution in the production of cellulosic shaped bodies, the process comprising:
(a) mixing cellulose and a water-containing amine oxide to form a suspension,
(b) creating a cellulose solution from the suspension by vaporization of water,
(c) measuring a first property of the cellulose solution and a second property different from the first property wherein the measured values of the first and second properties are used to calculate the actual composition of the solution and their deviation from values of a target composition is used to adjust the composition of the solution; and
(d) extruding the cellulose solution through an air gap into an aqueous regeneration bath where it is coagulated to form shaped bodies that are capable of undergoing further processing step.
2. The process according to claim 1, wherein the first and second properties of the cellulose solution are selected from the group consisting of: relative permittivity, inductive conductivity, microwave absorption, refractive index, density, water content, and ultrasonic speed.
3. The process according to claim 2, further comprising measuring the cellulose solution’s temperatures and the measured values of the first and second properties are adjusted on the basis of the measured temperature, wherein the timing of the temperature measuring is selected from the group consisting of during the measuring of the first and second property, before the measuring of the first and second property and after measuring of the first and second property.
4. The process according to claim 2, wherein at least one of the first and second property is measured in-line.
5. The process according to claim 2, wherein the solution composition is adjusted by manual intervention in the dosing of the suspension components of step (a).
6. The process according to claim 2, wherein operating conditions are adjusted by manual intervention in the operating conditions of step (b).
7. A device for performing a process for controlling the composition of a cellulose solution comprising cellulose and a water-containing amine oxide used in the production of cellulosic shaped bodies the device comprising:
(a) a slurrying apparatus communicatively connected with at least two metering devices for metering input of the cellulose and water-containing amine oxide;
(b) a dissolving and vaporization arrangement connected to the slurrying apparatus;
(c) an extruding device connected by a conduit to the dissolving and vaporizing arrangement and having a regeneration bath attached downstream therefrom;
(d) at least two measuring instruments contacting the conduit for measuring a first and a second property of the cellulose solution passing through the conduit; and
(e) a controlling circuit for controlling the composition of the cellulose solution by determining the actual composition of the cellulose solution in the conduit from the measured values of the first and second property and to determine the deviation from a preset target composition and adjust metering devices to correct for any deviation.
8. The device according to claim 7, where in the first and second property of the cellulose solution are different and selected from the group consisting of: relative permittivity, inductive conductivity, microwave absorption, refractive index, density, water content, and ultrasonic speed.
9. The device according to claim 8, further comprising a temperature measuring instrument for measuring the temperature of the cellulose solution and to compensate for temperature in the measured values of measuring instruments.
10. The device according to claim 7, wherein the measuring instruments, a microprocessor and the metering devices form the controlling circuit.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of facilitating the identification of a statistically significant change in the characteristic structure of tissue within the eye of a patient comprising:
(a) obtaining measurements acquired during at least two separate visits;
(b) evaluating the results of the measurements to identify a change in tissue characteristics occurring between the measurements, said evaluation including at least two different types of analyses, said two different analyses being selected from the group consisting of:
(i) a global analysis of a tissue characteristic;
(ii) a regional analysis of a tissue characteristic; and
(iii) a local analysis of a tissue characteristic; and
(c) displaying or storing the results of the at least two different types of analyses
2. A method of facilitating the identification of a statistically significant change in the topography of a structure in the eye of a patient comprising:
(a) obtaining measurements acquired during at least two separate visits;
(b) evaluating the results of the measurements to identify a topographical change occurring between the measurements, said evaluation including at least two different types of analyses, said two different analyses being selected from the group consisting of:
(i) a global analysis of topography;
(ii) a regional analysis of topography; and
(iii) a local analysis of topography; and
(c) displaying or storing the results of the at least two different types of analyses.
3. A method as recited in claim 2, wherein the analyses assesses the rate of change in the topography.
4. A method as recited in claim 2, wherein at least one of the analyses performed in step (b) includes measurements obtained during at least three separate visits.
5. A method as recited in claim 2, further includes assessing the rate of change in the topography based on linear regression of measurements.
6. A method as recited in claim 2, further including two or more follow-up visits wherein the follow-up visits are grouped into at least two periods and said analyses assesses the rate of change for each period respectively, and displays the rates on a common display.
7. A method of facilitating the identification of a statistically significant change in the thickness of the retinal nerve fiber layer (RNFL) in the eye of a patient comprising the steps of:
(a) obtaining optical measurements of the RNFL at least two different times;
(b) evaluating the results of the measurements to identify a change in thickness of the RNFL occurring between measurements, said evaluation including at least two different types of analyses, said two different analyses being selected from the group consisting of:
(i) a global analysis of RNFL thickness;
(ii) a regional analysis of RNFL thickness; and
(iii) a local analysis of RNFL thickness; and
(c) displaying or storing the results of the at least two different types of analyses.
8. A method as recited in claim 7, wherein the analyses assesses the rate of change of RNFL thickness.
9. A method as recited in claim 7, wherein the evaluation step (b) includes spatial registration of measurements obtained at different times.
10. A method as recited in claim 7, wherein results of the at least two different types of analyses are simultaneously displayed on a common display.
11. A method as recited in claim 7, wherein results of the at least two different types of analyses are combined to achieve more sensitive detection of RNFL change.
12. A method as recited in claim 7, wherein the evaluating step (b) includes three different analyses, at least one global analysis, at least one regional analysis and at least one local analysis, the results of which are simultaneously displayed.
13. A method as recited in claim 7, wherein the evaluating step (b) includes three different analyses, at least one global analysis, at least one regional analysis and at least one local analysis, the results of which are combined to achieve more sensitive detection of RNFL change.
14. A method as recited in claim 7, wherein the evaluating step (b) includes detecting blood vessels and excluding changes in blood vessel regions to improve accuracy of detection.
15. A method as recited in claim 7, wherein the evaluating step (b) includes detecting the optic nerve head (ONH) and excluding changes in ONH regions to improve accuracy of detection.
16. A method as recited in claim 7, wherein the evaluating step (b) includes confirming, within each type, the analysis results of a measurement with those of a consecutive measurement to improve accuracy of detection.
17. A method as recited in claim 7, wherein said local analysis includes one of a pixel comparison or a combination of a few adjacent pixels comparison derived from a two dimensional image.
18. A method as recited in claim 17, wherein the results of the local analysis are displayed by color coded overlays on the two dimensional image, a different two dimensional image, or a measurement data image, to indicate locations of reduced RNFL thickness.
19. A method as recited in claim 18, wherein the evaluation includes determining if selected image pixels exceed a first predetermined threshold and determining if there are a sufficient cluster of pixels exceeding a second predetermined threshold to indicate a reduced thickness RNFL.
20. A method as recited in claim 18, wherein the pixels corresponding to blood vessels are masked in the analysis to provide more accurate assessment of RNFL change.
21. A method as recited in claim 7, wherein the regional analysis includes mapping RNFL thickness in a region defined by a ring surrounding the optic nerve head of the eye.
22. A method as recited in claim 21, wherein the results of the regional analysis is displayed on a graphic illustrating a ring laid out over the quadrants of the eye and by color coding the regions within the ring that correspond to regions of reduced RNFL thickness.
23. A method as recited in the previous claim 22, wherein the evaluation includes determining if selected points within the ring exceed a first predetermined threshold and determining if there are a sufficient number of adjacent points that exceed a second predetermined threshold to indicate a reduced thickness RNFL.
24. A method as recited in the previous claim 22, wherein the points corresponding to blood vessels are masked in the analysis to provide more accurate assessment of RNFL change.
25. A method as recited in claim 7, wherein the regional analysis includes mapping RNFL thickness in a region defined by a segment of an annular ring surrounding the optic nerve head of the eye.
26. A method as recited in claim 7, wherein the global analysis includes calculating an average RNFL thickness over at least a portion of region defined by a ring surrounding the optic nerve head (ONH) of the eye or at least a portion of region defined by quadrants surrounding the ONH.
27. A method as recited in claim 7, wherein the global analysis includes calculating an average RNFL thickness across a region defined by a ring or a quadrant surrounding the optic nerve head of the eye.
28. A method as recited in claim 27, wherein the results are calculated and displayed as points of a trend line on a trend chart.
29. A method as recited in the previous claim 28, further including extrapolating the change in RNFL thickness and displaying the extrapolated results on the trend chart.
30. A method as recited in the previous claim 29, further including obtaining one or more additional measurements at a subsequent time, performing a global analysis of the results, generating information to generate a revised trend line and displaying both the original trend line and the new trend line on the trend chart.
31. A method as recited in claim 7, wherein the step of evaluating the results of the measurements to evaluate a change in thickness of the RNFL occurring between measurements is performed by directly comparing the measurements.
32. A method as recited in previous claim 31, wherein the evaluation of change requires at least three separate visits and the step of evaluating change is performed by directly comparing a later measurement with at least two earlier measurements to improve accuracy.
33. A method as recited in claim 7, wherein the step of evaluating the results of the measurements to evaluate a change in thickness of the RNFL occurring between measurements is performed by a statistical analysis of the trend of the measurements.
34. A method as recited in previous claim 33, wherein the step of evaluating the results of the measurements to evaluate a change in thickness of the RNFL occurring between measurements acquired with multiple systems is performed by the statistical analysis of the trend of the measurements accounting for measurement differences across systems.
35. A method as recited in claim 7, further includes determining if a reduction in RNFL is statistically significant and said reduction is noted on a display.
36. A method as recited in claim 7, further includes assessing the rate of RNFL change based on linear regression of measurements.
37. A method as recited in claim 7, further including two or more follow-up visits wherein the follow-up visits are grouped into at least two periods and said analyses assesses the rate of change for each period respectively, and displays the rates on a common display.
38. A method as recited in claim 7, wherein the test for a statistically significant change uses individual-base test-retest variability.
39. A method as recited in claim 7, wherein the test for a statistically significant change uses population-base test-retest variability.