Light flux determination of particle contamination
First Claim
1. A method for automated non-destructive inspection of injectable pharmaceutical solutions, in transparent containers, for particle contamination, said method comprising the steps of:
- a. moving the solution container, whereby particles, contained therein, are placed in motion;
b. fully illuminating the solution in the container, while the particles are in motion, with forward scatter lighting;
wherein there is an instantaneous increase of the normal current flowing from a first light detector element, which detects the forward scatter lighting, caused by reflection of light by individual particles;
with said instantaneous increase of current being proportional to the size of the individual particles;
c. directing said increase of current to first current detector means;
d. back lighting a volume of the solution in the container with collimated light, during the period when the solution in the container is fully illuminated with forward scatter lighting, wherein there is light extinction caused by individual particles passing through said volume, with an instantaneous decrease of current from a second light detector element, which detects said collimated light, from normal non-particle illumination in said volume, and wherein said instantaneous decrease of current is proportional to the size of the individual particles;
e. directing said decrease of current to second current detector means;
f. summing the absolute values of the detected increases and decreases of current into an optical signature of particle contaminants in the container solution; and
g. accepting containers having optical signatures falling within pre-determined acceptable optical signature ranges.
0 Assignments
0 Petitions
Accused Products
Abstract
A method and device for the automated non-destructive single inspection of solutions in transparent containers for particle contamination, in injectable pharmaceutical solutions, with commercially viable acceptance percentages, while maintaining security within guidelines based on skilled human inspection. The containers are fully illuminated with forward scatter lighting with total light flux for detection of low contrast particles, with the size of the particles being evaluated by the maximum instantaneous increase of detector current as the particle moves through the detection zone. Simultaneously therewith, narrow detection volumes are back lighted with collimated light flux for detection of high contrast or dark particles, within the detection volume, by light extinction with a decrease of detector current from the normal non-particle illumination. The maximum pulsatile current decrease is used to determined the size of the particle. Separate illumination elements provide the forward scatter light and the back lighting, and separate, non-overlapping detector areas capture the separate increase and decrease of detector current. Either separate detectors with separate lenses are utilized for detection of the increase and decrease of detector current or mirrors are utilized to reflect the respective images through a single lens onto separated sections of a single detector element.
36 Citations
29 Claims
-
1. A method for automated non-destructive inspection of injectable pharmaceutical solutions, in transparent containers, for particle contamination, said method comprising the steps of:
-
a. moving the solution container, whereby particles, contained therein, are placed in motion; b. fully illuminating the solution in the container, while the particles are in motion, with forward scatter lighting;
wherein there is an instantaneous increase of the normal current flowing from a first light detector element, which detects the forward scatter lighting, caused by reflection of light by individual particles;
with said instantaneous increase of current being proportional to the size of the individual particles;c. directing said increase of current to first current detector means; d. back lighting a volume of the solution in the container with collimated light, during the period when the solution in the container is fully illuminated with forward scatter lighting, wherein there is light extinction caused by individual particles passing through said volume, with an instantaneous decrease of current from a second light detector element, which detects said collimated light, from normal non-particle illumination in said volume, and wherein said instantaneous decrease of current is proportional to the size of the individual particles; e. directing said decrease of current to second current detector means; f. summing the absolute values of the detected increases and decreases of current into an optical signature of particle contaminants in the container solution; and g. accepting containers having optical signatures falling within pre-determined acceptable optical signature ranges. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. A device for automated non-destructive inspection of injectable pharmaceutical solutions, in transparent containers, for particle contamination, said device comprising:
-
a. means for moving the solution container whereby particles, contained therein, are placed in motion; b. means for fully illuminating the solution in the container, while the particles are in motion, with forward scatter lighting;
wherein there is an instantaneous increase from the normal current flowing from a first light detector element, which detects the forward scatter lighting, caused by reflection of light by individual particles;
with said instantaneous increase of current being proportional to the size of the individual particles;c. first current detector means for detecting said instantaneous increase of current; d. means for back lighting a volume of the solution in the container with collimated light, during the period when the solution in the container is fully illuminated with forward scatter lighting, wherein there is light extinction caused by individual particles passing through said volume, with an instantaneous decrease of current from the normal current flowing from a second light detector element, which detects the back lighting and extinction thereof, and wherein said instantaneous decrease of current is proportional to the size of the individual particles which cause said light extinction; f. second current detector means for detecting said decrease of current; g. means for summing the absolute values of the detected increases and decreases of current into an optical signature of particle contaminants in the container solution; and h. comparison means for comparing the optical signal to a pre-determined optical signature range for determining acceptance of the container solution. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
-
Specification