IL35417A - Synchronous storage of digitized measurements in a rotary photometric analyser - Google Patents

Description

This invention relates, in general, to an improved data acquisition, processing and storage system for rotary photometric analyzers. In oneaspect, this invention relates to an improved analyzer which keeps exact track of the identity of individual samples and the data obtained therefrom. In a further aspect, this invention relates to improved analyzers wherein the data for any individual sample is integrally synchronized with the sample.

Figure 1 is a perspective view of a rotary photometric analyzer showing the rotatable cuvet disk with reagent and sample chambers on its upper surface.

Figure 2 is a cross-sectional view showing the magnetic memory attached to the same shaft on which the cuvet disk rotates.

In recent years the need for rapid, automatic, analytical devices has increased markedly due to the numerous microanalytical studies in biochemical research, routine clinical testing for physicians and hospitals, enzymatic studies and the like. In addition to the increased demand for analyses, in certain fields it is often critical that a series of reactions be started at exactly the same time if reliable results are to be obtained. This is particularly important for enzymatic studies wherein detectable changes often take place after the reaction has proceeded for only a few seconds or minutes. However, few devices are available which can analyze Recently, multistation analytical photometers which utilize a centrifugal field have become available for the rapid microanalysis of a wide variety ofliquids such as body fluids, e.g., blood serum, food products, and the like. Since numerous analyses can be performed rapidly and simultaneously these devices are of particular interest wherein a large number of samples is involved or a variety of tests on one sample is desired. Moreover, since these devices allow the use of relatively small volumes of reagents, i.e., in the microliter range, the use of expensive reagents can be minimized.

One such device which utilizes a centrifugal field in microanalytical studies is described in Analytical Biochemistry 28,545-562 (1969). This device employes the principle of double-beam spectrophotometry wherein absorbencies of a liquid sample and a reference solution are intercompared. The system is basically a series of cuvets arranged around the periphery of a rotor so that when it is spun, centrifugal force simultaneously mixes and transfers reagents and samples to the cuvets where the concentration is measured spectrophoto-metrically. A sample loading disk is provided which consists of rows of cavities arranged concentrically. Reagents are placed in the inner-most cavity and serum samples in the center cavity of the sample loading disk which is ten indexed and positioned in the rotor with each reagent and serum sample having its respective cuvet. As the rotor is accelerated, centrifugal force moves the reagent and sample to the outermost cavity where they are mixed and then transferred through a small channel to the cuvet. The filled cuvets ra idl s in As indicated in the article the electronic signal generated photoelectrically can be displayed on a cathode ray tube and recorded photographically. Alternatively, digital data processing can be utilized with processing and printing out the results.

In the photometric analysis of a number of samples which are simultaneously spinning in the centrifugal field, it is necessary to measure each sample, make a decision or a calculation which depends on the history of that sample, and store the results while attention is diverted to the next sample. It is also necessary to identify the samples by some means such as a synchronizing signal derived from a point on the rotor.

In a typical rotary photometric analyzer, 30 samples are carried at up to 1800 rpm by a 6 inch diameter rotor. It is necessary to store about 50 bits of information about each sample. Core storage could be used but would undoubtedly be too expensive for such a small store. Moreover, a delay line would be useful only if the rotor could be synchronized to the line's recirculation time. Even slight variations in the speed of the rotor disk containing the cuvets could introduce errors into the analyzer.

Accordingly, it is an object of this invention to provide an improved rotary photometric analyzer. Another object of this invention is to provide an improved analyzer wherein the data obtained is integrally synchronized with each individual sample. A further object of this invention is to provide a rotary photometric analyzer wherein the magnetic memory is positioned on the same shaft as the rotatable disko These and other objects will readily < In its broad aspect, the Invention relates to an improved rotary photometric analtzer* The improvement comprises positioning the magnetic memory on the same rotatable shaft as the disk containing the covets* Data recorded on the magnetic drum is thereby integrally synchronized with each individual sample* In the drawings, Figure 1 is a perspective view of a rotary photometric analyzer comprised of a cuvet disk 10, which is rotated by drive motor 16* The cuvet disk contains reagent and sample chambers 1½, and euvets 12, arranged around th peripheral edge* As th disk rotates the c ontents of each cuvet is analyzed photometrically* A light beam emanates from light source 18, passes through the cuvet and is measured by photodeteetor 20* The data is processed and printed out at station 22· Figure 2, shows a cross-section of the rotatble cuvet disk 10 with reagent and sample chambers ih and cuvet 12* The disk is rotated by drive motor 6 around a central shaft* From light source 18 a beam is passed through cuvet 2 and measured by photodeteetor 20* The data obtained for each sample is stored on magnetic memory 23» and retrieved when desired by read-write heads 2k The magnetic memory 23 Is positioned on the same shaft that rotates the cuvet disk and hence its movement is synchronized with that of the disk* The improved analyzer provides advantages which are not found In known instruments* As previously indicated, by positioning a drum or disk magnetic memory on the same shaft as the cuvet rotor, excellent synchronization is achieved* Moreover, the magnetic memory can be located at most any point on the shaft which turns the cuvet disk* For convenience and optimum design, however, analyzers between the motor and cuvet rotor or on the opposite side of the motor from the cuvet rotor.

As previously indicated, the magnetic memory can be either the drum or disk type which are known in the art of data acquisition, processing and storage. The particular magnetic memory employed in this invention contains at least one data track with read-write heads. Additionally, a separate timing track and "once around" pulse are provided on the drum as a time base for the entire system. The "once around" pulse is generated optically by means of a hole in the drum and a photoelectric pickup.

As will be apparent, since the cuvet disk is turning at speeds such as 1800 revolutions per minute data is acquired much faster than it can be printed out. Since the digital print out is slow, the data obtained from initial scan of cuvets must be stored temporarily on the first track of the memory. After a predetermined time, for example, when the chemical reaction is complete the absorbence of each sample is measured individually and the initial reading on the first track substracted by a serial adder and the new data feed to the second track and stored. A separate track can serve as a time base for the entire system. This time base can be used to syncronize optical or other display of the mani pulated data.

Although the invention has been illustrated by the pre-ceeding disclosure it is not to be construed as being limited to the particular embodiments or materials disclosed therein. Rather, the invention encompasses the generic area as hereinbefore disclose Various modifications and embodiments thereof can be made without

Claims (5)

35 7/¾ CLAIMSs

1. In a device for the automatic and essentially simultaneous photometric analysis of a plurality of liquid samples wherein said samples to be analyzed are contained in cuvets arranged vertically and concentrically around a horizontally disposed rotatable disk, and wherein a light source projects a light beam into each cuvet as it is rotated past said source, said light beam passing through said liquid sample and the absorbence thereof detected photometrically and the data therefrom digitally recorded, the improvement which comprises positioning the magnetic memory on the same rotatable shaft as the disk, thereby integrally synchronizing the data obtained with each individual sample.

2. The device of claim 1 wherein said magnetic memory is cylindrical or disk like in shape and positioned on the same rotatable shaft as the disk.

3. The device of claim 2 wherein said magnetic memory is comprised of at least one read head and at least one read-write head.

4. U> The device of claim 3 wherein said magnetic memory contains a clock track which can be separate from or the same as the data track*

5. The device of claim k wherein said clock track is used to synchronize the optical or other display of data from or reduced from the data track. Attorney or App cants