Chemical apparatus and process disinfecting – deodorizing – preser – Analyzer – structured indicator – or manipulative laboratory... – Means for analyzing liquid or solid sample
Patent
1989-02-03
1997-09-09
McMahon, Timothy
Chemical apparatus and process disinfecting, deodorizing, preser
Analyzer, structured indicator, or manipulative laboratory...
Means for analyzing liquid or solid sample
427 81, 436 65, 436148, G01N 3349
Patent
active
056653115
DESCRIPTION:
BRIEF SUMMARY
This invention relates to the measurement of various haemostasis, clotting, and the like properties of blood, and specifically to apparatus enabling measurements of such quantities to be made on blood. A device of this kind is disclosed in European Patent Specification No. 129425.
In that specification there is disclosed apparatus for the investigation of blood, comprising a columnar reservoir for holding the blood, an elongate tube leading from the reservoir to a waste blood holding vessel, and means for introducing into the reservoir a fluid immiscible with blood to displace the blood through the tube, while simultaneously stirring the blood in the columnar reservoir (hereinafter referred to as "apparatus of the type described").
I have now discovered a number of modifications and improvements to the apparatus disclosed in European Patent Specification No. 129425, which not only enable more reliable and more reproducible measurements to be made of clotting and heamostasis but also enable a number of other quantities to be measured.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, apparatus of the type described includes a pair of parallel channels, each channel comprising a columnar reservoir, elongate tube, waste blood holding vessel, and means for introducing a displacing fluid, as described above.
The use of two parallel channels enables a number of measurements to be made which are not possible with a simple single channel instrument. For example, in a preferred embodiment of this aspect of the invention, each channel has a punching station, at which, as disclosed in European Patent Specification No. 129425, a through-hole is punched through the elongate tube, to simulate bleeding. So that the size of the holes in the two tubes is exactly the same, both holes may be punched by a single parallel-sided punching needle. In an alternative embodiment, two exactly similar needles may be provided at corresponding places in the tubes of the two channels.
The use of parallel channels is particularly advantageous, because it enables measurements of clotting and haemostasis is kinds to be carried out on whole blood. Thus, in one embodiment, the columnar reservoir of both channels is filled with native blood, and caused to flow through the respective elongate tube, by displacement. Both channels are pierced, and the time it takes for haemostasis to occur (i.e. the formation of a platelet plug in the two holes) is measured in both channels. Because the test is carried out in both channels using whole blood, the platelet plug formed simulates very closely platelet plugs formed in arterial bleeding.
An anticoagulant agent is then introduced in to the blood flowing in one of the channels. This prevents the blood flowing in that channel from clotting, so that thrombolysis of the platelet plug in that channel can be investigated but does not interfere with the haemostatic plug formation because the haemostatic plug has already been formed when the anticoagulant is introduced. A preferred anticoagulant is heparin, because of its low interference with the thrombolytic process.
After a period of time the blood in the channel which is not anticoagulated will clot, and this can be measured by appropriate pressure transducers. In the channel to which the anticoagulant has been added, the platelet plug will eventually dissolve, and therefore thrombolysis time can be measured.
The two-channel instrument of the first embodiment of the present invention is also useful in other clinical diagnostic techniques, for example to determine the effects of various pharmaceuticals substances on clotting, haemostasis and thrombolysis. Native blood containing saline (control) may be utilised in one channel of the apparatus, and identical blood containing the pharmaceutical substance to be investigated in the other, and thus the effect on the various properties of the blood can be monitored under closely controlled conditions.
In a second aspect, the invention is concerned with the effect of various substances
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patent: 3900290 (1975-08-01), Hornstra
patent: 4213456 (1980-07-01), Bottger
patent: 4319194 (1982-03-01), Cardinal et al.
patent: 4604894 (1986-08-01), Kratzer et al.
patent: 4634679 (1987-01-01), Horres
patent: 4780418 (1988-10-01), Kratzer
Gorog Peter
Kovacs Iren
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