US5372946A — Blood coagulation time test apparatus and method

Claim 1

Independent Claim 161 words

A cuvette for use with a drive means in determining a clotting time for a blood sample, comprising; a planar member having at least one enclosed conduit formed therein, said at least one conduit having an open distal end and proximal end and at least one restricted region positioned therebetween, wherein said at least one restricted region has a roughened surface texture that promotes the coagulation of blood flowing therepast, said distal end being selectively engagable with the drive means; a fluid reservoir for retaining said blood sample whereby a predetermined volume of blood is accessible by said proximal end of said at least one conduit, wherein said predetermined volume of blood is drawn into said at least one conduit and reciprocally moved back and forth across said at least one restricted region by the drive means, said clotting time being determined when said predetermined volume of blood clots and obstructs said at least one restricted region by a predetermined amount.

Claim 2

Dependent Claim 161 words

A cuvette for use with a drive means in determining a clotting time for a blood sample, comprising; a planar member having at least one enclosed conduit formed therein, said at least one conduit having an open distal end and proximal end and at least one restricted region positioned therebetween, wherein said at least one restricted region has a roughened surface texture that promotes the coagulation of blood flowing therepast, said distal end being selectively engagable with the drive means; a fluid reservoir for retaining said blood sample whereby a predetermined volume of blood is accessible by said proximal end of said at least one conduit, wherein said predetermined volume of blood is drawn into said at least one conduit and reciprocally moved back and forth across said at least one restricted region by the drive means, said clotting time being determined when said predetermined volume of blood clots and obstructs said at least one restricted region by a predetermined amount.

Claim 3

Dependent Claim 63 words

The cuvette according to claim 1, wherein at least one drain conduit is formed within said planar member, said drain conduit being interconnected to said fluid reservoir and engaged by the drive means whereby blood can be removed from said fluid reservoir into said at least one drain conduit after said predetermined volume of blood is drawn into said at least one conduit.

Claim 4

Dependent Claim 53 words

The cuvette according to claim 2, wherein said fluid reservoir includes a primary chamber and a secondary chamber, said blood sample being applied to said primary chamber wherein an excess of blood in said primary chamber overflows into said secondary chamber via overflow ports present between said primary chamber and said secondary chamber.

Claim 5

Dependent Claim 107 words

The cuvette according to claim 3, wherein said primary chamber has at least one standpipe positioned therein, said at least one standpipe interconnecting with said proximal end of said at least one conduit whereby said at least one standpipe extends upwardly within said primary chamber a predetermined distance below said overflow ports, said at least one drain conduit being interconnected to said primary chamber below said standpipe, whereby said at least one conduit means can draw blood from said primary chamber above said standpipe and below said overflow ports and said at least one drain conduit means can draw blood from said primary chamber below said standpipe.

Claim 6

Dependent Claim 15 words

The cuvette according to claim 1, wherein said cuvette is formed from a translucent material.

Claim 7

Dependent Claim 64 words

The cuvette according to claim 3, further including an annular cap member, said annular cap member fitting over said fluid reservoir covering said secondary chamber and having a sloped surface that directs said blood sample into said primary chamber, whereby the presence of said cap member over said secondary chamber prevents blood from spilling out of said second chamber as said cuvette is manipulated.

Claim 8

Dependent Claim 44 words

The cuvette according to claim 1, further including a stopping means within said fluid reservoir for stopping a discharging end of a syringe at a predetermined point within said fluid reservoir when said blood sample is applied to said fluid reservoir with said syringe.

Claim 9

Independent Claim 149 words

A method of conducting a coagulation time test on a blood sample drawn from a patient, comprising the steps of: depositing said blood sample into a fluid reservoir; drawing a predetermined volume of blood from said blood sample into a capillary tube from said fluid reservoir wherein said capillary tube has at least one restricted region formed therein; reciprocating said predetermined volume of blood from a first position on one side of said restricted region to a second position on an opposite side of said restricted region and back again; counting the time elapsed each time said predetermined volume of blood reciprocates between said first position and said second position; and providing an indication to an operator when the time elapsed for one cycle of travel for the blood between said first position and said second position is a predetermined percentage longer then an immediately preceding cycle of travel.

Claim 10

Independent Claim 149 words

A method of conducting a coagulation time test on a blood sample drawn from a patient, comprising the steps of: depositing said blood sample into a fluid reservoir; drawing a predetermined volume of blood from said blood sample into a capillary tube from said fluid reservoir wherein said capillary tube has at least one restricted region formed therein; reciprocating said predetermined volume of blood from a first position on one side of said restricted region to a second position on an opposite side of said restricted region and back again; counting the time elapsed each time said predetermined volume of blood reciprocates between said first position and said second position; and providing an indication to an operator when the time elapsed for one cycle of travel for the blood between said first position and said second position is a predetermined percentage longer then an immediately preceding cycle of travel.

Claim 11

Dependent Claim 50 words

The method according to claim 8, further including the step of draining blood from said fluid reservoir into a drain capillary tube after said step of drawing, thereby substantially emptying said fluid reservoir of said blood sample allowing said fluid reservoir to be manipulated without spillage of said blood sample.

Claim 12

Dependent Claim 34 words

The method according to claim 8, wherein said fluid reservoir and said capillary tube are contained within a disposable cuvette and further comprising the step of coupling said cuvette to a reciprocating drive means.

Claim 13

Dependent Claim 40 words

The method according to claim 8, wherein said restricted region has a roughened surface texture thereby promoting coagulation of said predetermined volume of blood in said roughened region as said predetermined volume of blood is reciprocated across said roughened region.

Claim 14

Dependent Claim 43 words

The method according to claim 9, wherein said fluid reservoir, said capillary tube and said drain capillary tube are contained within a disposable cuvette and further comprising the steps of coupling said capillary tube and said drain capillary tube to separate drive means.

Claim 15

Dependent Claim 88 words

The method of claim 8, wherein first photoelectric sensor is positioned at said first position and a second photoelectric sensor is positioned at said second position, wherein said first and second photoelectric sensors can detect the presence of said predetermined volume of blood in said capillary tube and wherein said step of counting is performed by a microprocessor coupled to said first and second photoelectric sensor that measures the time interval between the activation of said first and second photoelectric sensors by the reciprocating predetermined volume of blood.

Claim 16

Dependent Claim 25 words

The method according to claim 8, further including the step of heating said predetermined volume of blood in said capillary tube to a predetermined temperature.

Claim 17

Dependent Claim 43 words

The method according to claim 8, further including detecting if a portion of said predetermined volume of blood has been drawn beyond an acceptable point in said capillary tube and indicating to an operator the presence of said portion beyond said acceptable point.

Claim 18

Dependent Claim 14 words

The method according to claim 8, wherein said predetermined percentage is approximately 125 percent.

Claim 19

Dependent Claim 23 words

The method according to claim 8, wherein said step of reciprocating includes pneumatically reciprocating said predetermined volume of blood in said capillary tube.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1997-12-12	1998-06-13	1998-12-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2001-12-12	2002-06-13	2002-12-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2005-12-12	2006-06-13	2006-12-13	$7700.00	Window Closed / Lapsed

Blood coagulation time test apparatus and method

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