Cuvette-based apparatus for blood coagulation measurement and testing

Abstract

An apparatus for measuring blood clotting time includes a blood clot detection instrument and a cuvette for use with the blood clot detection instrument. The cuvette includes a blood sample receptor-inlet; a channel arrangement including at least one test channel for performing a blood clotting time measurement, a sampling channel having at least one surface portion that is hydrophilic, communicating with the blood sample receptor-inlet and the at least one test channel, and a waste channel having at least one surface portion that is hydrophilic, communicating with the sampling channel; and a vent opening communicating with the sampling channel. The sampling channel, the vent opening and the waste channel, coact to automatically draw a requisite volume of a blood sample deposited at the blood receptor-inlet, into the sampling channel. More specifically, air compressed within the blood clot detection instrument, the at least one test channel of the cuvette, and the section of the sampling channel extending beyond the vent opening of the cuvette, coacts with the waste channel to cause a leading edge of the blood sample drawn into the sampling channel from the blood receptor-inlet, to pull back within the sampling channel and uncover an optical sensor in of the blood clot detection instrument. The uncovering of the optical sensor activates a pump module of the blood clot detection instrument, which draws the requisite volume of the blood sample into the at least one test channel.

1 . A cuvette for use with a blood clot detection instrument, the cuvette comprising:
 a main body including:
 a blood sample receptor-inlet; 
 a channel arrangement comprising:
 at least one test channel for performing a blood clotting time measurement; 
 a sampling channel communicating with the blood sample receptor-inlet and the at least one test channel, at least the sampling channel having at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic; and 
 a waste channel communicating with the sampling channel; and 
 
 a vent opening communicating with the sampling channel, 
   wherein the sampling channel, the vent opening and the waste channel coact to automatically draw a requisite volume of a blood sample deposited at the blood receptor-inlet, into the sampling channel.   
     
     
         2 . The cuvette of  claim 1 , wherein the coaction between the sampling channel and the vent opening includes a force generated by the at least one surface portion of the sampling channel that is hydrophilic and which draws the blood from the blood sample deposited at the blood sample receptor-inlet into the sampling channel and venting of air through the vent opening which is displaced from the sampling channel by the incoming blood. 
     
     
         3 . The cuvette of  claim 1 , wherein the channel arrangement further comprises a vent channel connecting the vent opening with the sampling channel. 
     
     
         4 . The cuvette of  claim 1 , wherein the channel arrangement further comprises a member associated with the waste channel for delaying the filling of the waste channel until the sampling channel is filled. 
     
     
         5 . The cuvette of  claim 1 , wherein the channel arrangement is formed in a surface of the main body. 
     
     
         6 . The cuvette of  claim 5 , further comprising a substrate for closing and sealing at least a portion of the channel arrangement formed in the surface of the main body. 
     
     
         7 . The cuvette of  claim 6 , wherein the substrate forms the at least one surface portion of the sampling channel that is hydrophilic. 
     
     
         8 . The cuvette of  claim 6 , wherein the substrate comprises a film with a hydrophilic surface, the hydrophilic surface of the substrate forming the at least one surface portion of the sampling channel that is hydrophilic. 
     
     
         9 . The cuvette of  claim 6 , wherein the substrate comprises a film and a layer of hydrophilic material disposed on the film, the hydrophilic material forming the at least one surface portion of the sampling channel that is hydrophilic. 
     
     
         10 . The cuvette of  claim 9 , wherein the hydrophilic material is an adhesive which attaches the substrate to the main body. 
     
     
         11 . The cuvette of  claim 1 , further comprising a blood clotting reagent disposed in the at least one test channel. 
     
     
         12 . The cuvette of  claim 1 , wherein the at least one test channel includes a section having at least one textured surface. 
     
     
         13 . The cuvette of  claim 1 , wherein the at least one test channel includes a restriction. 
     
     
         14 . The cuvette of  claim 1 , wherein the main body is made of one of a hydrophobic material, a hydrophilic material, or a combination of a hydrophobic material and a hydrophilic material. 
     
     
         15 . The cuvette of  claim 1 , wherein the waste channel has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic. 
     
     
         16 . The cuvette of  claim 1 , wherein the at least one test channel has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic or hydrophobic. 
     
     
         17 . The cuvette of  claim 3 , wherein the vent channel has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic. 
     
     
         18 . The cuvette of  claim 4 , wherein the member associated with the waste channel comprises a jumper channel or a restriction. 
     
     
         19 . The cuvette of  claim 18 , wherein the jumper channel or the restriction has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic. 
     
     
         20 . The cuvette of  claim 1 , wherein the channel arrangement further comprises a jumper channel connecting the waste channel with the sampling channel, the jumper channel for delaying the filling of the waste channel until the sampling channel is filled. 
     
     
         21 . An apparatus for measuring blood clotting time, the apparatus comprising:
 A) a blood clot detection instrument, the blood clot detection instrument comprising:
 a pump module; and 
 at least one pressure sensor; and 
   B) a cuvette for use with the blood clot detection instrument, the cuvette comprising:
 a main body including: 
 i) a blood sample receptor-inlet; 
 ii) a channel arrangement comprising:
 a) at least one test channel for communicating with the pump module when the cuvette is operatively coupled to the clot detection instrument; 
 b) a sampling channel communicating with the blood sample receptor-inlet and the at least one test channel, at least the sampling channel having at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic; and 
 c) a waste channel communicating with the sampling channel; 
 
  and 
 iii) a vent opening communicating with the sampling channel, 
   wherein compressed air within the blood clot detection instrument and the at least one test channel, the sampling channel, the vent opening and waste channel, coact to automatically draw a requisite volume of a blood sample deposited at the blood receptor-inlet, into the sampling channel, and   wherein the at least one test channel of the cuvette, and the pump module and the at least one pressure sensor of the clot detection instrument, coact to perform a blood clotting time measurement on the requisite volume of the blood sample.   
     
     
         22 . The apparatus of  claim 21 , wherein the coaction between the sampling channel and the vent opening includes a force generated by the at least one surface portion of the sampling channel that is hydrophilic and which draws the blood from the blood sample deposited at the blood sample receptor-inlet into the sampling channel and venting of air through the vent opening which is displaced from the sampling channel by the incoming blood. 
     
     
         23 . The apparatus of  claim 21 , wherein the channel arrangement further comprises a vent channel connecting the vent opening with the sampling channel. 
     
     
         24 . The apparatus of  claim 21 , wherein the channel arrangement further comprises a member associated with the waste channel for delaying the filling of the waste channel until the sampling channel is filled. 
     
     
         25 . The apparatus of  claim 21 , wherein the channel arrangement is formed in a surface of the main body. 
     
     
         26 . The apparatus of  claim 25 , further comprising a substrate for closing and sealing at least a portion of the channel arrangement formed in the surface of the main body. 
     
     
         27 . The apparatus of  claim 26 , wherein the substrate forms the at least one surface portion of the sampling channel that is hydrophilic. 
     
     
         28 . The apparatus of  claim 26 , wherein the substrate comprises a film with a hydrophilic surface, the hydrophilic surface of the substrate forming the at least one surface portion of the sampling channel that is hydrophilic. 
     
     
         29 . The apparatus of  claim 26 , wherein the substrate comprises a film and a layer of hydrophilic material disposed on the film, the hydrophilic material forming the at least one surface portion of the sampling channel that is hydrophilic. 
     
     
         30 . The apparatus of  claim 29 , wherein the hydrophilic material is an adhesive which attaches the substrate to the main body. 
     
     
         31 . The apparatus of  claim 21 , further comprising a blood clotting reagent disposed in the at least one test channel. 
     
     
         32 . The apparatus of  claim 21 , wherein the at least one test channel includes a section having at least one textured surface. 
     
     
         33 . The apparatus of  claim 21 , wherein the at least one test channel includes a restriction. 
     
     
         34 . The apparatus of  claim 21 , wherein the main body is made of one of a hydrophobic material, a hydrophilic material, or a combination of a hydrophobic material and a hydrophilic material. 
     
     
         35 . The apparatus of  claim 21 , wherein the waste channel has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic. 
     
     
         36 . The apparatus of  claim 21 , wherein the at least one test channel has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic or hydrophobic. 
     
     
         37 . The apparatus of  claim 23 , wherein the vent channel has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic. 
     
     
         38 . The apparatus of  claim 24 , wherein the member associated with the waste channel comprises a jumper channel or a restriction. 
     
     
         39 . The apparatus of  claim 38 , wherein the jumper channel or restriction has at least one surface portion, a coating, an insert or liner, and any combination thereof, that is hydrophilic. 
     
     
         40 . The apparatus of  claim 21 , wherein the channel arrangement further comprises a jumper channel connecting the waste channel with the sampling channel, the jumper channel for delaying the filling of the waste channel until the sampling channel is filled. 
     
     
         41 . A blood clot detection instrument for automatically measuring blood clotting time of a blood sample contained in a test channel of a cuvette, the blood clot detection instrument comprising:
 a pump module for communicating with the test channel of the cuvette;   a pressure sensor; and   a central processing unit executing instructions for:
 operating the pump module in a pressure alternating mode that causes a viscosity of the blood sample to increase over time, the increase in viscosity of the blood causing a pumping pressure of the pump module to increase over time; 
 obtaining a baseline pumping pressure from the pressure sensor upon initial operation of the pump module in the pressure alternating mode; 
 obtaining additional pumping pressures over time from the pressure sensor; 
 determining a pumping pressure difference value between each additional pumping pressure and the baseline pumping pressure; 
 comparing the pumping pressure difference value to a predetermined threshold value; and 
 indicating the blood clotting time of the blood sample when the pumping pressure difference value equals or exceeds the predetermined threshold value, 
   the indicated blood clotting time comprising a duration of time extending between the measurement of the additional pumping pressure used for determining the pumping pressure difference value that exceeded the predetermined threshold value and the measurement of the baseline pumping pressure.   
     
     
         42 . The blood clot detection instrument of  claim 41 , wherein the predetermined threshold may be fixed or dynamic. 
     
     
         43 . The blood clot detection instrument of  claim 41 , wherein the pump module, in the pressure alternating mode, creates positive and negative pressures in the test channel of the cuvette. 
     
     
         44 . The blood clot detection instrument of  claim 41 , wherein the pump module, in the pressure alternating mode, reciprocally moves the blood sample back and forth across a textured section or restricted area of the test channel, thereby mixing the blood sample with a reagent disposed in the test channel that triggers and accelerates clotting of the blood sample. 
     
     
         45 . The cuvette of  claim 1 , wherein the at least one test channel comprises three test channels and further comprising a reagent in each of the test channels. 
     
     
         46 . The cuvette of  claim 45 , wherein the reagents are all the same, different, or combinations thereof. 
     
     
         47 . The apparatus of  claim 21 , wherein the at least one test channel comprises three test channels and further comprising a reagent in each of the test channels. 
     
     
         48 . The apparatus of  claim 47 , wherein the reagents are all the same, different, or combinations thereof. 
     
     
         49 . The apparatus of  claim 21 , wherein air compressed within the blood clot detection instrument, the at least one test channel of the cuvette, and the section of the sampling channel extending beyond the vent opening of the cuvette, coacts with the waste channel to cause a leading edge of the blood sample drawn into the sampling channel from the blood receptor-inlet, to pull back within the sampling channel and uncover an optical sensor of the blood clot detection instrument, the volume of the blood sample in the sampling channel at the time when the blood sample is pulled back to uncover the optical sensor, equaling the requisite volume, the uncovering of the optical sensor activating the pump module of the blood clot detection instrument, which draws the requisite volume of the blood sample into the at least one test channel. 
     
     
         50 . The cuvette of  claim 1 , further comprising:
 a first substrate with hydrophilic properties for closing and sealing the sampling channel and the waste channel; and   a second substrate with hydrophobic properties for closing and sealing the at least one test channel.   
     
     
         51 . The cuvette of  claim 50 , wherein the sampling channel and the waste channel are formed in a first surface of the cuvette and the first substrate is affixed to the first surface, and the at least one test channel is formed in second surface of the cuvette and the second substrate is affixed to the second surface. 
     
     
         52 . The cuvette of  claim 51 , wherein the first and second surfaces are opposed to one another. 
     
     
         53 . The cuvette of  claim 50 , wherein the channel arrangement further comprises:
 a vent channel connecting the vent opening with sampling channel; and   a jumper channel connecting the waste channel to the sampling channel, for delaying the filling of the waste channel until the sampling channel is filled,   wherein the first substrate closes and seals the vent channel and the jumper channel.   
     
     
         54 . The apparatus of  claim 21 , further comprising;
 a first substrate with hydrophilic properties for closing and sealing the sampling channel and the waste channel; and   a second substrate with hydrophobic properties for closing and sealing the at least one test channel.   
     
     
         55 . The apparatus of  claim 54 , wherein the sampling channel and the waste channel are formed in a first surface of the cuvette and the first substrate is affixed to the first surface, and the at least one test channel is formed in second surface of the cuvette and the second substrate is affixed to the second surface. 
     
     
         56 . The apparatus of  claim 55 , wherein the first and second surfaces are opposed to one another. 
     
     
         57 . The apparatus of  claim 54 , wherein the channel arrangement further comprises:
 a vent channel connecting the vent opening with sampling channel; and   a jumper channel connecting the waste channel to the sampling channel, for delaying the filling of the waste channel until the sampling channel is filled,   wherein the first substrate closes and seals the vent channel and the jumper channel.