Device for sampling blood droplets under vacuum conditions
A blood extraction device ( 100 ) and method for withdrawing a controlled number of drops of blood from a patient, in whom there is created an incision of such dimension that blood does not freely flow therefrom. A release unit ( 160 ) urges drops of blood to flow from the incision, for example by applying a vacuum, and a disabling unit ( 145, 146, 170 ) is coupled to the incision unit for disabling the release unit when a predetermined number of drops of blood have been withdrawn.
1. A blood extraction device for withdrawing a quantity of blood from a patient, said blood extraction device comprising:
an incision unit for creating an incision in the patient;
a release unit for urging blood drops to flow from said incision, and
a disabling unit coupled to the release unit for disabling the release unit;
a collecting receptacle disposed in spaced relationship with the release unit for collecting a predetermined plurality of discrete drops of blood that freely fall thereon from the incision without contacting any element of the device; and
a drop counting unit disposed for counting blood drops flowing directly from the incision onto the receptacle and signaling only when the predetermined plurality of discrete drops of blood have been applied to said receptacle, wherein
the disabling unit is adapted to disable the release unit automatically when the predetermined plurality of discrete drops of blood have been withdrawn.
2. The device according to claim 1 , wherein the collecting receptacle comprises a single use chemical test strip on which the blood drops are gathered.
3. The device according to claim 2 , further comprising:
an imaging device for optically imaging the chemical test result obtained by the chemical test strip; and
an electronic circuit coupled to the imaging device for transmitting data representative of an optical image of the result to a remote unit.
4. The device according to claim 2 , wherein:
the chemical test strip is visibly identified by a unique identity code,
the disabling unit is responsively coupled to an electronic circuit for control thereby, and
the electronic circuit is adapted to determine an identity of the chemical test strip and control the disabling unit accordingly.
5. The device according to claim 1 , wherein the incision unit comprises a lancet.
6. The device according to claim 1 , wherein the release unit comprises a vacuum unit.
7. The device according to claim 1 , wherein the disabling unit comprises an electro-optical sensor for optically sensing the number of blood drops extracted.
8. A method for withdrawing a quantity of blood from a patient, said method comprising:
creating an incision in the patient;
urging blood drops to flow downwardly directly from said incision on to a collection receptacle disposed in spaced relationship with a release unit for collecting a predetermined plurality of discrete drops of blood that freely fall thereon from the incision without contacting any element of the device;
counting the plurality of discrete drops of blood that flow downwardly directly from the incision to the receptacle; and
inhibiting blood flow automatically when said predetermined plurality of discrete drops of blood have been withdrawn from the patient.
9. The method according to claim 8 , wherein the receptacle is a single use test strip on which the drops of blood that flow from the incision are gathered.
10. The method according to claim 9 , further comprising:
optically imaging a test result obtained by the test strip; and
transmitting data representative of an image of the result to a remote unit.