Noninvasive Measurement of Blood Coagulation
Noninvasive Measurement of Blood Coagulation
The investigators have developed an optical system that measures the coagulation status of
 patients in vivo in a non-invasive manner. The system is based on a small optical sensor that
 emits coherent light into the skin and collects the reflected light from the red blood cells
 in the blood vessels in the skin under the sensor. The sensor is placed on the fingertip, and
 during a brief period of occlusion of blood flow by a small pneumatic cuff, red cell movement
 becomes Brownian in nature and is thereby affected by the viscosity of the blood. In patients
 who have a bleeding tendency, red blood cell movement will be faster, while in patients with
 a hypercoagulable state the red cell movement will be slower. Treatment with anticoagulant
 medications is expected to affect the movement of the red blood cells and these changes can
 be detected by the sensor. The investigators plan to test the device in normal subjects and
 in subjects taking Coumadin, direct oral anticoagulants, antiplatelet drugs and heparin-based
 medications. The investigators will determine whether anticoagulants affect the noninvasive
 measurement and compare the results with standard laboratory tests of coagulation.
Overview: The investigators plan to measure the coagulation status with the new sensor in
 patients who are attending the Coagulation Clinic in Meir Hospital Center. The investigators
 will measure their coagulation status with the new sensor during the participants' routine
 clinic visits. During their visits, The participants' care will not be affected or influenced
 by the results of the data obtained by the new sensor. The accumulated data will be collected
 and later correlated with their clinical status and with routine clotting parameters that are
 measured, depending on the type of anticoagulation the participants receive. Specifically, in
 those receiving warfarin, INR will be assessed during their visit, while in patients
 receiving direct oral anticoagulants (DOACs), factor Xa activity will be assessed.
 Inparticipants receiving heparin, PTT will be assessed.

 Patients and control subject: Subjects will be recruited from the Coagulation Clinic. The
 participants will consist of patients attending the clinic for follow-up of their prescribed
 anticoagulation treatment. Patients to be studied will include subjects receiving warfarin
 anticoagulation, NOACs, heparin and anti-platelet therapy (aspirin, clopidrogel or other
 anti-platelet medications). Normal subjects receiving no anticoagulation will also be studied
 and will serve as the control group.

 Protocol: Experimental subjects will be selected from patients attending the Coagulation
 Clinic. Patients will be seen in the clinic and receive their usual follow-up care. After
 obtaining informed consent, the participants' coagulation status will be assessed with the
 new sensor. Patients on warfarin medications will have a venous blood sample obtained (5 ml)
 for determination of INR. Patients receiving NOACs will have a venous blood sample obtained
 (5 ml) for determination of Factor Xa activity. At a later date, the coagulation status of
 the patients as assessed by the new sensor will be compared to the coagulation status as
 assessed by the standard laboratory methods.

 Normal controls will be recruited from hospital personnel. Normal controls will have their
 coagulation status assessed by the new sensor only. Since normal control are not receiving
 anticoagulation therapy, blood samples for measurement of INR or factor Xa activity will not
 be drawn. Normal controls will receive no financial compensation.

 Methodology: The pneumatic cuff is attached to the root of the index finger. The sensor cuff
 is attached several centimeters distal to the pneumatic cuff. Measurement is taken for a
 60-second control period, and then the pneumatic cuff is inflated to above-systolic blood
 pressure (200 mm Hg) for 180 seconds, and measurement is taken during this period of time.
 The cuff is then deflated, and another 60-second measurement is taken. Data is collected by
 the measuring device for later analysis.
Inclusion Criteria:

 Subjects receiving anticoagulant therapy, including warfarin, DOACS, heparin, and
 antiplatelet drugs

 Exclusion Criteria:

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