Non-invasive method for detecting deep venous thrombosis in the human body
First Claim
1. A non-invasive method for detecting deep venous thrombosis in a human body, said method comprising the steps of:
- (a) securing an inflatable cuff to a body limb of interest wherein said body limb comprises skin, tissues, oxyhemoglobin and deoxyhemoglobin;
(b) attaching a radiation source and operatively associated photodetector to the body limb proximate to said inflatable cuff;
(c) actuating said radiation source so that radiation penetrates through the skin and into the deep venous system of the body limb to enable detecting of changes in the amount of deoxyhemoglobin in said deep venous system;
(d) effecting changes in the amount of deoxyhemoglobin in the body limb by inflating said cuff during said radiation source actuation to a pressure below arterial pressure to trap blood in the venous system for a determining a time period and by deflating said cuff during said same radiation source actuation;
(e) actuating said photodetector to detect changes occurring during the trapping of the blood in the venous system after said cuff is inflated and during the emptying of the venous system after said cuff is deflated by measuring reflectance contributions including contribution from the skin, tissues, oxyhemoglobin and deoxyhemoglobin of the body limb; and
(f) detecting the presence of deep venous thrombosis by subtracting the reflectance contributions of the skin, tissues and oxyhemoglobin from the reflectance contribution of the deoxyhemoglobin and comparing the reflectance contribution of the deoxyhemoglobin to predetermined reflectance values for a normal body limb.
1 Assignment
0 Petitions
Accused Products
Abstract
A non-invasive method for detecting deep venous thrombosis in a human body wherein changes are effected in the amount of deoxyhemoglobin in the body limb by trapping blood in the venous system for a determinate time period and then releasing the trapped blood in the venous system. During the period that the changes in the amount of deoxyhemoglobin are effected, first and second light sources emit light of two selected wavelengths which penetrate into the deep venous system of the body limb so that the reflectance contributions can be used to measure changes in the flow and amount of deoxyhemoglobin and to thereby detect the presence or absence of deep venous thrombosis.
-
Citations
14 Claims
-
1. A non-invasive method for detecting deep venous thrombosis in a human body, said method comprising the steps of:
-
(a) securing an inflatable cuff to a body limb of interest wherein said body limb comprises skin, tissues, oxyhemoglobin and deoxyhemoglobin; (b) attaching a radiation source and operatively associated photodetector to the body limb proximate to said inflatable cuff; (c) actuating said radiation source so that radiation penetrates through the skin and into the deep venous system of the body limb to enable detecting of changes in the amount of deoxyhemoglobin in said deep venous system; (d) effecting changes in the amount of deoxyhemoglobin in the body limb by inflating said cuff during said radiation source actuation to a pressure below arterial pressure to trap blood in the venous system for a determining a time period and by deflating said cuff during said same radiation source actuation; (e) actuating said photodetector to detect changes occurring during the trapping of the blood in the venous system after said cuff is inflated and during the emptying of the venous system after said cuff is deflated by measuring reflectance contributions including contribution from the skin, tissues, oxyhemoglobin and deoxyhemoglobin of the body limb; and (f) detecting the presence of deep venous thrombosis by subtracting the reflectance contributions of the skin, tissues and oxyhemoglobin from the reflectance contribution of the deoxyhemoglobin and comparing the reflectance contribution of the deoxyhemoglobin to predetermined reflectance values for a normal body limb. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A non-invasive method for detecting deep venous thrombosis in a human body, said method comprising the steps of:
-
(a) securing an inflatable cuff to a body limb of interest wherein said body limb comprises skin, tissues, oxyhemoglobin and deoxyhemoglobin; (b) attaching first and second light sources and an operatively associated photodetector to the body limb proximate to said inflatable cuff, said first light source emitting light having a wavelength between about 600 to 800 nanometers and said second light source emitting light having a wavelength between about 800 to 1000 nanometers; (c) actuating said first and second light sources so that light emitted therefrom penetrates through the skin and into the deep venous system of the body limb to enable detecting of changes in the amount of deoxyhemoglobin in said deep venous system; (d) effecting changes in the amount of deoxyhemoglobin in the body limb by inflating said cuff during said light source actuation to a pressure below arterial pressure to trap blood in the venous system for a determinate time period and by deflating said cuff during said same light source actuation to release blood from the venous system; (e) actuating said photodetector to detect changes occurring during the trapping of the blood in the venous system after said cuff is inflated and during the emptying of the venous system after said cuff is deflated by measuring light reflectance contributions from said first and second light sources including contributions from the skin, tissues, oxyhemoglobin and deoxyhemoglobin of the body limb; and (f) detecting the presence of deep venous thrombosis by subtracting the reflectance contributions of the skin, tissues and oxyhemoglobin from the reflectance contribution of the deoxyhemoglobin and comparing the reflectance contribution of the deoxyhemoglobin to predetermined reflectance values for a normal body limb. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. A non-invasive method for detecting deep venous thrombosis in a human body, said method comprising the steps of:
-
(a) securing an inflatable cuff to a leg wherein said leg comprises skin, tissues, oxyhemoglobin and deoxyhemoglobin; (b) attaching a radiation source and operatively associated photodetector to the leg proximate to said inflatable cuff; (c) actuating said radiation source sot hat radiation penetrates through the skin and into the deep venous system of the leg to enable detecting of changes in the amount of deoxyhemoglobin in said deep venous system; (d) effecting changes in the amount of deoxyhemoglobin in the leg by inflating said cuff during said radiation source actuation to a pressure below arterial pressure to trap blood in the venous system for a determinate time period and by deflating said cuff during said same radiation source actuation to release blood from the venous system; (e) actuating said photodetector to detect changes occurring during the trapping of the blood in the venous system after said cuff is inflated and during the emptying of the venous system after said cuff is deflated by measuring reflectance contributions including contributions from the skin, tissues, oxyhemoglobin and deoxyhemoglobin of the leg; and (f) detecting the presence of deep venous thrombosis by subtracting the reflectance contributions of the skin, tissues and oxyhemoglobin from the reflectance contribution of the deoxyhemoglobin and comparing the reflectance contribution of the deoxyhemoglobin to predetermined reflectance values for a normal leg.
-
-
14. A non-invasive method for detecting deep venous thrombosis in a human body, said method comprising the steps of:
-
(a) securing an inflatable cuff to a leg wherein said leg comprises skin, tissues, oxyhemoglobin and deoxyhemoglobin; (b) attaching first and second light sources and an operatively associated photodetector to the leg proximate to said inflatable cuff, said first light source emitting light having a wavelength between about 600 to 800 nanometers and said second light source emitting light having a wavelength between about 800 to 1000 nanometers; (c) actuating said first and second light sources so that light emitted therefrom penetrates through the skin and into the deep venous system of the leg to enable detecting of changes int he amount of deoxyhemoglobin in said deep venous system; (d) effecting changes int he amount of deoxyhemoglobin in the leg by inflating said cuff during said light source actuation to a pressure below arterial pressure to trap blood in the venous system for a determinate time period and by deflating said cuff during said same light source actuation to release blood from the venous system; (e) actuating said photodetector to detect changes occurring during the trapping of the blood int eh venous system after said cuff is inflated and during the emptying of the venous system after said cuff is deflated by measuring light reflectance contributions from said first and second light sources including contributions from the skin, tissues, oxyhemoglobin and deoxyhemoglobin of the leg; and (f) detecting the presence of deep venous thrombosis by subtracting the reflectance contributions of the skin, tissues and oxyhemoglobin from the reflectance contribution of the deoxyhemoglobin and comparing the reflectance contribution of the deoxyhemoglobin to predetermined reflectance values for a normal leg.
-
Specification