Apparatus and method for detecting deep vein thrombosis

• US 5,991,654 A
• Filed: 06/06/1997
• Issued: 11/23/1999
• Est. Priority Date: 06/06/1997
• Status: Expired due to Term

• Current Assignee: Huntleigh Technology, Inc., Nuctech Company Limited (Tsinghua Tongfang Co., Ltd.)
• Original Assignee: KCI Technologies Incorporated (3M Company)
• Inventors: Tumey, David M., Randolph, Larry Tab
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): SHAW, SHAWNA JEANNINE
• Application Number:
  US08/870,232
• Time in Patent Office: 900 Days
• Field of Search: 600/473, 600/480, 600/482, 600/485, 600/492, 600/504, 600/506, 600/507, 600/479, 600/408, 600/476, 600/310, 128/920, 128/925
• US Class Current: 600/479
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/1073 Measuring volume, e.g. of limbs
• CPC Class Codes: Y10S 128/925 Neural network

Abstract

An apparatus for detecting Deep Vein Thrombosis (DVT) in a patient includes a computer based device, a device disposed on a predetermined position on a calf of the patient for measuring blood volume, another device for measuring temperature of the calf and still another device for measuring calf size. A cuff is operably connected to the computer based device and envelops a portion of a thigh of the patient and is controllably restrictable by the computer based device to produce a controlled venous occlusion of the patient'"'"'s deep veins for a predetermined period. A method for detecting DVT using the device is also provided.

Claims

1. An apparatus for detecting deep vein thrombosis (DVT) in a patient, said apparatus comprising:

an automated system for generating an output indicative of DVT, said automated system being adapted to manipulate biocharacteristic signals to arrive at the output indicative of DVT;

a first biocharacteristic gathering device operably associated with said automated system for providing said automated system with a first biocharacteristic signal, said first biocharacteristic gathering device being a photo-plethysmographic device adapted to be placed at a predetermined position on a calf of the patient for measuring blood volume, the first biocharacteristic signal being a blood volume signal from said photo-plethysmographic device;

a second biocharacteristic gathering device operably associated with said automated system for providing said automated system with a second biocharacteristic signal; and

said automated system comprising a multiple risk factor analyzer, said multiple risk factor analyzer being adapted to perform a weighted analysis of the first and second biocharacteristic signals to arrive at the output indicative of DVT.

2. The apparatus for detecting DVT as recited in claim 1, wherein said multiple risk factor analyzer comprises a neural network.

3. The apparatus for detecting DVT as recited in claim 1, said apparatus further comprising a cuff adapted to produce a controlled occlusion of the deep and superficial veins of the patient'"'"'s leg.

4. The apparatus for detecting DVT as recited in claim 3, wherein said cuff is operable by said automated system to produce the controlled occlusion of the deep and superficial veins of the patient'"'"'s leg for a determinable time period.

5. The apparatus for detecting DVT as recited in claim 4, wherein said automated system is adapted to retrieve the first biocharacteristic signal from said first biocharacteristic gathering device prior to said determinable time period and repeatedly during said determinable time period.

6. The apparatus for detecting DVT as recited in claim 5, wherein said risk factor analyzer is adapted to perform the weighted analysis of the first and second biocharacteristic signals with reference to time.

7. The apparatus for detecting DVT as recited in claim 6, wherein said second biocharacteristic gathering device comprises a temperature measurement device adapted to determine the temperature of the patient'"'"'s calf as the second biocharacteristic signal.

8. The apparatus for detecting DVT as recited in claim 6, wherein said second biocharacteristic gathering device comprises a size measurement device adapted to determine the size of the patient'"'"'s calf as the second biocharacteristic signal.

9. The apparatus for detecting DVT as recited in claim 8, said apparatus further comprising a manual entry system for manually reporting the second biocharacteristic signal to said automated system.

10. The apparatus for detecting DVT as recited in claim 9, wherein said manual entry system comprises a touch screen display.

11. An apparatus for detecting deep vein thrombosis (DVT) in a patient'"'"'s leg, said apparatus comprising:

an automated system for generating an output indicative of DVT in the patient'"'"'s leg, said automated system being adapted to manipulate biocharacteristic signals to arrive at the output indicative of DVT;

a first biocharacteristic gathering device operably associated with said automated system for providing said automated system with a first biocharacteristic signal from the patient'"'"'s leg;

a second biocharacteristic gathering device operably associated with said automated system for providing said automated system with a second biocharacteristic signal from the patient'"'"'s leg; and

said automated system comprising a multiple risk factor analyzer, said multiple risk factor analyzer being adapted to perform a weighted analysis of the first and second biocharacteristic signals to arrive at the output indicative of DVT.

12. The apparatus for detecting DVT as recited in claim 11, wherein said multiple risk factor analyzer comprises a neural network.

13. The apparatus for detecting DVT as recited in claim 12, wherein said neural network is trained to perform a relative evaluation of the first and second biocharacteristic signals to arrive at an assessment of the patient'"'"'s overall risk for DVT.

14. The apparatus for detecting DVT as recited in claim 13, wherein said first biocharacteristic gathering device comprises a blood volume measurement device.

15. The apparatus for detecting DVT as recited in claim 14, wherein said second biocharacteristic gathering device comprises a calf temperature measurement device.

16. A method for detecting deep vein thrombosis (DVT) in a patient'"'"'s leg, said method comprising the steps of:

obtaining a first biocharacteristic signal and a second biocharacteristic signal, said first biocharacteristic signal and said second biocharacteristic signal each being indicative of blood flows in the patient'"'"'s leg;

producing a controlled occlusion of the deep and superficial veins of the patient'"'"'s leg such that blood volume in the patient'"'"'s leg is substantially maximized;

eliminating said controlled occlusion of the deep and superficial veins of the patient'"'"'s leg to allow natural flows of blood from the patient'"'"'s leg;

re-obtaining said first biocharacteristic signal and said second biocharacteristic signal during the period of natural flows following said eliminating said controlled occlusion step; and

performing a weighted analysis over time of said first biocharacteristic signal and said second biocharacteristic signal to arrive at an assessment of the patient'"'"'s DVT status.

17. The method for detecting DVT as recited in claim 16, wherein said performing a weighted analysis step comprises utilizing a neural network to balance known DVT risk factors.

18. The method for detecting DVT as recited in claim 17, wherein said known DVT risk factors comprise abnormal venous emptying.

19. The method for detecting DVT as recited in claim 18, wherein said known DVT risk factors further comprise abnormal leg temperature changes.

20. The method for detecting DVT as recited in claim 18, wherein said known DVT risk factors further comprise abnormal leg size changes.

21. The method for detecting DVT as recited in claim 16, wherein said first biocharacteristic signal is obtained by a photo-plethysmographic device.

22. The method for detecting DVT as recited in claim 21, wherein said controlled occlusion is produced by inflating a cuff, said cuff being adapted to produce an occluding pressure at a thigh portion of the patient'"'"'s leg.

23. The method for detecting DVT as recited in claim 22, wherein said obtaining a first biocharacteristic signal and a second biocharacteristic signal step is conducted under the control of an automated system, said automated system being adapted to further control the inflation of said cuff.