Method to augment blood circulation in a limb

Surgery: kinesitherapy – Kinesitherapy – Device with applicator having specific movement

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C601S148000

Reexamination Certificate

active

06231532

ABSTRACT:

CROSS REFERENCE TO RELATED APPLICATIONS
N/A
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
N/A
BACKGROUND OF THE INVENTION
The velocity of blood flow in a patient's legs is known to decrease during confinement in bed. Such pooling or stasis of blood is particularly pronounced during surgery, immediately after surgery, and when the patient has been confined to bed for an extended period of time. Additionally, blood stasis is a significant cause leading to the formation of thrombi in the patient's legs, which may eventually cause serious injury or even death. Additionally, in certain patients, it is desirable to move fluid out of interstitial spaces in extremity tissues in order to reduce swelling associated with edema in the extremities. By enhancing the circulation in the limb, the arterial and venous blood flow could be improved.
Intermittent pneumatic compression (IPC) devices are used to improve circulation and minimize the formation of thrombi in the limbs of patients. These devices typically include a compression sleeve or garment which wraps around the patient's limb. The sleeve has one or more separate inflatable chambers which are connected to a source of compressed fluid, generally air. The chamber or chambers are inflated to provide a compressive pulse to the limb, thereby increasing blood circulation and minimizing the formation of thrombi. In a multi-chambered sleeve, the compression pulses typically begin around the portion of the limb farthest from the heart, for example, the ankle, and progress sequentially toward the heart. The chamber or chambers are maintained in the inflated state for a predetermined duration, and all the chambers are depressurized simultaneously. After another predetermined period of time, the compression pulse repeats. Typical compression devices are described in U.S. Pat. No. 4,396,010 and U.S Pat. No. 5,876,359, filed Nov. 14, 1994, the disclosures of which are incorporated herein by reference.
Deep vein thrombosis and other venous and arterial conditions may also be diagnosed and evaluated by various air plethysmography techniques. These techniques use one or more pressure cuffs wrapped around one or more portions of a patient's limb. Volume changes of blood flow in the limb are monitored by monitoring the pressure in the cuff or cuffs with the limb in various positions and due to various position changes of the limb, often after application of a venous tourniquet to cause the limb to fill with blood. The venous tourniquet may be applied by a pressure cuff around a portion of the limb, for example, the thigh.
SUMMARY OF THE INVENTION
The present invention relates to a method for augmenting blood flow by applying pressure to a limb and determining the time for the venous system in a limb to refill with blood. The venous refill time is then used as the depressurization time between compression pulses for subsequent compression cycles of an intermittent pneumatic compression device.
More particularly, pulses of compressed gas to a compression sleeve wrapped around a limb cause blood to flow toward the patient's body or heart. When the sleeve is depressurized, causing the chamber or chambers to deflate, the venous system in the limb refills with blood and eventually returns to a steady state. The time in which the venous system refills and returns to a steady state varies from patient to patient. Accordingly, the present invention provides a method of sensing the venous refill time. This time is used to adjust the depressurization time between pulses. By adjusting the depressurization time in this manner, compressive pulses can be provided to the limb once it has refilled, rather than waiting a predetermined or standard time, such as 60 seconds, which may be longer than desired. This allows blood flow to be customized and augmented over time for each individual patient and minimizes the time that blood is allowed to pool in the limb.
The venous refill time is preferably determined by monitoring the pressure in the chamber of the sleeve while the limb refills with blood and sensing when the pressure reaches a plateau, which indicates that the limb has refilled with blood and reached a steady state. In a multi-chambered sleeve, the pressure may be monitored in one of the chambers, for example, the middle or calf chamber of a sleeve for the leg. Alternatively, the venous refill time can be sensed by applying a venous tourniquet to the patient's limb and measuring the time for the limb to engorge with blood, since no venous flow would be allowed past the tourniquet. The tourniquet can be applied by inflating a thigh chamber of a multi-chambered sleeve.
The venous refill time can be determined at start up to set the depressurization time. Additionally, the venous refill time can be determined periodically during use of the sleeve on the patient and the depressurization time adjusted accordingly as necessary.


REFERENCES:
patent: 2674231 (1954-04-01), Erickson
patent: 2699165 (1955-01-01), Ferrier
patent: 2781041 (1957-02-01), Weinberg
patent: 3826249 (1974-07-01), Lee et al.
patent: 3896794 (1975-07-01), McGrath
patent: 4044759 (1977-08-01), Ghayouran
patent: 4066084 (1978-01-01), Tillander
patent: 4086920 (1978-05-01), Miniere
patent: 4186732 (1980-02-01), Christoffel
patent: 4204547 (1980-05-01), Allocca
patent: 4311135 (1982-01-01), Brueckner et al.
patent: 4396010 (1983-08-01), Arkans
patent: 4583522 (1986-04-01), Aronne
patent: 4738249 (1988-04-01), Linman et al.
patent: 4781189 (1988-11-01), Vijil-Rosales
patent: 5022387 (1991-06-01), Hasty
patent: 5050613 (1991-09-01), Newman et al.
patent: 5109832 (1992-05-01), Proctor et al.
patent: 5117812 (1992-06-01), McWhorter
patent: 5186163 (1993-02-01), Dye
patent: 5218954 (1993-06-01), Van Bemmelen
patent: 5372573 (1994-12-01), Habib
patent: 5437610 (1995-08-01), Cariapa et al.
patent: 5458562 (1995-10-01), Cooper
patent: 5566677 (1996-10-01), Raines et al.
patent: 5575762 (1996-11-01), Peeler et al.
patent: 5588954 (1996-12-01), Ribando et al.
patent: 5588955 (1996-12-01), Johnson, Jr. et al.
patent: 5626556 (1997-05-01), Tobler et al.
patent: 5630424 (1997-05-01), Raines et al.
patent: 5634889 (1997-06-01), Gardner et al.
patent: 5669872 (1997-09-01), Fox
patent: 5674262 (1997-10-01), Tumey
patent: 5711760 (1998-01-01), Ibrahim et al.
patent: 5715828 (1998-02-01), Raines et al.
patent: 5718232 (1998-02-01), Raines et al.
patent: 5724981 (1998-03-01), Apple
patent: 5725485 (1998-03-01), Ribando et al.
patent: 5730136 (1998-03-01), Laufer et al.
patent: 5741294 (1998-04-01), Stromberg
patent: 5749853 (1998-05-01), O'Donnell et al.
patent: 5830164 (1998-11-01), Cone et al.
patent: 5840049 (1998-11-01), Tumey et al.
patent: 5843007 (1998-12-01), McEwen et al.
patent: 5876359 (1999-03-01), Bock et al.
patent: 5902229 (1999-05-01), Tsitlik et al.
patent: 5904145 (1999-05-01), Reid
patent: 5904666 (1999-05-01), DeDecker et al.
patent: 5931797 (1999-08-01), Tumey et al.
patent: 0 698 387 A1 (1996-02-01), None
patent: WO 95/01770 (1995-01-01), None
patent: WO 96/28088 (1996-09-01), None

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Method to augment blood circulation in a limb does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method to augment blood circulation in a limb, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method to augment blood circulation in a limb will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2533757

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.