Multi-mode inflatable limb occlusion device

Abstract

Methods for adaptive cuff inflation for the purposes of occluding a limb of a subject include inflating a cuff to a pressure at or above limb occlusion pressure and periodically deflating the cuff to detect amplitude of oscillometric oscillations reaching or exceeding a predetermined threshold, whereby indicating that the cuff pressure has reached an updated systolic blood pressure. Selecting the cuff to be wide enough to define limb occlusion pressure at or below the systolic blood pressure assures that this maneuver does not compromise cessation of blood flow to the limb. Devices are disclosed configured to operate in at least two of the following three operating modes: a tourniquet mode, a remote conditioning mode and a blood pressure monitoring mode.

Description

CROSS-REFERENCE DATA[0001]This application is a divisional application of my co-pending U.S. patent application Ser. No. 13 / 836,418 filed Mar. 15, 2013, which is in turn a continuation-in-part of U.S. patent application Ser. No. 13 / 351,257 filed Jan. 17, 2012 and entitled “Dual-Mode Remote Ischemic Preconditioning Devices and Methods”, now U.S. Pat. No. 8,795,323. The '418 application is also a continuation-in-part of U.S. patent application Ser. No. 13 / 362,039 entitled “AUTOMATIC DEVICES FOR REMOTE ISCHEMIC PRECONDITIONING” filed 31 Jan. 2012, now U.S. Pat. No. 8,753,283, which is in turn a continuation of the U.S. patent application Ser. No. 12 / 820,273 entitled “METHODS AND DEVICES FOR REMOTE ISCHEMIC PRECONDITIONING AND NEAR-CONTINUOUS BLOOD PRESSURE MONITORING” filed Jun. 22, 2010, now U.S. Pat. No. 8,114,026, which in turn claims a priority benefit from the U.S. Provisional Patent Application No. 61 / 219,536 filed Jun. 23, 2009 entitled “BLOOD PRESSURE CUFF INCORPORATING A PRECO...

AI Technical Summary

Benefits of technology

[0008]Accordingly, it is an object of the present invention to overcome these and other drawbacks of the prior art by providing novel methods of adaptive limb occlusion allowing automatic determination of minimal cuff occlusion pressure and periodic adjustment thereof to follow changes in blood pressure of the subject.

[0010]It is yet a further object of the present invention to provide a self-contained multi-mode limb occlusion device which can operate as a smart tourniquet once activated; the cuff in this tourniquet is inflated to the minimal occlusion pressure to stop the bleeding through the limb. Such optimal cuff pressure may be automatically determined by the device and adjusted depending on the changes in the blood pressure of the subject.

[0026]Keeping the predetermined safety margin low and frequently detecting updated systolic blood pressure of the subject allows occluding the limb at the lowest cuff pressure, whereby minimizing tissue compression, pain, risk of nerve compression and other complications following removal of the cuff.

[0037]The method may further include steps to minimize cuff pressure needed for maintaining of limb occlusion—by selecting more frequent checks of systolic blood pressure in step (b) and by lowering the safety margin in step (d).

[0044]Also disclosed are methods for reducing likelihood or preventing vision loss in subjects experiencing or at risk of vision loss by applying repeated remote conditioning treatments to these subjects in the amount and frequency sufficient to reduce the progression or prevent vision loss (also referred to a acquired blindness).

Problems solved by technology

Many of such circumstances involve a clinical situation in which perfusion (normal blood flow to a target organ or tissue) is temporarily interrupted leading to ischemia (lack of oxygen delivery to the organ).

Despite the fact that all three modalities described above (limb tourniquet, blood pressure monitor, and device for remote conditioning) may be accomplished by using an inflatable cuff, there are no known devices configured to accomplish more than one of these modalities.

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