Method for promoting circulation of blood

Claim 1

A method for promoting circulation of blood through a patient's heart and extremity comprising the steps of: a) applying an inflatable enclosure to the extremity, so that upon inflation and deflation of the enclosure, the extremity is alternately compressed and decompressed; b) sensing a QRS complex in a heart cycle of the patient and computing an average time period between a selected number of successive sensed QRS complexes; c) initiating a timing cycle for compressing and decompressing said extremity, said timing cycle being comprised of an adjustable time delay, a compression period and a decompression period, said timing cycle being calculated relative to said average time period, said timing cycle being initiated at a QRS complex next following said selected number of successive sensed QRS complexes, said timing cycle being re-calculated at each succeeding QRS complex; d) inflating the inflatable enclosure at the end of said time delay following the initiation of said timing cycle, thereby effecting compression of the extremity at the conclusion of the time delay; e) maintaining said inflation of the inflatable enclosure over said compression period and venting the inflatable enclosure to initiate said deflation after said compression period; and f) controlling said timing cycle relative to said average time period so as to initiate said decompression period sufficiently late in said heart cycle to facilitate both entry of a QRS-associated pulse wave into said extremity and ventricular ejection of blood from said heart, but before said next occurring QRS complex, thereby promoting circulation of blood through said heart and said extremity of the patient, said controlling of said timing cycle comprising the steps of: i) comparing a final time period between a last-occurring pair of successive QRS complexes in said average time period with said average time period to determine if said final time period differs in duration from said average time period by either of at least a first predetermined amount shorter than said average time period or a second pre-determined amount longer than said average time period; ii) adjusting said timing cycle to be a first selected amount longer than said average time period when said final time period is at least said first predetermined amount shorter than said average time period; iii) adjusting said timing cycle to be a second selected amount shorter than said average time period when said final time period is at least said second predetermined amount longer than said average time period; and iv) adjusting said timing cycle to be approximately equal to said average time period when said final time period differs from said average time period by less than said first pre-determined amount shorter and said second pre-determined amount longer than said average time period.

Claim 2

A method for promoting circulation of blood through a patient's heart and extremity comprising the steps of: a) applying an inflatable enclosure to the extremity, so that upon inflation and deflation of the enclosure, the extremity is alternately compressed and decompressed; b) sensing a QRS complex in a heart cycle of the patient and computing an average time period between a selected number of successive sensed QRS complexes; c) initiating a timing cycle for compressing and decompressing said extremity, said timing cycle being comprised of an adjustable time delay, a compression period and a decompression period, said timing cycle being calculated relative to said average time period, said timing cycle being initiated at a QRS complex next following said selected number of successive sensed QRS complexes, said timing cycle being re-calculated at each succeeding QRS complex; d) inflating the inflatable enclosure at the end of said time delay following the initiation of said timing cycle, thereby effecting compression of the extremity at the conclusion of the time delay; e) maintaining said inflation of the inflatable enclosure over said compression period and venting the inflatable enclosure to initiate said deflation after said compression period; and f) controlling said timing cycle relative to said average time period so as to initiate said decompression period sufficiently late in said heart cycle to facilitate both entry of a QRS-associated pulse wave into said extremity and ventricular ejection of blood from said heart, but before said next occurring QRS complex, thereby promoting circulation of blood through said heart and said extremity of the patient, said controlling of said timing cycle comprising the steps of: i) comparing a final time period between a last-occurring pair of successive QRS complexes in said average time period with said average time period to determine if said final time period differs in duration from said average time period by either of at least a first predetermined amount shorter than said average time period or a second pre-determined amount longer than said average time period; ii) adjusting said timing cycle to be a first selected amount longer than said average time period when said final time period is at least said first predetermined amount shorter than said average time period; iii) adjusting said timing cycle to be a second selected amount shorter than said average time period when said final time period is at least said second predetermined amount longer than said average time period; and iv) adjusting said timing cycle to be approximately equal to said average time period when said final time period differs from said average time period by less than said first pre-determined amount shorter and said second pre-determined amount longer than said average time period.