Abstract: A biomedical interface pressure transducer which is useful for interposing between a limb or tissue and an occlusive band, tourniquet cuff or other biomedical apparatus in order to estimate the pressure and pressure gradient applied to a selected area of the limb or tissue is disclosed. The pressure transducer comprises a modified MEMS pressure sensor and a conformable semisolid body enclosed in a shear relief membrane which translates the pressure applied by the occlusive band to the modified MEMS pressure sensor mounted on a flexible substrate with patterned electrical interconnect tracks allowing the connection of the pressure sensor to digital communication and control circuitry.

Abstract: A system for controlling blood flow through a zone of a patient limb, the zone being bounded by a proximal end and a distal end, comprises: a cuff configured for securing to the limb and for covering the zone, the cuff being inflatable to provide pressure to the zone for occluding the flow of blood flowing through the zone in the direction from the proximal to distal ends of the zone; an array of sensors fitting between the cuff and the limb and arranged for sensing and signaling the amount of penetration of blood flow into the zone; and a control instrument connected to the array and to the cuff for regulating the pressure in the cuff to occlude the blood flow in the zone depending upon the amount of blood flow penetration signaled by the array.

Abstract: A biomedical interface pressure transducer which is useful for interposing between a limb or tissue and an occlusive band, tourniquet cuff or other biomedical apparatus in order to estimate the pressure and pressure gradient applied to a selected area of the limb or tissue is disclosed. The pressure transducer comprises a modified MEMS pressure sensor and a conformable semisolid body enclosed in a shear relief membrane which translates the pressure applied by the occlusive band to the modified MEMS pressure sensor mounted on a flexible substrate with patterned electrical interconnect tracks allowing the connection of the pressure sensor to digital communication and control circuitry.

Abstract: An internal tourniquet and method for establishing hemostasis within a portion of a limb to facilitate surgery controls flow of a fluid into a capsule surrounding substantially all of a human joint. Blood concentration in the capsule is sensed; and pressure in the capsule is controlled to maintain a fluid pressure in the capsule within a predetermined pressure tolerance window. The concentration of blood in the capsule is maintained below a predetermined maximum concentration while the fluid pressure is within the pressure tolerance window.

Abstract: A system for controlling blood flow through a zone of a patient limb, the zone being bounded by a proximal end and a distal end, comprises: a cuff configured for securing to the limb and for covering the zone, the cuff being inflatable to provide pressure to the zone for occluding the flow of blood flowing through the zone in the direction from the proximal to distal ends of the zone; an array of sensors fitting between the cuff and the limb and arranged for sensing and signaling the amount of penetration of blood flow into the zone; and a control instrument connected to the array and to the cuff for regulating the pressure in the cuff to occlude the blood flow in the zone depending upon the amount of blood flow penetration signaled by the array.

Abstract: An overlapping occlusive cuff for improved application of pressure to the limb, comprising: an inflatable bladder; a sheath for containing the inflatable bladder wherein the sheath has a length sufficient to encircle the limb and overlap on itself in a substantially circumferential direction around the limb; sheath securing means for securing the overlapped sheath around the limb; and stiffening means for superimposing over a region of the overlapped and secured sheath to constrain the shape of the sheath beneath the region when the bladder is inflated. The stiffening means includes securing means for securing the overlapping sheath in a substantially circumferential direction around the limb independently of the sheath securing means such that the sheath remains overlapped and secured in a substantially circumferential direction if the sheath securing means is not engaged or becomes ineffective while the bladder is inflated.

Abstract: A tourniquet system comprising: an inflatable occlusive band for encircling a limb of a subject and for inflating to apply pressure to the encircled limb to occlude blood flow into the limb distal to the band, wherein an inner surface of the band faces the limb; inflation pressure regulation means responsive to a variable inflation pressure regulation signal for regulating the pressure to which the occlusive band is inflated and for producing an inflation pressure signal representative of the pressure to which the band is inflated; applied pressure sensing means located at a predetermined location fixed relative to the band for producing an applied pressure signal representative of the pressure applied by the inflated band to the limb in a direction normal to inner surface of the band at the predetermined location; and pressure-regulating means responsive to the applied pressure signal for producing an inflation pressure regulation signal to maintain the pressure applied by the inflated band to the limb at th