A flexible elongate tubular spring structure for a flexible scoring balloon catheter configured for insertion into a vessel within a mammalian cardiovascular system or other fluid or air carrying conduit or duct within a living mammalian body, the scoring balloon catheter comprising an inflatable elongate balloon having a working region spanning a length, an outer surface along its working region, a first internal passage along which a guide wire is insertable, a second internal passage for passage of a pressurized fluid in communication with the interior of the balloon, and a first longitudinal axis centrally aligned with and extending through the first internal passage, wherein the working region of the balloon in a folded, undeployed, or unexpanded state respectively has a folded, undeployed, or unexpanded outer cross sectional area perpendicular to the first longitudinal axis, wherein the working region of the balloon in an expanded or deployed state respectively has an expanded or deployed outer cross sectional area perpendicular to the first longitudinal axis that is greater than the folded outer cross sectional area, the undeployed outer cross sectional area, and the unexpanded cross sectional area, and wherein the tubular spring structure has a distal end, a proximal end, a length therebetween within which a lumen resides, and a second longitudinal axis centrally aligned with its lumen, and wherein the tubular spring structure comprises:
- (i) a plurality of annular ring structures, each annular ring structure having an unexpanded length and providing along its length a lumen having a central axis longitudinally extending therethrough and a relaxed cross sectional area perpendicular to the central axis which in the absence of the balloon is less than the folded, undeployed, or unexpanded outer cross sectional area of the balloon's working region, wherein each annular ring structure is configured for circumferential engagement with the outer surface of the balloon such that the central axis of the annular ring structure is longitudinally aligned with a portion of the first longitudinal axis, wherein each annular ring structure is configured for resilient expansion in radial directions perpendicular to the central axis including outward radial expansion away from the central axis in response to radial forces exerted on the annular ring structure by expansion of the balloon, and wherein each annular ring structure of the plurality of annular ring structures comprises each of:
- (a) a distal annular spring having a circumference and configured for circumferentially residing around the outer surface of the balloon, wherein the distal annular spring is configured for resilient radial expansion relative to a plane perpendicular to the central axis, and wherein the distal annular spring is configured for exerting an inward circumferential compressive force toward the central axis in response to outward radial expansion of the distal annular spring away from the central axis beyond the relaxed cross sectional area;
- (b) a proximal annular spring longitudinally separated from the distal annular spring, the proximal annular spring having a circumference and configured for circumferentially residing around the outer surface of the balloon, wherein the proximal annular spring is configured for resilient radial expansion relative to a plane perpendicular to the central axis, and wherein the proximal annular spring is configured for exerting an inward circumferential compressive force toward the central axis in response to outward radial expansion of the proximal annular spring away from the central axis beyond the relaxed cross sectional area;
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- (c) a set of spacing elements peripherally disposed around the annular ring structure, and further disposed between the distal annular spring of the annular ring structure and the proximal annular spring of the annular ring structure, wherein the set of spacing elements couples the distal annular spring of the annular ring structure to the proximal annular spring of the annular ring structure and maintains a longitudinal separation distance between the distal annular spring of the annular ring structure and the proximal spring of the annular ring structure;
- wherein each distinct pair of adjacent annular ring structures of the plurality of annular ring structures is longitudinally organized as a first annular ring structure disposed distal to and separated by the longitudinal spatial gap from a second annular ring structure, wherein the proximal annular spring of the first annular ring structure resides at a distal side of a longitudinal spatial gap that separates the first annular ring structure from the second annular ring structure, and wherein the distal annular spring of the second annular ring structure resides at a proximal side of the longitudinal spatial gap that separates the first annular ring structure from the second annular ring structure;
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- (ii) a plurality of scoring links, wherein each scoring link has a length, wherein for each distinct pair of adjacent annular ring structures within the plurality of annular ring structures only a single scoring link extends from the distal annular spring of the first annular ring structure to the proximal annular spring of the second annular ring structure such that the single scoring link structurally couples the distinct pair of adjacent annular ring structures and spans the longitudinal spatial gap that separates the first annular ring structure from the second annular ring structures of the distinct pair of annular ring structures, wherein each scoring link comprises a set of scoring structures along at least portions of its length, wherein each scoring structure is configured as a traumatic element with respect to contact with tissue within the vessel, conduit, or duct, wherein serially successive scoring links along the length of the tubular spring structure are disposed at or indexed across different radial positions relative to each other about a circumference of the second longitudinal axis, and wherein the length of each scoring link is greater than the unexpanded length of each annular ring structure within the adjacent pair of annular ring structures coupled thereby.