Fluid barrier for intraluminal ultrasound imaging and associated devices, systems, and methods

An intraluminal imaging device, comprising:

• a catheter configured to be positioned within a body lumen of a patient, the catheter comprising a proximal portion, a distal portion, and an exterior surface;
• a flex circuit comprising a proximal portion, a distal portion, an exterior surface, an interior surface, and a plurality of electrical components disposed on the interior surface, wherein the flex circuit defines a cavity, wherein the plurality electrical components are disposed adjacent to the cavity, wherein the proximal portion of the flex circuit is coupled to the distal portion of the catheter;
• and
• a coating extending over a location where the proximal portion of the flex circuit is coupled to the distal portion of the catheter, wherein the coating is separate from the flex circuit and the catheter, wherein the coating is disposed outside of the flex circuit and the catheter, wherein the coating directly contacts both the exterior surface of the distal portion of the catheter and the exterior surface of the proximal portion of the flex circuit such that the coating hermetically seals the cavity, wherein the coating comprises a proximal boundary at the distal portion of the catheter, a distal boundary at the flex circuit, and a continuous length between the proximal boundary and the distal boundary, wherein the continuous length overlaps the location where the proximal portion of the flex circuit is coupled to the distal portion of the catheter.