Flexible tissue injection catheters with controlled depth penetration

Claim 1

A flexible tissue injection catheter with controlled depth penetration, said catheter comprising: a) an elongate hollow catheter body having a proximal end and a distal end with a flexible portion at a distal tip thereof, said catheter body being sized and constructed to be advanced intravascularly into an interior body cavity of a subject; b) a hollow needle housed throughout the catheter body, said needle having a distal portion with a sharp tip and a proximal portion in fluid communication with a fluid source, said needle further having a retracted needle position wherein the sharp tip of the needle is disposed within the catheter body, and an advanced needle position wherein the sharp tip of the needle extends a fixed distance beyond a distal end face of the catheter body, c) a needle stop attached to the needle that tethers the distal portion of the needle during flexure while the proximal portion of the needle remains freely slideable within the catheter body, d) a distance compensator portion of the proximal portion of the needle that extends from the proximal end of the catheter body when the catheter body is not deflected and moves at least partially within the catheter body when the flexible portion is deflected, and e) an advancement mechanism attached to the needle for advancing the needle distally a fixed distance to the advanced needle position, wherein the needle stop prevents withdrawal of the distal portion of the needle into the catheter body upon flexure of the catheter prior to actuation of the advancement mechanism to move the needle—to the advanced needle position, thereby exposing a fixed length of the sharp tip of the needle.

Claim 17

A system comprising: a) a flexible tissue injection catheter comprising an elongate hollow catheter body having a proximal end and a distal end with a flexible portion at the distal tip thereof, said catheter body being sized and constructed to be advanced intravascularly into an interior body cavity of a subject; b) a hollow injection needle with a sharp distal tip and a hub; and c) an operator controlled adjustable needle stop fixedly attached to the distal end of the catheter body and to the needle hub wherein the adjustable needle stop comprising in co-axial arrangement: a substantially cylindrical outer needle holder; a hollow needle carriage having a series of exterior precisely spaced circumferential notches, and a proximal portion with a slot shaped to receive the hub of the hollow needle, said needle carriage being slideably mounted within the needle holder for longitudinal advancement between a recessed position, in which the distal tip of the needle does not protrude from the distal end of the needle holder, and a series of progressively advanced positions, which positions expose a series of precisely controlled increments of the distal tip thereof, said series of positions being established by the series of circumferential notches; a detent mechanism mounted on the outer needle holder which cooperates with the longitudinal series of precisely spaced circumferential notches during the longitudinal movement to provide an audible and/or tactile signal each time the needle carriage is advanced by the operator from one position to the next position in the series of progressively advanced positions; and an external locking mechanism for locking longitudinal movement of the needle carriage within the needle holder.

Claim 18

A system comprising: a) a flexible tissue injection catheter comprising an elongate hollow catheter body having a proximal end and a distal end with a flexible portion at the distal tip thereof, said catheter body being sized and constructed to be advanced intravascularly into an interior body cavity of a subject; b) a hollow injection needle with a sharp distal tip and a hub; and c) an operator controlled adjustable needle stop fixedly attached to the distal end of the catheter body and to the needle hub wherein the adjustable needle stop comprising in co-axial arrangement: a substantially cylindrical outer needle holder; a hollow needle carriage having a series of exterior precisely spaced circumferential notches, and a proximal portion with a slot shaped to receive the hub of the hollow needle, said needle carriage being slideably mounted within the needle holder for longitudinal advancement between a recessed position, in which the distal tip of the needle does not protrude from the distal end of the needle holder, and a series of progressively advanced positions, which positions expose a series of precisely controlled increments of the distal tip thereof, said series of positions being established by the series of circumferential notches; a detent mechanism mounted on the outer needle holder which cooperates with the longitudinal series of precisely spaced circumferential notches during the longitudinal movement to provide an audible and/or tactile signal each time the needle carriage is advanced by the operator from one position to the next position in the series of progressively advanced positions; and an external locking mechanism for locking longitudinal movement of the needle carriage within the needle holder.