Patent Description:
Catheters are used for an ever-growing number of procedures. For example, catheters are used for diagnostic, therapeutic, and ablative procedures, to name just a few examples. Typically, the catheter is manipulated through the patient's vasculature and to the intended site, for example, a site within the patient's heart.

It is known to incorporate various electronic components into the tips of intravascular catheters. For instance, piezoelectric ultrasound transducers and supported electronics packages (implemented, for example, as an application-specific integrated circuit (ASIC) or field-programmable gate array (FPGA)) may be mounted within the tip of an intracardiac echocardiography (ICE) catheter, such as disclosed in <CIT> and <CIT>. The relatively small size of such components, however, increases the complexity, and therefore the cost, of manufacture.

<CIT> relates to a medical device for introduction into a body, wherein a flexible printed circuit for the medical device may comprise a flexible substrate, a plurality of conductive pads, and a plurality of conductive traces.

<CIT> relates to a medical device for introduction into a body, comprising an ultrasound transducer having an increased number of elements for obtaining sharper images while avoiding increasing the stiffness associated with the wiring.

<CIT> relates to a device comprising a touch panel, a liquid crystal display and a flexible printed circuit.

<CIT> relates to a multi-electrode mapping catheter for providing instantaneous whole chamber voltage mapping of a heart chamber while enabling real time electroanatomic mapping utilizing a single heartbeat.

<CIT> relates to a cardiac tissue ablation catheter comprising an inflatable and flexible balloon disposed at a distal region of an elongate member, wherein an outer surface of the balloon carries a flexible circuit.

The invention is disclosed in appended independent product claim <NUM> and method of manufacturing claim <NUM>. Additional embodiments are disclosed in the dependent claims. Further disclosed herein is a flexible electronic circuit, including: a plurality of leaves having a proximal section, a distal section, and an intermediate section, wherein the plurality of leaves are bonded to each other within the distal section and loose within the intermediate section; a plurality of conductive connector pads disposed on the plurality of leaves within the intermediate section; and a plurality of test connector pads disposed on the plurality of leaves within the proximal section.

In embodiments of the invention, the plurality of leaves are bonded to each other within the proximal section. They can be bonded to each other to form a stepped profile within the proximal section.

Alternatively, the plurality of leaves form a ribbon configuration within the proximal section.

The flexible electronic circuit can also include at least one of an ultrasound transducer array and an electronics package mounted to the plurality of leaves within the distal section.

Optionally, the flexible electronic circuit according can include a plurality of tooling alignment holes within the proximal section.

Also disclosed herein is a method of manufacturing a flexible electronic circuit, including the steps of: providing a plurality of leaves having a proximal section, a distal section, and an intermediate section, wherein the plurality of leaves are bonded to each other within the distal section and loose within the intermediate section; disposing a plurality of conductive connector pads on the plurality of leaves within the intermediate section; disposing a plurality of test connector pads on the plurality of leaves within the proximal section; and severing the proximal section from the intermediate section to create a plurality of flying leads from the loose leaves within the intermediate section.

At least one of an ultrasound transducer array and an electronics package can be mounted to the plurality of leaves within the distal section.

It is also contemplated that the method can include steps of: connecting the plurality of test connector pads to a testing apparatus and testing operability of the at least one of the ultrasound transducer array and the electronics package via the connected testing apparatus prior to severing the proximal section from the intermediate section.

The method can also include securing a wiring harness to the plurality of flying leads. For example, the method can include securing the wiring harness to the plurality of conductive connector pads disposed within the intermediate section of the plurality of leaves.

The plurality of leaves of the proximal section are bonded into a stacked configuration. In embodiments of the disclosure, the stacked configuration has a stepped profile.

Alternatively, the plurality of leaves of the proximal section can be arranged into a ribbon configuration.

In aspects of the disclosure, the method further includes forming a plurality of tooling alignment holes in the plurality of leaves within the proximal section.

The instant disclosure also provides a flexible electronic circuit, including: a plurality of leaves having a proximal section, a distal section, and an intermediate section, wherein the plurality of leaves are bonded to each other within the proximal section and the distal section, and the plurality of leaves are loose within the intermediate section; a transducer package mounted to the plurality of leaves within the distal section; a plurality of conductive connector pads disposed on the plurality of leaves within the intermediate section; and a plurality of test connector pads disposed on the plurality of leaves within the proximal section.

Embodiments of the flexible electronic circuit further include a plurality of test tooling alignment holes in the plurality of leaves within the proximal section.

It is contemplated that the plurality of leaves within the proximal section may be bonded to each other in a stacked configuration, such as a stacked configuration having a stepped profile. Alternatively, the plurality of leaves within the proximal section may be bonded to each other in a ribbon configuration.

The foregoing and other aspects, features, details, utilities, and advantages of the present invention will be apparent from reading the following description and claims, and from reviewing the accompanying drawings.

While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments.

Aspects of the instant disclosure relate to flexible electronic circuits suitable for use to connect electronics packages integrated into the distal ends of intravascular catheters (e.g., positioned within the distal tip assemblies of such catheters). Those of ordinary skill in the art will appreciate that the teachings herein can be applied to good advantage in connection with various types of catheters, including, but not limited to, intracardiac echocardiography (ICE) catheters, such as the ViewFlex™ Xtra ICE Catheter (Abbott Laboratories, Abbott Park, Illinois).

For purposes of illustration, <FIG> depicts a perspective view of a representative catheter <NUM>, including a shaft <NUM> having a proximal portion <NUM> and a distal portion <NUM>, which terminates in a tip <NUM>. Insofar as the basic construction of catheter <NUM> will be familiar to those of ordinary skill in the art, the details thereof will be omitted herein, except to the extent relevant to an understanding of the instant disclosure.

<FIG> is a schematic representation of the interior of distal portion <NUM> of catheter <NUM>, including tip <NUM>. Tip <NUM> can include a flexible electronic circuit <NUM>, including a flexible substrate <NUM> (which can be formed from a plurality of leaves according to the teachings herein) and a transducer package (e.g., ultrasound array <NUM> and electronics package <NUM>) mounted to substrate <NUM>. A wiring harness <NUM>, including a plurality of wires, interconnects flexible electronic circuit <NUM> to an external device, such as an ultrasound imaging console. Only three wires are shown within wiring harness <NUM>, but it should be understood that this is merely exemplary and that more or fewer wires may be used in a device according to the present teachings.

<FIG> depicts a first embodiment of flexible electronic circuit <NUM>. As shown in <FIG>, flexible electronic circuit includes a plurality of leaves <NUM>. Seven leaves are shown in <FIG>, but this number is merely exemplary; more or fewer leaves may be used in a device according to the present teachings.

Each leaf <NUM> has a distal section <NUM>, a proximal section <NUM>, and an intermediate section <NUM>. Within distal section <NUM>, leaves <NUM> are bonded to each other (e.g., through the use of thermosetting adhesives as part of a laminating process), such as in the stacked arrangement shown in <FIG>, to provide substrate <NUM> upon which a transducer package can be mounted (the transducer package, which is visible in <FIG>, is omitted from <FIG> for the sake of clarity of illustration). Those of ordinary skill in the art will also be familiar with techniques suitable for applying conductive traces to leaves <NUM> within distal section <NUM> as part of substrate <NUM>.

Conversely, within intermediate section <NUM>, leaves <NUM> are loose and have disposed thereon a plurality of conductive connector pads <NUM>. As used herein, the term "loose" means not bonded to each other; thus, within intermediate section <NUM>, leaves <NUM> are not bonded to each other, and can therefore be referred to as "loose leaves" or a "loose leaf configuration. " Moreover, because leaves <NUM> are not bonded to each other within intermediate section <NUM>, intermediate section <NUM> forms a plurality of flying leads to which the wires of wiring harness <NUM> may be secured.

Of course, conductive connector pads <NUM> are also conductively coupled into distal section <NUM>, so as to carry signals, such as power and communications signals, to and from the transducer package. Insofar as conductive coupling between the attachment point for a wiring harness and a transducer package will be familiar to those of ordinary skill in the art, it need not be further described herein.

Leaves <NUM> are also bonded within proximal section <NUM> in order to form a convenient coupon portion to connect flexible circuit <NUM> to testing equipment during manufacture. In the embodiment of flexible circuit <NUM> depicted in <FIG>, leaves <NUM> are bonded into a stack having a stepped profile within proximal section <NUM>.

A plurality of test connector pads <NUM>, which are ultimately conductively coupled into distal section <NUM> and the transducer package mounted therein, are disposed on leaves <NUM> within proximal section <NUM>. The use of a stepped profile within proximal section <NUM> simplifies the conductive connection between test connector pads <NUM> and distal section <NUM>, in particular by reducing the need to create vias through leaves <NUM> that are "higher" in the stack in order to conductively couple to leaves <NUM> that are "lower" in the stack.

It is contemplated, however, to bond leaves <NUM> within proximal section without creating the stepped profile, in which case test connector pads <NUM> could all be placed on the "upper" surface of the stack, all on the "lower" surface of the stack, or distributed between both the "upper" and "lower" surfaces of the stack. It should be recognized that distributing test connector pads <NUM> onto both the "upper" and "lower" surfaces would also reduce the need to create vias through leaves <NUM>, though not to the extent as the stepped profile shown in <FIG>.

Because leaves <NUM> are bonded to each other within proximal section <NUM>, the location of and spacing between test connector pads <NUM> is known and substantially (that is, within the margins permitted by the flexing of leaves <NUM>) fixed. This simplifies proof testing of flexible circuit <NUM> during manufacture by ensuring that a plurality of testing probes can be attached to test connector pads <NUM>, and thus conductively coupled to the transducer package within distal section <NUM>, quickly and reliably, without the need for special tooling or alignment and connection on a probe-by-probe basis, as would be necessary were leaves <NUM> loose within proximal section <NUM>.

To further simplify testing and facilitate proper alignment with testing apparatus, additional datums can be provided within proximal portion <NUM>. For instance, in embodiments of the disclosure, leaves <NUM> can include one or more alignment holes within proximal portion <NUM>, which mate with corresponding protrusions on a testing apparatus to ensure proper alignment to test connector pads <NUM>.

<FIG> depicts a second embodiment of flexible electronic circuit <NUM>. In the embodiment of <FIG>, as in the embodiment of <FIG>, leaves <NUM> are bonded to each other in a stack within distal section <NUM> and loose within intermediate section <NUM>. In proximal section <NUM>, however, leaves <NUM> are fanned out and arranged in a ribbon configuration for insertion into one or more flexible printed circuit (FPC) connectors, which can, in turn, be connected to testing apparatus. Optionally, leaves <NUM> can be bonded to each other in the ribbon configuration, so as to facilitate insertion into a single FPC connector.

Like the stepped profile described above, the ribbon configuration reduces the need to create vias through leaves <NUM>, and indeed may entirely eliminate the need to do so. On the other hand, it may require leaves <NUM> to be individually inserted into FPC connectors, though this is still likely simpler manufacturing process than individually connecting each test connector pad <NUM> to a corresponding test probe.

Once testing is complete and the functionality of flexible circuit <NUM> is verified, proximal section <NUM> can be severed (e.g., along cut-line <NUM> in <FIG> and <FIG>), leaving the flying leads of intermediate section <NUM> as the most proximal section of flexible circuit <NUM>. Flexible circuit <NUM> can be installed into tip <NUM> of catheter <NUM>, with wiring harness <NUM> secured to conductive connector pads <NUM>.

Although several embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention as defined by the claims.

For example, rather than using individual wires, wiring harness <NUM> could utilize one or more long flex and/or printed circuits.

Other configurations of leaves <NUM> within proximal section <NUM> are also contemplated, but not claimed. For instance half of leaves <NUM> could be formed into a first stack as described above, and the remainder of leaves <NUM> could be formed into a second stack as described, with the two stacks placed side-by-side analogous to the ribbon configuration described above.

All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other.

Claim 1:
A flexible electronic circuit (<NUM>) for an intravascular catheter, comprising:
a plurality of leaves (<NUM>) having a proximal section (<NUM>), a distal section (<NUM>), and an intermediate section (<NUM>), wherein the plurality of leaves (<NUM>) are bonded to each other within the distal section (<NUM>) into a stacked configuration through the use of thermosetting adhesives as part of a laminating process and loose within the intermediate section (<NUM>);
a plurality of conductive connector pads (<NUM>) disposed on the plurality of leaves (<NUM>) within the intermediate section (<NUM>); and
a plurality of test connector pads (<NUM>) disposed on the plurality of leaves (<NUM>) within the proximal section (<NUM>),
wherein the plurality of leaves (<NUM>) are bonded to each other within the proximal section (<NUM>) to form a stepped profile or a ribbon configuration within the proximal section (<NUM>).