TECHNICAL FIELD

The present disclosure relates generally to medical devices and, more particularly, to systems, devices and methods related to catheters used to perform ablation functions.

BACKGROUND

Cardiac ablation is a procedure by which cardiac tissue is treated to inactivate the tissue. The tissue targeted for ablation may be associated with improper electrical activity, for example. Cardiac ablation can lesion the tissue and prevent the tissue from improperly generating or conducting electrical signals.

SUMMARY

In Example 1, a catheter system includes a catheter. The catheter includes a catheter tip and an ultrasound assembly at least partially positioned within the catheter tip. The ultrasound assembly includes a first optical fiber coupled to an optical-to-ultrasound transducer and a second optical fiber coupled to an ultrasound-to-optical transducer. The optical-to-ultrasound transducer is configured to generate an ultrasound signal in response to a pulsed optical signal. The ultrasound-to-optical transducer is configured to generate an optical signal in response to a received ultrasound signal.

In Example 2, the catheter system of Example 1, wherein the optical-to-ultrasound transducer is a coating applied to a distal end of the first optical fiber.

In Example 3, the catheter system of Example 2, wherein the coating comprises at least one of an elastomer, carbon nanotubes, gold nanostructures, polymer, carbon black, graphene, and graphite.

In Example 4, the catheter system of any of Examples 1-3, further comprising third, fourth, and fifth optical fibers, each coupled to its own ultrasound-to-optical transducer, each ultrasound-to-optical transducer configured to generate an optical signal in response to a received ultrasound signal.

In Example 5, the catheter system of any of Examples 1-4, wherein the first optical fiber has a greater diameter than the other optical fibers.

In Example 6, the catheter system of any of Examples 1-5, wherein the first optical fiber is positioned centrally among the other optical fibers.

In Example 7, the catheter system of any of Examples 1-6, wherein the ultrasound assembly includes at least one optical fiber configured for one of force sensing, pressure sensing, and shape sensing.

In Example 8, the catheter system of any of Examples 1-7, further comprising at least one optical coherence tomography (OCT) emitting/receiving optical fiber configured to emit light and receive light reflected back to the OCT emitting/receiving optical fiber.

In Example 9, the catheter system of any of Examples 1-8, further comprising a laser source coupled to the first optical fiber, wherein the laser source is configured to generate the pulsed optical signal.

In Example 10, the catheter system of any of Examples 1-9, wherein the optical signal corresponds to a signature of a tissue structure.

In Example 11, the catheter system of Example 10, wherein the signature comprises a plurality of pixels, each of which is indicative of tissue structure at different depths of the tissue.

In Example 12, the catheter system of any of Examples 10-11, further comprising a control system comprising a memory and a processor, wherein the control system is configured to receive the optical signal, compare the signature to a previously-received signature, and based on the comparison, determine that the tissue has been ablated.

In Example 13, the catheter system of any of Examples 10-11, further comprising a control system comprising a memory and a processor, wherein the control system is configured to receive the optical signal, compare a signature of a first portion of tissue to a signature of a second portion of tissue, and based on the comparison, determine that the first portion of tissue has been ablated.

In Example 14, the catheter system of any of the Examples 12-13, wherein the comparison includes comparing pixel brightness.

In Example 15, the catheter system of any of the Examples 12-13, wherein the comparison includes comparing pixel contrast.

In Example 16, a catheter system includes a catheter. The catheter includes a catheter tip and an ultrasound assembly at least partially positioned within the catheter tip. The ultrasound assembly includes a first optical fiber coupled to an optical-to-ultrasound transducer and a second optical fiber coupled to an ultrasound-to-optical transducer. The optical-to-ultrasound transducer is configured to generate an ultrasound signal in response to a pulsed optical signal. The ultrasound-to-optical transducer is configured to generate an optical signal in response to a received ultrasound signal.

In Example 17, the catheter system of Examples 16, wherein the optical-to-ultrasound transducer is a coating applied to a distal end of the first optical fiber.

In Example 18, the catheter system of Example 17, wherein the coating comprises at least one of an elastomer, carbon nanotubes, gold nanostructures, polymer, carbon black, graphene, and graphite.

In Example 19, the catheter system of Example 16, wherein the ultrasound assembly further comprises third, fourth, and fifth optical fibers, each coupled to its own ultrasound-to-optical transducer, each ultrasound-to-optical transducer configured to generate an optical signal in response to a received ultrasound signal.

In Example 20, the catheter system of Example 19, wherein the first optical fiber is positioned centrally among the other optical fibers.

In Example 21, the catheter system of Example 16, wherein the first optical fiber has a greater diameter than the other optical fibers.

In Example 22, the catheter system of Example 16, wherein the catheter tip includes a cooling chamber, and wherein a distal end of the first optical fiber is coupled to a proximal end of the cooling chamber.

In Example 23, the catheter system of any of Examples 1-22, further comprising a temperature sensor positioned within the catheter tip adjacent the distal end of the first optical fiber.

In Example 24, the catheter system of Example 16, wherein the optical signal corresponds to a signature of a tissue structure.

In Example 25, the catheter system of Example 24, further comprising a control system comprising a memory and a processor, wherein the memory stores instructions that cause the processor to receive the optical signal, compare the signature to a previously-received signature, and based on the comparison, determine that the tissue has been ablated.

In Example 26, the catheter system of Example 25, wherein the signature comprises a plurality of pixels, each of which is indicative of tissue structure at different depths of the tissue, and wherein the comparison includes comparing one of pixel brightness and pixel contrast.

In Example 27, the catheter system of Example 24, further comprising a control system comprising a memory and a processor, wherein the memory stores instructions that cause the processor to receive the optical signal, compare a signature of a first portion of tissue to a signature of a second portion of tissue, and based on the comparison, determine that the first portion of tissue has been ablated.

In Example 28, the catheter system of Example 27, wherein the signature comprises a plurality of pixels, each of which is indicative of tissue structure at different depths of the tissue, and wherein the comparison includes comparing one of pixel brightness and pixel contrast.

In Example 29, the catheter system of Example 16, wherein the first optical fiber includes a first set of optical gratings, wherein the optical-to-ultrasound transducer is configured to generate an ultrasound signal at a first frequency. The catheter further comprises a third optical fiber coupled to a second optical-to-ultrasound transducer and having a second set of optical gratings. The second optical-to-ultrasound transducer is configured to generate an ultrasound signal at a second frequency. The catheter further comprises a fourth optical fiber coupled to a third optical-to-ultrasound transducer and having a third set of optical gratings. The third optical-to-ultrasound transducer is configured to generate an ultrasound signal at a third frequency.

In Example 30, the catheter system of Example 29, further comprising a first optical coupler configured to split light between an intermediate optical fiber and the first optical fiber; and a second optical coupler configured to split light from the intermediate optical fiber to the third and fourth optical fibers.

In Example 31, a method for monitoring tissue ablation using an ultrasound assembly including a first optical fiber and a second optical fiber. The method includes transmitting a pulsed optical signal through the first optical fiber to an optical-to-ultrasound transducer, converting the pulsed optical signal into an ultrasound signal, and converting a reflected ultrasound signal into an output optical signal via an ultrasound-to-optical transducer. The output optical signal is indicative of a current tissue structure. The method further includes comparing the current tissue structure to a previous tissue structure and, based on the comparison, determining that a portion of tissue has been damaged by ablation.

In Example 32, the method of Example 31, wherein the output optical signal is transmitted via the second optical fiber.

In Example 33, the method of Example 31, wherein the output optical signal corresponds to a signature indicative of the current tissue structure, and wherein the comparison includes comparing a current signature with a previous signature.

In Example 34, the method of Example 33, wherein the signature includes a plurality of pixels.

In Example 35, the method of Example 33, wherein the comparison includes comparing a characteristic of the plurality of pixels to determine that a portion of tissue has been damaged by ablation.

In Example 36, the method of Example 35, wherein the characteristic includes at least one of pixel brightness and pixel contrast.

In Example 37, the method of Example 34, wherein each of the plurality of pixels is indicative of tissue structure at a different depth of the tissue.

While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

