Patent Description:
Ablation is a medical technique for producing tissue necrosis. It is used to help treat different pathologies including cancer, Barret's esophagus, or cardiac arrhythmias, among others. Various energy sources may be utilized for ablation. For example, in radiofrequency (RF) ablation, an external electrode is placed on a patient's body, and an alternating potential is applied to the tip of a catheter that is placed in contact with the tissue to be treated within the patient's body. The application of alternating current with an oscillating frequency above several hundreds of kHz avoids the stimulation of excitable tissue while delivering heat by means of the Joule's effect. The increase in tissue temperature produces denaturation and changes in tissue fiber anisotropy of the biological molecules, including proteins such as collagen, myosin, or elastin.

<CIT> discloses a system for performing ablation and lesion prediction. This known system comprises a catheter including a plurality of optical ports, formed at it its distal section, providing a plurality of distinct viewing directions. The system further includes a console, coupled to the catheter, said console comprising a computing device configured to acquire optical signals from the catheter, and analyze the acquired optical signals to detect changes in optical properties of the tissue. In particular, the console may include hardware (e.g., circuits), firmware, software means, or any combination thereof, to perform analysis of the optical signals and generate models for predicting lesion depths and ablation times.

The invention is defined in independent claims <NUM> and <NUM>. Preferred aspects of the invention are defined in the dependent claims. Any method discussed herein after are presented for illustrative purposes only and do not, as such, form part of the invention.

In aspects presented herein, processing devices may synchronize signals from catheter systems and optical systems using time stamps in order to improve the accuracy of an ablation model from which an estimated lesion depth can be generated.

In an aspect, an example method comprises activating a catheter energy source, acquiring a catheter energy signal from the catheter energy source, assigning an activation time stamp and deactivation time stamp to the catheter energy signal, and determining a time of ablation based on a time period between the activation time stamp and deactivation time stamp. The method then comprises acquiring an optical measurement signal from a catheter optical port, assigning an input time stamp and switching time stamp to the optical measurement signal, and processing the optical measurement signal in order to acquire a denaturation result. The method further comprises synchronizing the time of ablation and the denaturation result using the time stamps in order to generate a synchronized model and generating an estimated lesion depth from the synchronized model.

In another aspect, an example system is described. The system comprises a catheter energy source, a catheter coupled to the catheter energy source, a catheter optical port, and a computing device coupled to the catheter energy source and the catheter. The computing device comprises a processor and a memory. The memory contains instructions that when executed, the processor causes the computing device to activate the catheter energy source, acquire a catheter energy signal from the catheter energy source, assign an activation time stamp and deactivation time stamp to the catheter energy signal, and determine a time of ablation based on a time period between the activation time stamp and deactivation time stamp. The processor then causes the computing device to acquire an optical measurement signal from the catheter optical port, assign an input time stamp and switching time stamp to the optical measurement signal, and process the optical measurement signal in order to acquire a denaturation result. The processor further causes the computing device to synchronize the time of ablation and the denaturation result using the time stamps in order to generate a synchronized model and to generate an estimated lesion depth from the synchronized model.

In yet another aspect, an example non-transitory computer-readable medium has instructions stored on it that, when executed by at least one computing device, cause the at least one computing device to perform operations. The operations comprise activating a catheter energy source, acquiring a catheter energy signal from the catheter energy source, assigning an activation time stamp and deactivation time stamp to the catheter energy signal, and determining a time of ablation based on a time period between the activation time stamp and deactivation time stamp. The operations then comprise acquiring an optical measurement signal from a catheter optical port, assigning an input time stamp and switching time stamp to the optical measurement signal, and processing the optical measurement signal in order to acquire a denaturation result. The operations further comprise synchronizing the time of ablation and the denaturation result using the time stamps in order to generate a synchronized model and generating an estimated lesion depth from the synchronized model.

Further features and advantages, as well as the structure and operation of various aspects, are described in detail below with reference to the accompanying drawings. It is noted that the specific aspects described herein are not intended to be limiting. Such aspects are presented herein for illustrative purposes only. Additional aspects will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate aspects of the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable a person skilled in the pertinent art to make and use the disclosure.

Aspects of the present disclosure will be described with reference to the accompanying drawings.

Provided herein are system, apparatus, device, method and/or computer-readable medium aspects, and/or combinations and sub-combinations thereof for improving the accuracy of an ablation model through synchronization.

Denaturation of biological molecules of tissue creates a lesion on the tissue. Assessing characteristics of the lesion is important to producing tissue necrosis sufficient to treat different pathologies without damaging healthy tissue. The lesion can be assessed using optical ports located at the tip of the catheter and various optical data processors. Because of asynchronous acquisition and processing of various signals, it may be difficult to understand ablation effects in tissue and to avoid damaging healthy tissue using current systems and methods. Current systems and method for generating ablation models and estimating lesion depth do not provide the accuracy needed to prevent improper denaturation of biological molecules due to a synchronicity of signal acquisition and processing. Improper denaturation occurs where a lesion is created on a tissue in order to treat different pathologies but where healthy tissue is damaged due to an over-ablation of the tissue, or where the tissue is not sufficiently ablated.

In a system that does not use a time stamping approach to generate an estimated lesion depth from a synchronized model, an ablation signal and a signal relating to optical measurement of a tissue may not correspond to one another. Thus, a user may view an estimated lesion depth and believe it accurately reflects a correspondence between an amount of energy applied to a tissue and the extent of denaturation of the tissue. Based on this information, the user may improperly continue or improperly stop applying energy to the tissue. In actuality, the extent of denaturation of the tissue may be more or less than expected, resulting in damaged healthy tissue or undamaged unhealthy tissue.

Aspects herein solve these technological problems using an innovative time stamping approach that generates an estimated lesion depth from a synchronized model. An ablation catheter containing a multi-port optical component may be used to apply energy, from an energy source, to a tissue and to transmit optical measurement data from different tissue sites, through the catheter, to a console for processing. In such an aspect, the energy source may either be activated or deactivated, and only one optical port may actively provide optical measurement data at a given time. A clock in the console for processing may be used to assign time stamps to data items in order to track the status of the energy source and the data from the optical ports. Once data items have been time stamped, the console can generate an estimated lesion depth that reflects an accurate timing relationship between energy applied to the tissue and the optical measurement data from the different tissue sites.

According to aspects of the invention, a processor may assign an activation time stamp and a deactivation time stamp to a catheter energy signal (that is, the ablation signal) in accordance with the activation and deactivation of a catheter energy source. The processor may also assign an input time stamp and a switching time stamp to an optical measurement signal in accordance with the acquisition of the optical measurement signal from a catheter optical port of a catheter. The processor may determine a time of ablation and denaturation result using the signals, synchronize the time of ablation and denaturation result using the time stamps in order to generate a synchronized model, and generate an estimated lesion depth from the synchronized model. Because the estimated lesion depth is generated from the synchronized model, there is an accurate relation between when energy is applied to a tissue and when denaturation occurs in the tissue.

Aspects herein provide various benefits. For example, the time stamping approach provides an accurate estimated lesion depth to a user that reflects when the user applies energy to a tissue and when denaturation occurs in the tissue. In other words, while a user is ablating a tissue and producing tissue necrosis to treat different pathologies, the user can accurately assess characteristics of the ablation lesion to ensure that pathologies are treated and healthy tissue is protected. Therefore, the time stamping approach solves the above technological problem by improving the accuracy of an ablation model through synchronization in order to allow for the treatment of different pathologies without damaging healthy tissue.

It is noted that although this application may refer specifically to cardiac ablation, the aspects described herein may target other pathologies as well, along with additional energy sources for ablation, including but not limited to cryogenic, radiofrequency (RF), microwave, laser, ultrasound, and pulsed electric fields. The principles of using energy to treat other pathologies are similar, and therefore the techniques used to apply the energy are similar. It is also noted that the aspects described herein may be used in vivo or in vitro.

<FIG> illustrates a catheter <NUM> according to aspects of the present disclosure. Catheter <NUM> includes a proximal section <NUM>, a distal section <NUM>, and a sheath <NUM> coupled between proximal section <NUM> and distal section <NUM>. In an aspect, sheath <NUM> includes one or more radiopaque markers for navigation purposes. In one aspect, catheter <NUM> includes a communication interface <NUM> between catheter <NUM> and a processing device <NUM>. Communication interface <NUM> may include one or more optical fibers and connectors between processing device <NUM> and catheter <NUM>. In other examples, communication interface <NUM> may include an interface component that allows wireless communication, such as Bluetooth, WiFi, cellular, and the like, to communicate with the catheter <NUM> or other processing components in a catheter system.

In an aspect, sheath <NUM> and distal section <NUM> are disposable. As such, proximal section <NUM> may be reused by attaching a new sheath <NUM> and proximal section <NUM> each time a new procedure is to be performed. In another aspect, proximal section <NUM> is also disposable.

Proximal section <NUM> may house various electrical and optical components used in the operation of catheter <NUM>. A first optical source may be included within proximal section <NUM> to generate a source beam of radiation for optical evaluation. The first optical source may include one or more laser diodes or light emitting diodes (LEDs). The beam of radiation generated by the optical source may have a wavelength within the infrared range. In one example, the beam of radiation has a central wavelength of <NUM>. The optical source may be designed to output a beam of radiation at only a single wavelength, or it may be a swept source and be designed to output a range of different wavelengths. The generated beam of radiation may be guided towards distal section <NUM> via the optical transmission medium connected between proximal section <NUM> and distal section <NUM> within sheath <NUM>. Some examples of optical transmission media include single mode optical fibers and/or multimode optical fibers. In one aspect, the electrical transmission medium and the optical transmission medium are provided by the same hybrid medium allowing for both electrical and optical signal propagation.

In some aspects, proximal section <NUM> may include a second optical source, such as a laser energy source, to generate laser energy that is applied at distal section <NUM> for tissue ablation. In some aspects, the laser energy source may emit an ablation beam of laser energy at a wavelength of <NUM> or a wavelength of <NUM>. The laser energy from the source in the proximal section <NUM> may propagate down the catheter <NUM> via an optical transmission medium connected between proximal section <NUM> and distal section <NUM> within sheath <NUM>, and the laser energy may be output from the distal section <NUM> of catheter <NUM> to target tissue. For example, the laser energy from the source may produce an optical power of 5W to 12W that is applied to target tissue for <NUM>-<NUM> seconds to produce transmural lesions in heart tissue. In another example, the laser energy from the source may produce an optical power of 30W to 50W that is applied to target tissue for <NUM>-<NUM> seconds. In some aspects, processing device <NUM> may include one or more components, such as detectors, electronics, and/or other components of an optical circuit/system as described herein. In other aspects, these one or more components, such as detectors, electronics, and/or other components of an optical circuit/system may be included in the proximal section <NUM>.

In an aspect, proximal section <NUM> includes one or more components of an interferometer in order to perform low coherence interferometry (LCI) using the light generated from the second optical source. Due to the nature of interferometric data analysis, in an aspect, the optical transmission medium used for guiding the light to and from distal section <NUM> does not affect the state and degree of light polarization. In another aspect, the optical transmission medium affects the polarization in a constant and reversible way.

Proximal section <NUM> may include further interface elements with which a user of catheter <NUM> can control the operation of catheter <NUM>. For example, proximal section <NUM> may include a deflection control mechanism that controls a deflection angle of distal section <NUM>. The deflection control mechanism may require a mechanical movement of an element on proximal section <NUM>, or the deflection control mechanism may use electrical connections to control the movement of distal section <NUM>. Proximal section <NUM> may include various buttons or switches that allow a user to control when laser energy is applied at distal section <NUM>, or when the beams of radiation are transmitted from distal section <NUM>, allowing for the acquisition of optical data. In some aspects, proximal section <NUM> may include a deflection control mechanism for controlling one or more pull wires that are coupled to the distal section <NUM>. In some aspects, deflection control mechanism and the one or more pull wires allow for steering of the distal section of catheter <NUM> in order to maneuver within and target specific tissue regions for ablation.

Distal section <NUM> includes a plurality of optical view ports 112a-n. In some aspects, plurality of optical view ports 112a-n may be referred to herein as orifices or windows in the catheter tip. In an aspect, one or more of optical view ports 112a-n are machined into the outer body of distal section <NUM>. Optical view ports 112a-n may be distributed over the outside of distal section <NUM>, resulting in a plurality of distinct viewing directions. In some aspects, optical view ports 112a-n may transmit and collect light (e.g., optical signals) at various angles from the distal section <NUM>. Optical view ports 112a-n also allow for a plurality of directions (e.g., beam directions) in which laser energy may be directed for tissue ablation through one or more of the optical view ports. In an aspect, each of the plurality of viewing directions are substantially non-coplanar. Optical view ports 112a-n may also be designed with irrigation functionality to cool distal section <NUM> and surrounding tissue during ablation.

Catheter optical view ports 112a-n may be components of catheter <NUM>. Catheter optical view ports 112a-n may be used to monitor structural changes in tissue of patient <NUM>. Catheter optical view ports 112a-n may monitor structural changes in tissue of patient <NUM> through a source beam of radiation. The source beam of radiation may be from an optical source in catheter <NUM>, including one or more laser diodes or LEDs, or may be from an external signal generator, as further discussed below. The source beam may interact with a tissue of a patient. Optical transmission media may guide light reflected back from the patient's tissue, through catheter optical view ports 112a-n, towards processing device <NUM>.

<FIG> illustrate cross-section views of sheath <NUM>, according to aspects of the present disclosure. Sheath <NUM> may include all of the elements interconnecting proximal section <NUM> with distal section <NUM>. Sheath 106a illustrates an aspect that houses an irrigation channel <NUM>, deflection mechanism <NUM>, electrical connections <NUM>, and optical transmission medium <NUM>. <FIG> illustrates a protective cover <NUM> wrapped around both electrical connections <NUM> and optical transmission media <NUM>. Electrical connections <NUM> may be used to provide signals to optical modulating components located in distal section <NUM>. In other aspects, optical transmission media <NUM> and components may be located within a protective cover that is separate from the protective cover <NUM> in which the electrical connections <NUM> is housed. One or more optical transmission media <NUM> guide light generated from the optical source (exposure light) towards distal section <NUM>, while another subset of optical transmission media <NUM> guides light returning from distal section <NUM> (scattered or reflected light) back to proximal section <NUM>. In another example, the same one or more optical transmission media <NUM> guides light in both directions. In some aspects, the optical transmission medium <NUM> comprises one or more single mode optical fibers and/or multimode optical fibers.

Irrigation channel <NUM> may be a hollow tube used to guide cooling fluid towards distal section <NUM>. Irrigation channel <NUM> may include heating and/or cooling elements disposed along the channel to affect the temperature of the fluid. In another aspect, irrigation channel <NUM> may also be used as an avenue for drawing fluid surrounding distal section <NUM> back towards proximal section <NUM>.

Deflection mechanism <NUM> may include electrical or mechanical elements designed to provide a signal to distal section <NUM> in order to change a deflection angle of distal section <NUM>. The deflection system enables guidance of distal section <NUM> by actuating a mechanical control placed in proximal section <NUM>, according to an aspect. This system may be based on a series of aligned and uniformly spaced cutouts in sheath <NUM> aimed at providing unidirectional deflection of distal section <NUM>, in combination with a wire which connects the deflection mechanism control in proximal section <NUM> with the catheter tip at distal section <NUM>. In this way, a certain movement of the proximal section may be projected to the distal section. Other aspects involving the combination of several control wires attached to the catheter tip may enable the deflection of the catheter tip along different directions.

<FIG> illustrates a cross-section of sheath 106b. Sheath 106b depicts an aspect having most of the same elements as sheath 106a from <FIG>, except that there are no electrical connections <NUM>. Sheath 106b may be used in situations where modulation (e.g., multiplexing) of the generated beam of radiation is performed in proximal section <NUM>. In some aspects, sheath 106b may be implemented in a diagnostic catheter that is used for laser or cryogenic ablation.

Disclosed herein are aspects of an ablation catheter and console system that uses optical coherence tomography (OCT) and/or optical coherence reflectometry (OCR), refractometry, or other methods to perform tissue ablations, track scar formation in real-time, and monitor/verify lesion geometries and isolation by directly observing the scar pattern in tissue. To assess if a scar is formed, the methods, devices, and systems described herein acquire optically reflected/refracted light from the tissue, determine optical properties of the reflected light (e.g., by measuring intensity and polarization and computing phase retardation and/or birefringence of tissue based on the measurements), and monitor changes, as these optical properties change when tissue is scarred when compared to healthy tissue. By identifying the changes in optical properties of the tissue, lesion depths and denaturation times in tissue may be predicted for various ablation times, as described herein.

<FIG> illustrates an example diagram of a system <NUM> for performing ablation and lesion prediction, according to aspects of the present disclosure. The system <NUM> includes catheter <NUM>, console <NUM>, signal generator <NUM>, display <NUM>, and irrigation pump <NUM>. The catheter <NUM>, console <NUM>, signal generator <NUM>, display <NUM>, and irrigation pump <NUM> may be communicatively coupled together via wired and/or wireless connections. In some aspects, catheter <NUM> may include catheter <NUM> and its features as described with respect to <FIG>. In some aspects, a distal section of catheter <NUM> is positioned at a portion of tissue in patient <NUM>. It is understood that the aspects described herein may be used in vivo and/or in vitro.

In some aspects, catheter <NUM> may be positioned at a portion of tissue subject to ablation using energy generated by signal generator <NUM>. In some aspects, signal generator <NUM> may be an electronic device configured to generate radiofrequency (RF), cryogenic, or electroporation (e.g., pulsed electric field) signals for ablation. The signal generator <NUM> may be coupled to catheter <NUM> directly or via the console <NUM>, and may send energy to catheter <NUM> to ablate the portion of tissue at a selected tissue site. In some aspects, the portion of tissue may comprise myocardial tissue, cardiac muscle tissue, skeletal tissue, or the like. Energy may be applied to the portion of tissue through optical view ports in the distal section of catheter <NUM>. After applying the energy, structural changes in the tissue may be observed by acquiring optical signals via one or more optical view ports of catheter <NUM>.

Console <NUM> may comprise a computing device configured to acquire the optical signals from catheter <NUM> and analyze the optical signals to detect changes in optical properties of the tissue. In some aspects, console <NUM> may include hardware (e.g., circuits), firmware, software, or any combination thereof to perform analysis of the optical signals and generate models for predicting lesion depths and ablation times as described herein. In some aspects, console <NUM> may send light through an optical circuit within itself and the catheter <NUM> and into the tissue to monitor scar progression, contact between the tissue and catheter <NUM>, and other characteristics of the tissue. In some aspects, console <NUM> may be referred to herein as a control console, a processing device, and/or controller. Console <NUM> may be coupled to display <NUM>, which may present results from the optical signal analysis and lesion predictions and allow a user to select/view, modify, and/or control parameters related to operation of catheter <NUM>, console <NUM>, signal generator <NUM>, and/or irrigation pump <NUM>.

In some aspects, irrigation pump <NUM> may be coupled to catheter <NUM> via a tubing. In some aspects, irrigation pump <NUM> may allow for fluid to be pumped through the tubing and released at the tissue site through catheter <NUM> (e.g., through optical view ports or through separate irrigation slits at the distal section of catheter <NUM>). Fluid from the irrigation pump <NUM> may cool the distal section of catheter <NUM> and the surrounding tissue during ablation, and also flush away any debris during and/or after ablation.

In some aspects, catheter <NUM> may be coupled to console <NUM> via one or more optical connections <NUM> and one or more electrical connections <NUM>. Optical connections <NUM> may include single mode optical fibers and/or multimode optical fibers that allow acquisition and/or transmission of optical signals to and from catheter <NUM> and console <NUM> for further analysis. Electrical connections <NUM> may include wiring, pins, and/or components used for supplying power and energy from signal generator <NUM> to catheter <NUM> for ablation.

In some aspects, the optical and electrical connections <NUM>, <NUM> may be connected to console <NUM> via a communication interface <NUM>. Communication interface <NUM> may allow for transmission of various signals (e.g., optical and electrical signals) between catheter <NUM> and console <NUM>. In some aspects, the communication interface <NUM> may include a connector that facilitates proper alignment of optical fibers between the catheter <NUM> and console <NUM>. In some aspects, the connector design may include both electrical and optical extension lines.

<FIG> is a block diagram further illustrating elements of system <NUM> for improving the accuracy of an ablation model through synchronization, according to some aspects of the present disclosure. As discussed above, system <NUM> may include signal generator <NUM>, catheter <NUM>, and console <NUM>. Signal generator <NUM> outputs ablation energy signal <NUM>. Console <NUM> determines a time of ablation <NUM> and a denaturation result <NUM>, which are in turn used to determine estimated lesion depth <NUM>. Catheter <NUM>, which outputs optical measurement signals 410a-n received from its optical ports 112a-n to console <NUM>, may be used with patient <NUM>. Console <NUM> may include hardware, firmware, software, or any combination thereof to activate signal sources (e.g., signal generator <NUM>), acquire signals (e.g., ablation energy signal <NUM> or optical measurement signal 410a-n), assign time stamps to signals based on certain occurrences, perform analysis of signals in order to generate results (e.g., denaturation result <NUM>), and perform synchronization of signals in order to generate a result (e.g., estimated lesion depth <NUM>) from a synchronized model. For example, console <NUM> may include a clock useful for timestamping.

<FIG> is a timing diagram <NUM> including time stamps used for improving the accuracy of an ablation model through synchronization, according to some aspects of the present disclosure. Timing diagram <NUM> illustrates the timing of respective waveforms, where a waveform is shown with an amplitude of "<NUM>" when a signal is on or active, and the waveform is shown with an amplitude of "<NUM>" when a signal is off or inactive. Timing diagram <NUM> includes ablation energy signal <NUM>, optical measurement signal <NUM>-<NUM>, optical measurement signal <NUM>-<NUM>, and optical measurement signal <NUM>-<NUM>. Each optical measurement signal 410a-n corresponds to a signal received from one of the optical ports <NUM> at the distal end of catheter <NUM>, containing information regarding the tissue of patient <NUM> viewable by the respective optical port <NUM>. A person of skill in the art will recognize that more or fewer optical measurement signals <NUM> may be included in timing diagram <NUM> based on the number of optical ports 112a-n at the distal end of catheter <NUM>.

As illustrated in timing diagram <NUM>, console <NUM> may use its clock to assign a time stamp to ablation energy signal <NUM> when signal generator <NUM> is activated (<NUM>) (shown in the example of <FIG> as time = <NUM>). This time stamp may be considered an activation time stamp. Console <NUM> may also assign a time stamp to ablation energy signal <NUM> when signal generator <NUM> is deactivated (<NUM>) (shown in the example of <FIG> as time = <NUM>). This time stamp may be considered a deactivation time stamp. Console <NUM> may reactivate signal generator <NUM> and assign a time stamp to ablation energy signal <NUM> when signal generator <NUM> is reactivated (<NUM>) (shown in the example of <FIG> as time = <NUM>). This time stamp may be considered a subsequent activation time stamp. Console <NUM> may assign a time stamp to ablation energy signal <NUM> when signal generator <NUM> is deactivated (<NUM>) after reactivation. This time stamp may be considered a subsequent deactivation time stamp.

Console <NUM> may determine a time period between each activation time stamp and deactivation time stamp pairing. This time period may be considered a time of ablation because it reflects the time that signal generator <NUM> was activated in order to provide an energy for ablation of a tissue of patient <NUM>. Where there are multiple activations, any subsequent activation time period may be added to the time of ablation to determine a total time period. This total time period may be considered a total time of ablation because it reflects the total time that signal generator <NUM> was activated in order to provide an energy for ablation of a tissue of patient <NUM>.

Console <NUM> may acquire optical measurement signal <NUM>-<NUM> from a catheter optical port 112a. Catheter optical port 112a may have a unique viewing angle of the tissue of patient <NUM>. The unique viewing angle may view a first location of the tissue of patient <NUM>. Console <NUM> may acquire optical measurement signal <NUM>-<NUM> through catheter <NUM> and optical connection <NUM>. As illustrated in timing diagram <NUM>, console <NUM> may assign a time stamp to optical measurement signal <NUM>-<NUM> when optical measurement signal <NUM>-<NUM> is first acquired (<NUM>) from catheter optical port 112a. This time stamp may be considered an input time stamp. Console <NUM> may assign a time stamp to optical measurement signal <NUM>-<NUM> when optical measurement signal <NUM>-<NUM> is no longer being acquired (<NUM>) from catheter optical port 112a, such as when console <NUM> switches its inputs from catheter optical port 112a to a different catheter optical port, such as catheter optical port 112b. This time stamp may be considered a switching time stamp.

Once console <NUM> switches its input from catheter optical port 112a to catheter optical port 112b, console <NUM> may acquire optical measurement signal <NUM>-<NUM> from catheter optical port 112b. Optical measurement signal <NUM>-<NUM> may be considered a subsequent optical measurement signal 410a-n and catheter optical port 112b may be considered a different catheter optical port in optical ports 112a-n. In an aspect, after signal acquisition from catheter optical port 112a has completed, an optical switch at console <NUM> may close the connection with catheter optical port 112a and open a connection with catheter optical port 112b, so that optical measurement signal <NUM>-<NUM> from catheter optical port 112b may be acquired by console <NUM>. This switch may occur at a predetermined time period after data collection from catheter optical port 112a begins. According to some aspects, the predetermined time period may be selected based on the amount of time it takes to obtain sufficient data from which an optical property corresponding to optical port 112a's field of view may be determined. For example, the predetermined time period may be <NUM> milliseconds. In another example, the predetermined time period may be <NUM> millisecond. In yet another example, the predetermined time period may be another time period less than or more than <NUM> milliseconds.

Catheter optical port 112b may have a unique viewing angle of the tissue of patient <NUM>. The unique viewing angle may view a second location of the tissue of patient <NUM>. Console <NUM> may acquire optical measurement signal <NUM>-<NUM> through catheter <NUM> and optical connection <NUM>. As illustrated in timing diagram <NUM>, console <NUM> may assign a time stamp to optical measurement signal <NUM>-<NUM> when optical measurement signal <NUM>-<NUM> is first acquired (<NUM>) from catheter optical port 112b. This time stamp may be considered a subsequent input time stamp. Console <NUM> may assign a time stamp to optical measurement signal <NUM>-<NUM> when optical measurement signal <NUM>-<NUM> is no longer being acquired (<NUM>) from catheter optical port 112b, such as when console <NUM> switches its input from catheter optical port 112b to a different catheter optical port, such as catheter optical port 112c. This time stamp may be considered a subsequent switching time stamp.

Similar time-stamping actions may be taken on other signals received from catheter <NUM>, such as optical measurement signal <NUM>-<NUM>, optical measurement signal <NUM>-<NUM>, etc..

Console <NUM> may include an optical system to process optical measurement signals 410a-n, to calculate optical properties, to acquire denaturation result <NUM>, or to generate graphical representations (e.g., estimated lesion depth <NUM>). The optical system may utilize low-coherence interferometry (LCI), optical coherence tomography (OCT), optical coherence refractometry (OCR), or other optical modalities to perform imaging and to obtain optical measurement signal 410a-n. Optical measurement signal 410a-n may be an OCT signal, an OCR signal, or another signal that would be appreciated by a person of ordinary skill in the art.

Console <NUM> may include an optical system to process optical measurement signal <NUM>-<NUM> and/or optical measurement signal <NUM>-<NUM> in order to acquire denaturation result <NUM>. Console <NUM> may implement a process on optical measurement signal <NUM>-<NUM> and/or optical measurement signal <NUM>-<NUM> in order to acquire denaturation result <NUM>. Console <NUM> may implement a process on optical measurement signal <NUM>-<NUM> and/or optical measurement signal <NUM>-<NUM> in order to obtain an optical property of the tissue of patient <NUM> at the first location and/or the second location in order to obtain denaturation result <NUM>.

The process may be optimized in different software layers. The process may include optimization algorithms in order to optimize the quality of information. The optimization algorithms may rearrange data, remove glitches in data, conduct a Hilbert transform on data, remove phase noise from data, linearize phase of data, compensate for polarization mode of data, conduct a Fourier transform on data, or conduct other processing of data. Optical properties may include polarization and/or birefringence. Birefringence, or a loss of birefringence, may be correlated with necrosis and muscle fiber denaturation. Optical properties may include spectral information and/or other properties that would be appreciated by a person of ordinary skill in the art. Denaturation result <NUM> may represent a denaturation time.

Console <NUM> may synchronize time of ablation <NUM> and denaturation result <NUM> in order to generate a synchronized model. Console <NUM> may synchronize time of ablation <NUM> and denaturation result <NUM> using the activation time stamp, deactivation time stamp, input time stamp, or switching time stamp in order to generate a synchronized model. Console <NUM> may also synchronize time of ablation <NUM> and denaturation result <NUM> using the subsequent activation time stamp, subsequent deactivation time stamp, subsequent input time stamp, or subsequent switching time stamp from any or all of optical measurement signals 410a-n in order to generate a synchronized model. Console <NUM> may synchronize time of ablation <NUM> and denaturation result <NUM> by associating <NUM>'s and <NUM>'s, as illustrated by timing diagram <NUM>. The synchronized model may reflect an association between when energy is being applied to tissue of patient <NUM> and when structural changes are occurring in tissue of patient <NUM>.

As illustrated by <FIG>, console <NUM> may switch between various optical ports 112a-n to obtain respective optical measurement signals 410a-n while signal generator <NUM> is actively generating ablation optical signal <NUM>. The timestamps added by console <NUM> to each optical signal <NUM> and 410a-n allow denaturation results <NUM> to be repeatedly and consistently determined throughout ablation and mapped to the ablation optical signal <NUM>.

Console <NUM> may generate a graphical representation from the synchronized model. A graphical representation may illustrate or identify, for example, estimated lesion depth <NUM> at a particular area of tissue of patient <NUM> as determined using, for example, each measurement optical signal 410a-n from a respective optical port 112a-n. Estimated lesion depth <NUM> may be a function of time of ablation <NUM> over denaturation result <NUM>. Estimated lesion depth <NUM> may represent a height and a width of a lesion formed by the energy applied by signal generator <NUM> to a tissue of patient <NUM>. By providing synchronized observations from measurement optical signals 410a-n throughout ablation, a more accurate depiction of ablation results can be provided and displayed to a user.

The tissue of patient <NUM> may comprise myocardial tissue, cardiac muscle tissue, skeletal tissue, or the like. An example study was conducted in order to develop a lesion depth estimation algorithm using optical property measurements from ablated tissue. In the study, tissue samples were excised from swine hearts, and an end of the catheter was perpendicularly positioned at the endocardial surface of the tissue using a micropositioner. The tissue samples included right atrial free wall, superior vena cava, left atrial roof, mitral annulus, and left atrial appendage. In aspects, graphical representations may be other representations that would be appreciated by a person of ordinary skill in the art.

Returning to <FIG>, console <NUM> may interface display <NUM> through communications channel <NUM>. Communications channel <NUM> may be wired, wireless, or a combination thereof. Communications channel <NUM> may include optical connections or electrical connections. Optical connections may include single mode optical fibers or multimode optical fibers that allow acquisition or transmission of optical signals, and electrical connections may include wiring, pins, or components used for supplying power and energy. Communications channel <NUM> may include any combination of Local Area Networks, Wide Area Networks, the Internet, etc. Control logic or data may be transmitted to and from console <NUM> via communications channel <NUM>.

Console <NUM> may provide display information to display <NUM>. Display information may include ablation energy signal <NUM>, optical measurement signals 410a-n, optical properties, time of ablation <NUM>, denaturation result <NUM>, graphical representations (e.g., estimated lesion depth <NUM>), or other information. Display information may include contact information of catheter <NUM> (i.e., whether catheter <NUM> is sufficiently contacting the tissue) and/or other information useful for a user of display <NUM>. Display <NUM> may include a graphical user interface (GUI). The GUI may include a front view of a tip of catheter <NUM> showing different sections that correspond to catheter optical ports 112a-n. The GUI may show which catheter optical ports 112a-n are in contact with tissue of patient <NUM> and which beams from catheter optical ports 112a-n are in operation.

The GUI may include a plurality of tiles, each tile showing an optical readout for a respective catheter optical port 112a-n. The number of tiles displayed corresponds to the number of catheter optical ports 112a-n. Each tile may represent an image resulting from processing, by console <NUM>. Individual tiles may be switched on or off, and thus may appear or disappear, based on activity.

The GUI may also include one or more charts illustrating ablation energy data, birefringence data, phase data, and/or estimated lesion depth <NUM>. The GUI may include a panel or indicator showing the occurrence of stable contact between catheter <NUM> or catheter optical ports 112a-n and tissue of patient <NUM>, loss in birefringence, status of the ablation energy (e.g., activated or deactivated), and estimated lesion depth <NUM>. The GUI may include a button or a text box allowing user selection or customization of parameters selected for ablation or for operating catheter <NUM> during ablation.

Because the ablation energy signal <NUM> has been synchronized with optical data from optical measurement signals 410a-n, display <NUM> provides a viewer, such as a surgeon, with more accurate feedback regarding the results of ablation at a given time than was previously available.

<FIG> is a flowchart of a method <NUM> for improving the accuracy of an ablation model through synchronization, according to an aspect of the invention. Method <NUM> can be performed by processing logic that can comprise hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (e.g., instructions executing on a processing device), or a combination thereof. It is to be appreciated that not all steps may be needed to perform the disclosure provided herein. Further, some of the steps may be performed simultaneously, or in a different order than shown in <FIG>, as will be understood by a person of ordinary skill in the art.

Method <NUM> shall be described with reference to <FIG>. However, method <NUM> is not limited to those example aspects.

In <NUM>, an ablation energy source is activated. In an example, console <NUM> activates signal generator <NUM>. Console <NUM> may activate signal generator <NUM> in order to provide ablation energy to catheter <NUM> for ablation of a tissue of patient <NUM>. Signal generator <NUM> may be a device configured to generate energy, such as radiofrequency (RF), cryogenic, laser, electroporation (e.g., pulsed electric field), or another form of energy.

In <NUM>, a catheter energy signal is acquired from the ablation energy source. In an example, console <NUM> acquires ablation energy signal <NUM> from signal generator <NUM>. Console <NUM> may collect ablation energy signal <NUM> as it is provided to catheter <NUM> from signal generator <NUM>.

In <NUM>, an activation time stamp is assigned to the ablation energy signal when the ablation energy source is activated in <NUM>, and a deactivation time stamp is assigned to the catheter energy signal when the catheter energy source is deactivated. For example, console <NUM> assigns an activation time stamp to ablation energy signal <NUM> when signal generator <NUM> is activated by console <NUM> in <NUM>, and a deactivation time stamp to ablation energy signal <NUM> when signal generator <NUM> is deactivated by console <NUM>, as described above with respect to <FIG>.

In <NUM>, a time of ablation is determined based on a time period between the activation time stamp and the deactivation time stamp from <NUM>. In an example, console <NUM> determines time of ablation <NUM> based on a time period between the activation time stamp and the deactivation time stamp from <NUM>.

The time of ablation may reflect the time that signal generator <NUM> was activated in order to provide an energy for ablation of a tissue of patient <NUM>.

Console <NUM> may determine a subsequent time period between a subsequent activation time stamp and a subsequent deactivation time stamp. This subsequent time period may be added to the previous time period in order to determine a total time period. This total time period may be considered the time of ablation because it reflects the total time that signal generator <NUM> was activated in order to provide an energy for ablation of a tissue of patient <NUM>.

In <NUM>, an optical measurement signal is acquired from a catheter optical port. In an example, console <NUM> acquires optical measurement signals <NUM>-a-n from catheter optical port 112a.

Optical measurement signals 410a-n may include measurements from the light reflected from the tissue of patient <NUM> and guided back towards console <NUM> through transmission media in catheter <NUM>. Each of catheter optical ports 112a-n can be switched on or off using console <NUM> in order to acquire a respective optical measurement signal 410a-n at different times. A catheter optical port 112a-n may be considered "on" or "open" when an optical switch at console <NUM> allows a respective optical measurement signal 410a-n to be acquired. A catheter optical port 112a-n may be considered "off" or "closed" when an optical switch at console <NUM> does not allow respective optical measurement signal 410a-n to be acquired.

A given catheter optical port 112a may have a unique viewing angle of the tissue of patient <NUM>. The unique viewing angle may view a first location of the tissue of patient <NUM>. Console <NUM> may acquire optical measurement signal <NUM>-<NUM> from catheter optical port 112a through catheter <NUM> and optical connection <NUM>.

An existence of multiple distinct ports in catheter optical ports 112a-n may result in multiple distinct optical measurement signals 410a-n being acquired by console <NUM>. Console <NUM> may acquire subsequent optical measurement signals <NUM>, for example, optical measurement signal <NUM>-<NUM> from other catheter optical ports <NUM>. For example, console <NUM> may acquire optical measurement signal <NUM>-<NUM> from catheter optical port 112b at a predetermined time after acquiring optical measurement signal <NUM>-<NUM> from catheter optical port 112a. For example, the predetermined time may be <NUM> milliseconds. In another example, the predetermined time may be <NUM> millisecond. In yet another example, the predetermined time may be another time period less than <NUM> milliseconds. In order to acquire optical measurement signal <NUM>-<NUM> from catheter optical port 112b, console <NUM> may switch an input from catheter optical port 112a to catheter optical port 112b after the predetermined time has passed.

Catheter optical port 112b may have a unique viewing angle of the tissue of patient <NUM>. The unique viewing angle may view a second location of the tissue of patient <NUM>. Console <NUM> may acquire optical measurement signal <NUM>-<NUM> through catheter <NUM> and optical connection <NUM>.

In <NUM>, an input time stamp is assigned to the optical measurement signal when it is first acquired from the catheter optical port in <NUM> and a switching time stamp is assigned to the optical measurement signal when it is no longer being acquired from the catheter optical port. In an example, console <NUM> assigns an input time stamp to optical measurement signal <NUM>-<NUM> when optical measurement signal <NUM>-<NUM> is first acquired from catheter optical port 112a in <NUM>, and a switching time stamp to optical measurement signal <NUM>-<NUM> when optical measurement signal <NUM>-<NUM> is no longer being acquired from catheter optical port 112a, as illustrated in timing diagram <NUM>.

In <NUM>, the optical measurement signal from <NUM> is processed in order to acquire a denaturation result. In an example, console <NUM> processes optical measurement signals 410a-n from <NUM> in order to acquire denaturation result <NUM>.

In <NUM>, the time of ablation from <NUM> and the denaturation result from <NUM> are synchronized using the activation time stamp and deactivation time stamp from <NUM> and the input time stamp and switching time stamp from <NUM>, in order to generate a synchronized model. In an example, console <NUM> synchronizes time of ablation <NUM> from <NUM>, and denaturation result <NUM> from <NUM> using the activation time stamp and deactivation time stamp from <NUM> and the input time stamp and switching time stamp from <NUM>, in order to generate a synchronized model.

Console <NUM> may also synchronize time of ablation <NUM> and denaturation result <NUM> using the subsequent activation time stamp, subsequent deactivation time stamp, subsequent input time stamp, or subsequent switching time stamp in order to generate a synchronized model. Console <NUM> may synchronize time of ablation <NUM> and denaturation result <NUM> by associating activation and deactivation timestamps (e.g., changes between <NUM>'s and <NUM>'s, as illustrated by timing diagram <NUM>). The synchronized model may reflect an association between times when energy is being applied to tissue of patient <NUM> and when structural changes are occurring in tissue of patient <NUM>.

In <NUM>, an estimated lesion depth is generated from the synchronized model in <NUM>. In an example, console <NUM> generates estimated lesion depth <NUM> from the synchronized model from <NUM>.

Estimated lesion depth <NUM> may be a function of time of ablation <NUM> over denaturation result <NUM>. Estimated lesion depth <NUM> may represent a height and a width of a lesion formed by the energy applied by signal generator <NUM> to a tissue of patient <NUM>.

Console <NUM> may provide estimated lesion depth <NUM> and/or a graphical representation thereof to display <NUM>. Display <NUM> may display estimated lesion depth <NUM> and/or a graphical representation thereof. Display <NUM> may include a graphical user interface (GUI).

Various aspects can be implemented, for example, using one or more computer systems, such as computer system <NUM> shown in <FIG>. Computer system <NUM> can be used, for example, to implement method <NUM> of <FIG>, console <NUM> of <FIG>, and the like. For example, computer system <NUM> can assign time stamps to various signals in order to generate a synchronized model. Computer system <NUM> can also generate an estimated lesion depth from the synchronized model, according to some aspects. Computer system <NUM> can be any computer capable of performing the functions described herein.

One or more processors <NUM> may each be a graphics processing unit (GPU). In an aspect, a GPU is a processor that is a specialized electronic circuit designed to process mathematically intensive applications. The GPU may have a parallel structure that is efficient for parallel processing of large blocks of data, such as mathematically intensive data common to computer graphics applications, images, videos, etc..

Computer system <NUM> also includes a main or primary memory <NUM>, such as random access memory (RAM). Main memory <NUM> may include one or more levels of cache. Main memory <NUM> has stored therein control logic (i.e., computer software) and/or data.

According to an exemplary aspect, secondary memory <NUM> may include other means, instrumentalities or other approaches for allowing computer programs and/or other instructions and/or data to be accessed by computer system <NUM>. Such means, instrumentalities or other approaches may include, for example, a removable storage unit <NUM> and an interface <NUM>. Examples of the removable storage unit <NUM> and the interface <NUM> may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and/or any other removable storage unit and associated interface.

In an aspect, a tangible, non-transitory apparatus or article of manufacture comprising a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon is also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system <NUM>, main memory <NUM>, secondary memory <NUM>, and removable storage units <NUM> and <NUM>, as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system <NUM>), causes such data processing devices to operate as described herein.

Based on the teachings contained in this disclosure, it will be apparent to persons skilled in the relevant art(s) how to make and use aspects of this disclosure using data processing devices, computer systems and/or computer architectures other than that shown in <FIG>. In particular, aspects can operate with software, hardware, and/or operating system implementations other than those described herein.

It is to be appreciated that the Detailed Description section, and not any other section, is intended to be used to interpret the claims. Other sections can set forth one or more but not all exemplary aspects as contemplated by the inventor(s), and thus, are not intended to limit this disclosure or the appended claims in any way.

While this disclosure describes exemplary aspects for exemplary fields and applications, it should be understood that the disclosure is not limited thereto. Other aspects and modifications thereto are possible. For example, and without limiting the generality of this paragraph, aspects are not limited to the software, hardware, firmware, and/or entities illustrated in the figures and/or described herein. Further, aspects (whether or not explicitly described herein) have significant utility to fields and applications beyond the examples described herein.

Aspects have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. Also, alternative aspects can perform functional blocks, steps, operations, methods, etc. using orderings different than those described herein.

References herein to "one aspect," "an aspect," "an example aspect," or similar phrases, indicate that the aspect described can include a particular feature, structure, or characteristic, but every aspect can not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same aspect. Further, when a particular feature, structure, or characteristic is described in connection with an aspect, it would be within the knowledge of persons skilled in the relevant art(s) to incorporate such feature, structure, or characteristic into other aspects whether or not explicitly mentioned or described herein. Additionally, some aspects can be described using the expression "coupled" and "connected" along with their derivatives. For example, some aspects can be described using the terms "connected" and/or "coupled" to indicate that two or more elements are in direct physical or electrical contact with each other.

Claim 1:
A system (<NUM>) for improving the accuracy of an ablation model through synchronization, comprising:
a catheter energy source (<NUM>);
a catheter (<NUM>) coupled to the catheter energy source (<NUM>), comprising a catheter optical port (112a-n); and
a computing device (<NUM>, <NUM>) coupled to the catheter energy source (<NUM>) and the catheter (<NUM>), the computing device (<NUM>, <NUM>) comprising:
a processor (<NUM>); and
a memory (<NUM>), wherein the memory (<NUM>) contains instructions stored thereon that when executed by the processor (<NUM>) cause the computing device (<NUM>, <NUM>) to:
activate the catheter energy source (<NUM>);
acquire a catheter energy signal (<NUM>) from the catheter energy source (<NUM>);
assign an activation time stamp to the catheter energy signal (<NUM>) when the catheter energy source (<NUM>) is activated and a deactivation time stamp to the catheter energy signal (<NUM>) when the catheter energy source (<NUM>) is deactivated;
determine a time of ablation (<NUM>) based on a time period between the activation time stamp and the deactivation time stamp;
acquire an optical measurement signal (410a-n) from the catheter optical port (112an);
assign an input time stamp to the optical measurement signal (410a-n) when the optical measurement signal (410a-n) is first acquired from the catheter optical port (112a-n) and a switching time stamp to the optical measurement signal (410a-n) when the optical measurement signal (410a-n) is no longer being acquired from the catheter optical port (112an);
process the optical measurement signal (410a-n) in order to acquire a denaturation result (<NUM>);
synchronize the time of ablation (<NUM>) and the denaturation result (<NUM>) using the activation time stamp, deactivation time stamp, input time stamp, and switching time stamp in order to generate a synchronized model; and
generate an estimated lesion depth (<NUM>) from the synchronized model.