Abstract: In some implementations, a method of ablating body tissue includes (a) locating an inflatable balloon portion of a cryotherapy balloon catheter at a treatment site internal to a patient's body, and inflating the inflatable balloon portion; (b) employing electrodes that are disposed on an expandable surface of the inflatable balloon portion to electrically characterize body tissue at the treatment site; (c) ablating the body tissue by supplying a cryotherapy agent to the inflatable balloon portion to cool the body tissue to a therapeutic temperature; (d) employing the electrodes to determine whether the ablating caused desired electrical changes in the body tissue; and (e) repeating (c) and (d) when it is determined that the ablating did not cause the desired electrical changes.

Abstract: Systems and methods to monitor cardiac mechanical vibrations using information indicative of lead motion are described. In an example, a system including an implantable medical device can include an excitation circuit configured to provide a non-tissue stimulating, non-therapeutic electrical excitation signal to a portion of an implantable lead. A receiver circuit can be configured to obtain information indicative of a mechanical vibration of the implantable lead due at least in part to one or more of an impact of at least a portion of the heart to the implantable lead, or friction contact between the implantable lead and cardiac tissue. The system can include a processor circuit configured to determine one or more of a lead mechanical status, or information indicative of valvular activity using the information indicative of the mechanical vibration of the implantable lead.

Abstract: An ambulatory medical device can include an excitation circuit configured to be electrically coupled to an implantable lead, the excitation circuit configured to provide a non-tissue-stimulating first signal to the implantable lead when the implantable lead is located at or near a tissue site. In an example, the system can include a detection circuit configured to be electrically coupled to the implantable lead and configured to receive a second signal, in response to the first signal, from the implantable lead, the second signal is determined at least in part by a motion of the implantable lead.

Abstract: Systems and methods for rhythm discrimination using the motion of an implantable lead are described. In an example, an implantable medical device can include a receiver circuit configured to be electrically coupled to an implantable lead and be configured to obtain information indicative of a movement of the implantable lead due at least in part to a motion of a heart. The device can include an arrhythmia detection circuit configured to determine an arrhythmia status using the information indicative of the movement of the implantable lead and an arrhythmia classification circuit configured to determine one or more of a location or a type of an arrhythmia, using the information indicative of the movement of the implantable lead, when the arrhythmia status indicates that an arrhythmia is occurring or has occurred.

Abstract: Systems and methods for cardiac contraction detection using information indicative of lead motion are described. In an example, an implantable medical device can include a receiver circuit configured to be electrically coupled to conductor comprising a portion of an implantable lead and be configured to obtain information indicative of a movement of the implantable lead due at least in part to a motion of a heart. The device can include a processor circuit configured to determine whether a cardiac mechanical contraction occurred during a specified interval included in the obtained information indicative of the movement of the implantable lead. The processor circuit can be configured to determine information about the cardiac mechanical contraction using the obtained information indicative of the movement of the implantable lead.

Abstract: Systems and methods to monitor cardiac function using information indicative of lead motion are described. In an example, a system including an implantable medical device can include a receiver circuit configured to be electrically coupled to conductor comprising a portion of an implantable lead and be configured to obtain information indicative of a movement of the implantable lead due at least in part to a motion of a heart. The system can include a sensing circuit configured to obtain information indicative of cardiac electrical activity. The system can include a processor circuit configured to construct a template representative of a contraction of the heart, where the template can be constructed using the information indicative of the movement of the implantable lead due at least in part to the motion of the heart during the contraction, and using the information indicative of the cardiac electrical activity sensed during the contraction.

Abstract: Devices, systems, and methods provide for renal sympathetic nerve activity modification and termination. Apparatuses are configured for intravascular delivery of a denervation therapy to a renal artery of a patient, and preferably create a lesion or lesions that define a pattern that completes at least one revolution of the renal artery. Various denervation therapy elements may be employed, including a cryotherapy arrangement, a drug eluting arrangement, an RF ablation arrangement, an ultrasonic ablation catheter, a laser ablation catheter, a microwave ablation catheter, or a combination of these therapy elements.

Abstract: Acoustic energy is delivered to innervated vascular that contributes to renal sympathetic nerve activity, such as innervated tissue of the renal artery and abdominal aorta. Focused acoustic energy is delivered via an intravascular device of sufficient power to ablate innervated renal or aortal tissue. Focused acoustic energy may be delivered via an intravascular or extracorporeal device to image and locate target innervated renal or aortal tissue. Intravascular, extravascular, or transvascular focused ultrasound devices provide for high precision denervation of innervated vascular to terminate renal sympathetic nerve activity.

Abstract: Apparatuses and methods facilitate delivery of optical or photoacoustic energy to innervated vascular that contributes to renal sympathetic nerve activity. The optical energy delivered may be of sufficient power to scan or image innervated renal or aortal tissue. The optical energy delivered may be of sufficient power to ablate innervated renal or aortal tissue, such as by thermal laser ablation or photoacoustic laser ablation. A catheter for intravascular or extravascular deployment supports an optical fiber arrangement comprising a coupling for receiving light from a laser light source. An optics arrangement is supported by the catheter and coupled to the optical fiber arrangement. The optics arrangement includes one or more optical elements arranged to receive the laser light and direct optical energy to target innervated tissue or a water source from which a cavitation bubble may be created and launched for acoustically shocking the target innervated tissue.

Abstract: A cryotherapy system includes a cryotherapy catheter having an inflatable balloon portion and a pressure regulator. The inflatable balloon portion includes an outer balloon and an inner balloon within the outer balloon. The inner balloon is configured to receive during a cryotherapy procedure a cryogenic agent for extracting heat from body tissue at a desired location. The inflatable balloon portion is at a distal end of the cryotherapy catheter. The pressure regulator is adapted to maintain a positive pressure between the inner balloon and the outer balloon during a cryotherapy procedure.

Abstract: Methods and apparatus associated with irrigated tissue ablation procedures.

Abstract: Methods and apparatus in accordance with at least some of the present disclosure employ a measured heat transfer property to evaluate electrode/tissue contact. Methods and apparatus in accordance with at least some of the present disclosure employ the relationship between impedance measurements and sub-surface temperature to control power.

Abstract: A medical device system includes an elongated body with a distal end that is configured and arranged for insertion into a patient. A housing is disposed in the distal end of the body. A rotatable magnet is disposed in the housing. At least one magnetic field winding is configured and arranged to generate a magnetic field at the location of the magnet. The magnetic field causes rotation of the magnet at a target frequency. An array of magnetic field sensors is disposed external to the patient. The magnetic field sensors are configured and arranged to sense the location and orientation of the magnet in relation to the array of magnetic field sensors.

Abstract: An embodiment of a system for ablating tissue comprises an electrode configured for use to deliver RF power to ablate the tissue, and a heat flow sensor configured to provide a measurement of heat flow from the electrode to blood or irrigation fluid. According to some embodiments, the system further comprises an RF source configured to generate RF power connected to the electrode (PE) to ablate tissue, and a controller configured to control a level of RF power and a duration for an ablation procedure. The controller is programmed to implement a process to estimate RF power dissipated in tissue (PT), including calculating power loss due to convective heat flow (PCONV) from the tissue through the electrode to the blood or the irrigation fluid to cool the electrode, and calculating the RF power dissipated in tissue (PT) by subtracting PCONV from PE.

Abstract: Devices, systems, and methods for monitoring and analyzing physiologic parameters within the body using an intrabody ultrasound signal are disclosed. An illustrative method includes receiving an ultrasound signal transmitted from a remote device containing encoded sensor data, converting the ultrasound signal into an electrical signal, decoding the sensor data from the electrical signal and generating a first physiological waveform, generating a second physiological waveform by analyzing fluctuations of the electrical signal caused by physiologic modulation of the ultrasound signal during propagation through the body, and analyzing one or more characteristics of the first and second waveforms to determine one or more physiologic parameters within the body.

Abstract: In some implementations, a cryotherapy delivery system includes a cryotherapy catheter having a distal treatment component that delivers, during a cryotherapy procedure, cryotherapy to a treatment site inside a patient's body; a controller that controls the delivery of the cryotherapy during the cryotherapy procedure; and a sensor that measures values of a respiration parameter of the patient during the cryotherapy procedure, and provides measured values to the controller. The controller can determine, prior to delivery of cryotherapy, a baseline value for the respiration parameter; detect, during delivery of the cryotherapy, a change in the respiration parameter relative to the baseline value; and suspend delivery of the cryotherapy when the change exceeds a threshold.

Abstract: A cryotherapy catheter can include an elongate member and an inflatable balloon portion at a distal end of the elongate member. The inflatable balloon portion can have an external surface and an interior chamber, and the external surface can include a cooling region and a thermally insulated region. The interior chamber can be configured to receive during a cryotherapy procedure a cryogenic agent for extracting heat from body tissue that is in contact with the cooling region. A thermal profiling component can be disposed in the interior chamber and configured to thermally insulate the thermally insulated region from the cryogenic agent to minimize heat extraction by the cryogenic agent from body tissue that is in contact with the thermally insulated region.

Abstract: A method, system, and device for detecting whether an expandable member completely occludes an anatomic passageway allows a user, such as a physician, clinician, or surgeon, to perform a medical procedure more efficiently and increases the procedure's chances of success. An incomplete occlusion can be immediately detected by monitoring the pressure difference across the expandable member. Through this method, a user can quickly diagnose the problem and reposition the expandable member in the anatomic passageway. In particular, in a cryoablation procedure, devices incorporating this method can help ensure a uniform and complete lesion in the pulmonary vein to electrically isolate the pulmonary vein from the atrium, thus preventing atrial fibrillation.

Abstract: In some implementations, a method of ablating body tissue includes (a) locating an inflatable balloon portion of a cryotherapy balloon catheter at a treatment site internal to a patient's body, and inflating the inflatable balloon portion; (b) employing electrodes that are disposed on an expandable surface of the inflatable balloon portion to electrically characterize body tissue at the treatment site; (c) ablating the body tissue by supplying a cryotherapy agent to the inflatable balloon portion to cool the body tissue to a therapeutic temperature; (d) employing the electrodes to determine whether the ablating caused desired electrical changes in the body tissue; and (e) repeating (c) and (d) when it is determined that the ablating did not cause the desired electrical changes.

Abstract: A system for controllably delivering ablation energy to tissue includes an ablation device operable to supply ablation energy to body tissue causing bubbles to form in the tissue, an ultrasound transducer configured to detect energy spontaneously emitted by collapsing or shrinking bubbles that are resonating in the tissue, and a control element operably coupled to the ablation device and the ultrasound transducer element, the control element being configured to adjust the ablation energy supplied to the tissue in response to the energy detected by the ultrasound transducer to prevent tissue popping caused by bubble expansion.