Navigation system for cardiac therapies using gating

Abstract

An image guided navigation system for navigating a region of a patient which is gated using ECG signals to confirm diastole. The navigation system includes an imaging device, a tracking device, a controller, and a display. The imaging device generates images of the region of a patient. The tracking device tracks the location of the instrument in a region of the patient. The controller superimposes an icon representative of the instrument onto the images generated from the imaging device based upon the location of the instrument. The display displays the image with the superimposed instrument. The images and a registration process may be synchronized to a physiological event.

1 . An image guided navigation system for guiding an instrument through a region of a patient, said image guided navigation system comprising:
 an anatomical gating device operable to sense a first physiological event and a second physiological event, the first physiological event being different from the second physiological event;   an imaging device operable to capture image data of the region of the patient in response to the second physiological event by comparing one characteristic of the first physiological event with respect a first threshold and when a second characteristic of said second physiological event to a second threshold;   a tracking device operable to track the position of the instrument in the region of the patient;   a controller in communication with said anatomical gating device, said imaging device and said tracking device and operable to register said image data with the region of the patient in response to the first and second physiological events, said controller further operable to superimpose an icon representing the instrument onto the image data of the region of the patient based upon the position tracked by said tracking device; and   a display operable to display the image data of the region of the patient with the superimposed icon of the instrument.   
   
   
       2 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 1 , wherein the first physiological event is the generation of an R-wave during a cardiac cycle and the second physiological event is diastole during a cardiac cycle. 
   
   
       3 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 2 , the anatomical gating device generates a diastolic detection window for confirming whether the patient is in diastole before capturing image data. 
   
   
       4 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 3 , wherein the anatomical gating device is operable to confirm diastole during the diastolic detection window by comparing at least one characteristic of the ECG signal to one previously stored characteristic being selected from the group consisting of the presence of an R-wave, slew and DC offset. 
   
   
       5 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 3 , wherein the diastolic detection window extends from about 62% to about 80% of the duration of the R-R interval following the detection of an R-wave. 
   
   
       6 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 3 , wherein the diastolic detection window is centered at about 70% of the duration of the R-R interval following the detection of an R-wave during normal sinus rhythms. 
   
   
       7 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 3 , wherein the diastolic detection window is centered at about 45% of the duration of the R-R interval following R-wave detection during arrhythmias. 
   
   
       8 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 1 , wherein the first physiological event is associated with the presence of an R-wave of an ECG signal, the anatomical gating device operable to determine the presence of an R-wave by comparing at least one characteristic of the ECG signal to at least one corresponding threshold, the at least one characteristic selected from the group consisting of slew, turning point and amplitude. 
   
   
       9 . The image guided navigation system for guiding an instrument through a region of a patient as set forth in  claim 1 , wherein the anatomical gating device is operable to detect the onset of systole by calculating slew, amplitude and turning point of an ECG signal to determine the presence of an R-wave in the ECG signal, and generate a diastolic detection window in response to the variability of the interval between adjacent R-waves in the ECG signal. 
   
   
       10 . The image guided navigation system as defined in  claim 1  wherein said imaging device is selected from a group of 2D, 3D or 4D imaging devices comprising a C-arm fluoroscopic imager, a magnetic resonance imager (MRI), a computed tomography (CT) imager, a positron emission tomography (PET) imager, an isocentric fluoroscopy imager, a bi-plane fluoroscopy imager, an ultrasound imager, a multi-slice computed tomography (MSCT) imager, positron emission tomography-computed tomography (PET/CT), high definition computed tomography (HDCT), dual source computed tomography, a high-frequency ultrasound (HIFU) imager, an optical coherence tomography (OCT) imager, an intra-vascular ultrasound imager (IVUS), an ultrasound imager, an intra-operative CT imager, an intra-operative MRI imager, a single photon emission computer tomography (SPECT) imager, and a combination thereof. 
   
   
       11 . The image guided navigation system as defined in  claim 1 , wherein said instrument is operable to deliver a therapy to the patient, the therapy is selected from a group comprising lead placement, drug delivery, gene delivery, cell delivery, ablation, mitral valve repair, aortic valve repair, leadless pacemaker placement, leadless pressure sensor placement, and a combination thereof. 
   
   
       12 . The image guided navigation system as defined in  claim 1 , wherein said instrument is selected from a group comprising a catheter, a guide wire, a stylet, an insert, a needle and a combination thereof. 
   
   
       13 . Method for image guiding an instrument in a region of a patient, the method comprising:
 identifying a first physiological event;   comparing at least one characteristic of the first physiological event to a first predetermined threshold;   identifying a second physiological event different from the first physiological event;   comparing at least one characteristic of the second physiological event to a second predetermined threshold;   capturing image data during the second physiological event when the at least one characteristic of the first physiological event exceeds the first threshold and when the at least one characteristic of the second physiological event exceeds the second threshold;   registering the captured image data to the patient during the second physiological event; and   displaying the location of the instrument on the image data of the region of the patient by superimposing an icon of the instrument on the image data.   
   
   
       14 . The method for guiding an instrument to a region of a patient as set forth in  claim 13 , wherein the identification of a first physiological event is the identification of an R-wave during a cardiac cycle. 
   
   
       15 . The method for guiding an instrument to a region of a patient as set forth in  claim 14 , wherein identifying a second physiological event is the identification of diastole during a cardiac cycle. 
   
   
       16 . The method for guiding an instrument to a region of a patient as set forth in  claim 15 , wherein the identification of an R-wave during a cardiac cycle includes comparing at least one characteristic of an ECG signal to a corresponding threshold, the at least one characteristic selected from the group consisting of slew, turning point and amplitude. 
   
   
       17 . The method for guiding an instrument to a region of a patient as set forth in  claim 15 , wherein the identification of diastole during the cardiac cycle includes comparing at least one characteristic of an ECG signal to a previously stored characteristic selected from the group consisting of the presence of an R-wave, slew and DC offset. 
   
   
       18 . A method for image guiding an instrument in a region of a patient, said method comprising:
 generating a gating signal from an anatomical gating device, the gating signal responsive to the presence of arrhythmias and ectopic beats;   capturing image data during diastole in response to the gating signal generated by the anatomical gating device;   registering the captured image data to the patient; and   displaying the location of the instrument on the image data of the region of the patient by superimaging an icon of the instrument on the image data.   
   
   
       19 . The method for image guiding an instrument in a region of a patient as set forth in  claim 18 , further comprising detecting at the onset of systole by calculating slew, amplitude and turning point of an ECG signal to determine the presence of an R-wave in the ECG signal, and generating a diastolic detection window in response to the variability of the interval between adjacent R-waves in the ECG signal. 
   
   
       20 . The method for image guiding an instrument in a region of a patient as set forth in  claim 19 , wherein generating a diastolic detection window includes comparing the turning point of the ECG signal to a predetermined threshold. 
   
   
       21 . The method for image guiding an instrument in a region of a patient as set forth in  claim 19 , wherein generating a diastolic detection window includes comparing the amplitude of the ECG signal to a predetermined threshold. 
   
   
       22 . The method for image guiding an instrument in a region of a patient as set forth in  claim 20 , wherein the diastolic detection window is centered at about 45% to about 70% of the duration of the R-R interval following the onset of an R-wave. 
   
   
       23 . The method for image guiding an instrument in a region of a patient as set forth in  claim 20 , wherein the width of the diastolic detection window is about 75 milliseconds. 
   
   
       24 . The method for image guiding an instrument in a region of a patient as set forth in  claim 18 , wherein generating a gating signal from the anatomical gating device includes determining whether the onset of an R-wave has occurred. 
   
   
       25 . The method for image guiding an instrument in a region of a patient as set forth in  claim 24 , wherein displaying the location of the instrument on the image data includes displaying a previously acquired image of the instrument when the onset of an R-wave has occurred.