Systems and methods for gating an imaging device

Abstract

A method and system for automatically gating an imaging device is disclosed. Physiological process information of a patient may be derived from a plethysmographic signal, for example, by analyzing the plethysmographic signal transformed by a continuous wavelet transform. Other techniques for deriving physiological process information of a patient include, for example, analyzing a scalogram derived from the continuous wavelet transform. The physiological process information may be used to automatically gate imaging data acquired from an imaging device in order to synchronize the imaging data with the physiological process information.

What is claimed is: 
     
         1 . A method of obtaining imaging data from a patient, the method comprising:
 receiving from a sensor a plethysmographic signal;   determining, using a processor, respiration information based on the plethysmographic signal; and   gating an imaging device based on the respiration information.   
     
     
         2 . The method of  claim 1 , wherein the imaging device comprises one of a computed tomography device, a positron emission tomography device, and a magnetic resonance imaging device. 
     
     
         3 . The method of  claim 1 , wherein the respiration information comprises respiration rate. 
     
     
         4 . The method of  claim 1 , wherein the respiration information comprises phase information of the patient's respiratory cycle. 
     
     
         5 . The method of  claim 4 , wherein the imaging device is gated in phase with the patient's respiratory cycle. 
     
     
         6 . The method of  claim 4 , wherein the imaging device is gated to obtain images of the patient at the beginning of inspiration or expiration. 
     
     
         7 . The method of  claim 1 , wherein the respiration information comprises identification of atypical breaths. 
     
     
         8 . The method of  claim 1 , further comprising determining, using the processor, cardiac information based on the plethysmographic signal, wherein gating the imaging device comprises gating the imaging device based on the respiration information and the cardiac information. 
     
     
         9 . The method of  claim 1 , further comprising identifying at least one period of voluntary or involuntary patient movement, wherein gating the imaging device comprises gating the imaging device based on the respiration information and the at least one period. 
     
     
         10 . The method of  claim 1 , further comprising performing a continuous wavelet transform based on the plethysmographic signal to generate a transformed signal, wherein the respiration information is determined based on the transformed signal. 
     
     
         11 . A system for Obtaining imaging data from a patient, the system comprising:
 an imaging device configured to generate an imaging signal; and   a processor coupled to the imaging device, wherein the processor is configured to:   receive a plethysmographic signal;   determine respiration information based on the plethysmographic signal; and   gate the imaging device based on the respiration information.   
     
     
         12 . The system of  claim 11 , wherein the imaging device comprises one of a computed tomography device, a positron emission tomography device, and a magnetic resonance imaging device. 
     
     
         13 . The system of  claim 11 , wherein the respiration information comprises respiration rate. 
     
     
         14 . The system of  claim 11 , wherein the respiration information comprises phase information of the patient's respiratory cycle. 
     
     
         15 . The system of  claim 14 , wherein the processor is configured to gate the imaging device in phase with the patient's respiratory cycle. 
     
     
         16 . The system of  claim 14 , wherein the processor is configured to gate the imaging device at the beginning of inspiration or expiration. 
     
     
         17 . The system of  claim 11 , wherein the respiration information comprises identification of atypical breaths. 
     
     
         18 . The system of  claim 11 , wherein the processor is further configured to determine cardiac information based on the plethysmographic signal and wherein the processor is configured to gate the imaging device based on the respiration information and the cardiac information. 
     
     
         19 . The system of  claim 11 , wherein the processor is configured to identify at least one period of voluntary or involuntary patient movement and wherein the processor is configured to gate the imaging device based on the respiration information and the at least one period. 
     
     
         20 . The system of  claim 11 , wherein the processor is configured to perform a continuous wavelet transform based on the plethysmographic signal to generate a transformed signal and wherein the processor is configured to determine the respiration information based on the transformed signal.