Multi-variable feedback control of stimulation for inspiratory facilitation

Abstract

An exemplary method includes delivering stimulation according to one or more stimulation parameters to cause contraction of the diaphragm, monitoring chest activity related to respiration and, in response to the monitoring, adjusting one or more of the one or more stimulation parameters during contraction of the diaphragm and continuing the delivering. Various other exemplary methods, devices, systems, etc., are also disclosed.

1 . A method comprising: 
 delivering stimulation according to one or more stimulation parameters to cause contraction of the diaphragm;    monitoring chest activity related to respiration; and    in response to the monitoring, adjusting one or more of the one or more stimulation parameters during contraction of the diaphragm and continuing the delivering.    
   
   
       2 . The method of  claim 1 , wherein the delivering delivers stimulation to a phrenic nerve.  
   
   
       3 . The method of  claim 1 , wherein the one or more stimulation parameters include pulse width.  
   
   
       4 . The method of  claim 1 , wherein the one or more stimulation parameters include frequency.  
   
   
       5 . The method of  claim 1 , wherein the one or more stimulation parameters include voltage.  
   
   
       6 . The method of  claim 1 , wherein the adjusting includes adjusting a frequency parameter.  
   
   
       7 . The method of  claim 1 , wherein the monitoring includes impedance monitoring.  
   
   
       8 . A method comprising: 
 providing an intrinsic inspiratory target;    sensing information related to inspiration;    determining an error using the intrinsic inspiratory target and the information; and    adjusting one or more stimulation parameters based at least in part on the error.    
   
   
       9 . The method of  claim 8 , wherein the providing includes providing an intrinsic inspiratory target related to an activity state.  
   
   
       10 . The method of  claim 9 , wherein the activity state includes an activity state selected from the group consisting of sleep and awake states.  
   
   
       11 . The method of  claim 8 , wherein the sensing includes sensing impedance.  
   
   
       12 . The method of  claim 8 , wherein the intrinsic inspiratory target includes information on lung volume with respect to time.  
   
   
       13 . The method of  claim 8 , wherein the intrinsic inspiratory target includes information on inspiratory flow with respect to time.  
   
   
       14 . The method of  claim 8 , wherein the adjusting includes proportional control.  
   
   
       15 . The method of  claim 8 , wherein the adjusting includes a control algorithm selected from the group consisting of proportional, integral and derivative control algorithms.  
   
   
       16 . A method comprising: 
 controlling inspiration for a set number of inspirations using a closed-loop controller that relies on one or more adjustable stimulation parameters;    recording values for the one or more adjustable parameters;    determining an average value for each of the one or more adjustable parameters; and    controlling inspiration based at least in part on the average value for each of the one or more adjustable parameters.    
   
   
       17 . The method of  claim 16 , wherein the controlling based at least in part on the average value for the one or more adjustable parameters uses open-loop control.  
   
   
       18 . A method comprising applying stimulation to a phrenic nerve wherein the stimulation includes a waveform having a plurality of frequency components and wherein each of the frequency components has a frequency greater than approximately 1 Hz.  
   
   
       19 . The method of  claim 18 , wherein each of the frequency components has a frequency less than approximately 50 Hz.  
   
   
       20 . A method comprising: 
 stimulating a phrenic nerve using a waveform having one or more frequency components;    sensing information related to inspiration; and    based at least in part on the information, adjusting one or more of the frequency components to achieve a desired inspiratory flow.    
   
   
       21 . The method of  claim 20  wherein the adjusting includes adjusting pulse width.  
   
   
       22 . A method comprising stimulating a phrenic nerve using a plurality of electrodes and a plurality of frequencies.  
   
   
       23 . The method of  claim 22  wherein each of the plurality of frequencies are greater than approximately 1 Hz.  
   
   
       24 . The method of  claim 22  wherein each of the plurality of frequencies are less than approximately 50 Hz.  
   
   
       25 . An implantable device comprising: 
 a sensor to sense information related to inspiration;    memory to store information related to intrinsic inspiration;    control logic to determine one or more stimulation parameters based at least in part on the information related to intrinsic inspiration wherein the one or more stimulation parameters include at least one frequency parameter; and    a pulse generator to deliver stimulation according to the one or more stimulation parameters.    
   
   
       26 . The device of  claim 25 , wherein the sensor senses impedance.  
   
   
       27 . The device of  claim 25 , wherein the control logic includes a control algorithm selected from the group consisting of proportional, integral and derivative control algorithms.  
   
   
       28 . The device of  claim 25 , wherein the control logic determines an error using the information related to intrinsic inspiration and information related to inspiration sensed during delivery of stimulation.