Non-blood contacting mechanical device that improves heart function after injury
A method and device are provided for non-blood contact mechanically assisting an injured (e.g., infarcted) ventricle by coupling an inflatable bladder or other volume adjustable device to the injured ventricle and selectively inflating the bladder or increasing the size of the volume in systole to apply force against the injured ventricle and deflating the bladder or reducing the size of the volume in diastole to remove force against the injured ventricle. When no mechanical assistance is being provided to the injured ventricle, the inflatable bladder or volume adjustable device is preferably maintained at a predetermined pressure so as to selectively stiffen the injured tissue and alter ventricular geometry a desired amount. The method is implemented by a mechanical assist device including the volume adjustable device, a coupling means that couples the volume adjustable device to the injured ventricle, a pulsatile device that selectively increases and decreases the volume of the volume adjustable device, and a controller responsive to the pace of the heart and adapted to selectively change the size of the volume adjusting device in different modes of operation.
1. A method for optimizing the use of a mechanical assist device for providing static assistance to injured tissue of a ventricle of a subject's heart,
wherein the mechanical assist device includes a fluid fill chamber configured to statically stiffen the tissue and for being selectively placed over the injured tissue, and a fluid reservoir that is in fluid communication with the fluid fill chamber via a feed line for adjusting the volume of the fluid fill chamber at least by supplying a fluid to the fluid fill chamber,
the method comprising:
obtaining data concerning the subject's heart using magnetic resonance Imaging (MRI) and ultrasound imaging;
inputting the obtained data into a subject-specific model that includes a coupled lumped parameter model of the subject's cardiovascular system and a finite element model of the subject's heart to predict optimal device volume; and,
using the subject-specific model to optimize the fluid fill chamber of the mechanical assist device,
wherein the subject specific model is further used to identify and simulate strain patterns in the subject's heart in order to optimize positioning and control of the fluid fill chamber, thereby reducing leaflet chordae tension.
2. The method according to claim 1 , wherein the subject specific model is used to optimize the position, size, or volume of the fluid fill chamber.
3. The method according to claim 2 , wherein each of the position, size, and volume of the fluid fill chamber is optimized.
4. The method according to claim 1 , wherein the data concerning the subject's heart that is obtained using MM and ultrasound imaging includes end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, stroke work, O 2 consumption, aortic flow, aortic pressure, mitral valve regurgitation, regional strain, regional stress, or any combination thereof.