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 mechanical assist device configured for selectively stiffening injured tissue of a ventricle, to alter ventricle geometry a desired amount, or both, comprising:
a first fluid fill chamber configured to provide dynamic assistance to the ventricle, and for being selectively coupled to the injured tissue;
a first fluid reservoir that is in fluid communication with the first fluid fill chamber via a first feed line for supplying a fluid to the first fluid fill chamber;
a pulsatile device for cyclically changing the volume of fluid in the first fluid fill chamber;
a second fluid fill chamber configured to statically stiffen the ventricle and for being selectively placed over said injured tissue in overlapping arrangement with the first fluid fill chamber; and,
a second fluid reservoir that is in fluid communication with the second fluid fill chamber via a second feed line for adjusting the volume of the second fluid fill chamber at least by supplying a fluid to the second fluid fill chamber.
2. The mechanical assist device of claim 1 , wherein the pulsatile device is configured to increase the volume of fluid in the first fluid fill chamber when the ventricle is in systole and decrease the volume of fluid in the first fluid fill chamber when the ventricle is in diastole.
3. The mechanical assist device of claim 1 , further comprising a controller that is configured to control the pulsatile device by synchronizing the pulsatile device with the cardiac cycle of the ventricle.
4. The mechanical assist device of claim 1 , further comprising a volume adjustment device that is configured to statically maintain the volume of fluid in the second fluid fill chamber.
5. The mechanical assist device of claim 4 , wherein the volume adjustment device is further configured to vary the volume of fluid in the second fluid fill chamber over time in accordance with a desired stiffness of the injured tissue.