PIEZOELECTRIC HEART ASSIST APPARATUS

• US 3,857,382 A
• Filed: 09/10/1973
• Issued: 12/31/1974
• Est. Priority Date: 10/27/1972
• Status: Expired due to Term

• Current Assignee: Adrian Kantrowitz, Donald A. Molony, Dov Jaron, Maryon J. Williams Jr, Sylvon Fich, Walter Welkowitz
• Original Assignee: Adrian Kantrowitz, Donald A. Molony, Dov Jaron, Maryon J. Williams Jr, Sylvon Fich, Walter Welkowitz
• Inventors: Williams, Maryon J. Jr., Welkowitz, Walter, Fich, Sylvon, Jaron, Dov, Kantrowitz, Adrian, Molony, Donald A.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US05/395,799
• Time in Patent Office: 477 Days
• Field of Search: 128/1D,214R,273,346 3/1,DIG.2 251/9 417/322,478
• US Class Current: 600/17
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/161 mechanically acting upon the outside of the patient's blood vessel structure, e.g. compressive structures placed around a vessel
• CPC Class Codes: A61M 60/274 the inlet and outlet being the same, e.g. para-aortic counter-pulsation blood pumps
• CPC Class Codes: A61M 60/289 Devices for mechanical circulatory actuation assisting the residual heart function by means mechanically acting upon the patient's native heart or blood vessel structure, e.g. direct cardiac compression [DCC] devices
• CPC Class Codes: A61M 60/486 generated by electro-active actuators, e.g. using electro-active polymers or piezoelectric elements
• CPC Class Codes: A61M 60/857 Implantable blood tubes

Abstract

An implantable piezoelectric heart assist apparatus generates pressure waves of approximately the same amplitude and frequency as the natural heart. The apparatus includes a brass support sandwiched between piezoelectric ceramics to form a piezoelectric bender. The bender compresses a tube which is sutured into the descending thoracic aorta. The bender is loaded at one end to change its resonant frequency and, upon application of a driving signal, the bender oscillates to generate pressure in the thoracic aorta.

Claims

1. Apparatus for providing mechanical assistance to a heart by generating pressure waves in the bloodstream, the pressure waves being introduced in the bloodstream so that diastolic pressure is increased;

the apparatus comprising;

a tubular fluid path of resilient material adapted to be surgically connected to the bloodstream;

piezoelectric means for alternately compressing and releasing said tubular fluid path and for generating sinusoidal pressure waves in said tubular fluid path in response to a driving signal; and

a frame;

said piezoelectric means including at least two piezoelectric bender means each bender means having a central support and a piezoelectric ceramic bonded thereto, each bender means configured as a cantilever with one end fixed to said frame and the other end free, and having a mass operably loading the free end thereof to provide a predetermined resonant frequency;

whereby upon application of said driving signal, each piezoelectric bender means resonates at a frequency in the range of the heart frequency to generate pressure waves in said tubular fluid path thereby increasing the mean arterial blood flow.

2. The apparatus of claim 1 wherein said piezoelectric means fUrther includes:

an arm mounted transversely of said tubular fluid path for oscillation in said frame about the axis of said tubular fluid path;

said arm having one of said masses secured to each end thereof to form a counterbalance;

whereby upon application of said driving signal, said central supports resonate to oscillate said arm to compress said tubular fluid path between said supports for generating said pressure waves therein.

3. The apparatus of claim 2 and further including:

two arms mounted on opposite sides of said frame for oscillation therein about the axis of said tubular fluid path;

each central support resonating about an axis distinct from the axis of said tubular fluid path;

said central support including a U-shaped brace on its free end, said brace having slots in the legs of the '"'"''"'"''"'"''"'"'U'"'"''"'"''"'"''"'"' which slots are parallel to the longitudinal dimension of the cantilever, and an elongated pin positioned through said slots and fixed in the ends of said arms;

whereby the resonating of said supports is coupled through the slot and pin to oscillate said arms, and the arm and support move about different axes without binding.

4. The apparatus of claim 2 wherein said tubular fluid path has means connectible to the bloodstream at two different locations whereby all the blood passes through said tubular fluid path between said piezoelectric cantilever means and said base.

5. The apparatus of claim 2 wherein said tubular fluid path has means connectible to the bloodstream at one surgical location and pressure waves are propagated into the main bloodstream.

6. The apparatus of claim 2 wherein each mass is radially adjustable on said arm with respect to the axis of rotation for adjusting the resonant frequency of said piezoelectric cantilever means.