External cardiac assistance

• US 3,866,604 A
• Filed: 09/28/1973
• Issued: 02/18/1975
• Est. Priority Date: 09/28/1973
• Status: Expired due to Term

• Current Assignee: Kontrol Cardiovascular Incorporated
• Original Assignee: Alfred E. Magro, Armando Federico, Michael L. Rishton, Richard W. Curless
• Inventors: Curless, Richard W., Federico, Armando, Magro, Alfred E., Rishton, Michael L.
• Primary Examiner(s): Trapp, Lawrence W.
• Application Number:
  US05/401,676
• Time in Patent Office: 508 Days
• Field of Search: 128/24R,64,89R,297,299,DIG.20
• US Class Current: 601/152
• CPC Class Codes: A61H 2201/0103 inflatable
• CPC Class Codes: A61H 2201/0173 Means for preventing injuries
• CPC Class Codes: A61H 2201/1238 with hydraulic or pneumatic drive
• CPC Class Codes: A61H 2205/10 Leg
• CPC Class Codes: A61H 2230/04 Heartbeat characteristics, e.g. E.G.C., blood pressure modulation
• CPC Class Codes: A61H 31/006 Power driven
• CPC Class Codes: A61H 9/0078 with intermittent or alternately inflated bladders or cuffs mattresses for preventing bed-sores with alternated pressurized chambers A61G7/05776

Abstract

The flow of blood through the circulatory system of animals is augmented by sequential application of peristaltic pumping pressure along either or both of the legs and/or arms to develop a counterpulse in the aorta. The counterpulse is generated by equipment interconnected with electrocardiographic equipment and synchronized therewith to begin the same time as the beginning of diastole in the patient. A series of bladders arrayed lengthwise along the limb are pressurized simultaneously or in rapid sequence for peristaltic pumping and simultaneously deflated at the end of diastole. Each of the bladders is surrounded by casing means which are rendered rigid during pumping operations to provide a reaction wall and non-rigid between operations for ease of handling and wrapping and unwrapping the limb. The apparatus as a whole provides low real and apparent weight for the patient to carry, high speed of inflation and deflation, low bulk and cost of related pumping equipment, accommodation of a variety of sizes of patients and protection against ejection from the equipment by the pressures generated therein and fail safe mode in case of power failure. The apparatus may be adjusted to suit the pumping needs of different patients with simple checkout and adjustment by the clinical or hospital technician.

Claims

1. Apparatus for external cardiac assistance comprising:

means defining a plurality of non-distensible gas fillable bladders which are wrappable aobut a human limb and unwrappable therefrom, said means including within said bladders compression preventing means for preventing complete local compression of opposing walls thereof at any point therein while allowing lateral gas flow;

means for selectively inflating and deflating said bladders by admission of gas and withdrawal of gas therefrom to selectively pressurize the cardiovascular system at the location in the limb wrapped by said bladders;

means defining a common casing blanket for overlying a series of bladder wrappings along a limb and being similarly wrappable about said limb and unwrappable therefrom along with said bladders; and

means for selectively hardening and softening the blanket casing comprising a filling of particulate material therein and means for drawing and releasing a vacuum therein to provide a substantially cylindrical reaction wall for the bladders and for softening the blanket casing to make it flexible for wrapping and unwrapping operations.

2. Apparatus in accordance with claim 1 wherein:

said compression preventing means comprise a bladder filling of fully reticulated foam.

3. Apparatus in accordance with claim 1 wherein:

said means for bladder pressurizing and depressurzing comprise means defining a manifold and metering valves therein associated with a series of said bladders, the valves being separately adjustable to establish said sequential bladder inflation sequence and alternatively to establish a common adjustment of volume filled during inflation without movement of any parts during the inflation, and further comprising means for increasing deflation flow rate comprise relation to inflation flow rate for all bladders.

4. Apparatus in accordance with claim 3 wherein:

said means for increasing deflation flow rate comprise passages through said valve means and flapper valve means threreon positioned to draw open under the influence of deflation suction.

5. Apparatus in accordance with claim 4 wherein:

said valves comprise a valving member moveable with respect to a valve seat to define an annular metering clearance therein, means for adjusting the valving member/seat clearance from outside the manifold, said passage means passing through said valving member and said flapper valve means comprising a disk secured to a face said valving member away from said valve seat.

6. Apparatus in accordance with claim 3 and further comrpsing:

means for measuring pressurization of each bladder and temporal relation of pressurization of the various bladders.

7. Apparatus in accordance with claim 6 and furhter comprising:

means for synchronizing bladder inflation and deflation with a patient'"'"''"'"'s cardiovascular functioning to begin inflation essentially at the dicrotic notch portion of the aortic pressure wave and complete deflation just prior to initiation of isometric contraction, and wherein;

said means for increasing deflation flow comprise passages through said valve means and flapper valve means thereon positioned to draw open under the influence of delfation suction, said valves comprise a vlavingmembermoveable with valving member moveable to a valve seat to define an annular metering clearance therein and comprising means for adjusting the vAlving member/seat clearance from outside the manifold, said passage means pass through said valving member, and said flapper valve means comprise a disk secured to a face said valving member away from said valve seat.

8. Apparatus in accordance with claim 1 wherein:

said means for pressurizing and depressurizing said bladders comprise means defining a gas pump acessing each bladder through both a pump inlet at subatmospheric pressure and a pump outlet at superatmospheric pressure with a pressure tank and firt valve betwen said outlet and bladders and a vacuum tank and second valve between said inlet and bladders and means for transferring a specific volume from said pressure tank to said bladders during inflation and from said bladders to said vacuum tank during deflation.

9. Apparatus in accordance with claim 8 wherein:

said means for transferring a specific volume comprise means defining a metering tank in line between said pressure tank and bladder.

10. Apparatus in accordance with claim 9 wherein:

said means for pressurizing and depressurizing said bladders further comprise a manifold and third valve means interconnecting said bladders with said first and second valves, and further comprising;

means for increasing the rate of bladder deflation flow through said third valve in relation to the rate of bladder inflation flow therethrough.

11. Apparatus in accordance with claim 10 wherein:

said means for increasing deflation flow comprise passages through said third valve and flapper valve means positioned thereon to draw open under the influence of deflation suction, said third valve comprises a valving member moveable with respect to a valve seat to define an annular metering clearance therein and also comprises means for adjusting the valving member/seat clearance from outside the manifold, said passage means pass through said valving member, said flapper valve means comprise a disk secured to face said valving member away from said valve seat, said blanket and bladders are in a preassembled form as a pair of pants in chaps arrangement with an array of bladders along each leg, and said means for selectively hardening and softening said blanket casing comprise a filling of particulate material therein and gas pump means separate from said bladder pressurizing gas pump means for drawing at least two distinct levels of vacuum in said casing, and further comprising;

means defining a supporting table for said pants and a backrest and pants securing means on said table, interlock means preventing bladder pressurization until said pants are hardened, and means for synchronizing bladder inflation and deflation with a patient'"'"''"'"'s cardiovascular functioning to begin inflation essentially at the dicrotic notch portion of the aortic pressure wave and complete deflation just prior to initiation of isometric contraction.

12. Apparatus in accordance with claim 11 and furhter comprising:

a plurality of said third valves accessing separate bladders and having different gas flow rates for inflation but essentially equal gas flow rates for deflation and a plurality of bladder pressure monitors, means for displaying the inflation sequence of said bladders in response to signals from said bladder pressure monitors, and means for individually adjusting said inflation flow rates.