CARDIAC SYNCHRONIZATION SYSTEM AND METHOD

• US 3,835,845 A
• Filed: 10/24/1972
• Issued: 09/17/1974
• Est. Priority Date: 10/24/1972
• Status: Expired due to Term

• Current Assignee: Charles E. Maher
• Original Assignee: Charles E. Maher
• Inventors: Maher, Charles E.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/300,290
• Time in Patent Office: 693 Days
• Field of Search: 128/1D,2.5P,2.5R,2.6R,30,64
• US Class Current: 601/150
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61H 2230/04 Heartbeat characteristics, e.g. E.G.C., blood pressure modulation
• 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

Improved internal circulatory assist apparatus comprising control means whereby the optimum synchronization of the assist apparatus with the beat of the heart can be effectively achieved while using any of a plurality of parts of the body as monitor sites for obtaining an arterial signal representative of the patient'"'"''"'"'s heartbeat. The control means consists of a marker means, such as a pip on an oscilloscope, which is adjustable by variable-delay circuitry throughout a range equal to the time difference between the sensing of a selected cardiac event at an earliest-reacting monitoring site and the sensing of a selected cardiac event at a later-reacting monitoring site.

Claims

1. In an external circulatory assist apparatus comprising means to pressurize a portion of a patients body, means to synchronize actuation of said pressurization means on a portion of the body with the heart cycle of a patient being treated, means for creating an arterial waveforms signal representative of said heart cycle, and display means for monitoring a said waveform signal exhibiting a dicrotic notch portion representative of said heart cycle in the form of visible traces on said display means the improvement wherein said synchronizing means includes:

A. means to provide first and second intensified marker pips on said display means displaying a marker trace representative of said arterial waveform derived from a patient, B. a first means to adjust the position of said first marker pip relative to and along said waveform to a characteristic and identifiable position of arterial waveforms, said adjusting means also forming, C. means to, concurrently with the adjustment of said first marker pip, move a second intensified pip along said waveform at a constant distance from said first marker, and D. A second independent adjusting means to bring said intensified trace into register with the dicrotic notch of said waveform, said first and second adjusting means for moving said trace pips further forming variable-time adjusting means and synchronization means between a patients heart cycle and the start of said pressurization of his body.

2. simultaneously positioning a second marker pip representative of the time and duration of said pressurization action on said arterial trace proximate and dicrotic notch portion of said trace so that said second pip coincides with the dicrotic notch of said arterial trace, and simultaneously adjusting, through setting a variable time delay means, the synchronization of a patient'"'"''"'"'s heartbeat with said pulsed pressurizing action, and

3. Apparatus as described in claim 2 wherein said variable delay means provides a delay variable over a time difference At least equal to the time elapsing from diastole in a patient'"'"''"'"'s heart cycle to the time such diastole is registered in said patient'"'"''"'"'s digital extremities.

4. Apparatus as defined in claim 1 wherein said position adjusting means provide means to adjust said marker pip over a portion of the waveform equivalent in length to time elapsing from diastole in a patient'"'"''"'"'s heart cycle to the time such diastole is registered in said patient'"'"''"'"'s digital extremities.

5. In apparatus for applying external pressure assist action to the limbs of a patient in cyclic synchronization with the heartbeat of said patient, wherein said assist is achieved with means for transmitting pressure to said limbs through a fluid-filled bladder pressurizing means surrounding said limbs, means for creating an arterial waveform signal representative of said heartbeat and display means for monitoring a said waveform signal representative of said hearbeat in the form of visible traces on said display means, wherein the apparatus also includes a visual cycle-phasing monitor comprising:

A. a multi-channel display means for displaying

6. In apparatus for applying external pressure assist action to the limbs of a patient in cyclic synchronization with the heartbeat of said patient, wherein said apparatus comprises means for producing a pressure command signal, means for transmitting pressure through a hydraulic cylinder to said limbs through a fluid-filled bladder pressurizing means surrounding said limbs in response to means for activating said pressure command signal, and means for creating an arterial waveform signal representative of said heartbeat and display means for monitoring a said waveform signal representative of said heartbeat in the form of visible traces on said display means, and wherein the apparatus includes A. an ideal pressure waveform generator means, B. actual limb pressure waveform sensing means, C. said display means forming means for continually comparing said ideal and actual waveforms, and D. variable valve means, responsible to a signal from said comparing means, to modify fluid flow to said hydraulic cylinder and thereby to transmit pressure to said limbs through said fluid-filled bladder more nearly achieve said ideal-pressure waveform at said limbs the improvement wherein said apparatus comprises:

A. means to provide a first marker pip on display apparatus displaying a marker trace representative of said arterial waveform derived from a patient, B. means to adjust the position of said marker pip relative to said waveform to a characteristic and identifiable configuration of arterial waveforms, said adjusting means Also forming, C. means to, form an intensified trace on said waveform, D. means to move, concurrently with said adjusting, an intensified trace along said waveform at a constant distance from said first marker, and E. means to bring said intensified trace into register with the dicrotic notch of said waveform, thereby adjusting the synchronization for activating said pressure command signal.

7. Apparatus as defined in claim 6 comprising:

A. a multi-channel oscillosopce adapted to display

8. In a process for synchronizing a pulsed pressurizing action of an external pressure circulatory assist apparatus with the heartbeat cycle of a patient being treated with said apparatus, said process including the steps of using a display means exhibiting a trace derived from an arterial pressure sensor as a means to judge when said pressurizing action is to be initiated, the improvement comprising the steps of