Human powered mechanical CPR device with optimized waveform characteristics

• US 9,149,412 B2
• Filed: 06/14/2012
• Issued: 10/06/2015
• Est. Priority Date: 06/14/2012
• Status: Expired due to Fees

• Current Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Original Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Inventors: Faller, Frederick W., Freeman, Gary A.
• Primary Examiner(s): Yu, Justine
• Assistant Examiner(s): STANIS, TIMOTHY A
• Application Number:
  US13/523,561
• Publication Number:
  US 20130338550A1
• Time in Patent Office: 1,209 Days
• Field of Search: 601/41, 601/97
• US Class Current: 1/1
• CPC Class Codes: A61H 2011/005 with belt or strap expanding and contracting around an encircled body part
• CPC Class Codes: A61H 2201/1215 Rotary drive
• CPC Class Codes: A61H 2201/1253 driven by a human being, e.g. hand driven
• CPC Class Codes: A61H 2201/1418 Cam
• CPC Class Codes: A61H 2201/149 rotation-linear or vice versa
• CPC Class Codes: A61H 2201/1664 linear
• CPC Class Codes: A61H 2203/0456 Supine
• CPC Class Codes: A61H 31/006 Power driven
• CPC Class Codes: A61H 31/007 Manual driven

Abstract

A CPR compression device driven by a cam, in which the cam is shaped to provide a desired compression waveform. The cam controls movement of a compression pad, and has angular regions shaped to provide a compression stroke, a high compression hold, and a release phase of the chest contacting means.

Claims

1. A device for compressing the chest of a patient, where said patient is characterized by a chest and a sternum defining an area of said sternum, said device comprising:

a compression pad adapted to contact the chest of the patient in the area of the patient'"'"'s sternum, and limited to the area of the patient'"'"'s sternum;

a drive system operable to exert force on the compression pad to impart repeated cycles of compression and release of compression on the chest of the patient;

wherein the drive system comprises a cam system operable to force the compression pad downward, and the cam system comprises a radial cam, and the radial cam comprises a cam plate and a cam shaft, said cam shaft being operable to rotate the cam plate and said radial cam is operably connected to the compression pad through a follower; and

wherein the cam plate is operable to rotate through a first portion of rotation, a second portion of rotation and a third portion of rotation, and said cam is shaped such that, for the first portion of rotation, the cam follower is translated in a first direction at a uniform compression rate to provide a compression to the patient at uniform rate, for the second portion of rotation comprising 90°

to 180°

of rotation of the cam plate, the cam follower is held substantially stationary to provide a static period of compression by a shape of the cam plate in the second portion comprising an isodiametric top radius where a radius of a contact point with the follower is a substantially fixed radius relative to the cam shaft, in which the compression component is held at a substantially constant threshold of compression, for the third portion of rotation, the follower is translated in a second direction at a rate substantially greater than the uniform compression rate, such that the compression pad is released from downward tension upon the chest of the patient.

2. A device for compressing the chest of a patient comprising:

chest compressing means for compressing the chest of the patient;

means for converting substantially uniform human-powered input powering the means for compressing into a non-uniform compression waveform;

means for applying human power to the means for converting;

wherein the means for converting comprises a cam, said cam having angular regions constituting an increase radius zone corresponding to a compression stroke of the chest compressing means, a constant maximum radius zone corresponding to a maximum compressive position of the chest contacting means, and a decrease radius zone corresponding to a release phase of the chest compressing means, wherein said constant maximum radius zone spans 90°

to 180°

of rotation of the cam.

3. The device of claim 2 wherein the cam has an additional angular region constituting a constant minimum zone with a constant minimum radius corresponding to a minimum compressive position of the chest compressing means.

4. A device for compressing the chest of a patient comprising:

means for contacting the chest of the patient;

a cam follower operably engaged with the contacting means;

a cam operably connected to a cam shaft and a means for rotating the cam shaft;

wherein the cam is shaped to provide a compression wave form including a compression phase characterized by a compression rise time, followed by a high threshold hold, followed by a release of compression which is substantially faster than the compression rise time; and

wherein the cam comprises a cam plate and a cam shaft, said cam shaft being operable to rotate the cam plate through a first portion of rotation, a second portion of rotation and a third portion of rotation, and said cam is shaped such that, for the first portion of rotation, the cam follower is translated in a first direction at a uniform compression rate to provide a compression to the patient at a uniform rate, for the second portion of rotation comprising 90°

to 180°

of rotation of the cam plate, the cam follower is held substantially stationary to provide a static period of compression by a shape of the cam plate in the second portion comprising an isodiametric top radius where a radius of a contact point with the follower is a substantially fixed radius relative to the cam shaft, in which the contacting means is held at a substantially constant threshold of compression, for the third portion of rotation, the follower is translated in a second direction at a rate substantially greater than the uniform compression rate, such that the contacting means is released from downward tension upon the chest of the patient.

5. A device for compressing the chest of a patient comprising:

a backboard adapted for positioning under the thorax of the patient;

a gantry fixed to the backboard and disposed above the backboard, said gantry disposed relative to the backboard such that the gantry is disposed over the chest of the patient when the backboard is disposed under the thorax of the patient;

a compression pad adapted to contact the chest of the patient to transmit compressive forces to the chest;

a follower piston vertically fixed to the compression pad and disposed above the compression pad such that upward and downward motion of the piston results in upward and downward motion of the compression pad;

a cam plate operably engaged with the piston, and a cam shaft, said cam shaft being operable to rotate the cam plate;

a motor or hand crank operable to rotate the cam plate;

wherein the cam plate is operable to rotate through a first portion of rotation, a second portion of rotation and a third portion of rotation, and said cam is shaped such that, for the first portion of the rotation, the follower piston is translated downwardly at a uniform compression rate to force the compression pad downward to provide a compression to the patient at a uniform rate, for the second portion of angular rotation comprising 90°

to 180°

of rotation of the cam plate, the cam follower and compression pad are held substantially stationary to provide a static period of compression by a shape of the cam plate in the second portion comprising an isodiametric top radius where a radius of a contact point with the follower is a substantially fixed radius relative to the cam shaft, in which the compression pad is held at a substantially constant threshold of compression, for the third portion of rotation, the follower piston and compression pad are translated upwardly at a rate substantially greater than the uniform compression rate, such that the compression pad is released from downward tension upon the chest of the patient.

6. A device for compressing the chest of a patient comprising:

a backboard adapted for positioning under the thorax of patient;

a gantry fixed to the backboard and disposed above the backboard, said gantry disposed relative to the backboard such that the gantry is disposed over the chest of the patient when the backboard is disposed under the thorax of the patient;

a compression pad adapted to contact the chest of the patient to transmit compressive forces to the chest;

a follower piston vertically fixed to the compression pad and disposed above the compression pad such that upward and downward motion of the piston results in upward and downward motion of the compression pad,

a cam plate operably engaged with the piston, and a cam shaft, said cam shaft being operable to rotate the cam plate;

a motor or hand crank operable to rotate the cam plate;

wherein the cam plate is operable to rotate through a first portion of rotation, a second portion of rotation, a third portion of rotation, and a fourth portion of rotation, and said cam is shaped such that, the first portion of angular rotation, the follower piston is translated downwardly at a uniform compression rate to force the compression pad downward to provide a compression to the patient at a uniform rate, for the second portion of rotation comprising 90°

to 180°

of rotation of the cam plate, the cam follower and compression pad are held substantially stationary to provide a static period of compression by a shape of the cam plate in the second portion comprising an isodiametric top radius where a radius of a contact point with the follower is a substantially fixed radius relative to the cam shaft, in which the compression pad is held at a substantially constant threshold of compression, for the third portion of rotation, the follower piston and compression pad are translated upwardly at a rate substantially greater than the uniform compression rate, such that the compression pad is released from downward tension upon the chest of the patient, and for the fourth portion rotation, the follower piston and compression pad are held substantially stationary to provide a static period of relaxation of the chest.

7. A device for compressing the chest of a patient comprising:

a backboard adapted for positioning under the thorax of patient;

a gantry fixed to the backboard and disposed above the backboard, said gantry disposed relative to the backboard such that the gantry is disposed over the chest of the patient when the backboard is disposed under the thorax of the patient;

a compression pad adapted to contact the chest of the patient to transmit compressive forces to the chest;

a follower piston vertically fixed to the compression pad and disposed above the compression pad such that upward and downward motion of the piston results in upward and downward motion of the compression pad,

a cam plate operably engaged with the piston, and a cam shaft, said cam shaft being operable to rotate the cam plate;

a motor or hand crank operable to rotate the cam plate;

wherein the cam plate is operable to rotate through a first portion of rotation, a second portion of rotation, a third portion of rotation, and a fourth portion of rotation, and said cam is shaped such that, for the first portion of rotation, the follower piston is translated downwardly at a uniform compression rate to force the compression pad downward to provide a compression to the patient at a uniform rate, for the second portion of rotation comprising 90°

to 180°

of rotation of the cam plate, the cam follower and compression pad are held substantially stationary to provide a static period of compression by a shape of the cam plate in the second portion comprising an isodiametric top radius where a radius of a contact point with the follower is a substantially fixed radius relative to the cam shaft, in which the compression pad is held at a substantially constant threshold of compression, for the third portion of rotation, the follower piston and compression pad are translated upwardly at a rate substantially greater than the uniform compression rate, such that the compression pad is released from downward tension upon the chest of the patient, and for the fourth portion of rotation, the follower piston and compression pad are held substantially stationary to provide a static period of compression at a low threshold.