Patent EA-003223-B1 (EA)
Title: Modular cpr assist device
Inventor: MOLLENAUER KENNETH H
IPC: A61H31/00
Filed: 1999-05-17
Abstract: 1. A device for repeatedly compressing the chest of a patient, said device comprising: a belt circumferentially surrounding the chest of the patient; a drive mechanism operably connected to the belt so that operation of the drive mechanism by the motor causes the belt to tighten around the chest of the patient; a motor operably connected to the drive mechanism through a clutch, wherein said clutch may be operated to connect the motor to the drive mechanism while the device is in operation; a control system operably connected to the clutch and capable of causing the clutch to disconnect the motor from the drive mechanism while the device is in operation. 2. A device for repeatedly compressing the chest of a patient, said device comprising: a belt circumferentially surrounding the chest of the patient; a panel which is located near the patient's chest; a drive spool mounted on the panel and operably connected to the belt so that revolution of the drive spool spools the belt upon the spool; a spindle mounted on the panel substantially parallel to the drive spool, said spindle engaging the belt to reverse travel of the belt from transverse direction relative to the chest and toward the drive spool to the opposite transverse direction relative to the chest away from the drive spool. 3. The device of claim 2 wherein the panel comprises a left panel and a right panel, and the right panel and left panel are hinged together so as to allow them to fold together and unfold to a substantially flat configuration. 4. The device of claim 3, wherein the left panel and the right panel are hinged together near the location of the spindle, thereby permitting substantially complete enclosure of the chest by the belt when the left and right panels are not completely unfolded to a substantially flat configuration. 5. A device for compressing the chest of a patient comprising: a belt adapted to extend around the chest of the patient and fastened on the patient; belt tensioning means operably connected to the belt for repeatedly tightening and loosening the belt around the chest of the patient; a motor operably connected to the belt tensioning means, said motor capable of operating the belt tensioning means repeatedly to cause the belt to tighten about the chest of the patient and loosen about the chest of the patient; a brake operably connected to the belt tensioning means and capable of holding the belt tensioning means in a tightened state about the chest of the patient; a clutch between the motor and the belt tensioning means, said clutch capable of connecting and disconnecting the motor from the belt tensioning means, said clutch being capable of engagement and disengagement while the motor is in operation; and a controller for controlling operation of the motor, brake and clutch, said controller programmed to operate the motor brake and clutch to cause repeated cycles of tightening of the clutch to a set threshold of tightness, momentarily hold the belt at this threshold of tightness, and release of the belt. 6. A device for compressing the chest of a patient comprising: a belt adapted to extend around the chest of the patient and fastened on the patient; belt tensioning means operably connected to the belt for repeatedly tightening and loosening the belt around the chest of the patient; a motor operably connected to the belt tensioning means, said motor capable of operating the belt tensioning means repeatedly to cause the belt to tighten about the chest of the patient and loosen about the chest of the patient; a brake operably connected to the belt tensioning means and capable of holding the belt tensioning means in a tightened state relative to the chest of the patient; a controller for controlling operation of the motor and brake, said controller programmed to operate the motor and brake to cause repeated cycles of tightening of the belt to a set threshold of tightness, momentarily hold the belt at this threshold of tightness, and release of the belt. 7. A device for compressing the chest of a patient comprising: a belt adapted to extend around the chest of the patient and fastened on the patient; a drive spool operably connected to the belt so that revolution of the drive spool spools the belt upon the spool; a motor operably connected to the belt tensioning means, said motor capable of operating the belt tensioning means repeatedly to cause the belt to tighten about the chest of the patient and loosen about the chest of the patient; a brake operably connected to the belt tensioning means and capable of holding the belt tensioning means in a tightened state; a controller for controlling operation of the motor and brake, said controller programmed to operate the motor and brake to cause repeated cycles of tightening of the belt to a set threshold of tightness, momentarily hold the belt at this threshold of tightness, and release of the belt. 8. A device for compressing the chest of a patient comprising: a belt adapted to extend around the chest of the patient and fastened on the patient; a drive spool operably connected to the belt so that revolution of the drive spool spools the belt upon the spool; a motor operably connected to the belt tensioning means, said motor capable of operating repeatedly to cause the belt to tighten about the chest of the patient and loosen about the chest of the patient; a brake operably connected to the belt tensioning means and capable of holding the belt tensioning means in a tightened state; a controller for controlling operation of the motor and brake, said controller programmed to operate the motor and brake to cause repeated cycles of tightening of the belt to hold the belt tensioning means at definite points of the repeated cycles. 9. A device for compressing the chest of a patient comprising: a belt adapted to extend around the chest of the patient and fastened on the patient; a drive spool operably connected to the belt so that revolution of the drive spool spools the belt upon the spool; a motor operably connected to the belt tensioning means, said motor capable of operating the belt tensioning means repeatedly to cause the belt to tighten about the chest of the patient and loosen about the chest of the patient; a brake operably connected to the belt tensioning means and capable of holding the belt tensioning means in a tightened state; a controller for controlling operation of the motor; a current sensor operably connected to the motor, said current sensor adapted to sense current drawn by the motor and transmit a corresponding current signal to the controller; said controller programmed to operate the motor and drive spool to take up slack in the belt after initial placement of the belt on the patient's chest by rotating the motor in a tightening rotation until the current signal provided by the current sensor rapidly increases; said controller further programmed to operate the motor and the coupling and drive spool to cause repeated cycles of tightening of the belt about the chest of the patient and loosening of the bell about the chest of the patient. 10. A chest compression device of claim 9 further comprising: a linear encoder scale on the belt and an encoder scanner located in apposition to the scale, said encoder transmitting an encoder position to the controller; said controller further programmed to associate the encoder position to the point of rapid increase in the current signal during initial placement thereby defining a slack-limit position of the belt, and to operate the motor to limit loosening of the belt during cycles to the slack-limit position. 11. An apparatus for use in resuscitating a patient having cardio-circulatory arrest, comprising: belt means adapted to be passed around the thorax of a patient; a belt tightening means for drawing a portion of the belt to one side of the thorax, thereby to tighten the band to produce intra-thoracic pressures sufficient to propel the blood of the patient into the extrathoracic regions, the belt tightening means being operable at a cardiac resuscitative rate to alternately so tauten and then loosen the band to permit the elastic tissues of the patient's body to return blood to the intrathoracic region; a motor operably connected to the belt tightening means through a clutch, said clutch being operable while the device is operating to connect and disconnect the motor to the belt tightening means. 12. A method of performing chest compression on a patient, said method comprising: providing a belt around the patient's chest; providing a belt tightening mechanism operably connected to the belt; operating the belt tightening mechanism to tighten the belt in order to compress the chest to a first state of compression, then holding the belt tighten momentarily, then releasing the belt to allow the belt to loosen and allow the chest to relax. 13. A method of performing chest compression on a patient, said method comprising: providing a belt around the patient's chest; providing a belt tightening mechanism operably connected to the belt; operating the belt tightening mechanism to tighten the belt in order to compress the chest to a first state of compression, then holding the belt tight momentarily, then releasing the belt to allow the belt to loosen and allow the chest to relax; and after releasing the belt to allow the belt to loosen and allow the chest to relax, holding the belt taut before the chest has fully relaxed to obtain a second state of compression. 14. A method of performing chest compression on a patient, said method comprising: providing a belt around the patient's chest; providing a belt tightening mechanism operably connected to the belt; operating the belt tightening mechanism to perform a compression step to tighten the belt in order to compress the chest to a first state of compression, then perform a first holding step to hold the belt tight momentarily, then perform a releasing step to release the belt to allow