A device is described for performing mechanical cardiopulmonary resuscitation. The device comprises a housing which in use is secured to the chest of a patient, the housing and securing means providing inelastic encirclement of the patient's chest. Pneumatically operated pressing means projects from the housing to bear on the patient's breast bone and suitable valving is contained in the housing to apply cyclic displacement of the pressing means.

A portable self-contained apparatus for delivery of cardiopulmonary resuscitation (CPR) including an arrangement for applying cyclical chest compression and a lung ventilator operatively connected to the chest compression arrangement to deliver volume control ventilation simultaneously with chest compression or asynchronously with chest compression after a predetermined number of compressions. Span adjustment for the thumper accommodates patients with different chest sizes and also adjusts the length of stroke and force of the chest compression thumper as well as the volume of the ventilator output. A ratchet connected to the thumper allows natural expansion of the chest during inhalation by the patient while allowing compression by the apparatus. A control arrangement allows selectively operating the chest compression thumper and the ventilator in a predetermined sequence as well as monitor a patient's vital signs.

A pneumatic percussor includes a three-way valve that is gated on by a control circuit (50) to gate compressed air from a compressor (10) to a percussor cup (70). The percussor cup (70) is a resilient bellows that is expandable in response to pressurized air that is gated through the three-way valve (28). A variable orifice (62) regulates the air flow to the percussor cup (70). A check valve (60) is connected in parallel with the variable orifice (62) to exhaust air to the atmosphere. The control circuit (50) gates the three-way valve on for a short duration during which the percussor cup (70) is inflated and when the control circuit (50) gates the three-way valve (28) off, the check valve (60) relieves the pressure from the inside of the percussor cup (70) to deflate it. The expansion and contraction of the percussor cup (70) delivers a therapeutic rhythmic action to the portion of the body external to the thoracic cavity thereby stimulating the expectoration of the mucus from the lungs.

Apparatus for compressing the chest of a patient to stimulate blood circulation, includes a torso wrap (32) that has a back portion (40) lying at the back of the patient's chest and a front portion (42) lying at the front of the patient's chest, and includes a compressor assembly with an actuator (16) having a pressing member (12) that can apply a series of force pulses to the sternum of the patient to stimulate blood circulation. The actuator is energized by pressured fluid, with a controlled pressured fluid source (20) connected by an elongated flexible hose (24) to the actuator so the pressured fluid source and a control (22) can lie on the ground and only the actuator lies on the torso wrap. The actuator includes a cylinder (66) and a plurality of telescoping piston parts (64, 66) to provide a long stroke in an actuator of small height. A stabilizer (150) that limits tilt of the actuator from the vertical, includes a saucer-shaped member that presses against the front of the patient.

An apparatus and method for performing cardio-plumonary resuscitation with active reshaping of a patient's chest are disclosed. A piston positioned near a patient's sternum is intermittently activated to produce cycles of direct compression on the patient's heart while an annular collar is simultaneously placed securely around a patient's thoracic cavity to limit the circumferential changes in the thoracic cavity. The combination of the annular collar and piston combine to direct blood flow both by direct cardiac compression/decompression and by varying the intrathoracic cavity pressure. The annular collar can be formed by a single non-extensible membrane or by a non-extensible outer membrane and an extensible inner membrane with a bladder therebetween filled with a substantially non-compressible fluid. The collar may be attached to the piston and the piston actively driven away from the patient during decompression resulting in an active reshaping of the chest to lower central venous pressure and thereby induce a rapid return of blood to the thoracic cavity.