1. A method for determining a patient-ventilator breath contribution index in a spontaneously breathing, mechanically ventilated patient, comprising:
measuring electrical activity of a patient’s respiratory muscle during inspiration and without mechanical ventilatory assist;
measuring a patient’s inspiratory volume without mechanical ventilatory assist;
calculating a patient’s efficiency to generate an inspiratory volume without mechanical ventilatory assist as a first ratio between the inspiratory volume measured without mechanical ventilatory assist and the electrical activity of the patient’s respiratory muscle measured without mechanical ventilatory assist;
measuring electrical activity of the patient’s respiratory muscle during inspiration and with mechanical ventilatory assist;
measuring a patient’s inspiratory volume with mechanical inspiratory assist;
calculating a patient’s efficiency to generate an inspiratory volume with mechanical ventilatory assist as a second ratio between the inspiratory volume measured with mechanical ventilatory assist and the electrical activity of the patient’s respiratory muscle measured with mechanical ventilatory assist; and
calculating the patient-ventilator breath contribution index as a third ratio between the calculated patient’s efficiency to generate an inspiratory volume without mechanical ventilatory assist and the calculated patient’s efficiency to generate an inspiratory volume with mechanical ventilatory assist.
2. A method as defined in claim 1, wherein calculating the patient’s efficiency to generate an inspiratory volume without mechanical ventilatory assist comprises calculating the first ratio as a ratio of the inspiratory volume measured without mechanical ventilatory assist over the electrical activity of the patient’s respiratory muscle measured without mechanical ventilatory assist.
3. A method as defined in claim 1, wherein the patient’s respiratory muscle is the patient’s diaphragm.
4. A method as defined in claim 1, wherein the patient’s inspiratory volume is a tidal inspiratory volume.
5. A method as defined in claim 1, wherein calculating the patient’s efficiency to generate an inspiratory volume with mechanical ventilatory assist comprises calculating the second ratio as a ratio of the inspiratory volume measured with mechanical ventilatory assist over the electrical activity of the patient’s respiratory muscle measured with mechanical ventilatory assist.
6. A method as defined in claim 1, wherein calculating the patient-ventilator breath contribution index comprises calculating the third ratio as a ratio of the calculated patient’s efficiency to generate an inspiratory volume without mechanical ventilatory assist over the calculated patient’s efficiency to generate an inspiratory volume with mechanical ventilatory assist.
7. A system for determining a patient-ventilator breath contribution index in a spontaneously breathing, mechanically ventilated patient, comprising:
a first detector of electrical activity of a patient’s respiratory muscle during inspiration without mechanical ventilatory assist and with mechanical ventilatory assist;
a second detector of a patient’s inspiratory volume without mechanical ventilatory assist and with mechanical ventilatory assist; and
a calculator determining:
a patient’s efficiency to generate an inspiratory volume without mechanical ventilatory assist as a first ratio between the detected patient’s inspiratory volume without mechanical ventilatory assist and the detected electrical activity of the patient’s respiratory muscle during inspiration and without mechanical ventilatory assist;
a patient’s efficiency to generate an inspiratory volume with mechanical ventilatory assist as a second ratio between the detected patient’s inspiratory volume with mechanical ventilatory assist and the detected electrical activity of the patient’s respiratory muscle during inspiration and with mechanical ventilatory assist; and
the patient-ventilator breath contribution index as a third ratio between the calculated patient’s efficiency to generate an inspiratory volume without mechanical ventilatory assist and the calculated patient’s efficiency to generate an inspiratory volume with mechanical ventilatory assist.
8. A system as defined in claim 7, wherein the calculator calculates the first ratio as a ratio of the detected patient’s inspiratory volume without mechanical ventilatory assist over the detected electrical activity of the patient’s respiratory muscle during inspiration and without mechanical ventilatory assist.
9. A system as defined in claim 7, wherein the patient’s respiratory muscle is the patient’s diaphragm.
10. A system as defined in claim 9, wherein the first detector comprises an array of electrodes mounted on a free end section of a catheter for positioning at the level of the patient’s diaphragm to sense signals representative of the electrical activity of the patient’s diaphragm, and wherein the calculator is responsive to the signals sensed by the array of electrodes to produce a measurement of the electrical activity of the patient’s diaphragm.
11. A system as defined in claim 7, wherein the patient’s inspiratory volume is a tidal inspiratory volume.
12. A system as defined in claim 11, wherein the second detector comprises a detector of a patient’s inspiratory flow and an integrator of the detected patient’s inspiratory flow.
13. A system as defined in claim 7, wherein the calculator calculates the second ratio as a ratio of the detected patient’s inspiratory volume with mechanical ventilatory assist over the detected electrical activity of the patient’s respiratory muscle during inspiration and with mechanical ventilatory assist.
14. A system as defined in claim 7, wherein the calculator calculates the third ratio as a ratio of the calculated patient’s efficiency to generate an inspiratory volume without mechanical ventilatory assist over the calculated patient’s efficiency to generate an inspiratory volume with mechanical ventilatory assist.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An adjustable-length compression spring, having
a casing (1) filled with pressure fluid;
a guide and seal unit (6) which closes the casing (1) at a first end (5) ;
a piston rod (8) which, through the guide and seal unit (6), is extended from, and sealed towards, the first end (5) and has an outer end (9);
a piston (12) which is joined to the piston rod (8) and sealingly guided in the casing (1);
a first sectional casing chamber (15) which is unilaterally defined by the piston (12) and filled with pressure fluid;
a second sectional casing chamber (16) which is connectable to the first sectional casing chamber (15) and filled with pressure fluid;
an operating valve (20) for connection to each other of the sectional casing chambers (15, 16), the valve (20) comprising a valve pin (22) to be actuated from outside the casing (1) by an operating element (27, 28), the valve pin (22) being displaceable between a position of release and a position of blocking such that
in the position of release of the valve pin (22), the connection between the sectional casing chambers (15, 16) is released; and
in the position of blocking of the valve pin (22), the connection between the sectional casing chambers (15, 16) is shut off;
the adjustable-length compression spring comprising a locking mechanism (29) which is disposed in the casing (1) inside the piston rod (8), having
a first locking element (30) which is in pushing connection with the operating element (27, 28);
a second locking element (36) which is in pushing connection with the valve pin (22);
both of which cooperate through actuation of the first locking element (30) by the operating element (27, 28) shifts of the second locking element (36) between a first engaged position and a second engaged position such that the valve pin (22) in a first engaged position of the second locking elements (36), is in a position of release and in a second engaged position of the second locking elements (36), is in a position of blocking.
2. A compression spring according to claim 1, comprising a snap-in guide element (33), stationary in the casing (1), for guidance of a first of the locking elements (30) in the direction of displacement of the valve pin (22), the locking elements (30, 36) cooperating with the snap-in guide element (33)
such that change-over between the two locking positions is obtained by rotation, regularly in the same sense of rotation (57), of the second locking element (36), which is not longitudinally guided by the snap-in guide element (33), in relation to the first locking element (30), which is longitudinally guided; and
such that the locking positions are obtained by locking cooperation of the second locking element (36) with the snap-in guide element (33).
3. A compression spring according to claim 2, wherein the longitudinally guided locking element (30) comprises an intermediate stop (61) for defined motion of rotation of the second locking element (36) such that, prior to the second locking element (36) cooperating with the snap-in guide element (33) for locking engagement, the longitudinally guided locking element (30) disengages from catching recess (35) of the second locking element (36), by way of which the second locking element (36) cooperates with the snap-in guide element (33) for locking engagement.
4. A compression spring according to claim 3, wherein the intermediate stop (61) is inclined such that the motion of rotation of the second locking element (36) supports a motion of displacement of the longitudinally guided locking element (30) for disengagement thereof from the catching recess (35) of the second locking element (36).
5. A compression spring according to claim 2, wherein the longitudinally guided locking element (30) has inclined delivery wall sections (46, 56), along which the second locking element (36) slides upon displacement from the position of release into the position of blocking and from the position of blocking into the position of release, one and the same delivery wall section (56) of the longitudinally guided locking element (30) being used for displacement from the position of release into the position of blocking as well as for displacement from the position of blocking into the position of release.
6. A compression spring according to claim 1, wherein change-over is obtained by rotation of the second locking element (36) by 180\xb0.
7. A compression spring according to claim 1, wherein one of the locking elements (30) is integrally joined to a valve-operating rod (26), by way of which the operating element (27, 28) cooperates with the valve pin (22) via the locking mechanism (29).