Heart-related parameters monitoring apparatus

Claim 1

Apparatus for determining the magnitude of heart-related parameters in a patient; comprising; means for detecting blood volume, and thereby blood volume variation, in said patient, and for providing a signal representative of said blood volume, and thereby said blood volume variation; said means for detecting being attachable to said patient to thereby detect said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said minimum amplitude and said maximum amplitude, a maximum rate of change of said signal being representative of the maximum rate of increase of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum rate of change of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; means for measuring said maximum amplitude, said minimum aplitude, said maximum rate of change of said signal, said first difference, said second different, said first time interval, and said second time interval; and means for calculating the magnitude of selected ones of said parameters, said means for calculating being connected to both said means for detecting and means for measuring; wherein means for calculating calculates the magnitude of the pulse pressure parameter in accordance with the following expression; ##EQU17## wherein P pi =pulse pressure during cycle i K pp =constant determined by a first calibration r 1 =constant r 2 =constant R il =(ΔV iVm /ΔV i ) where ΔV iVm =volume change at time t iVm during cycle i corresponding to maximum rate of volume change, V imax ΔV i =maximum volume change during cycle i Δt iVm =time interval from start of cycle i to time of maximum rate of volume change V imax .

Claim 11

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the pulse pressure parameter in accordance with the following expression: ##EQU22## wherein P pi =pulse pressure during cycle i K pp =constant determined by a first calibration r 1 =constant r 2 =constant R il =(ΔV iVm /ΔV i ) where .[.ΔV iVm =volume change at time t iVm during cycle i corresponding to maximum rate of volume change, V imax .]. .Iadd.ΔV iVm =volume change at time t iVm during cycle i corresponding to maximum rate of volume change, V imax .Iaddend. ΔV i =maximum volume change during cycle i Δt iVm =time interval from start of cycle i to time of maximum rate of volume change V imax .

Claim 12

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the pulse pressure parameter in accordance with the following expression: ##EQU22## wherein P pi =pulse pressure during cycle i K pp =constant determined by a first calibration r 1 =constant r 2 =constant R il =(ΔV iVm /ΔV i ) where .[.ΔV iVm =volume change at time t iVm during cycle i corresponding to maximum rate of volume change, V imax .]. .Iadd.ΔV iVm =volume change at time t iVm during cycle i corresponding to maximum rate of volume change, V imax .Iaddend. ΔV i =maximum volume change during cycle i Δt iVm =time interval from start of cycle i to time of maximum rate of volume change V imax .

Claim 13

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the mean .[.artial.]. .Iadd.arterial .Iaddend.pressure P mi in accordance with the following expression: ##EQU23## where K 4 =constant determined for each subject b 3 =constant P mmi =pseudo mean arterial blood pressure during cycle i ΔV i =maximum volume change during cycle i ΔV imax =maximum time rate of change of ΔV i =V imax ##EQU24##

Claim 14

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the mean .[.artial.]. .Iadd.arterial .Iaddend.pressure P mi in accordance with the following expression: ##EQU23## where K 4 =constant determined for each subject b 3 =constant P mmi =pseudo mean arterial blood pressure during cycle i ΔV i =maximum volume change during cycle i ΔV imax =maximum time rate of change of ΔV i =V imax ##EQU24##

Claim 15

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the systolic pressure (P si parameter in accordance with the following expression: P.sub.si =P.sub.mi +(1-g.sub.0)P.sub. pi wherein g 0 =constant.

Claim 16

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the systolic pressure (P si parameter in accordance with the following expression: P.sub.si =P.sub.mi +(1-g.sub.0)P.sub. pi wherein g 0 =constant.

Claim 17

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representive of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the systolic pressure (P si ) parameter in accordance with the following expression: P.sub.si =P.sub.mi +(1-g.sub.i)P.sub. pi wherein: g i =(ΔV iAV /ΔV i ) P pi =pulse pressure during cycle i ΔV i =represented by said first difference ΔV iAV =represented by the difference between said minimum amplitude and an amplitude equal to the average value of a pulse in a cycle i.

Claim 18

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representive of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the systolic pressure (P si ) parameter in accordance with the following expression: P.sub.si =P.sub.mi +(1-g.sub.i)P.sub. pi wherein: g i =(ΔV iAV /ΔV i ) P pi =pulse pressure during cycle i ΔV i =represented by said first difference ΔV iAV =represented by the difference between said minimum amplitude and an amplitude equal to the average value of a pulse in a cycle i.

Claim 19

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the arterial blood pressure, P mi parameter in accordance with the following expression: ##EQU25## where K 4 =constant determined for each subject b 3 =constant P mmi =pseudo mean arterial blood pressure during cycle i ΔV i =maximum volume change during cycle i ΔV imax =maximum time rate of change of V i =V imax P o =constant G(t)=a function of t and T.

Claim 20

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the arterial blood pressure, P mi parameter in accordance with the following expression: ##EQU25## where K 4 =constant determined for each subject b 3 =constant P mmi =pseudo mean arterial blood pressure during cycle i ΔV i =maximum volume change during cycle i ΔV imax =maximum time rate of change of V i =V imax P o =constant G(t)=a function of t and T.

Claim 23

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of .[.charge.]. .Iadd.change .Iaddend.of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the pulse pressure parameter in accordance with the following expression: ##EQU27## wherein P pi =pulse pressure during cycle i K pp =constant determined by a first calibration r 1 =constant r 2 =constant R i1 =(ΔV iVm /V i ) where ΔV iVm =volume change at preselected time t iVm during cycle i ΔV i =maximum volume change during cycle i Δt iVm =time interval from start of cylcle i to predetermined time of t iVm .

Claim 24

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of .[.charge.]. .Iadd.change .Iaddend.of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the pulse pressure parameter in accordance with the following expression: ##EQU27## wherein P pi =pulse pressure during cycle i K pp =constant determined by a first calibration r 1 =constant r 2 =constant R i1 =(ΔV iVm /V i ) where ΔV iVm =volume change at preselected time t iVm during cycle i ΔV i =maximum volume change during cycle i Δt iVm =time interval from start of cylcle i to predetermined time of t iVm .

Claim 27

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal .[.representation.]. .Iadd.representative .Iaddend.of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of mean pulse pressure in accordance with the following expression: .[.(1) P mi =K 1 r ic a .]. .Iadd.(1) P' mi =K l r ic a .Iaddend. where K 1 =calibration constant .[.P' mi =(P s +P d )/2-P o .]. .Iadd.P' mi =(P si +P di )/2-P o .Iaddend. P si =systolic blood pressure, in cycle i .[.P mi =(P s +P d )/2.]. .Iadd.P mi =(P si +P di )/2 .Iaddend. P di =diastolic blood pressure, in cycle i a=constant P o =constant.

Claim 28

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal .[.representation.]. .Iadd.representative .Iaddend.of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of mean pulse pressure in accordance with the following expression: .[.(1) P mi =K 1 r ic a .]. .Iadd.(1) P' mi =K l r ic a .Iaddend. where K 1 =calibration constant .[.P' mi =(P s +P d )/2-P o .]. .Iadd.P' mi =(P si +P di )/2-P o .Iaddend. P si =systolic blood pressure, in cycle i .[.P mi =(P s +P d )/2.]. .Iadd.P mi =(P si +P di )/2 .Iaddend. P di =diastolic blood pressure, in cycle i a=constant P o =constant.

Claim 31

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and the said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and wherein the means for calculating calculates implicitly the magnitude of mean pulse pressure in accordance with the following .[.expressure.]. .Iadd.expression.Iaddend.: ##EQU29## where P mo =constant at calibration φ 1i +φ 2i =PP i =pulse pressure during cycle i k=constant j=constant .[.P 2i =P mo +φ 2i +P o .]. .Iadd.P si =P mo +φ 2i +P o .Iaddend. P di =P mo -φ 1i +P o P mi =(P.sub. si +P di )/2 P o =constant r i =ratio of exponentials K 3 =coefficient (variable or constant). .Iadd.

Claim 32

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and the said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and wherein the means for calculating calculates implicitly the magnitude of mean pulse pressure in accordance with the following .[.expressure.]. .Iadd.expression.Iaddend.: ##EQU29## where P mo =constant at calibration φ 1i +φ 2i =PP i =pulse pressure during cycle i k=constant j=constant .[.P 2i =P mo +φ 2i +P o .]. .Iadd.P si =P mo +φ 2i +P o .Iaddend. P di =P mo -φ 1i +P o P mi =(P.sub. si +P di )/2 P o =constant r i =ratio of exponentials K 3 =coefficient (variable or constant). .Iadd.

Claim 35

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the mean arterial pressure P mi in accordance with the following expression: ##EQU31## where PP i =Pulse Pressure=P s -P d P s =Systolic blood pressure P d =Diastolic blood pressure k=constant K'=constant.

Claim 36

A method for determining the magnitude of heart-related parameters in a patient; comprising: detecting blood volume, and thereby blood volume variation, in said patient and providing a signal representative of said blood volume, and thereby said blood volume variation; said blood volume variation being cyclic in nature whereby said signal comprises a cyclic curve having, in each cycle of variation, a variable slope, a maximum amplitude representative of the maximum amount of blood volume, a minimum amplitude representative of the minimum amount of blood volume, a first time interval between said maximum amplitude and said minimum amplitude, a maximum rate of change of said signal being representative of the maximum rate of change of blood volume, a second time interval between the minimum amplitude and the time of the maximum rate of change of said signal, a first difference in amplitude between said maximum amplitude and said minimum amplitude, a second difference in amplitude between the maximum amplitude and the amplitude at the time of maximum change of rate of said signal being representative of the difference in volume between the maximum amount of blood volume and the volume at the time of maximum rate of change of said blood volume, and a pulse repetition period; measuring said maximum amplitude, said minimum amplitude, said maximum rate of change of said signal, said first difference, said second difference, said first time interval, and said second time interval; and calculating the magnitude of the mean arterial pressure P mi in accordance with the following expression: ##EQU31## where PP i =Pulse Pressure=P s -P d P s =Systolic blood pressure P d =Diastolic blood pressure k=constant K'=constant.