Device and system that identifies cardiovascular insufficiency
First Claim
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1. A computer-assisted method for identifying a volume status of a patient, the method comprising:
- administering a cardiovascular preload to the patient;
continuously recording, prior to, during, and after the step of administering the cardiovascular preload to the patient, a pulse density signal from a non-invasive transducer transmitting data from the patient;
applying, using a processor, a first filter to the pulse density signal to identify a first respiration sampling period recorded prior to the step of administering the cardiovascular preload and a second respiration sampling period recorded after the step of administering the cardiovascular preload;
applying, using the processor, a second filter to the pulse density signal to identify a first plurality of cardiac cycles occurring during the first respiration sampling period and a second plurality of cardiac cycles occurring during the second respiration sampling period; and
calculating, using the processor, a variation of the pulse density signal before and after the step of administering the cardiovascular preload, wherein the variation is used as an index of the volume status of the patient, wherein the variation is a quotient of a difference between a mean pulse density signal between the second and the first respiration sampling periods to a sum of the mean pulse density signal of the second and the first respiration sampling periods, wherein the mean pulse density signal for each respiration sampling period is a quotient of a sum of a difference between a maximum point on the pulse density signal and a minimum point on the pulse density signal for each cardiac cycle occurring during such respiration sampling period to a total number of cardiac cycles occurring during such respiration sampling period.
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Abstract
A system and method for identifying volume status of a patient are disclosed. A pulse density signal is recorded from the patient. The pulse density signal is filtered to capture a respiration sampling period and a plurality of cardiac cycles occurring during the respiration sampling period. Mean pulse pressure and peak blood flow velocity for the respiration sampling period are calculated and are used as indices of volume status of the patient.
21 Citations
25 Claims
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1. A computer-assisted method for identifying a volume status of a patient, the method comprising:
administering a cardiovascular preload to the patient; continuously recording, prior to, during, and after the step of administering the cardiovascular preload to the patient, a pulse density signal from a non-invasive transducer transmitting data from the patient; applying, using a processor, a first filter to the pulse density signal to identify a first respiration sampling period recorded prior to the step of administering the cardiovascular preload and a second respiration sampling period recorded after the step of administering the cardiovascular preload; applying, using the processor, a second filter to the pulse density signal to identify a first plurality of cardiac cycles occurring during the first respiration sampling period and a second plurality of cardiac cycles occurring during the second respiration sampling period; and calculating, using the processor, a variation of the pulse density signal before and after the step of administering the cardiovascular preload, wherein the variation is used as an index of the volume status of the patient, wherein the variation is a quotient of a difference between a mean pulse density signal between the second and the first respiration sampling periods to a sum of the mean pulse density signal of the second and the first respiration sampling periods, wherein the mean pulse density signal for each respiration sampling period is a quotient of a sum of a difference between a maximum point on the pulse density signal and a minimum point on the pulse density signal for each cardiac cycle occurring during such respiration sampling period to a total number of cardiac cycles occurring during such respiration sampling period. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A system for identifying a volume status of a patient, the system comprising:
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an activator that administers a cardiovascular preload to the patient; a sensor that records a pulse density signal from a non-invasive transducer transmitting data from the patient prior to, during, and after the cardiovascular preload is administered to the patient; a controller that controls the sensor to initiate the record of the pulse density signal; a processor that is configured to;
(i) apply a first filter to filter the pulse density signal to identify a first respiration sampling period and a second respiration sampling period, (ii) apply a second filter to filter the pulse density signal to identify a first plurality of cardiac cycles occurring during the first respiration sampling period and a second plurality of cardiac cycles occurring during the second respiration sampling period, and (iii) calculate a variation of the pulse density signal before and after the cardiovascular preload is administered to the patient, wherein the variation is used as an index of the volume status of the patient, wherein the variation is a quotient of a difference between a mean pulse density signal between the second and the first respiration sampling periods to a sum of the mean pulse density signal of the second and the first respiration sampling periods, wherein the mean pulse density signal for each respiration sampling period is a quotient of a sum of a difference between a maximum point on the pulse density signal and a minimum point on the pulse density signal for each cardiac cycle occurring during such respiration sampling period to a total number of cardiac cycles occurring during such respiration sampling period. - View Dependent Claims (8, 9, 10, 11)
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12. A system for identifying a volume status of a patient, the system comprising:
an activator that administers a cardiovascular preload to the patient; a sensor that records a pulse density signal from a non-invasive transducer transmitting data from the patient prior to, during, and after the cardiovascular preload is administered to the patient; a controller that controls the sensor to initiate the record of the pulse density signal; a signal conditioning module comprising an amplifier that amplifies the pulse density signal and a converter that converts the amplified signal to a digital signal, the signal conditioning module being configured to transmit the converted, amplified signal; a signal processing module configured to;
(i) receive the converted, amplified signal from the signal conditioning module, (ii) apply a first filter to filter the signal to identify a first respiration sampling period and a second respiration sampling period, (iii) apply a second filter to filter the signal to identify a first plurality of cardiac cycles occurring during the first respiration sampling period and a second plurality of cardiac cycles occurring during the second respiration sampling period, and (iv) calculate a variation of the pulse density signal before and after the cardiovascular preload is administered to the patient, wherein the variation is used as an index of the volume status of the patient, wherein the variation is a quotient of a difference between a mean pulse density signal between the second and the first respiration sampling periods to a sum of the mean pulse density signal of the second and the first respiration sampling periods, wherein the mean pulse density signal for each respiration sampling period is a quotient of a sum of a difference between a maximum point on the pulse density signal and a minimum point on the pulse density signal for each cardiac cycle occurring during such respiration sampling period to a total number of cardiac cycles occurring during such respiration sampling period.- View Dependent Claims (13, 14, 15, 16)
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17. A non-invasive apparatus configured to identify a volume status of a patient, the apparatus comprising:
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means for administering a cardiovascular preload to the patient means for recording a pulse density signal from a non-invasive transducer transmitting data from the patient prior to, during, and after administering the cardiovascular preload to the patient; means for applying a first filter to the pulse density signal to identify a first respiration sampling period recorded prior to the step of administering the cardiovascular preload and a second respiration sampling period recorded after the step of administering the cardiovascular preload; means for applying a second filter to the pulse density signal to identify a first plurality of cardiac cycles occurring during the first respiration sampling period and second plurality of cardiac cycles occurring during the second respiration sampling period; and means for calculating a variation of the pulse density signal before and after administering the cardiovascular preload, wherein the variation is used as an index of the volume status of the patient, wherein the variation is a quotient of a difference between a mean pulse density signal between the second and the first respiration sampling periods to a sum of the mean pulse density signal of the second and the first respiration sampling periods, wherein the mean pulse density signal for each respiration sampling period is a quotient of a sum of a difference between a maximum point on the pulse density signal and a minimum point on the pulse density signal for each cardiac cycle occurring during such respiration sampling period to a total number of cardiac cycles occurring during such respiration sampling period. - View Dependent Claims (18, 19, 20, 21)
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- 22. A computer-readable medium having stored therein instructions which, when executed by a processor, cause the processor to calculate a variation of a pulse density signal before and after administering a cardiovascular preload, wherein the variation is used as an index of the volume status of the patient, wherein the variation is a quotient of a difference between a mean pulse density signal between a second and a first respiration sampling period to a sum of the mean pulse density signal second and the first respiration sampling periods, wherein the mean pulse density signal for each respiration sampling period is a quotient of a sum of a difference between a maximum point on the pulse density signal and a minimum point on the pulse density signal for each cardiac cycle occurring during such respiration sampling period to a total number of cardiac cycles occurring during such respiration sampling period.
Specification