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US 2013/0172761 A1Published application
Method, apparatus and program for the automatic processing of blood pressure signals
OwnerSalvatore Romanoinventor
Life of this patent
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Abstract
The invention concerns an automated method, a system and means for processing the blood pressure from a detected pressure signal, the method operating in the time domain to determine a value (RES) connected to the energy efficiency of the monitored biological system.
Claims17
A method for automatic processing of blood pressure signals, the method comprising at least the following steps:
- A. sampling a detected pressure signal for one or more heartbeats, each heartbeat starting at an initial instant coinciding to that of an initial diastolic pressure and ending at a final instant coinciding to that of subsequent diastolic pressure and comprising a dicrotic point, each heartbeat having a systolic phase comprised between the initial diastolic point and the dicrotic point;
- B. automatically analyzing and discriminating a morphology of the sampled pressure signal for each heartbeat, determining an instant and pressure value of one or more characteristic points of the pressure signal selected from one or more of a point of initial diastolic blood pressure, a point of systolic pressure, a dicrotic point and one or more resonance points, each of which occurs when a second derivative of the pressure signal has a relative maximum, wherein at least a characteristic point of the pressure signal belongs to the systolic phase of the heartbeat and is different from the point of initial diastolic pressure;
- and
- C. for each heartbeat determining an energy efficiency value through the following sub-steps:
- determining a direct dynamic pressure wave impedance for each of said one or more characteristic points belonging to the systolic phase of the heartbeat into consideration with an exception of the point of initial diastolic pressure, said direct dynamic pressure impedance being given by a ratio between a value of the pressure signal in the characteristic point and a distance of the instant from the initial instant of the heartbeat into consideration, and determining an impedance of a direct pressure wave by adding with alternating signs the values of the dynamic direct impedances ordered according to a direct temporal order starting from the initial instant of the heartbeat into consideration up to the dicrotic instant, applying a positive sign to the first dynamic direct impedance according to the direct temporal order;
- for each of said one or more characteristic points determining a dynamic reflected impedance that is given by the ratio between the pressure at the characteristic point and the distance of the respective instant from the instant of a final beat, and determining the value of an impedance of reflected waves of pressure is obtained by adding the dynamic impedances with alternating signs of the second set of points thus determined, sorted according to a reverse temporal order starting from the instant of the final beat to the instant of the initial diastolic pressure, giving a positive sign to the first dynamic impedance according to the reverse temporal order;
- and
- determining said energy efficiency as the ratio between the impedance of the direct wave pressure and the impedance of the reflected waves.
5 more elements
An automatic apparatus for processing blood pressure signal, the apparatus comprising:
- processing means for executing the steps of a method comprising the steps of:
- A. sampling a detected pressure signal for one or more heartbeats, each heartbeat starting at an initial instant coinciding to that of an initial diastolic pressure and ending at a final instant coinciding to that of subsequent diastolic pressure and comprising a dicrotic point, each heartbeat having a systolic phase comprised between the initial diastolic point and the dicrotic point;
- B. automatically analyzing and discriminating a morphology of the sampled pressure signal for each heartbeat, determining an instant and pressure value of one or more characteristic points of the pressure signal selected from one or more of a point of initial diastolic blood pressure, a point of systolic pressure, a dicrotic point and one or more resonance points, each of which occurs when a second derivative of the pressure signal has a relative maximum, wherein at least a characteristic point of the pressure signal belongs to the systolic phase of the heartbeat and is different from the point of initial diastolic pressure;
- and
- C. for each heartbeat determining an energy efficiency value through the following sub-steps:
- determining a direct dynamic pressure wave impedance for each of said one or more characteristic points belonging to the systolic phase of the heartbeat into consideration with an exception of the point of initial diastolic pressure, said direct dynamic pressure impedance being given by a ratio between a value of the pressure signal in the characteristic point and a distance of the instant from the initial instant of the heartbeat into consideration, and determining an impedance of a direct pressure wave by adding with alternating signs the values of the dynamic direct impedances ordered according to a direct temporal order starting from the initial instant of the heartbeat into consideration up to the dicrotic instant, applying a positive sign to the first dynamic direct impedance according to the direct temporal order;
- for each of said one or more characteristic points determining a dynamic reflected impedance that is given by the ratio between the pressure at the characteristic point and the distance of the respective instant from the instant of a final beat, and determining the value of an impedance of reflected waves of pressure is obtained by adding the dynamic impedances with alternating signs of the second set of points thus determined, sorted according to a reverse temporal order starting from the instant of the final beat to the instant of the initial diastolic pressure, giving a positive sign to the first dynamic impedance according to the reverse temporal order;
- and
- determining said energy efficiency as the ratio between the impedance of the direct wave pressure and the impedance of the reflected waves.
6 more elements
A computer program, comprising coded means for executing, when operating in connection with processing means of an apparatus, the steps of a method comprising the steps of:
- A. sampling a detected pressure signal for one or more heartbeats, each heartbeat starting at an initial instant coinciding to that of an initial diastolic pressure and ending at a final instant coinciding to that of subsequent diastolic pressure and comprising a dicrotic point, each heartbeat having a systolic phase comprised between the initial diastolic point and the dicrotic point;
- B. automatically analyzing and discriminating a morphology of the sampled pressure signal for each heartbeat, determining an instant and pressure value of one or more characteristic points of the pressure signal selected from one or more of a point of initial diastolic blood pressure, a point of systolic pressure, a dicrotic point and one or more resonance points, each of which occurs when a second derivative of the pressure signal has a relative maximum, wherein at least a characteristic point of the pressure signal belongs to the systolic phase of the heartbeat and is different from the point of initial diastolic pressure;
- and
- C. for each heartbeat determining an energy efficiency value through the following sub-steps:
- determining a direct dynamic pressure wave impedance for each of said one or more characteristic points belonging to the systolic phase of the heartbeat into consideration with an exception of the point of initial diastolic pressure, said direct dynamic pressure impedance being given by a ratio between a value of the pressure signal in the characteristic point and a distance of the instant from the initial instant of the heartbeat into consideration, and determining an impedance of a direct pressure wave by adding with alternating signs the values of the dynamic direct impedances ordered according to a direct temporal order starting from the initial instant of the heartbeat into consideration up to the dicrotic instant, applying a positive sign to the first dynamic direct impedance according to the direct temporal order;
- for each of said one or more characteristic points determining a dynamic reflected impedance that is given by the ratio between the pressure at the characteristic point and the distance of the respective instant from the instant of a final beat, and determining the value of an impedance of reflected waves of pressure is obtained by adding the dynamic impedances with alternating signs of the second set of points thus determined, sorted according to a reverse temporal order starting from the instant of the final beat to the instant of the initial diastolic pressure, giving a positive sign to the first dynamic impedance according to the reverse temporal order;
- and
- determining said energy efficiency as the ratio between the impedance of the direct wave pressure and the impedance of the reflected waves.
5 more elements
A memory support readable by computer means, the memory comprising a program, said program comprising coded means for executing, when operating in connection with processing means of an apparatus, a method comprising the steps of:
- A. sampling a detected pressure signal for one or more heartbeats, each heartbeat starting at an initial instant coinciding to that of an initial diastolic pressure and ending at a final instant coinciding to that of subsequent diastolic pressure and comprising a dicrotic point, each heartbeat having a systolic phase comprised between the initial diastolic point and the dicrotic point;
- B. automatically analyzing and discriminating a morphology of the sampled pressure signal for each heartbeat, determining an instant and pressure value of one or more characteristic points of the pressure signal selected from one or more of a point of initial diastolic blood pressure, a point of systolic pressure, a dicrotic point and one or more resonance points, each of which occurs when a second derivative of the pressure signal has a relative maximum, wherein at least a characteristic point of the pressure signal belongs to the systolic phase of the heartbeat and is different from the point of initial diastolic pressure;
- and
- C. for each heartbeat determining an energy efficiency value through the following sub-steps:
- determining a direct dynamic pressure wave impedance for each of said one or more characteristic points belonging to the systolic phase of the heartbeat into consideration with an exception of the point of initial diastolic pressure, said direct dynamic pressure impedance being given by a ratio between a value of the pressure signal in the characteristic point and a distance of the instant from the initial instant of the heartbeat into consideration, and determining an impedance of a direct pressure wave by adding with alternating signs the values of the dynamic direct impedances ordered according to a direct temporal order starting from the initial instant of the heartbeat into consideration up to the dicrotic instant, applying a positive sign to the first dynamic direct impedance according to the direct temporal order;
- for each of said one or more characteristic points determining a dynamic reflected impedance that is given by the ratio between the pressure at the characteristic point and the distance of the respective instant from the instant of a final beat, and determining the value of an impedance of reflected waves of pressure is obtained by adding the dynamic impedances with alternating signs of the second set of points thus determined, sorted according to a reverse temporal order starting from the instant of the final beat to the instant of the initial diastolic pressure, giving a positive sign to the first dynamic impedance according to the reverse temporal order;
- and
- determining said energy efficiency as the ratio between the impedance of the direct wave pressure and the impedance of the reflected waves.
5 more elements
Dependencies are inferred from the claim text.