Non-invasive blood pressure measurement devices, systems and methods
AssigneeStryker Corporation
InventorClinton T. Siedenburg
Life of this patent
Estimating the term…
Abstract
The disclosed non-invasive blood pressure measurement systems and methods using the conservation of mass, conservation of momentum, and/or constitutive equation(s), which may also include the water hammer equation use pulse wave velocity and blood velocity. There are multiple manners by which pulse wave velocity and blood velocity may be assessed by transmitting energy, such as light or ultrasound, through tissues of the patient and measuring values and times of reflectivity of the energy from the interrogated tissues. Blood pressure can be determined from the one or more manners of assessing the PWV, blood velocity, and blood flow profile.
Claims19
A non-invasive blood pressure (NIBP) device, comprising:
- a transducer configured to:
- emit ultrasound towards a blood vessel of a patient;
- and
- detect a reflection of the ultrasound from the blood vessel;
- and
- a processor configured to:
- determine, by analyzing the reflection of the ultrasound, a change in a geometry of a radial cross section of a blood vessel caused by an ultrasound pulse;
- determine a strain on the blood vessel caused by the ultrasound pulse by analyzing the change in the geometry of the radial cross-section of the blood vessel;
- determine a Young's modulus of the blood vessel as a function of the stress on the blood vessel caused by the ultrasound pulse and the strain on the blood vessel caused by the ultrasound pulse;
- and
- determine a blood pressure of the patient as a function of the Young's modulus and a velocity of blood flowing through the blood vessel.
A method, comprising:
- emitting, by a transducer, ultrasound directed towards a blood vessel of a patient, the wave having energy;
- detecting, by the transducer, a reflection of the ultrasound from the blood vessel;
- determining, based on the reflection of the ultrasound, a change in a geometry of a radial cross-section of the blood vessel caused by an ultrasound pulse;
- determining a strain on the blood vessel caused by the ultrasound pulse by analyzing the change in the geometry of the radial cross-section;
- determining a Young's modulus of the blood vessel as a function of the strain on the blood vessel caused by the pulse and a stress on the blood vessel caused by the pulse;
- and
- determining a blood pressure as a function of the Young's modulus and a velocity of blood flowing through the blood vessel.
A method performed by a medical device, the method comprising:
- determining a velocity of blood flowing through a blood vessel;
- emitting, by a first transducer, ultrasound pulses toward the blood vessel;
- determining an amount of force applied to the blood vessel by the ultrasound pulses;
- determining an area over which the force is applied to the blood vessel by the ultrasound pulses;
- determining a stress on the blood vessel as a function of the amount of force and the area over which the force is applied to the blood vessel by the ultrasound pulses;
- emitting, by a second transducer, an ultrasound signal toward the blood vessel;
- detecting, by the second transducer, a reflection of the ultrasound signal from the blood vessel;
- determining, by analyzing the reflection of the ultrasound signal, a change in a circumference of a radial cross-section of the blood vessel caused by the ultrasound pulses;
- determining a strain on the blood vessel as a function of the change in the circumference of the radial cross-section of the blood vessel and the circumference of the radial cross-section of the blood vessel;
- determining a pulse wave velocity of the blood vessel as a function of the stress and the strain;
- determining a blood pressure of the blood vessel by multiplying the velocity of the blood flowing through the blood vessel and the pulse wave velocity of the blood vessel;
- and
- outputting the blood pressure.
Dependencies are inferred from the claim text.