Device for non-invasive measurement of blood pressure and ankle-brachial index
AssigneeSmithmarks, Inc.
InventorsLloyd A. Marks, Michael Smith
Life of this patent
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Abstract
A device for non-invasive measurement of blood pressure includes a blood pressure cuff, a plethysmographic electrode for acquiring an impedance plethysmogram distal to the cuff and a processing device to inflate and deflate the cuff, generate the impedance plethysmogram and to determine the systolic and diastolic blood pressures. It is determined when the cuff is completely occluding the extremity, e.g., by detecting pulses at a second, partially occluded cuff or by a photoplethysmogram attached to the big toe. The device can be used to measure systolic or diastolic blood pressure or both. It can also be used to take ankle-brachial measurements. An autocorrelation technique can be used to correct noise.
Claims35
A method for non-invasively measuring blood pressure of a patient, the method comprising:
- (a) attaching a pressure cuff to an extremity of the patient;
- (b) attaching a plethysmographic device to the extremity at a distal location relative to the pressure cuff;
- (c) inflating the cuff to cause occlusion in the extremity and deflating the cuff;
- (d) determining when the cuff has caused complete occlusion in step (c) by using a device for determining the complete occlusion;
- (e) taking a series of waveforms representing blood pulsations by using the plethysmographic device;
- (f) measuring the blood pressure from the waveforms in a processor by multiplying corresponding points in groups of the waveforms in the processor to produce product waveforms and measuring the blood pressure from the product waveforms;
- and
- (g) outputting the blood pressure measured in step (f) from the processor.
A device for non-invasively measuring blood pressure of a patient, the device comprising:
- (a) a pressure cuff for attachment to an extremity of the patient;
- (b) a plethysmographic device for attachment to the extremity at a distal location relative to the pressure cuff;
- (c) a device for determining when the cuff has caused complete occlusion;
- (d) a processor, connected to the pressure cuff and the plethysmographic device, for inflating and deflating the cuff, taking a series of waveforms representing blood pulsations by using the plethysmographic device, multiplying corresponding points in groups of the waveforms to produce product waveforms, and measuring the blood pressure from the product waveforms;
- and
- (e) an output for outputting the blood pressure measured by the processor.
Dependencies are inferred from the claim text.