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.

Abstract: A stretchable electrode for use in physiologic measurements on a human body, such as peripheral impedance plethysmography, is disclosed. One embodiment of the stretchable electrode comprises an uninsulated stainless steel wire braid formed into a tubular conductor surrounding an elastic core and attached to an elastic substrate or base. Other embodiments of the stretchable electrode include a garter spring, a flat braided or woven conductor and an undulating wire. The electrode may be placed about a limb of a human body and elastically stretched so that the conductor is in substantially continuous circumferential electrical contact with the skin of the limb. A method of attaching the stretchable electrode to the limb of a human body is also disclosed.

Abstract: A stretchable electrode for use in physiologic measurements on a human body, such as peripheral impedance plethysmography, is disclosed. One embodiment of the stretchable electrode comprises an uninsulated stainless steel wire braid formed into a tubular conductor surrounding an elastic core and attached to an elastic substrate or base. Other embodiments of the stretchable electrode include a garter spring, a flat braided or woven conductor and an undulating wire. The electrode is placed about a limb of a human body and elastically stretched so that the conductor is in substantially continuous circumferential electrical contact with the skin of the limb. A method of attaching the stretchable electrode to the limb of a human body is also disclosed.

Abstract: In a system and method for peripheral impedance plethysmography, an electrode for application to the patient's limb includes two outer current electrodes and two inner voltage electrodes. A distance between the two inner electrodes is automatically input into an analyzing device, either as a pre-stored value or as determined automatically from the electrode. Peripheral blood flow is calculated in accordance with that distance.

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. 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.

Abstract: A patient's peripheral pulse volume and blood pressure are measured. The quantities are used to obtain a quantitative measure of peripheral vascular function. The quantitative measure can be one or more of pulsatile limb blood flow, total limb blood flow, limb vascular compliance and limb vascular resistance.

Abstract: The utility of pulse volume measurement is expanded to detection of many conditions which have previously not been detected or have been detected using more complicated techniques. Such conditions include blood loss, septic shock, cardiogenic shock, neonatal sepsis, patent ductus arteriosus, limb ischemia, intra-aortic balloon pump performance, peripheral vascular disease, congestive heart failure, the effectiveness of vasoactive medications, syncope, dehydration, pre-eclampsia, deep vein thrombosis, thermal injuries, vascular instability due to renal dialysis, compromising of circulation to the hand caused by radial artery harvesting, changes in cardiac output, and hypertension. According to the present invention, such diagnoses can be performed by taking one measurement, by taking measurements over time to detect a change or by taking measurements before and after application of a treatment or stimulus.

Abstract: A plethysmographic or other signal is autocorrelated to give a first-pass determination of the distances among individual waveforms. A waveform is isolated, tested to determine whether its amplitude remains in suitable bounds for signal averaging, and convolved with the signal to match it with the other waveforms for averaging. Thus, a separate gating signal is not needed for signal averaging.