Abstract: Techniques for imaging a blood vessel are described. A transducer attached to a catheter is guided to a first site within a blood vessel. The catheter is moved to a second site proximal to the first site at a speed selected to enable the transducer to generate a signal indicative of a geometry wall, the lumen, and a portion of the side branch. A first image of the blood vessel obtained from the signal is oriented with a second image of the blood vessel such that a first portion of the first image aligns with a second portion of the second image.

Abstract: In a process for monitoring patients with chronic congestive heart failure, a high frequency current is passed between electrodes applied to two limbs of a patient. The current, voltage and phase angle between the measured current and voltage are measured to enable the calculation of congestive heart failure (CHF) indicia values. The calculated CHF indicia values are then compared with baseline values established when the patient is in a known, stable condition. Intervention is initiated if the differences between the calculated CHF indicia values and the baseline values are outside of established tolerances. The CHF indicia values may include resistance, reactance, impedance, total body water and extracellular water. Moreover, the CHF indicia values may include a figure of merit indicative of the hydration status of the patient.

Abstract: Stenotic regions in the vasculature of chronic hemodialysis patients are detected and monitored by blood velocity measuring.

Abstract: A coronary artery imaging system is described in which a catheter is provided with a forward looking sonic transducer for measuring fluid flow in arteries without disturbing the flow and a side-looking sonic transducer for imaging the arterial walls.

Abstract: In an electrocardiographic system there is a multielement electrode at two skin locations for providing an ECG signal of negligible magnitude between elements because of the close spacing while the pair of elements are sufficiently separated so that the motion of one element is at least partially independent of the motion of the other. Parallel ECG signals are obtained from different elements of two multielement electrodes. The difference between the signals is detected by logical circuitry to produce a signal indicating baseline shift. The elements are coaxial with a 250 K resistor in series with each outer element.

Abstract: In an electrocardiographic system there is a multielement electrode at two skin locations for providing an ECG signal of negligible magnitude between elements because of the close spacing while the pair of elements are sufficiently separated so that the motion of one element is at least partially independent of the motion of the other. Parallel ECG signals are obtained from different elements of two multielement electrodes. The difference between the signals is detected by logical circuitry to produce a signal indicating baseline shift.

Abstract: In an electrocardiographic system there is a multielement electrode at each skin location for providing an ECG signal of negligible magnitude between elements because of the close spacing while the pair of elements are sufficiently separated so that the motion of one element is at least partially independent of the motion of the other; thus, events causing a baseline shift will also cause a difference in potential between the two elements of a multielement electrode. That difference is detected by logical circuitry to produce a signal indicating baseline shift.