Abstract: A method, and a device utilizing that method, for continuously, noninvasively measuring a patient's blood pressure. Discrete values of systolic and diastolic blood pressure are noninvasively determined and input to a microprocessor. A continuous non-pressure waveform signal is generated through noninvasive monitoring of the patient and is also input to the microprocessor. The microprocessor calibrates the continuous non-pressure waveform signal using the discrete blood pressure values, thereby generating a continuous waveform signal of blood pressure.

Abstract: Method and apparatus are disclosed for determination and display of hemodynamic characteristic values of a patient in a variety of statistical forms and in relative or absolute terms, the measurement determination being made by non-invasive impedance plethysmography under control of a central processor. A characteristic value representative of variation of blood vessel cross-sectional area is measured across a patient's body section, blood pressure is measured in the body in simultaneity with the characteristic value, and signals representative of the characteristic value and blood pressure are then processed to obtain the hemodynamic characteristic values.

Abstract: A sterile preparation of synthetic erythrocytes consisting of hemoglobin fraction encapsulated within water-immiscible amphiphylic membranes provides a total hemoglobin of at least about 12 gm percent at a hematocrit of 50%. A lipid composition is prepared and dispersed by agitation in a sterile, stroma-free 30-45 gram percent hemoglobin fraction. The dispersion is pressurized to between about 400 to about 900 kg/cm.sup.2, and the pressure is substantially instantaneously released by passing the mixture to a lower pressure region through an orifice having an area of between about 0.1 and about 10.0 mm.sup.2, thereby forming the synthetic erythrocytes. The preparation is filtered through a filter which passes particles having a diameter less than about 0.22 micron to eliminate any monocellular organisms that may be present and to eliminate larger synthetic erythrocytes.

Abstract: A method and apparatus for determining and displaying hemodynamic characteristics of a living body instantaneously and over a time period, i.e., rate of blood flow, stroke volume, cardiac output, cardiac index, systemic vascular resistance, useful power of the heart and elastic properties of the walls of blood vessels. The improved method and apparatus deal with physical measurements of body electrical impedance and blood pressure in relationship with other known or derived factors to produce signals representing these characteristics and which may be displayed for the information of surgeons or others who may be interested in this information.

Abstract: Synthetic erythrocytes. Hemoglobin is encapsulated in lipid materials to form cells which are typically 0.1 to 10 microns in their greatest dimension. Preferably cholesterol and one or more phospholipids are included in the cell membrane. The lipid membrane is of such character and thinness that O.sub.2 --CO.sub.2 transfer thereacross is readily accomplished. The preferred encapsulation process utilizes ultrasonic energy.

Abstract: A method and apparatus for determining and displaying without invasion into the vascular system the instantaneous rate of blood flow, the stroke volume during a pulse or cycle, and the cardiac output over a time period. The system involves an arrangement of electronic units through which a signal representing impedance of a section of a living body is passed in a special order and which results in instantaneous and continuous indication of blood flow characteristics through this section.A principal feature of the system resides in the provision of two electrical channels one of which contains an electronic divider and the other an electronic differentiator both of which channels are connected with a multiplier which multiplies the signal from one channel with the signal from the other channel to produce a signal representative of the rate of instantaneous blood flow through the body section being tested.