Abstract: An automated assessment of a patient's peripheral vascular condition includes using a pulse oximeter to generate at least a perfusion index relative to a limb or digit of the patient. Pressure is applied to the limb or digit, and while increasing or decreasing the pressure, a change in the perfusion index is determined. The change is indicative of a cessation of blood flow or a return of blood flow in the limb or digit. A systolic blood pressure is thereafter determined based on the pressure applied at the time of cessation of blood flow or the return of blood flow in the limb or digit. Using a pulse oximeter to generate a perfusion index may include transmitting light into the limb or digit, detecting light that was transmitted into tissue in the limb or digit, and calculating the perfusion index based on the light transmitted through the tissue.

Abstract: An automated assessment of a patient's peripheral vascular condition includes using a pulse oximeter to generate at least a perfusion index relative to a limb or digit of the patient. Pressure is applied to the limb or digit, and while increasing or decreasing the pressure, a change in the perfusion index is determined. The change is indicative of a cessation of blood flow or a return of blood flow in the limb or digit. A systolic blood pressure is thereafter determined based on the pressure applied at the time of cessation of blood flow or the return of blood flow in the limb or digit. Using a pulse oximeter to generate a perfusion index may include transmitting light into the limb or digit, detecting light that was transmitted into tissue in the limb or digit, and calculating the perfusion index based on the light transmitted through the tissue.

Abstract: An automated assessment of a patient's peripheral vascular condition includes using a pulse oximeter to generate at least a perfusion index relative to a limb or digit of the patient. Pressure is applied to the limb or digit, and while increasing or decreasing the pressure, a change in the perfusion index is determined. The change is indicative of a cessation of blood flow or a return of blood flow in the limb or digit. A systolic blood pressure is thereafter determined based on the pressure applied at the time of cessation of blood flow or the return of blood flow in the limb or digit. Using a pulse oximeter to generate a perfusion index may include transmitting light into the limb or digit, detecting light that was transmitted into tissue in the limb or digit, and calculating the perfusion index based on the light transmitted through the tissue.

Abstract: Current-responsive light-emitting diodes of different colors are provided adjacent to the tip of the hand-held transducer probe of a medical Doppler device. Mechanism is provided to actuate the diodes of one color when the direction of internal body matter detected by the Doppler device is toward the probe and to actuate lights of a different color when the direction of detected internal body matter is away from the probe. In addition, power supply to the diodes is controlled so that increasing brightness indicates increasing velocity of the detected internal body matter.

Abstract: The analog broadband output signal of a medical Doppler device is sampled at a constant rate to convert the signal to digital form. The sample values are stored consecutively in a random access memory component. Such values are recalled from such component at a readout rate different from the sampling rate so as to create a frequency-shifted intermediate broadband signal corresponding to the Doppler output signal. Such intermediate signal is filtered and the power of the filtered intermediate signal is continuously compared to the power of the unfiltered intermediate signal. The readout rate from the memory component is adjusted to maintain approximately the same proportionate relationship of the power of the filtered intermediate signal to the power of the unfiltered intermediate signal. The continuously adjusted readout rate from the memory component indicates a "band edge" frequency above or below which a preselected proportion of the total power of the Doppler signal resides.