Apparatus and method for measuring an induced perturbation to determine blood pressure

A processor for determining a patient's physiological parameter with an apparatus having a calibration device configured to provide a calibration signal representative of the patient's physiological parameter, an exciter positioned over a blood vessel of the patient for inducing a transmitted exciter waveform into the patient, and a noninvasive sensor positioned over said blood vessel, said noninvasive sensor configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of said hemoparameter, said processor comprising:

• a first input configured to receive said calibration signal;
• a second input configured to receive said noninvasive sensor signal;
• a filter configured to separate from said noninvasive sensor signal a component representing a received exciter waveform;
• a relationship routine configured to determine a relationship between a property of said received exciter waveform and a property of said physiological parameter;
• and
• a determination routine configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.

A method of determining a patient's physiological parameter, comprising the steps of:

• providing a calibration signal representative of the patient's physiological parameter and storing the calibration signal;
• inducing a transmitted exciter waveform into the patient;
• noninvasively sensing a hemoparameter, and generating a noninvasive sensor signal representative of said hemoparameter and containing a component of a received exciter waveform;
• determining a relationship between a property of said received exciter waveform and a property of the physiological parameter;
• and
• determining said physiological parameter based at least in part on said calibration signal, said non-invasive sensor signal, and said relationship.

A monitor for determining a patient's blood pressure, comprising:

• an inflatable cuff positioned on an extremity of the patient and configured to provide a calibration signal representative of the patient's physiological parameter;
• an exciter positioned over a blood vessel of the patient and configured to induce a transmitted exciter waveform into the patient;
• a noninvasive sensor, positioned over said blood vessel and at a distance from said exciter, said noninvasive sensor configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of said hemoparameter containing a component of a received exciter waveform;
• a processor configured to determine a relationship between a property of said received exciter waveform and a property of said physiological parameter;
• wherein said processor is connected to receive said calibration signal and said noninvasive sensor signal;
• wherein said processor includes a filter configured to separate from said noninvasive sensor signal a component representing said received exciter waveform;
• and
• wherein said processor is configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.