Advanced respiratory monitor and system
Disclosed is a bioimpedance measurement system: A stabilized high frequency current generator is connected to PadSet electrodes via a Patient Cable. Electrodes are connected to an adaptive circuit that conditions the resulting voltage signal and converts it to digital form. Firmware performs signal acquisition and relays data to the device.
1. A respiratory monitoring method, comprising the steps of:
on a processor, determining minute ventilation (MV) and percent of MV predicted of a patient in real time based on bioimpedance signals detected by an electrode padset coupled to the processor and the patient's torso without a need for either calibration to known values or a baseline collected during normal ventilation and without patient cooperation, wherein the percent of MV predicted is based on a ratio of the MV and a predicted MV of the patient; and
outputting the determined percent of MV predicted on at least one graphical user interface (GUI) coupled to the processor in real time.
2. The respiratory monitoring method of claim 1 , further comprising providing an indication of at least one of hyperventilation, normal ventilation, and hypoventilation on the at least one GUI.
3. The respiratory monitoring method of claim 1 , further comprising providing an indication of at least one of hypoventilation, change in respiratory signal waveform, change in inspiratory expiratory ratio, and development of an inspiratory plateau, based on opioid induced respiratory depression on the at least one GUI.
4. The respiratory monitoring method of claim 1 , further comprising providing continuous measurement of ventilation within one minute of entering patient demographics into the processor.
5. The respiratory monitoring method of claim 4 , wherein the demographics are at least one of height, weight and gender of the patient.
6. The respiratory monitoring method of claim 4 , further comprising providing continuous measurement of ventilation without the need for patient specific calibration to a ventilator or a baseline when the patient is breathing normally.
7. The respiratory monitoring method of claim 1 , further comprising providing continuous measurement of ventilation as soon as the electrode padset is attached to the processor without entering demographic data.
8. The respiratory monitoring method of claim 1 , further comprising determining the MV and percent of MV predicted without requiring control over the patient's breathing.
9. The respiratory monitoring method of claim 1 , further comprising determining the MV and percent of MV predicted without requiring calibration of the processor to a known ventilator, spirometer, or pneumotachometer reading.
10. The respiratory monitoring method of claim 1 , further comprising filtering respiratory and cardiac signals based on a heat rate cutoff point with HR-RR cutoff filter filters.
11. The respiratory monitoring method of claim 10 , wherein the heart rate cutoff point is one of 30, 40, 50, or 60 beats per minute (bpm).
12. The respiratory monitoring method of claim 10 , wherein the heart rate cutoff point is based on at least one of patient demographics, MV or percentages of predicted MV, and a rapid shallow breathing index.
13. The respiratory monitoring method of claim 10 , wherein the heart rate cutoff point is entered manually into the HR-RR filter or is automatically updated by the processor.
14. The respiratory monitoring method of claim 10 , wherein the HR-RR cutoff filter provides at least one of a measure of gain of the bioimpedance signal, a scaling factor for an absolute value of bioimpedance trace displayed on the at least one GUI, an indication of a decrease in tidal volume, an indication of sedation level, and a diagnosis of respiratory disease.
15. The respiratory monitoring method of claim 1 , further comprising issuing an alert based on at least one of patient disease state, physician assessment, clinical or treatment environment, additional physiologic measurements, or an external reference with at least one audible or visual alarm.
16. The respiratory monitoring method of claim 15 , wherein the at least one audible or visual alarm is configured to be adaptive.
17. The respiratory monitoring method of claim 1 , wherein the predicted MV is based on patients' height, weight, and gender.
18. The respiratory monitoring method of claim 1 , wherein the method is for use on the patient when the patient is one of awake, unconscious, alert, in extremis, intubated on a ventilator, in respiratory distress, or after sedation.
19. The respiratory monitoring method of claim 1 , wherein the method is for non-invasive use.
20. The respiratory monitoring method of claim 1 , wherein a patient cable is adapted to transmit a high frequency current to the patient via the electrode padset.