A wrist-mounted device (101) for measuring at least one physiological parameter (Fig. 5) of a subject. The present invention enables such a measurement to preferably be transformed into clinically useful information about the subject. Such information may then optionally be sent to medical personnel (112), for example at a contact and/or monitoring center (114), through a gateway device (110). The gateway device (110) preferably communicates with the wrist-mounted device (101) of the present invention through a wireless communication channel (121).

Method and device for measuring physiological parameters at the wrist

A multi-parametric vital signs monitoring device configured for use as an ambulatory and a bedside monitor wherein the device can be patient-wearable and is battery powered. The monitoring device can be used with a charging cradle to provide power to the device in lieu of the battery as a power source for bedside applications, in which the cradle further serves as an intermediary device to enable a data link with a PC or other peripheral device. The monitoring device can include a wireless radio to enable bi-directional transfer of patient-related data to a separate remote station.

Vital signs monitor

A method and system is disclosed for operating a medical device with or without a cassette in place. A method is disclosed for adding additional VTBI to an ongoing infusion without stopping the infusion and with maintaining the infusion parameters. A method and system is disclosed for changing the CCA without having to interrupt or completely stop an ongoing infusion. Quick titration buttons are provided to allow improved navigation between various delivery display screens.

User interface improvements for medical devices

The present invention is directed toward a pulse oximetry system for the determination of a physiological parameter capable of removing motion artifacts from physiological signals comprises a hardware subsystem and a software subsystem. The software subsystem is used in conjunction with the hardware subsystem to perform a method for removing a plurality of motion artifacts from the photo-plethysmographic data and for obtaining a measure of at least one physiological parameter from the data. The method comprises acquiring the raw photo-plethysmographic data, transforming the data into the frequency domain, analyzing the transformed data to locate a series of candidate cardiac spectral peaks (primary plus harmonics), reconstructing a photo-plethysmographic signal in the time domain with only the candidate cardiac spectral peaks (primary plus harmonics), computing the second order derivative of the reconstructed photo-plethysmographic signal, analyzing the candidate second order derivative photo-plethysmographic signal to determine the absence or presence of cardiac physiologic signal characteristics, and finally selecting the best physiologic candidate from the series of potential cardiac spectral peaks (primary plus harmonics) based upon a second derivative scoring system. This scoring system is preferentially based upon second derivative processing analysis, but can be equally applied using the first, third, fourth or other similar derivative processing analysis.

Separating motion from cardiac signals using second order derivative of the photo-plethysmogram and fast fourier transforms

A patient monitoring system may determine one or more reference points of a physiological signal. The system may select one or more fiducial points on the physiological signal relative to the reference points. The one or more fiducial points may be selected by selecting a point spaced by a time interval relative to one of the reference points. The time interval may be a predetermined constant, or the time interval may depend on physiological information. The system may generate a fiducial signal based on the selected fiducial points, calculate physiological information such as a respiration rate based on the selected fiducial points, or both.

Systems and methods for determining respiration information from a photoplethysmograph

An artifact rejector for repetitive physiologic-event-signal data generated from electronically-controlled physiologic-event-measuring equipment includes a physiologic-event-signal averager in communication with such physiologic-event-measuring equipment. The artifact rejector is constructed to generate and store repetitive averaged physiologic-event-signal data based upon a substantially stable time relationship between corresponding physiologic-event-signal data and heart-beat-related-signal data. The repetitive averaged physiologic-event-signal data includes less noise than the repetitive physiologic-event-signal data. The artifact rejector generates and continuously updates an averaged-data template by storing such repetitive averaged physiologic-event-signal data for a preselected number of measured physiologic events. The artifact rejector also includes a physiologic-event-noise estimator and a physiologic-event-noise monitor in communication with such physiologic-event-measuring equipment, and capable of instructing the monitor to adjust the measurement cycle based upon estimated, monitored noise. The averager preferably includes a sharp roll-off, low pass filter and examples include a fourth-order Bessel filter, two cascaded, identical second-order Bessel filters, an elliptic filter, a Tchetschebyscheff filter, or finite impulse response filters. The heart-beat-related signal is preferably an ECG signal. A method of artifact rejection includes generating and storing repetitive averaged physiologic-event-signal data based upon a substantially stable time relationship between corresponding physiologic-event-signal data and heart-beat-related-signal data, with the repetitive averaged physiologic-event-signal data including less noise than the repetitive physiologic-event-signal data.

Thomas J. Dorsett

Papers

Artifact rejector for repetitive physiologic-event-signal data