Back to results
US 7,841,985 B2Granted
Sensor identification method and system
AssigneeDatex-Ohmeda, Inc.
InventorChristopher Hicks
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeDatex-Ohmeda, Inc.
InventorChristopher Hicks
Estimating the term…
An inventive method and system are provided for identifying a compatible photoplethysmographic sensor when interconnected to a given photoplethysmographic monitor. The method and system may further provide for the identification of which of a plurality of compatible sensors is interconnected to allow for selective calibration of the photoplethysmographic monitor. In this regard, the system and method may entail provision of a predetermined drive or test signal to a light source and/or identification element (i.e., sensor elements) of a photoplethysmographic sensor, and the obtainment of a corresponding output signal for use in sensor identification. In one approach, an output signal is obtained from at least one of three sensor elements each of which is interconnected between a different pair of sensor terminals which is a unique combination of two of four sensor terminals on the sensor. In this regard, individual circuits may be formed through each sensor element allowing for enhanced flexibility in signal application.
A method using a photoplethysmographic system, comprising:
A method using a photoplethysmographic system, comprising:
A method using a photoplethysmographic system, comprising:
A method using a photoplethysmographic system, comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Measuring for diagnostic purposes ; Identification of persons: using light, e.g. diagnosis by transillumination, diascopy, fluorescence
Sensors provided with means for identification, e.g. barcodes or memory chips: combined with means for recording calibration data
Medical diagnosis and surgery
Term ended 16 Oct 2025 (estimated)
The present invention relates to the field of photoplethysmography, and more specifically, to an improved method and system for identifying a photoplethysmographic sensor selectively interconnectable to a photoplethysmographic monitor, e.g. to confirm compatibility with and/or otherwise “calibrate” the monitor for accurate measurements. The invention is particularly apt for pulse oximetry applications.
In the field of photoplethysmography light corresponding with two or more different centered wavelengths may be employed to non-invasively determine various blood analyte concentrations. For example, blood oxygen saturation (SpO2) levels of a patient's blood may be monitored in pulse oximetry systems by measuring the absorption of oxyhemoglobin and reduced hemoglobin using red and infrared light. The measured absorption data allows for the determination of the relative concentration of reduced hemoglobin and oxyhemoglobin, and therefore SpO2 levels, since reduced hemoglobin absorbs more light than oxyhemoglobin in the red band and oxyhemoglobin absorbs more light than reduced hemoglobin in the infrared band; and since the absorption relationships of the two analytes in the red and infrared bands are known. See e.g., U.S. Pat. Nos. 5,934,277 and 5,842,979.
As may be appreciated, in order to accurately compute blood analyte concentrations, it is important for pulse oximetry systems to be preset, or “calibrated”, in relation to the center wavelengths of red and infrared light employed. In this regard, pulse oximetry arrangements typically comprise a disposable or reusable sensor that is releasably attached to a given patient's appendage (e.g., finger, ear lobe, infant foot or nasal septum) for a given patient monitoring procedure. The sensor carries at least one red light source and one infrared light source, as well a light detector to provide an output signal indicative of the light received thereby (e.g. the red and infrared light passing through the patient appendage). In turn, the sensor may be connected or selectively interconnectable to a cable that is selectively interconnectable to a photoplethysmographic monitor to process the detector output signals.
FIGS. 1A and 1B illustrate alternate embodiments of photoplethysmographic system applications of the present invention.
FIGS. 2A and 2B illustrate sensor, cable and monitor interconnections for the applications of FIGS. 1A and 1B.
FIG. 3 illustrates an automated sensor identification procedure which implements the present invention.
FIGS. 1A, 2A and 1B, 2B illustrate two alternate photoplethysmographic system applications of the present invention. The illustrated systems may each identify and selectively employ compatible sensors, including sensors that are compatible with each of the systems. In the later regard, the invention is no way limited to dual compatibility implementations.
In the application of FIG. 1A, a first photoplethysmographic monitor 20a is shown interconnected to an interconnectable sensor 10 via a first type of cable 30a, while in the application of FIG. 1B a second photoplethysmographic monitor 20b is shown interconnected to the interconnectable sensor 10 by a second type of cable 30b. For purposes of the present description, sensor 10 is of a type that is compatible with either of the monitors 20a, 20b. The first and second photoplethysmographic monitors 20a, 20b may vary in type, however, including differing electrical configurations of their respective cable interconnection ports 22a, 22b and corresponding internal photoplethysmographic measurement features.
By way of example, monitor 20a may be designed with port 22a including two electrical pins or sockets for driving two light sources of a photoplethysmographic sensor. On the other hand, monitor 20b may be designed with port 22b including three electrical pins or sockets for driving two or more light sources of a photoplethysmographic sensor.