Sensor and method for measurement of physiological parameters

• US 20020062070A1
• Filed: 01/18/2001
• Published: 05/23/2002
• Est. Priority Date: 11/23/2000
• Status: Active Grant

• Current Assignee: SenTec AG
• Original Assignee: SenTec AG
• Inventors: Roost, Matthias, Tschupp, Andreas, Lang, Joseph
• Granted Patent: US 6,760,610 B2
• Time in Patent Office: Days
• US Class Current: 600/322
• CPC Class Codes: A61B 2562/02 Details of sensors specially adapted for in-vivo measurements
• CPC Class Codes: A61B 2562/08 Sensors provided with means for identification, e.g. barcodes or memory chips
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/0017 transmitting optical signals transmission by light H04B10/00
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: A61B 5/1491 Heated applicators
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes

Abstract

Sensor (1) for the measurement of physiological parameters such as oxygen or carbon dioxide in the blood, comprising at least one measuring apparatus (17, 18, 19) and also a digital sensor signal processor (13) which is arranged in the sensor (1) and which is connected in signal conducting manner to the measuring apparatus (17, 18, 19) and which makes available a digital output signal.

Claims

1. Sensor (1) for the measurement of physiological parameters such as oxygen or carbon dioxide in the blood, comprising at least one measuring apparatus (17, 18, 19) and also a digital sensor signal processor (13) which is arranged in the sensor (1) and which is connected in signal conducting manner to the measuring apparatus (17, 18, 19) and which makes available a digital output signal.

2. Sensor (1) in accordance with claim 1, comprising at least one measuring apparatus (17, 18, 19) from the following group:

a measuring apparatus (19) for the measurement of the CO₂ content, in particular in accordance with Stow-Severinghaus,

a measuring apparatus (19) for the measurement of the O₂ content, in particular in accordance with Clark,

an optical measuring apparatus (17) with means for the pulse oximetric measurement of the arterial oxygen saturation comprising an LED (2;

2a, 2b) and a photodetector (3),

a measuring apparatus for the measurement of the pulse frequency,

a measuring apparatus for the measurement of the hematocrit (HCT)

a measuring apparatus for the measurement of the blood pressure (CNIBP)

a measuring apparatus for the measurement of components of the respiratory gas,

a measuring apparatus for the measurement of the body temperature,

a measuring apparatus for the measurement of the moisture content.

3. Sensor (1) in accordance with claim 1, characterised in that the measuring apparatus (17, 18, 19) is formed as an electrochemical measuring apparatus, in particular for the measurement of the transcutaneous CO₂ partial pressure or of the transcutaneous O₂ partial pressure.

4. Sensor (1) in accordance with claim 1, characterised in that the measuring apparatus (17, 18, 19) is formed as a semiconductor chip (19) and in that the semiconductor chip (19) permits the measurement of the concentration of a gas, such as CO₂, O₂, N or of a gas mixture such as an anaesthetic gas named Enflurane.

5. Sensor (1) in accordance with claim 1, characterised in that the measuring apparatus (17, 18, 19) is formed as an optical measuring apparatus comprising a light source (2) and a photodetector (3).

6. Sensor (1) in accordance with claim 5, characterised in that the measuring apparatus (17, 18, 19) includes a semiconductor chip (19) which permits the generation and/or measurement of light of different wavelengths.

7. Sensor (1) in accordance with claim 1, comprising an electrical heating apparatus (6) and also a temperature sensor (7).

8. Sensor (1) in accordance with claim 1, comprising a data memory (23) in which, in particular, a characteristic of the at least one measuring apparatus (17, 18, 19) and/or measured values and/or patient data can be stored.

9. Sensor (1) in accordance with claim 1, comprising a signal transmitting communicating means (26;

44;

44a) to a subsequent signal evaluation apparatus (37), wherein the communication means (26, 44) is formed as an at least two pole cable (26a, 26b) or as a cableless transmitter/receiver (44a).

10. Sensor (1) in accordance with claim 1, comprising an at least partly rigid circuit board (10) which is equipped with the electronic components (12, 13).

11. Sensor (1) in accordance with claim 10, characterised in that the circuit board (10) is equipped with an electrode (4;

20).

12. Sensor (1) in accordance with claim 10, characterised in that the circuit board (10) includes a flexible section (10a).

13. Sensor (1) in accordance with claim 12, characterised in that a preamplifier (12a) is arranged in the flexible section (10a) which is connected in signal-conducting manner to an inner electrical conductor (4a, 20a) of the electrode (4, 20).

14. Sensor (1) in accordance with claim 10, characterised in that a substantially full area, electrically conducting layer (10b) is arranged at the surface of or within the circuit board (10) and is preferably connected to ground.

15. Sensor (1) in accordance with claim (10), characterised in that the electrode (4;

20) has a longitudinal direction (L);

in that the circuit board (10) is arranged extending substantially perpendicular to this longitudinal direction (L), and in that the circuit board (10) is arranged within the length of the electrode (4;

20).

16. Sensor (1) in accordance with claim 10, characterised in that the circuit board (10) has an aperture (10c) and in that the electrochemical measuring apparatus (19) is arranged extending through the aperture (10c).

17. Sensor (1) in accordance with claim 10, characterised in that electronic components sensitive to disturbance are arranged on the circuit board (10) separated from the remaining electronic components.

18. Sensor (1) in accordance with claim 10, characterised in that the space between the circuit board (10) and the sensor surface (1b) has a heat conducting medium (8), with the heat conducting medium (8) preferably being cast in place.

19. Sensor (1) in accordance with claim 10, characterised in that the circuit board assembly (10) is surrounded at least partly by a metallic layer (16).

28. System for the measurement of physiological parameters comprising a sensor (1) in accordance with claim 1, and also comprising a signal evaluation device (37) with a digital sensor interface (38) and a processor (39).

20. Method for the measurement of physiological parameters, such as oxygen or carbon dioxide in the blood, in which an analog measured value of a measuring apparatus (17, 18, 19) is detected by a sensor (1), the analog measured value is converted into digital values in the sensor (1) and the digital values are supplied to a signal evaluation device (37).

21. Method in accordance with claim 20, characterised in that reference data (49) of the measuring apparatus (17, 18, 19) are stored in the sensor (1), in that the digital values corresponding to the reference data (49) are compensated, and in that the so compensated digital values are supplied to the signal evaluation device (37).

22. Method in accordance with claim 20, characterised in that a corresponding physiological parameter, such as the oxygen or the carbon dioxide in the blood or the pulse frequency, is calculated from the digital values in dependence on the characteristics of the measuring apparatus (17, 18, 19) using a processor (39) arranged in the signal evaluation device (37).

23. Method in accordance with claim 20, characterised in that patient data are stored in a memory of the sensor (1).

24. Method in accordance with claim 20, characterised in that at least parts of the values of the physiological parameters, such as oxygen or carbon dioxide in the blood or the pulse frequency, calculated in the signal evaluation device (37) are stored in a memory of the sensor (1).

25. Method in accordance with claim 24, characterised in that the sensor (1) is connected with a plurality of signal evaluation devices (37) timewise one after the other and separated again, and in that at least a part of the values calculated in the respective signal evaluation device (37) are stored in the memory of the sensor (1).

26. Method in accordance with claim 25, characterised in that the signal evaluation device (37) respectively connected to the sensor (1) takes over at least a part of the data stored in the memory of the sensor (1).

27. Method in accordance with claim 20, characterised in that the sensor is arranged on the ear, in particular on the earlobe.

29. System in accordance with claim 28, characterised in that the digital sensor interface (38) enables a digital signal transmitting connection to the sensor (1), with the digital sensor interface (38) being arranged after the processor (39) and with the signal evaluation device (37) being suited for the evaluation of the signals of different sensors (1) through a corresponding choice of the software of the processor (39):