Pressure sensor disconnect detection for a blood treatment device

• US 20070185429A1
• Filed: 08/01/2005
• Published: 08/09/2007
• Est. Priority Date: 04/13/2001
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: CHF Solutions, Inc.
• Inventors: Gelfand, Mark, O'Mahony, John, Merrick, Edwin, Merrick, Jayne
• Granted Patent: US 7,647,834 B2
• Time in Patent Office: Days
• US Class Current: 604/4.10
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1692 Detection of blood traces in dialysate
• CPC Class Codes: A61M 1/3401 Cassettes therefor
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/3607 Regulation parameters
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/36222 Details related to the interface between cassette and machine
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3641 Pressure isolators
• CPC Class Codes: A61M 2205/14 Detection of the presence or absence of a tube, a connector or a container in an apparatus
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3344 Measuring or controlling pressure at the body treatment site
• CPC Class Codes: A61M 2205/3375 Acoustical, e.g. ultrasonic, measuring means
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: G16H 20/40 : relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/63 : for local operation
• CPC Class Codes: G16H 50/20 : for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: Y10S 706/924 : Medical

Abstract

A system is disclosed for detecting an electrical sensor, the system includes a sensor signal processing circuit further comprising an input port to receive a connector including the output signal lines of the sensor, a resistor connected to the output signal line of said input port, wherein the resistor is connected to a predetermined voltage; a sensor circuit having a connector adapted to connect to the connector, wherein the sensor circuit has a resistance substantially less than the pull-resistor, and the sensor signal processing circuit detects an unconnected sensor based on the voltage applied by the resistor.

Claims

1. A system for detecting an electrical sensor comprising:

a sensor signal processing circuit further comprising an input port to receive a connector, wherein the input port is connected to a resistor and the resistor is connected to a predetermined voltage level;

a sensor circuit further comprising a connector adapted to connect to the input port of the sensor signal processing circuit, wherein the sensor circuit has a resistance substantially less than the resistor, and

wherein the sensor signal processing circuit detects an unconnected sensor based on a voltage applied by the resistor to the sensor signal processing circuit.

2. The system of claim 1 wherein the resistor is a pull-up resistor and the predetermined voltage is a voltage supply.

3. The system of claim 1 wherein the resistor is a pull-up resistor and the predetermined voltage is five (5) volts.

4. The system of claim 1 wherein the resistance of the resistor is at least three times the resistance of the sensor circuit.

5. The system of claim 1 wherein the resistance of the resistor is at least one Meg Ohm and the resistance of the sensor circuit is no greater than three Kilo Ohm.

6. The system of claim 1 wherein the resistor comprises a plurality of parallel resistors and each of the resistors is connected to different input port.

7. The system of claim 1 wherein the sensor circuit is on an extracorporeal blood circuit and the sensor signal processing circuit is included in a pump controller.

8. A system for detecting an electrical sensor circuit comprising:

a sensor signal processing circuit further comprising an input port, a signal line connecting the input port to the processing circuit, a pull-up resistor connected between the input port and a predetermined voltage, wherein said signal line is connected to an amplifier;

a sensor circuit comprising a connector adapted to connect to the connector, wherein the sensor circuit has a resistance substantially less than the pull-up resistor, and

wherein the sensor signal processing circuit detects an unconnected sensor based on the amplification of the voltage being outside a preset limit.

9. The system of claim 8 wherein the predetermined voltage is a voltage supply.

10. The system of claim 8 wherein the predetermined voltage is five (5) volts.

11. The system of claim 8 wherein the resistance of the pull-up resistor is at least three times the resistance of the sensor circuit.

12. The system of claim 8 wherein the resistance of the pull-up resistor is at least one Meg Ohm and the resistance of the sensor circuit is no greater than three Kilo Ohm.

13. The system of claim 8 wherein the pull-up resistor comprises a plurality of parallel pull-up resistors and each of the resistors is connected to different input port.

14. The system of claim 8 wherein the sensor circuit is on an extracorporeal blood circuit and the sensor signal processing circuit is included in a pump controller.

15. A system for detecting an electrical sensor circuit comprising:

a sensor signal processing circuit further comprising an input to receive a connector to an output of the sensor circuit, a signal line connecting the input to the processing circuit, and a resistor connected between a signal line and a predetermined voltage;

the sensor circuit comprising a connector adapted to connect to the input, wherein the sensor circuit has a resistance substantially less than the resistor, and

wherein the sensor signal processing circuit detects an unconnected sensor circuit based on the voltage being outside a predetermined limit.

16. The system of claim 15 wherein the resistor is a pull-up resistor and the predetermined voltage is a voltage supply.

17. The system of claim 15 wherein the resistor is a pull-up resistor and the predetermined voltage is five (5) volts.

18. The system of claim 15 wherein the resistance of the resistor is at least three times the resistance of the sensor circuit.

19. The system of claim 15 wherein the resistance of the resistor is at least one Meg Ohm and the resistance of the sensor circuit is no greater than three Kilo Ohm.

20. The system of claim 15 wherein the resistor comprises a plurality of parallel resistors and each of the resistors is connected to different input port.

21. The system of claim 15 wherein the sensor circuit is on an extracorporeal blood circuit and the sensor signal processing circuit is included in a pump controller.