Method and apparatus for safe CT scanner button presses

• US 6,751,688 B1
• Filed: 02/17/2000
• Issued: 06/15/2004
• Est. Priority Date: 02/17/2000
• Status: Expired due to Term

• Current Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Original Assignee: GE Medical Systems Global Technology Company LLC (GE Healthcare Technologies, Inc.)
• Inventors: Pitterle, David, El-Demerdash, Mohamed
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Farooq, Mohammad O.
• Application Number:
  US09/506,106
• Time in Patent Office: 1,580 Days
• Field of Search: 710/67, 710/73, 710/106, 340/310.01, 378/117
• US Class Current: 710/67
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes

Abstract

The present invention is, in one embodiment, a method for efficiently and reliably communicating button presses electronically on a network from one or more push button nodes each having at least one push button, to a master node. This method includes steps of: generating status messages indicative of a push button states at each of push button node; communicating the status messages to the master node via the network; determining, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages; and triggering a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages.

Claims

1. A method for efficiently and reliably communicating button presses electronically on a serial network from one or more push button nodes each having at least one push button, to a master node, said method comprising the steps of:

generating status messages indicative of a state of the at least one push button at each of the push button nodes when the at least one push button is pressed and generating status messages indicative of a state of the at least one push button at each of the push button nodes when the at least one push button is not pressed;

communicating the status messages to the master node via the network;

determining, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages; and

triggering a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages.

2. A method in accordance with claim 1 wherein the status messages are generated periodically at each of the push button nodes.

3. A method in accordance with claim 2 further comprising the step of checking, at the master node, expected status message arrivals from each of the push button nodes;

and further wherein the step of triggering a response of the master node comprises the step of defaulting, to a known safe state, status outputs of the master node that corresponding to the push-buttons of a push button node that misses a pre-determined number of wake-up cycles.

4. A method in accordance with claim 2 wherein the master node comprises a plurality of I/O ports corresponding each corresponding to a different one of the push buttons,

and wherein triggering a response of the master node, in accordance with the statuses of the push buttons comprises mirroring the statuses via the plurality of I/O ports.

5. A method in accordance with claim 1 wherein the network is a two-wire network comprising a plurality of push-button nodes, and communicating the status messages to the master node via the network comprises communicating the status messages to the master node via the two wires of the network.

6. A method in accordance with claim 1 and further comprising the steps of the master node addressing and communicating a display message to a display node;

and the addressed display node producing a display in accordance with the communicated display message.

7. A method in accordance with claim 6 wherein the master node addressing and communicating a display message to a display node comprising the step of the master node selectively generating and including a checksum with critical display messages.

8. A method for efficiently and reliably communicating button presses electronically on a serial network from one or more push button nodes each having at least one push button, to a master node, said method comprising the steps of:

generating status messages indicative of a state of the at least one push button at each of the push button nodes, wherein the status messages are generated periodically at each of the push button nodes;

communicating the status messages to the master node via the network;

determining, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages;

triggering a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages, wherein generating status messages indicative of a state of the at least one push button at each of the push button nodes comprises the step of generating, at each of the push button nodes, a checksum value included in the status message generated at the push button node; and

validating the checksum values at the master node to confirm that the master node is receiving valid status messages.

9. A method for efficiently and reliably communicating button presses electronically on a serial network from one or more push button nodes each having at least one push button, to a master node, said method comprising the steps of:

generating status messages indicative of a state of the at least one push button at each of the push button nodes, wherein the status messages are generated periodically at each of the push button nodes;

communicating the status messages to the master node via the network;

determining, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages;

triggering a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages;

generating, when a push button is pressed, a signal unique to the pressed push button and a signal representing a logical combination of states of all of the push buttons of a push button node on which the pressed push button is located; and

performing a redundancy check on the pressed push button using the signal representing the logical combination of states, at the push button node on which the pressed push button is located.

10. A method in accordance with claim 9 wherein generating a signal representing a logical combination of states of all of the push buttons of a push button node on which the pressed push button is located comprises logically ORing a signal for the push button being pressed with signals of all of the other buttons of the push button node on which the pressed push button is located.

11. A method for efficiently and reliably communicating button presses electronically on a serial network from one or more push button nodes each having at least one push button, to a master node, wherein the master node is hard-wired to a critical button of a push button node, said method comprising the steps of:

generating status messages indicative of a state of the at least one push button at each of the push button nodes, wherein the status messages are generated periodically at each of the push button nodes;

communicating the status messages to the master node via the network;

determining, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages;

triggering a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages;

immediately communicating a signal indicative of the at least one critical button being pressed separately from the generated status messages; and

immediately triggering a response of the master node in accordance with the immediately communicated signal;

said immediate communication and said immediate triggering occurring within a time less than a period of the periodically generated status messages.

12. A system for efficiently and reliably communicating button presses electronically, said system comprising a serial network of one or more push button nodes each having at least one push button, and a master node, said system configured to:

generate status messages indicative of a state of the at least one push button at each of the push button nodes when the at least one push button is pressed and generate status messages indicative of a state of the at least one push button at each of the push button nodes when the at least one push button is not pressed;

communicate the status messages to the master node via the wired network;

determine, at the master node, the state of the push buttons at each of the push button nodes from the communicated states messages; and

trigger a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages.

13. A system in accordance with claim 12 further configured to periodically generate status messages at each of the push button nodes.

14. A system in accordance with claim 13 further configured to check, at the master node, expected status message arrivals from each of the push button nodes;

and further wherein being configured to trigger a response of the master node comprises said system being configured to default, to a known safe state, status outputs of the master node that corresponding to the push-buttons of a push button node that misses a pre-determined number of wake-up cycles.

15. A system in accordance with claim 13 wherein the master node comprises a plurality of I/O ports corresponding each corresponding to a different one of the push buttons,

and wherein said system being configured to trigger a response of the master node, in accordance with the statuses of the push buttons comprises said system being configured to mirror the statuses via the plurality of I/O ports.

16. A system in accordance with claim 12 wherein the wired network is a serially-connected network.

17. A system in accordance with claim 12 wherein the wired network is a parallel-connected network.

18. A system in accordance with claim 12 and further comprising a watchdog timer at each of the push button nodes and the master node configured to guard against firmware errors.

19. A system in accordance with claim 12 wherein each push button is configured to be active high.

20. A system in accordance with claim 12 further comprising a display, and further wherein the master node is configured to address and communicate a display message to the display;

and the addressed display is configured to produce a display in accordance with the communicated display message.

21. A system in accordance with claim 20 wherein the display is incorporated in a push button node.

22. A system in accordance with claim 20 further comprising a display node in which the display is incorporated.

23. A system in accordance with claim 20 wherein the master node is further configured to selectively generate and include a checksum with critical display messages addressed to the display.

24. A system in accordance with claim 12 in a CT imaging system.

25. A system in accordance with claim 24 wherein the CT imaging system includes a gantry, and at least some of said push buttons are mounted on the gantry.

26. A system in accordance with claim 25 wherein said wired network comprises a controller area network bus.

27. A system for efficiently and reliably communicating button presses electronically, said system comprising a serial network of one or more push button nodes each having at least one push button, and a master node, said system configured to:

periodically generate status messages indicative of a state of the at least one push button at each of the push button nodes;

communicate the status messages to the master node via the wired network;

determine, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages;

trigger a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages;

generate, at each of the push button nodes, a checksum value included in the status message generated at the push button node; and

validate the checksum values at the master node to confirm that the master node is receiving valid status messages.

28. A system for efficiently and reliably communicating button presses electronically, said system comprising a serial network of one or more push button nodes each having at least one push button, and a master node, said system configured to:

periodically generate status messages indicative of a state of the at least one push button at each of the push button nodes;

communicate the status messages to the master node via the wired network;

determine, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages;

trigger a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages;

generate, when a push button is pressed, a signal unique to the pressed push button and a signal representing a logical combination of states of all of the push buttons of a posh button node on which the pressed push button is located; and

perform a redundancy check on the pressed push button using the signal representing the logical combination of states, at the push button node on which the pressed push button is located.

29. A system in accordance with claim 28 wherein said system being configured to generate a signal representing a logical combination of states of all of the push buttons of a push button node on which the pressed push button is located comprises said system being configured to logically OR a signal for the push button being pressed with signals of all of the other buttons of the push button node on which the pressed push button is located.

30. A system for efficiently and reliably communicating button presses electronically, said system comprising a serial network of one or more push button nodes each having at least one push button, and a master node hard-wired to a critical button of a push button node, said system configured to:

periodically generate status messages indicative of a state of the at least one push button at each of the push button nodes;

communicate the status messages to the master node via the wired network;

determine, at the master node, the state of the push buttons at each of the push button nodes from the communicated status messages;

trigger a response of the master node, in accordance with the statuses of the push buttons determined from the communicated status messages;

immediately communicate a signal indicative of the at least one critical button being pressed separately from the generated status messages; and

immediately trigger a response of the master node in accordance with the immediately communicated signal;

said system further configured such that the immediate communication and immediate triggering occurs within a time less than a period of the periodically generated status messages.