Diagonostic service system for CT scanners

A diagnostic service system for CT scanners, the system comprising:

• an anode monitor for monitoring an x-ray tube anode;
• a cathode monitor for monitoring an x-ray tube cathode;
• a tube power monitor for monitoring a selected electrical potential applied between the anode and the cathode;
• a latch array including a plurality of latches, at least one latch being operatively connected with each of the anode, cathode, and tube power monitors for continuously receiving a corresponding monitored condition until a latch clock signal is received, each latch being responsive to a latch clock signal to store the corresponding monitored condition in memory before a malfunction cascades and affects other monitored conditions;
• a fault detection and latching means for detecting malfunctions, the fault detection means being operatively connected with the anode, cathode, and tube power monitors for determining malfunctions from the monitored conditions, the fault detection means being operatively connected with the latch array for providing the latch clock signal to each latch to latch the monitored condition of the corresponding monitor in memory;
• a malfunction history memory means for storing the monitored conditions, the memory means being operatively connected with the latch array such that monitored conditions stored in the latch are selectively transferred to the memory means for each of a plurality of detected malfunctions to create a malfunction history;
• and,
• a display means for displaying selected portions of the malfunction history.

A medical diagnostic scanner system comprising:

• a source of penetrating radiation;
• a detector means for detecting radiation that has traversed an examination region and generating electronic detector data indicative thereof;
• an image reconstruction means for reconstructing an image representation from the electronic detector data;
• a monitor means for monitoring each of a plurality of scanner operating conditions;
• a latch array including a plurality of latches operatively connected with the monitor means, each latch being responsive to a clock signal to freeze the corresponding one of the monitored conditions in temporary storage;
• a fault detection means for detecting malfunctions, the fault detection means being operatively connected with the monitor means for determining malfunctions from the monitored conditions, the fault detection means being operatively connected with the latch array for clocking each latch to latch and freeze the corresponding monitored condition in response to a determined malfunction such that the latch array captures a snap shot of each monitored condition before a detected malfunction can cascade and affect other monitored conditions;
• a malfunction history means for storing the monitored conditions, the malfunction history means being operatively connected with the latch array such that monitored conditions latched in temporary storage in the latch are selectively transferred to the malfunction history means for each of a plurality of detected malfunctions to create a malfunction history;
• and,
• a display means for displaying selected portions of the malfunction history.

A medical diagnostic scanner which cycles through a sequence of operating modes comprising:

• means for non-invasively examining a portion of a patient disposed in an examination region;
• a detection means for producing electronic detector data indicative of the non-invasive examination;
• an image reconstruction for reconstructing an image representation from the electronic data;
• a monitor means for continuously monitoring which of the operating modes the scanner is in;
• a latch means operatively connected with the monitor means for selectively latching the monitored operating mode;
• a fault detection means for detecting a scanner malfunction, the fault detection means being operatively connected with the latch means for causing the latch means to latch the monitored operating mode before the detected malfunction cascades and affects other monitored conditions in response to a detected malfunction such that a snap shot of the operating mode when the malfunction occurred is latched;
• and,
• a display means for displaying an indication of the latched operating mode, such that the operating mode when the malfunction occurred is retrievable to assist in diagnosing a cause of the malfunction.

A method of monitoring a CT scanner for malfunctions, which CT scanner includes an x-ray tube mounted for rotation about a scan circle, the x-ray tube including an evacuated envelope, a rotatable anode disposed in the envelope, means for rotating the anode, and at least one cathode disposed in the envelope, an anode rotating means power supply for supplying motive power to the anode rotating means, a cathode power supply for providing a heating current to the cathode, a tube power supply for providing an electrical potential between the anode and the cathode, an x-ray detector array disposed across the scan circle from the x-ray tube to receive x-rays which have traversed a region of interest of a patient, rotating means for rotating the x-rays around the scan circle, an image reconstruction means for reconstructing image representations, the image reconstruction means including means for receiving information from the detector array about intensities of the x-rays which have traversed the region of interest and reconstructing an image of a cross section of the patient, the method comprising:

• monitoring the anode to determine whether the anode is rotating;
• monitoring the cathode to determine whether a selected heating current is provided thereto;
• monitoring the electrical potential between the anode and the cathode to determine whether a selected electrical potential is applied therebetween;
• causing an indication of the monitored anode rotation, the monitored cathode current, and the monitored tube power electrical potential to be stored temporarily in response to detecting a malfunction and before the detected malfunction cascades and changes the monitored anode rotation cathode current, and electrical potential indication;
• and,
• transferring the temporarily stored indication of monitored anode rotation, cathode current, and the tube electrical potential to long term memory after each of a plurality of malfunctions to create a malfunction history.