HeartStart MRx Monitor/Defibrillator; Model(s), Catalogue, or Code Number: M3535A, M3536A, M3536J, M3536MC The HeartStart MRx is for use for the termination of ventricular tachycardia and ventricular fibrillation. The device is for use by qualified medical personnel trained in the operation of the device and qualified by training in basic life support, advanced cardiac support, or defibrillation. It must be used by or on the order of a physician.

Issue 1: The potential for unintentional continued gantry/couch movement when a specific button series is used requiring use of manual stop. Issue 2. When performing a helical/Axial scan with ORI (Dose Right index)/ DOM (Dose Modulation), the WED (Water Equivalent Diameter) value might set itself to zero, and this may lead to an insufficient dose setting after the surview. If operator misses the insufficient dose and the WED value in User Interface and continues with the subsequent helical/Axial scans, then the obtained images will be noisy due to low dose setting. Issue 3: Due to a software failure, the ECG wave file is not saved. As a result, the cardiac offline image reconstruction fails due to the missing ECG wave file, and the user might rescan the patient. Issue 4: This issue is software fault in which the patient orientation will be changed to NULL under specific random scenarios resulting in radiation being delivered from the wrong orientation (surview scan) or in the wrong position (clinical scan) and will generate incorrect and undiagnosable surview/clinical images. Patients may be rescanned for surview and/or clinical images. Issue 5: During scanning, the preview image display is not consistent, the images are not arriving at a fixed rate, skipping images from time to time during scanning. The obtained images might not support making the clinical diagnosis and the user might decide to re-scan the patient. Issue 6: If a user presses the left and middle/right mouse buttons together or afterwards in a short time, both commands are executed and an incorrect auto ROI is created. This ROI coordinates won t be assigned as the object is empty. As a result, the threshold of contrast level will not be reached in the UI and this will prevent the system from automatically triggering the subsequent clinical scan. There is potential safety risk identified for additionally tracker shots and/or rescan of a patient when the clinical scan is not triggered. This issue only affects the manual ROI process.

Issue 1: The potential for unintentional continued gantry/couch movement when a specific button series is used requiring use of manual stop. Issue 2. When performing a helical/Axial scan with ORI (Dose Right index)/ DOM (Dose Modulation), the WED (Water Equivalent Diameter) value might set itself to zero, and this may lead to an insufficient dose setting after the surview. If operator misses the insufficient dose and the WED value in User Interface and continues with the subsequent helical/Axial scans, then the obtained images will be noisy due to low dose setting. Issue 3: Due to a software failure, the ECG wave file is not saved. As a result, the cardiac offline image reconstruction fails due to the missing ECG wave file, and the user might rescan the patient. Issue 4: This issue is software fault in which the patient orientation will be changed to NULL under specific random scenarios resulting in radiation being delivered from the wrong orientation (surview scan) or in the wrong position (clinical scan) and will generate incorrect and undiagnosable surview/clinical images. Patients may be rescanned for surview and/or clinical images. Issue 5: During scanning, the preview image display is not consistent, the images are not arriving at a fixed rate, skipping images from time to time during scanning. The obtained images might not support making the clinical diagnosis and the user might decide to re-scan the patient. Issue 6: If a user presses the left and middle/right mouse buttons together or afterwards in a short time, both commands are executed and an incorrect auto ROI is created. This ROI coordinates won t be assigned as the object is empty. As a result, the threshold of contrast level will not be reached in the UI and this will prevent the system from automatically triggering the subsequent clinical scan. There is potential safety risk identified for additionally tracker shots and/or rescan of a patient when the clinical scan is not triggered. This issue only affects the manual ROI process.

Issue 1: The potential for unintentional continued gantry/couch movement when a specific button series is used requiring use of manual stop. Issue 2. When performing a helical/Axial scan with ORI (Dose Right index)/ DOM (Dose Modulation), the WED (Water Equivalent Diameter) value might set itself to zero, and this may lead to an insufficient dose setting after the surview. If operator misses the insufficient dose and the WED value in User Interface and continues with the subsequent helical/Axial scans, then the obtained images will be noisy due to low dose setting. Issue 3: Due to a software failure, the ECG wave file is not saved. As a result, the cardiac offline image reconstruction fails due to the missing ECG wave file, and the user might rescan the patient. Issue 4: This issue is software fault in which the patient orientation will be changed to NULL under specific random scenarios resulting in radiation being delivered from the wrong orientation (surview scan) or in the wrong position (clinical scan) and will generate incorrect and undiagnosable surview/clinical images. Patients may be rescanned for surview and/or clinical images. Issue 5: During scanning, the preview image display is not consistent, the images are not arriving at a fixed rate, skipping images from time to time during scanning. The obtained images might not support making the clinical diagnosis and the user might decide to re-scan the patient. Issue 6: If a user presses the left and middle/right mouse buttons together or afterwards in a short time, both commands are executed and an incorrect auto ROI is created. This ROI coordinates won t be assigned as the object is empty. As a result, the threshold of contrast level will not be reached in the UI and this will prevent the system from automatically triggering the subsequent clinical scan. There is potential safety risk identified for additionally tracker shots and/or rescan of a patient when the clinical scan is not triggered. This issue only affects the manual ROI process.