MAUDE Adverse Event Report: SUPERSONIC MACH 40; ULTRASOUND DIAGNOSTIC IMAGING SYSTEM

Model Number SSIP95040-HOLX

Device Problem Incorrect Measurement (1383)

Patient Problem No Clinical Signs, Symptoms or Conditions (4582)

Event Date 08/03/2021

Event Type  malfunction  

Event Description

During a product demonstration of the (b)(4) software version (no patient involved), specifically the real-time shearwave elastography for liver, it was noticed that the viscosity measurement displayed incorrect values.The values were also shown when the viscosity measurement was deactivated.The liver viscosity values are one of many parameters used to evaluate liver morphology.It is not used as a single diagnostic parameter.The display of the wrong value can lead to confusion during the patient examination.

Manufacturer Narrative

On the related device, only the software versions (b)(4) + service pack 1 are affected.In the usa, only one device supersonic mach 40 is equipped with the (b)(4) version of the software and the liver tools option, and is impacted by the present issue.The risk of harm in present case is a misdiagnosis or delay in the medical treatment.This one was already captured in our product risk analysis ((b)(4)).In this one, the hazardous situation was assessed with a harm classified with a severity as minor & occurrence as occasional, giving a risk class of 6, being acceptable (according to our supersonic imagine / hologic quotation).We did review the risk analysis, considering the reported event and current investigation knowledge on the failure: we do consider the failure mode with an occurrence of 100% for each vi plus function use; nevertheless, the probability of harm occurrence remains the same, considering the following: the vi plus measurements are not linked to a specific clinical parameter; the vi plus function comes in addition to the shear wave mode to add more details about the exam (shear wave is the main one and a discrepancy with vi plus values could easily be seen); the viscosity is part of a set of around ten (10) others clinical parameters helping the global diagnosis for the liver: the vi plus feature is not determinant and optional.This is a new feature and only available within few manufacturers, justifying why this is not yet part of current international guidelines and therefore part of current diagnosis practices standards.If the others parameters are correctly measured, respecting the intended use defined in the user's guide, the risk of misdiagnosis with erroneous vi plus values is very low (i.E."occasional" classified), as the viscosity value is not critical compared to the others ones.Moreover, the bug appears in a specific workflow that remains optional when using the global liver tools available.Note: no harm was never reported / this issue occurred only during demonstration.About the harm severity, there is neither no change in the classification, being as minor (i.E."results in temporary injury or impairment not requiring professional medical intervention").Note: this diagnostic is used in the scope of liver fibrosis detection which is not directly life threatening.To conclude, the risk of harm remains the same.

Manufacturer Narrative

Vi plus feature enables to perform viscosity measurements only for liver examination (in addition to the shearwave elastography (swe) mode for liver).Investigation revealed that the incorrect vi plus values displayed come from a buffer* that was not flushed due to a coding mistake.A condition was not programmed, so all the data remaining in the buffer are displayed on the screen.*note : the buffer is managed by the code located in the crubicontextparameters.Cpp file, which is internal to the "measure" process.This buffer serves as a cache in "measure" for much of the information stored in shared memory.Each part of this buffer is specifically managed by initialization and update functions, all contained in the crubicontextparameters.Cpp file.One part of this buffer contains the elastography measurement maps, which must be set to zero when the elastography mode is activated.So, when viscosity is measured on a patient "#1" (considering the ultrasound system has been rebooted), data are accurate and correctly displayed.When another patient is examined later on for viscosity, it could happen that the patient "#1" data - still present in the buffer not purged - get displayed on screen under patient "#2".Therefore data are, in absolute, true and pertinent ones, but in the relative, belonging to another patient - hence incorrect values displayed.Please note that the wrong values are displayed when the patient #2 exam has not started.When the healthcare professional starts acquiring the patient #2 liver measurements, the vi plus values are correctly calculated.About values displayed even when the feature is disabled/unavailable - this is explained by the fact that the viscosity is combined (dependent) with the swe (ifu p.212) measurement.Viscosity can't be measured by itself but is derived from the swe measures (ifu p.221).Each time user is doing a swe measure, the impacted buffer is called.As once vi plus has been activated, this buffer still have viscosity values in it, it's displayed.That explains why vi plus values are seen also when feature is disabled or even when the feature is unavailable (viscosity being only assessed for liver) but swe called.Based on the risk assessment made by supersonic imagine / hologic (available in the initial report submitted on september 2nd 2021), the above described incident cannot lead to a serious injury or misdiagnosis that could result in a serious injury.The investigation is now complete and no further information is expected.We consider that this event is non-reportable.Section g1 : new address following a site move.

Event Description

During a product demonstration of the v3 software version (no patient involved), specifically the real-time shearwave elastography for liver, it was noticed that the viscosity measurement displayed incorrect values.The values were also shown when the viscosity measurement was deactivated.The liver viscosity values are one of many parameters used to evaluate liver morphology.It is not used as a single diagnostic parameter.The display of the wrong value can lead to confusion during the patient examination.

• Brand Name: SUPERSONIC MACH 40
• Type of Device: ULTRASOUND DIAGNOSTIC IMAGING SYSTEM
• MDR Report Key: 12414756
• MDR Text Key: 282962675
• Report Number: 3007253513-2021-00001
• Device Sequence Number: 1
• Product Code: IYN
• Combination Product (y/n): N
• PMA/PMN Number: K203645
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,foreig
• Remedial Action: Other
• Type of Report: Initial,Followup
• Report Date: 10/25/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 09/02/2021
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: SSIP95040-HOLX
• Was Device Available for Evaluation?: Yes
• Date Manufacturer Received: 08/03/2021
• Was Device Evaluated by Manufacturer?: Yes
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Reuse
• Patient Sequence Number: 1