Datascope Passport 2 Repair: Settings Not Retained Case Study

A Florida surgery center reported issues with their Datascope Passport 2 patient monitor. The device would not retain its configuration after being powered off and on. Specifically, it reverted from the desired 3-lead ECG heart rate source to the NIBP/Auto setting and reset its system clock to a default date of January 1, 1970. This issue prevents immediate use upon startup and requires reconfiguration each time.

Technician investigation

The PBES technician confirmed the reported symptoms by observing the device's behavior during a power cycle. They noted that after setting the monitor to a 3-lead ECG configuration for heart rate detection, the settings were lost when the monitor was turned off and back on. The system consistently defaulted to using Auto/NIBP as the heart rate source. The technician also verified that the system date and time reset to midnight, January 1, 1970, on every power-up, a classic sign of memory loss.

Root cause

Suspected: Failure of the internal battery responsible for retaining system settings and time (SRAM/CMOS battery). The documented symptoms—loss of user-configured settings and the system clock resetting upon power loss—are highly indicative of a depleted internal memory battery. However, the root cause was not explicitly confirmed in the service report.

Resolution

The technician's documented action was to re-configure the device settings to use a 3-lead ECG and save the configuration. While the report notes this 'works fine,' it also refers back to the persistent problem of settings loss on power cycle, indicating this was a temporary adjustment rather than a permanent fix. No replacement parts, such as an internal battery, were installed during this service call. An electrical safety inspection was also performed.

Verification

• Electrical Safety Inspection

Verification ensures the device is not only functional but also electrically safe for use on patients. While settings were adjusted, full functional verification after a power cycle would be required to confirm a permanent fix for this specific issue.

Technician insight

An experienced technician immediately recognizes that a device resetting its clock to a Unix epoch start date (January 1, 1970) and losing custom settings is almost always caused by a failed internal battery. This battery provides constant power to the memory that stores this data. While the technician on this call adjusted the settings, the diagnosis points directly to a required hardware replacement to truly resolve the issue.

What Causes a Patient Monitor to Lose Settings?

• Depleted internal CMOS/SRAM battery
• Corrupted firmware or software
• Faulty mainboard or power supply components
• Incorrect shutdown procedure
• Loose internal connections to the memory module

In this specific case, while the technician adjusted settings, the symptoms strongly suggest the root cause was a depleted internal battery, even though one was not replaced on this call.

FAQ

Why did the monitor's date reset to 1970?

This is a common symptom in electronic devices when the internal battery that maintains system time and settings fails. The date resets to the 'epoch,' or the starting point for many systems' clocks, which is often January 1, 1970.

Will changing the settings fix the problem permanently?

No. As seen in this case, simply re-saving the settings does not solve the underlying problem. The settings will likely be lost again the next time the device is powered off completely. The component causing the memory loss must be replaced.

Were any parts replaced in this Datascope Passport 2 repair?

According to the verified service report, no replacement parts were used in this repair. The technician noted the issue and adjusted settings as a temporary measure.

What is the heart rate source 'Auto/NIBP'?

This setting means the monitor will automatically use the non-invasive blood pressure (NIBP) cuff measurement to calculate a heart rate, rather than using the ECG leads. The user wanted to default to the 3-lead ECG source instead.