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Great work. I am a big fan of Raspberry pi. For hospital environment does raspberry pi have the reliability, stability and durability for health use case for re

by sahin 6y ago

Great work. I am a big fan of Raspberry pi. For hospital environment does raspberry pi have the reliability, stability and durability for health use case for real life environments? it will be so budget friendly, i am sure many hospitals in the world can use it...

mbreese 6y ago
My initial reaction was to say that there is no way the RPi would be reliable enough for clinical purposes. However, from the schematics, it looks like the RPi is only used for displaying the airflow curves and not used to control the ventilating. A microcontroller is used for that critical function. If this is the case, then this would make the reliability much better and there is a chance it could be useful to many places. If the SD card on the Pi dies (which, if they are logging the data to SD and not RAM, is a likely event), then they can have spare SDs available as part of the standard operating procedure. It's not ideal, but so long as the main microcontroller is functioning, the display could be considered non-critical. Although, ICU staff might disagree...
- baptistejamin 6y ago
  It's why there is a second board to handle critical tasks: https://news.ycombinator.com/item?id=25671318 https://news.ycombinator.com/item?id=25671318
  - mbreese 6y ago
    If I could ask -- I saw a LoRA circuit mentioned in the schematics... what is that used for?
    - pp-ir 6y ago
      Good question! The plan was to use it for the central alarm room in temporary hospitals where no network exists. We planned to develop a small gateway to gather all the devices alarms, linked to bed number. It was not developed, but hardware has the feature. The LoRa fairness will allow very few data to come up, but high level alarms vital could be transmitted several times in a second if needed. We know we cannot use it to transfer waveforms of course.
pp-ir 6y ago
Short answer is no, I don't trust Rpi for vital tasks. Long answer : In this project, Raspberry is used to display curves and set some parameters. The core (ventilator algorithm) is implemented on the STM32F411, there is just a serial link in-between. The STM32 also monitor the Raspberry... If there is no heartbeat on the serial link, the STM32 shuts down the power supply of the raspberry, and ventilation goes on. The fact is that it never happens yet during our tests (4 months uptime now for some devices). The ArchLinux is restricted to the bare minimum, and the Rust app do not overheat the CPU. Is it by chance, or not ? Before any MTBF conclusion, you need thousands of units running during months... On another project of medical datalogger, I also put a little arduino as hardware watchdog. If no heartbeat of the main application, it just resets the Rpi. I also use industrial SD card, which are far more reliable and provide SMART informations. See another article on this subject: https://blog.senx.io/a-10-year-warranty-thanks-to-iot/ https://blog.senx.io/a-10-year-warranty-thanks-to-iot/
- craftinator 6y ago
  This is good systems design. I've made a system with a similar design (RPI for display and UI, one STM32 for hardware control, another as watchdog) for an industrial marking system, and it's run almost daily for 3 years without any issues. The great thing about the Pi in this case is that it's non-critical, and if it ever does die, you spend $35 and put in a new SD card.
  - pp-ir 6y ago
    As soon as ANSM (french equivalent of US FDA) hears "linux", "wifi", "connected", they see a scary green monster... And to be honnest, I understand their point. How can you certify Linux ? So much code behind... It is not a car multimedia center, it is a ventilator, a class III vital device. In this project, what was really impressive is the gap between the bare minimum (a 4 lines lcd screen + a few buttons + a pressure sensor, and you can make people breath), and the doctors expectations (curves, flow meters, statistics, O2 sensors...). This is the same for lots of activity: experts cannot work with basic tools anymore. Only High level experts still can. Conclusion: do not work with high level experts to build your specifications. Also listen to normal experts and doctors that needs more UX assistance.
tonymet 6y ago
there’s no guarantee in linux when or if your code will execute. it works well for consumer apps but you can’t use linux eg to pilot an airplane or for life support
- baptistejamin 6y ago
  It's why there is a second board to handle critical tasks: https://news.ycombinator.com/item?id=25671318 https://news.ycombinator.com/item?id=25671318

by sahin 6y ago

mbreese 6y ago

My initial reaction was to say that there is no way the RPi would be reliable enough for clinical purposes. However, from the schematics, it looks like the RPi is only used for displaying the airflow curves and not used to control the ventilating. A microcontroller is used for that critical function. If this is the case, then this would make the reliability much better and there is a chance it could be useful to many places. If the SD card on the Pi dies (which, if they are logging the data to SD and not RAM, is a likely event), then they can have spare SDs available as part of the standard operating procedure. It's not ideal, but so long as the main microcontroller is functioning, the display could be considered non-critical. Although, ICU staff might disagree...

baptistejamin 6y ago
It's why there is a second board to handle critical tasks: https://news.ycombinator.com/item?id=25671318 https://news.ycombinator.com/item?id=25671318
- mbreese 6y ago
  If I could ask -- I saw a LoRA circuit mentioned in the schematics... what is that used for?
  - pp-ir 6y ago
    Good question! The plan was to use it for the central alarm room in temporary hospitals where no network exists. We planned to develop a small gateway to gather all the devices alarms, linked to bed number. It was not developed, but hardware has the feature. The LoRa fairness will allow very few data to come up, but high level alarms vital could be transmitted several times in a second if needed. We know we cannot use it to transfer waveforms of course.

pp-ir 6y ago

Short answer is no, I don't trust Rpi for vital tasks. Long answer : In this project, Raspberry is used to display curves and set some parameters. The core (ventilator algorithm) is implemented on the STM32F411, there is just a serial link in-between. The STM32 also monitor the Raspberry... If there is no heartbeat on the serial link, the STM32 shuts down the power supply of the raspberry, and ventilation goes on. The fact is that it never happens yet during our tests (4 months uptime now for some devices). The ArchLinux is restricted to the bare minimum, and the Rust app do not overheat the CPU. Is it by chance, or not ? Before any MTBF conclusion, you need thousands of units running during months... On another project of medical datalogger, I also put a little arduino as hardware watchdog. If no heartbeat of the main application, it just resets the Rpi. I also use industrial SD card, which are far more reliable and provide SMART informations. See another article on this subject: https://blog.senx.io/a-10-year-warranty-thanks-to-iot/ https://blog.senx.io/a-10-year-warranty-thanks-to-iot/

craftinator 6y ago
This is good systems design. I've made a system with a similar design (RPI for display and UI, one STM32 for hardware control, another as watchdog) for an industrial marking system, and it's run almost daily for 3 years without any issues. The great thing about the Pi in this case is that it's non-critical, and if it ever does die, you spend $35 and put in a new SD card.
- pp-ir 6y ago
  As soon as ANSM (french equivalent of US FDA) hears "linux", "wifi", "connected", they see a scary green monster... And to be honnest, I understand their point. How can you certify Linux ? So much code behind... It is not a car multimedia center, it is a ventilator, a class III vital device. In this project, what was really impressive is the gap between the bare minimum (a 4 lines lcd screen + a few buttons + a pressure sensor, and you can make people breath), and the doctors expectations (curves, flow meters, statistics, O2 sensors...). This is the same for lots of activity: experts cannot work with basic tools anymore. Only High level experts still can. Conclusion: do not work with high level experts to build your specifications. Also listen to normal experts and doctors that needs more UX assistance.

tonymet 6y ago

there’s no guarantee in linux when or if your code will execute. it works well for consumer apps but you can’t use linux eg to pilot an airplane or for life support

baptistejamin 6y ago
It's why there is a second board to handle critical tasks: https://news.ycombinator.com/item?id=25671318 https://news.ycombinator.com/item?id=25671318