We brought the cart to the Blood Bank for feedback from a small group.
Separate lids for each temp zone
Hinged on long side
Cold well dividers
No pan liners. Put products directly in cold well
Grid dividers, 2 rows of 6 compartments
Brainstorming session at staff meting Feb. 1
Numerical display is insufficient because it does not convey acceptable range.
Bar graph type is better, with markings for acceptable range.
Give alarm when close to edges of range or out of range
Cart material (plastic / metal)?
Stainless, for cleaning and durability. Metal side panels too.
- Power/battery status
- Product viability
- Running on Battery power
- Low battery
- Lid open
- Temp out of range
- Product has become not-viable
MTP (Massive transfusion protocol)
They have to run with the products from the blood bank to the patient
cart might not be agile enough for this application
could send the initial products via cooler (existing procedure) and follow up with a cart and backup products a few minutes later.
Seal top surface against leaks. Currently, liquid poured on the top shelf wold leak down around the fridge and platelet pan onto the electronics. This will be addressed when the cart is upgraded.
The control computer should have a battery backup, so that it can run when neither AC power nor main battery is available. The major power draw will be from display components (e.g. LEDs), so it may be necessary to use a low power display strategy when running on battery backup (e.g. flash the displays).
When a container is returned to the blood bank, they must decide whether any unused products should be restocked or discarded.
The current process goes like this:
- place container in return area
- scan products into the computer. Note disposition (e.g. to be restocked or discarded)
- computer assigns all units a status of “quarantine”
- place units in the quarantine bin (in refrigerator)
- (Later, e.g. at end of day) process quarantine items (i.e. assign final status and physically move to final location)
How is disposition determined?
If the product has been out of temperature range, it must be discarded. Since no sensing is available, the decision is made by inference. For example, if products are packed as when they were sent out, they are assumed to have remained in temp range and are restocked. However, if packing has changed substantially, products are usually assumed to have been out of range and are discarded.
If product temperature sensor reading is out of range for more than X time, give irreversible alarm to user and in log file
Thoughts following the feedback session
Temperature logging and reacceptance
The irreversible alarm for discard/restock status must be reset each time the cart is returned to the blood bank. How will that be implemented?
The cart will be used by two groups of people:
- Blood bank staff: also have the ability to reset the irreversible alarm.
- Other users: they should be told if the products are viable or non-viable, but not have the ability to reset the alarm.
Regarding cargo viability. The cart will have a few states:
- Idle (i.e, in blood bank, running, with no cargo) viability tracking disabled. Everything else still active.
- Active (i.e. holding products at temp, either in the blood bank or elsewhere in the hospital). Viability tracking engaged.
We might want to turn on/off other features too, like audible alarms. They won’t be needed when the cart is idle.
- We want the cart to keep a log file (e.g. temperature, lid open, battery status, etc) whenever the cart is operating.
- Rather than one continuous log file, it might be convenient to start a new file each time the status changes.
- Log files will not be downloaded each time the cart is returned to the blood bank, but it does seem to be important to want retain temperature logs. Maybe the files will be downloaded weekly.
How will the status be changed?
Status should only be changed by blood bank staff.
The mechanism could be a key or an RFID card reader.
Each time the switch is activated, the status will switch (Idle / Active).
For example, when the cart is loaded and ready to be take out into the hospital, the status could be changed from
The card could be swiped again when the cart is returned.
Visible: light: Green means viable, Red means not viable, Off means idle
Audible: sound if products are not-viable