The first stage of the setup is a quick and effective ID method. A photo of the patient is taken to ensure that it is clear which patient that machine has been setup for. No need for entering long strings of data or even scanning barcodes. And the image is not stored long-term, nullifying any privacy issues.
The second stage of the setup is to enter the patients weight. This will be used to calculate their probable haemoglobin (Hb) level after the units they are due have been transfused into them.
The green button is scrolled vertically to select a value, and is then swiped horizontally to confirm it.
This is a potential weak-point in the process as the value could be incorrectly entered, but it would be unlikely for this step to be automated and a human will almost certainly always have to fulfil this role. There is another potential issue with the weight being in kg (metric) which could be mistaken for lb/oz (imperial) but the United Kingdom and most of the world now exclusively use the metric system, minimising the risk.
The next stage of the setup procedure is to input the patients current Hb level. This will be taken into account when estimating the new Hb level later on after the transfusion(s) are complete.
As well as the patients current Hb level, the desired Hb level for them to reach is also entered. This is to ensure that the system does not 'assume' a safe Hb level, as it will differ for every patient. If the system calculates that the patient has probably reached this target but there are further transfusions planned, it will alert staff that an avoidable transfusion is about to occur (ADU: avoidable, delayed, or understansfusion; previously known as inappropriate and unnecessary).
The next stage is to select the total number of units due to be transfused. A typical routine transfusion will be between 2 and 3 units. 4 units is unusual and an ordinary haematology day unit might see a transfusion of 4 units to a single patient once a month. There are some surgical procedures which routinely require 6 units, and for this project this was considered the absolute maximum necessary.
In case the patient has previously received units but Ichor was not used and is therefore unaware of it, the user is given the opportunity to inform the system that the patient has already received units and this is not the first unit in this particular treatment.
All units of blood will be between 220-340ml, and this stage of the procedure allows users to specify the exact volume of the current unit being transfused. This will help the system to accurately predict the Hb increase caused by the bag (by also considering patient mass).
The final stage of the setup is to specify the desired duration for the transfusion to take. A typical transfusion will be 2 hours. All transfusions must be completed within 4 hours.
This is the screen which is displayed when a transfusion is in progress. The total expected transfusion time is displayed as an easily recognisable outer arc, accompanied by the time remaining and the time passed. The angles of the arcs correlate to the angles of hours on an analogue clock. The different times are also displayed numerically. There are two buttons at the top of the display, a "privacy" button and a "detail" button, these features are detailed below. The photo of the patient is displayed in the top right corner for identification purposes. The flow rate is displayed below the time arcs, and whether it matches the intended rate. Below this is displayed the total number of units and the current unit being transfused. At the bottom, a bar shows the current predicted Hb level of the patient.
15 minutes after the transfusion is started, the device reminds staff that a check of the patients vital signs is required. This is a mandatory check which in reality can be so delayed that it leads to a useless or dangerous situation.
As the transfusion progresses, the arcs of time alter their angle to show the correct time remaining and passed. The estimated Hb also continuously updates.
After the transfusion is complete, the device shows whether or not another unit is due for transfusion, and also the current estimated Hb level, allowing the staff to decide whether or not it is actually necessary to transfuse any more units. Obviously this estimation will not be certain and should be verified by a blood test. Fortunately, modern tests are fast and cheap, and the estimation will still provide useful information.
This screen shows the maximum duration for a transfusion, and hence the maximum size of the displayed arcs.
If at any point the transfusion rate is measured to be higher or lower than safe, the device will alert staff.
If there are no more units due to be transfused, the device will prompt staff to restart the unit.
When extra privacy is desired, a button at the top of the interface changes the display so that it does not show any numeric values, whilst still showing all required information to those who are familiar with the device.
When extra detailed information is required, a button changes the interface to remove most of the motion graphic elements and introduces additional numeric values of the parameters which are programmed into and monitored by the device. This enables these values to be double-checked at any time.
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Ichor
Ichor is a small tablet based device which measures and verifies the flow rate of blood into a patient during a transfusion. This reduces incidents of TACO (Transfusion Associated Circulatory Overload), the most common preventable cause of death related to blood transfusion. This device can also estimate the current Hb level of a patient by interpreting their mass, initial Hb and the volume of blood being infused, and can then recommend if the patient is unlikely to need another unit, despite being assigned one, thus lowering rates of I&U (Inappropriate and Unnecessary) transfusions.
The user (transfusion staff) experience was particularly interesting to me as existing methods were inefficient.
