.. _SoftwareOverview:
Software Overview#
Block Diagram#
![digraph g {
newrank=true
fontname="Courier New"
graph [fontsize=30 splines=true overlap=false rankdir = "TB"];
ratio = auto;
subgraph cluster_cpu0{
label="CPU0"
cpu0 [label="Messenger\ncpu0" shape="box" width=3]
gui [label="GUI"]
io [label="I/O"]
}
subgraph cluster_pi0 {
label="Raspi0"
pi0 [label="Messenger\nraspi0" shape="box" width=3]
manager [label="Session Manager"]
psycho [label="Psychoacoustic Model"]
pupil [label="Pupil Extraction"]
stim [label="Stimulus Manager"]
subgraph cluster_pi0_p1{
label="p1"
picam [label="PiCamera"]
}
subgraph cluster_pi0_p2{
label="p2"
sound [label="Sound Server"]
}
}
subgraph cluster_pi1{
label="Raspi1"
pi1 [label="Messenger\nraspi1" shape="box" width=3]
visman [label="Visual Manager"]
frameserve [label="Frameserver"]
}
{rank=same; pi0 pi1 cpu0}
cpu0 -> pi0 [label="control"]
pi0 -> cpu0 [label="data"]
pi0 -> pi1 [label="control"]
pi1 -> pi0 [label="data"]
cpu0 -> gui [label="data"]
gui -> cpu0 [label="control"]
cpu0 -> io [label="data"]
pi0 -> manager [label="control"]
manager -> pi0 [label="data"]
manager -> sound
manager -> picam
psycho -> manager
psycho -> stim
stim -> sound
picam -> pupil
picam -> manager
pupil -> psycho
pupil -> manager
stim -> manager
{rank=same; sound picam}
pi1 -> visman
visman -> pi1
visman -> frameserve
}](../_images/graphviz-ee903e681d2b38a4a180adff90c5aebe4cc1c541.png)
Draft Description#
Message-based architecture#
The system will consist of separable modules that communicate with a globally-defined enum of message types.
The system will consist of independent computers networked with an [ad-hoc or hosted? wireless network].
Messages will be serialized and sent as tcp packets between computers, and as inter-and intra-process packets within a computer.
Distribution of Labor#
One computer will serve as the clinician-facing interface that controls the operation of the examination
One computer will serve as the primary examination device, delivering auditory stimuli, measuring pupil dilation, and controlling the stepping algorithm
One computer will serve as the patient-facing interface, presenting visual stimuli (as well as physical enclosure for cameras and speakers)
Synchronization#
The two computers operating the examination will be tightly synchronized with a shared real-time clock
The examination computers will communicate asynchronously with the clinician-facing computer
GUI#
The GUI will be made with Qt6, written in PySide6
[control requirements]
[display requirements]
[utility requirements]
Image Capture#
Pupil images will be captured with a PiCam NoIR camera as single-channel luminance images from a YUV-encoded frame
Raw images will only be saved if explicitly requested, otherwise they will be shown in the GUI as a diagnostic
Pupil Processing#
Pupil diameter will be extracted as the shorter diameter of an ellipse fit on the edges of a tracked pupil to account for eccentricity/occlusion
[filtering and signal conditioning]
[preservation of provenance]
Psychoacoustic Model#
this’ll be a bit of work, ya!?
Sound#
Generation#
talk to avinash about stimuli
Presentation#
Sound will be presented with jack audio
Sound will be prebuffered in the presenting process, prioritizing continuity over low-latency