Ruby Neuro Server Components

server.rb

A simple socket implementation that accepts connections on port 8336 and spans a new thread for Client execution. The server can be run with command:

ruby server.rb

It can be tested with:

$ telnet localhost 8336
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

Once connected, one can send NeuroServer commands:

hello
200 OK

A list of available commands can be obtained sending help command:

hello:              Healthcheck
close:              Close client connection
role:               Displays client role [CONTROLLER, EEG, DISPLAY]
control:            Starts a CONTROLLER client, that can send commands to another clients
eeg:                Starts an EEG client
display:            Starts a DISPLAY client
status:             Shows status of connected clients
go N:               Go command for controllers. go 0 activates a go trial in EEG device 0
nogo N:             No Go command for controllers
setheader:          EEG command to set EDFHeaders
setcheader CH:      EEG command to set EDFChannelHeaders for channel CH
getheader N:        Display command to print all headers for EEG #N
watch:              Display command to enable data frames receipt
unwatch:            Display command to disable data frames receipt
! P CC M1 M2..:     Data frame for each CC channels having P packet_size, with its Mi measures.
                    M1, M2, M3, ... refers to the P * CC measures in each channel.
                    It's broadcasted for all display clients that are in watch state.

command_handler.rb

It just interprets commands received from connected clients.

data_structures.rb

Data structures for header commands. These data headers refers to:

• capture data (patient, equipment, etc); and
• channels data (unit, measure ranges, labels, etc).

client.rb

Encapsulates logic for all available commands.

Roles

All clients have a role, which initial value is UNSET. The available roles are CONTROLLER, EEG and DISPLAY. To assume these roles, one can issue the commands control, eeg or display, respectively. Once the role is set, it cannot be changed. Each role has a subset of commands available. Issuing a command that is not applicable to a role results in a BAD REQUEST response.

Controller

A Controller client can send messages to other connected clients. Currently, there are only two actions for controllers (go, nogo). Supposing two clients connected, the following example shows a control session between them:

Controller Client

Escape character is '^]'.
control
200 OK
role
200 OK
CONTROLLER
go 2
200 OK
nogo 2
200 OK

Another Client (any role)

Escape character is '^]'.
go
nogo

Only one controller client can be active at any moment.

EEG

An client accepts setheader and setcheader commands to configure headers with patient and channels data, respectively. Available header options can be found in data_structures.rb.

Display

A client display can be used to view current headers for other EEG clients. This example shows two EEG/Display sessions iteractions.

EEG Client

Escape character is '^]'.
eeg
200 OK  
setheader patient Mary
200 OK
setcheader 0 label ch1
200 OK
setcheader 1 label ch2
200 OK

Display Client

Escape character is '^]'.
display
200 OK
status
200 OK
controller: 
display: 2
eeg: 1
unset: 
getheader 1
patient Mary start_time 2012-09-11/17:41:48-0300 label ch1 label ch2