Medical Physicist's Notes · Display Unit

Five typical clusters, and the rules that decide each one.

Cluster planning is the design choice that decides 60-80 % of the RMS cable budget and most of the future-expansion flexibility. This post walks five typical clusters at a cyclotron / PET / theranostic facility, the rules that map detectors into them, and the standard-vs- ruggedised variant choice for each.

Five typical clusters

Where the display unit sits and what it aggregates

Cluster	Typical detectors	Ruggedised?	Example site
Vault corridor	Area gamma × 2 + neutron × 1 + (optional) interlock-door panel	Yes — corridor environment	Most cyclotron facilities deploy this cluster as the first one
Hot lab quadrant	Area gamma × 2 around dispensing bench + 1 at dose-calibrator + 1 at QC station	No — clean climate-controlled environment	PET production hot labs, theranostic dispensing labs
Theranostic ward	Area gamma × 4 — one outside each patient room	No — corridor environment	Lu-177 / I-131 inpatient wards
Egress + exhaust	Hand-foot frisker + stack monitor + 2 area gamma	Mixed — frisker indoor, others may need rugged	Combined egress + facility-perimeter cluster
Outdoor perimeter	Area gamma × 4 — perimeter posts around the building	Yes — outdoor exposure	Facilities with public-area dose-rate documentation requirements

Planning rules

Five rules that decide cluster mapping

Map detectors to clusters by physical proximity, not by detector type. The display unit aggregates four detectors regardless of type — neutron + gamma + contamination can sit in the same cluster if they share a corridor.
Long-haul cable cost dominates the budget. The cluster topology saves cable runs, conduit installation and patch-panel ports — typical savings 60-80 % vs direct-to-server cabling at a multi-cluster facility.
Reserve one spare slot per cluster. When the facility adds a new monitor a year later (a new clean-room boundary monitor, an inspector-requested perimeter point), it joins the existing cluster — no new cable run, no central reconfiguration.
Don't mix indoor and outdoor in the same cluster unless the display unit lives indoors. The standard variant doesn't survive long-term outdoor exposure; the ruggedised variant does.
Co-locate the display unit with the local team that uses it — radiopharmacist at the hot-lab cluster, nurse station at the ward cluster, security at the perimeter cluster. The display is doing situational-awareness work locally; the RMS server is doing the inspection-grade archive.

Standard vs ruggedised

When to specify the ruggedised variant

Vault corridor: temperature swings during cyclotron production runs, occasional cooling-system condensate. Use ruggedised.
Hot-lab clean room: climate-controlled clean environment. Standard unit is fine.
Theranostic ward corridor: hospital climate, occasional cleaning-fluid spray. Standard unit, mounted out of spray range.
Egress lane: high-traffic area, occasional knocks. Standard unit; mount above operator-hand height.
Outdoor perimeter shed: dust, humidity, temperature extremes. Use ruggedised in an outdoor enclosure.
Hot-lab boundary at the gowning interface: ruggedised because the boundary sees occasional cleaning-fluid spray during clean-room turn-over.