Aroha LIMS

A histology lab handles hundreds of small, irreplaceable objects every week: specimens, cassettes, wax blocks and glass slides. Each one must trace back to the right patient, and every report must be signed, versioned and defensible. At Aroha Cancer Centre in Meru that was done on paper. I'm building the system that replaces it.

The problem

• Paper chain of custody. Request forms, handwritten labels and logbooks make it hard to prove where a specimen is or who handled it.
• Reports without history. A correction to a signed report must never overwrite what was originally issued.
• Accreditation pressure. ISO 15189 expects traceability, audit trails and controlled signatures.

What I built

• Accessioning. A paper request form becomes a case with a human-readable accession number such as H26-00001.
• Barcode identity graph. Specimen, cassette, block and slide each get an immutable barcode that doubles as the database ID, so scanning whatever is in your hand opens exactly that object.
• Scan-driven lab tracking. Every stage change is recorded with the barcode, the time and the person.
• Label printing. A print agent on the lab network takes jobs from a Firestore queue and prints ZPL labels on Zebra printers.
• Pathologist workbench. Case queue, report templates and second reviews, ending in a signed PDF report.
• Billing, retention and a client portal. Referring clinics follow their cases and download reports.

Under the hood

Clients never write tracked data directly. Every change goes through a Cloud Function built on a single mutate() primitive that writes the record and its audit entry in one transaction. Reports are append-only: each signature creates an immutable version, corrections become amendments or addenda that record what they supersede, and security rules deny any client write to past versions. The front end is a SvelteKit single-page app with shadcn-svelte and Tailwind, on Firebase Auth, Firestore, Storage and Hosting.

Where it stands

Accessioning, tracking and search, and the pathologist workbench with reporting are complete. The remaining go-live gates are validating labels on the lab's Zebra printers and the ISO 15189 signature review.