AI Engineer · Düsseldorf
Lars Müller
At University Hospital Düsseldorf I build Monti, an AI early‑warning system meant to detect complications during cancer treatment from wristband data. With Benno I founded an AI agent on WhatsApp: solo self‑employed people use it to turn a voice message into a legally compliant e‑invoice.
Monti · University Hospital Düsseldorf
An early‑warning system for cancer treatment
Anyone on intensive cancer treatment comes to the hospital for a check about every three days. Monti is meant to replace that check with a wristband worn at home: a model learns each patient's normal pattern from the wristband data. When the pattern drifts, it notifies the hospital, and the hospital gets in touch with the patient. A study by the group with 79 patients showed that severe complications can be detected this way, and infections predicted up to two days before the clinical diagnosis.
- Role
- I build the study platform and the detection, from the model to the alert threshold.
- Deployment
- Running with patients in Düsseldorf and Aachen since 2025, each hospital with its own installation. Audit log, role model, daily backups.
- Data
- Heart rate, oxygen saturation, HRV, ECG, temperature and movement from the wristband, plus questionnaires in the app.
Studies npj Digital Medicine 2023 · blood cancer European Heart Journal Digital Health 2025 · heart failure
Benno · Founder
Voice message in, invoice out
Benno is an AI agent on WhatsApp. Solo self‑employed people tell it in a voice message what to invoice to which customer. It remembers customers and asks for anything missing in the same chat. It takes corrections on the spot. Only after a “yes” does it create the invoice and drop it into the chat as a PDF. No app, no login.
- Legal
- E‑invoice under EN 16931 (ZUGFeRD, PDF/A‑3), mandatory details under § 14 UStG, small‑business rule, reverse charge, § 35a, GoBD, DATEV export. From 2028, e‑invoicing is mandatory for every German business.
- How it works
- The agent works out what is meant: invoice, quote, question, export. “Turn quote 12 into the invoice” is enough. Python, FastAPI, PostgreSQL, language models in EU data centres.
- Company
- Benno UG (haftungsbeschränkt), Düsseldorf, since April 2026, alongside my job at the hospital.
Projects
trainarobot.run
Reinforcement learning in the browser, no install. PPO runs on WebGPU, the rollouts in parallel on your CPU cores, training a TurtleBot and a rover. Nothing leaves the tab.
BSI IT‑Grundschutz AI search
Ask the IT‑Grundschutz compendium a question and get a plain‑language answer. Every answer cites the module and paragraph it comes from.
Bachelor thesis: Active Pre‑Training with Phasic Policy Gradient
Active Pre‑Training with intrinsic rewards, combined with Phasic Policy Gradient. In Ms. Pac‑Man the agent scored higher without pre‑training than with it.
TurtleBot: autonomous navigation
As a working student I trained TurtleBots in the Gazebo simulation and transferred the learned policies to real robots.
Consulting
Consulting for select projects
My focus is AI agents that handle whole processes. Alongside Monti and Benno I make time for projects I find compelling. If you think yours is one of them, we talk it through in a free twenty‑minute first call: book a call
AI agents for whole processes
An agent takes a process from the incoming message to the finished document, asking back and confirming before anything becomes binding. That is how Benno produces its e‑invoices.
Testing AI agents
Simulated users hold conversations with the agent. A second model rates every reply. At Benno this test runs before a change reaches customers.
Software for regulated environments
Audit log, role model, backups and EU hosting are part of the design from the start. Monti runs that way at two university hospitals, each with its own installation.