gemma-3-27b-it-lora-cholect50-instruments

Gemma 3 27B-it LoRA — CholecT50 instrument recognition

LoRA adapter plus a 6-way linear classification head on google/gemma-3-27b-it, fine-tuned for multi-label instrument presence on CholecT50 frames.

This is the “Gemma 3 27B fine-tuned” row on the Instruments tab of the SDSC × Chicago Booth surgical video understanding leaderboard.

Prompt example

This closed-set example mirrors the leaderboard format, not a text-input API for this checkpoint.

[surgical frame]

Which instruments are visible in this laparoscopic cholecystectomy frame?
Select every matching label.

- grasper
- bipolar
- hook
- scissors
- clipper
- irrigator

Files

• adapter_model.safetensors / adapter_config.json — LoRA (r=128, alpha=256) on q/k/v/o_proj and out_proj
• classifier.pt — linear head over the 5376-d hidden state (6 tools)
• model_config.json — tool vocabulary and training hyperparameters

You need the adapter and the classification head; this is not a generative JSON adapter.

Training

• 10 epochs, lr 5e-6, effective batch size 2, seed 42
• 80,940 training frames / 19,923 validation frames

Evaluation

Full CholecT50 validation split (95% bootstrap CI):

References

• Skobelev, K., Fithian, E., Baranovski, Y., et al. A Comparative Study in Surgical AI: Potential and Limitations of Data, Compute, and Scaling. arXiv:2603.27341, 2026.
• Dataset: Nwoye, C. I., Yu, T., Gonzalez, C., et al. Rendezvous: Attention Mechanisms for the Recognition of Surgical Action Triplets in Endoscopic Videos. Medical Image Analysis, 78, 102433 (2022).

Limitations

Research baseline only. Not a medical device.