AI won’t fix healthcare unless it starts with the conversation.
In this episode, Zachary Lipton—Chief Technology & Science Officer at Abridge and Raj Reddy Associate Professor of Machine Learning at Carnegie Mellon University—joins Barr Yaron for a deep, technical, and emotional dive into how AI can truly transform clinical care.
From building a world-class ambient documentation system to tackling speech recognition in 28 languages, Zack shares what it takes to engineer trust into AI when the stakes are patient lives, not just clicks.
We cover:
- Why general-purpose models fail in clinical settings
- How Abridge designs for accuracy, context, and trust
- The tension between personalization and evaluation
- Why ambient AI might be the most promising foundation for fixing healthcare
This is one of the most in-depth looks at what it actually takes to build production-grade AI in medicine.
This episode is broken down into the following chapters:
00:00 – Intro
00:34 – What Abridge actually does (hint: it’s not just notes)
01:09 – Why documentation is killing the healthcare experience
03:05 – How we got to the current burnout crisis
04:16 – The key insight: healthcare is a conversation
07:33 – Building a digital scribe: the original vision for Abridge
09:15 – Why off-the-shelf models don’t cut it in clinical speech
11:36 – 28 languages, noisy ERs, and overlapping conversations
13:20 – Predicting what enters the medical lexicon next
14:21 – How Abridge adapts models for edge-case medical speech
15:18 – Beyond transcripts: the complexity of clinical note generation
17:10 – Foundation models are tools, not solutions
18:06 – The “Ship of Theseus” strategy of model orchestration
20:32 – Style transfer for doctors, patients, and payers
20:54 – Metrics: ASR evaluation vs. documentation quality
23:43 – Stratifying ASR performance by setting, language, and jargon
24:50 – Why eval is so hard when there’s no “gold note”
25:45 – The tension between personalization and general eval
28:05 – Lessons from machine translation: building robust eval pipelines
30:32 – Abridge’s “look at the f*cking data” (LFD) internal review
33:54 – Blinded clinical eval with linked evidence and audio
36:50 – Why human fallibility is just as real as AI hallucination
38:21 – What kind of CTO Zack actually is
40:32 – Why AI product development is its own discipline
42:44 – AI innovation now lies in the product-data-model loop
44:25 – Closing the loop: how design drives modeling
45:25 – How Abridge hires researchers who care about product
47:29 – The mission filter: if you’d be equally happy at Microsoft, go
49:35 – What’s next: the AI layer for healthcare, not point solutions
52:57 – Closing thoughts
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