Our Board

Executive Directors

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Lorin Gresser

Chief Executive Officer

Steve Varley

Chief Technology Officer

Non-executive Directors

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Karen Bach

Chair of the Board

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Lorin Gresser

Chief Executive Officer
Lorin founded Dem Dx in 2015 after graduating from medical school and has been the CEO of Dem Dx ever since. As well as her medical degree from King's College London she has a MA in Natural Sciences from Cambridge University and an MBA from Harvard University.
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Steve Varley

Chief Technical Officer
Steve started developing software from an early age of 16, writing machine code algorithms for home computers to extend the core functionality and provide such things as high-resolution screen dumps. He now has over 35 years experience in open systems software architecture, design, and development, including 10+ years in mobile app development. Steve holds a BA in Computing Science from Teesside University. He is passionate about building great tech teams where people love to work.

Non-executive Directors

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Karen Bach

Chair of the Board
Karen joined Dem Dx as Chair in 2021. She brings 30 years of experience in growing, international businesses with a focus on scale-ups particularly in health tech and media tech. Karen joined Dem Dx because she is blown away by the diagnostics tool and the productivity it delivers to resource-constrained health care organisations.
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Tracy Sambrook

Director
Tracy joined DemDx as an NED in 2021. She brings 20 years of finance experience, scaling and raising funding for growth-stage businesses across the tech sector. Tracy joined Dem Dx because of Dem Dx's capability to deliver significant and much needed transformation to frontline healthcare, offering an opportunity to improve healthcare delivery in both developed and developing healthcare environments.
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Michael Steel

Director
Following a successful career in strategy consulting, Michael founded Greenbrook Healthcare in 2006 and grew it to become the largest provider of NHS urgent treatment centres in the country. In 2019, the Greenbrook business was successfully sold to Totally plc with £40m+ turnover, 700+ staff and a reputation for high quality and safe service provision. Michael holds an MBA from INSEAD and an MPhil. in Economics from Oxford University.
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Dr Sally Johnson

Director
Sally is a practicing GP with 30 years experience in the NHS. Alongside her clinical roles she has worked as the Chief Medical Officer of NHS and International Private primary and urgent care organisations. She has expertise in developing and delivering high quality, innovative and safe services. Her interests include pathway innovation, clinical governance, telemedicine, regulatory compliance and workforce development. As well as supporting Dem Dx Sally is a practicing GP, CQC inspector and Medical Examiner.
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Graeme Cox

Director
Graeme is a technologist with 25 years experience in CEO/CTO roles for early-stage deep-tech businesses. He has been involved in the development of data-centric applications using machine learning since his degree in AI in the early '90s, and has built and worked in numerous high performing startups, including taking one of the UK's leading managed cybersecurity businesses from bootstrap to a successful exit to the global leader in Enterprise Computing. Graeme provides both NED & investment support to high-potential early stage companies and technical due diligence for VC and PE organisations, combining his practical experience in business management and fund-raising with his extensive experience in deep-tech fields such as AI/ML, cybersecurity, human biometrics and medical devices.