With over 150 years of combined experience, Althea's management team reflects an incredible breadth and depth of healthcare technology.

Our leadership applies their wealth of experience to propel our customer minded focus forward.


Dan Siler

CEO of Althea’s US operations

Dan Siler is CEO of Althea’s US operations, where he’s been focused on providing integrated solutions in healthcare technology management since 2019. 

Dan began his career as a field engineer with GE Healthcare, specializing in Mammography, X-Ray and CT products. After transitioning to an ISO in 2005, he held a wide degree of leadership roles in field service. 

Prior to Althea US, Dan spent over 15 years with ReMedPar, helping to relocate the organization to Charlotte, NC and creating a Center of Excellence for  CT, MRI, X-Ray, Mammography, Ultrasound Parts and Probes, Injectors and Low Temp Sterilization units.


Michael Colyer

Operations Director

Michael Coyer serves as the Operations Director for Althea US. In his role, he leads quality repair and testing to deliver industry-leading value and quality. 

Beginning his career serving in the US Army is where Michael discovered a love for electronics and healthcare technology management. Following his service, he lead a team of diagnostic imaging engineers.

More recently, Michael spearheaded the X-Ray team as a Modality Manager at a leading parts organization. After developing talented technicians for the past 40 years, Michael is committed to building teams that drive the exceptional level of quality our customers expect.


Mark Hartman

Vice President of Sales

As the Vice President of Sales, Mark oversees sales team operations across the US. He is responsible for overall sales effectiveness, strategic accounts and client relationships, as well as for articulating the company’s service offerings to prospective clients across healthcare. 

Mark has spent the last 15 years leveraging his clinical experience into sales and leadership roles within the diagnostic imaging and healthcare technology management industries.

Mark is a graduate of The University of Dayton where he earned a bachelor’s degree in business. He’s is passionate about healthcare and strives to help organizations implement solutions that simultaneously control costs while improving patient care and outcomes.


Billy Lambert

Director of US Sales

As the Director of US Sales, Billy Lambert oversees the growth and expansion of Althea’s business and sales performance across every one of our US markets. 

Leveraging his depth of expertise in both clinical and sales positions, Billy has spent the last 15 years in a variety of roles with escalating responsibility. Beginning as an EMT and working up to leadership roles within GE, Siemens and Philips Healthcare.

He deeply understands Althea’s customer-first focus, and our differentiators in diagnostic imaging and healthcare technology management. He holds a master’s degree in management from the University of St. Francis and is registered in both Nuclear Medicine and Radiologic Technology.


Michael Gossman

Contrast Injector Modality Manager

Michael Gossman is our Contrast Injector Modality Manager. He holds over 27 years of combined experience in the Biomedical and Diagnostic Imaging industries. 

As a 12-year veteran of the US Army, Michael completed his training at USAMEOS, Fitzsimons Army Medical Center in Aurora, CO as a Biomedical Equipment Repair Technician. Following his service, he worked as a CT Service Engineer across the Southeast and later expanded his skills in Imaging by working with several ISOs. 

He is a graduate of Southern Illinois University at Carbondale and holds a Bachelor of Science in Electronics Management.


Kevin Swain

CT Modality Manager

Kevin Swain is the primary CT Modality Manager for Althea US. With an incredible depth of experience, he is one of our most seasoned leaders in CT service.

Kevin began his career with GE in 1989. He held a variety of roles with escalating responsibility including field service, global support, lead CT engineer at GoldSeal and service integration. 

Prior to Althea US, Kevin worked at ReMedPar, moving from CT Modality Leader to CT Modality Manager. He graduated DeVry Institute of Technology with a Bachelors of Science in Electronic Engineering Technology.


Jeff Cherry

Radiology Equipment Sales Manager

Jeff Cherry serves as the Radiology Equipment Sales Manager for Althea US, where he oversees and analyzes the Radiology division of our business, to achieve maximum efficiency and effectiveness.

Excelling in building profitable business deals where all parties win, Jeff is an experienced Project and Sales Manager with a demonstrated history of working in hospital & healthcare facilities.

He is a graduate of Tennessee Technological University, and holds a Bachelor of Business Management, with a focus in Business Administration and Management.