About Oxygen Concentrator Store

Our History and Who We Are

With more than 15 year of experience, AMSR is one of the oldest and most experienced oxygen concentrator retailers in America. AMSR is accredited by the Accreditation Commission for Health Care and holds a national BBB A+ rating.

Our Respiratory Specialists are fully trained on every product we carry and are available 7 days a week to answer any questions you have. Let our experts help you select the right device for you and your oxygen requirements.

Management Team

Jenny Hopkins AMSR Picture

Jenny Hopkins  CEO and Partner

  • Email Jenny Hopkins
  • Call Jenny Hopkins
  • 303-483-7156

Jenny is a managing partner at Crescendo Capital Partners and has been involved with AMSR since 2009. Her background includes more than 20 years of experience leading organizations for Hewlett Packard and Agilent Technologies. Outside of work Jenny enjoys golfing, skiing, and running.

Shannon Walter AMSR Picture

Shannon Walter  Director of Operations

  • Email Shannon Walter
  • Call Shannon Walter
  • 303-483-7138

Shannon joined AMSR in February of 2012. Originally from North Carolina, she moved to Denver after college and began her first accounting job with Marriott Hotels. Shannon loves the fast pace of a smaller business and the opportunity to always be improving.

Cindy George AMSR Picture

Cindy George  Director of Sales and Marketing

  • Email Cindy George
  • Call Cindy George
  • 303-483-7139

Cindy George brought her direct marketing prowess and sparkling personality to AMSR in October, 2013. Prior to that, she had spent almost 15 years in the direct response marketing industry, selling everything from computer learning, to nutraceuticals, to hopes and dreams. In her free time, Cindy revels in the wins and wallows in the losses of her home-state KC Cheifs and KU Jayhawks.

Scott Ridl AMSR Picture

Scott Ridl  Web Manager

  • Email Scott Ridl
  • Call Scott Ridl
  • 303-483-7155

Scott joined AMSR in 2008 and has over 10 years of experience as a web manager. He graduated from The Art Institute with a degree in Web Design & Interactive Media. He enjoys hiking, biking and playing guitar in his free time.

Marissa Ganje AMSR Picture

Marissa Ganje  Warehouse Manager

  • Email Marissa Ganje
  • Call Marissa Ganje
  • 303-483-7159

Marissa joined AMSR in 2012. She recently graduated from the University of Colorado at Colorado Springs. She oversees our rental program as well as inventory and transactions.

Samira Shaikh AMSR Picture

Samira Shaikh Customer Service Manager

  • Email Samira Shaikh
  • Call Samira Shaikh
  • 303-483-7142

Samira is a Chicago Native with over 12 years under her belt in the Call Center Industry. She has an extensive background working in Law, Life & Health Insurance, Credit Unions and Banks in the call center environment. She is a very competitive individual that is always looking to break records and push the envelope. Big fan of boxing and basketball.

David Arnett AMSR Picture

David Arnett Marketing Manager

  • Email David Arnett
  • Call David Arnett
  • 303-463-0101

David began working with AMSR in December of 2015 and brings with him a successful background in sales and marketing. He has over 18 years of experience with brand identity, marketing strategy, graphic design, website development, social media, email, and text campaigns. He loves working with AMSR customers and providing them with information relevant to their needs.

He recently moved to Denver from Panama City Beach, FL with his husband and enjoys all the wonderful outdoor activities that the mountains around Denver offer. Yes, he traded the beach (and humidity) for our beautiful mountains and fresh, clean air.


Maddie Hager AMSR Picture

Maddie Hager Process Engineer

  • Email Maddie Hager
  • Call Maddie Hager
  • 303-672-8001

Maddie joined AMSR at the start of 2016. She was originally from North Dakota and graduated from NDSU with a degree in Process Engineering. She spends her free time in the mountains and enjoys snowboarding, hiking, and camping.

Customer Service

Adelena Oritz-Lovato AMSR Picture

Adelena Oritz-Lovato  Customer Service Agent

  • Email Adelena Oritz-Lovato
  • Call Adelena Oritz-Lovato
  • 303-483-7153

Adelena, a proud Colorado Native, attends school at the University of Colorado Denver for Biology and Political Science. She has over 6 years of experience in customer service field and is enjoying the new challenges AMSR has brought her. Outside of work, Adelena enjoys playing volleyball, reading, and learning about other cultures and languages.

Sergio Gonzalez AMSR Picture

Sergio Gonzalez  Customer Service Agent

  • Email Sergio Gonzalez
  • Call Sergio Gonzalez
  • 303-483-7152

Sergio, originally from Dallas, Texas, has over 4 years of experience in the customer support field. Outside of work he enjoys many of the outdoor activities that Colorado has to offer. He is also an avid MMA, baseball, and basketball fan.


Danielle Jason AMSR Picture

Danielle Jason  Product Marketing Manager

  • Email Danielle Jason
  • Call Danielle Jason
  • 303-672-8004

Danielle joined AMSR in the summer of 2016. Originally from Wisconsin, she graduated from the University of Wisconsin Whitewater, in 2014, with a Professional Writing, Publishing, and Advertising degree. In her free time Danielle enjoys video games, reading, and hiking.

Jacob Scheuerman  AMSR Picture

Jacob Scheuerman Marketing Assistant

  • Email Jacob Scheuerman
  • Call Jacob Scheuerman
  • 303-382-2851

Jacob is a true native, born and raised in Parker, Colorado. A graduate from Baylor University, in Waco Texas, Jacob enjoys cycling, hiking, skiing, and reading. His favorite part of his role is being a part of the team that helps create the face and brand of AMSR.

Sales Team

Nick Vannatta AMSR Picture

Nick Vannatta  Lead Oxygen Specialist

  • Email Nick Vannatta
  • Call Nick Vannatta
  • 303-483-7158

Nick joined AMSR in 2007. He has been factory-trained by Respironics, DeVilbiss, Inogen, Invacare, and SeQual. He is also certified to repair select Respironics and SeQual products. Nick enjoys getting to know his customers, and they often ask for him by name.

Bret Bennett AMSR Picture

Bret Bennett Oxygen Specialist

  • Email Bret Bennett
  • Call Bret Bennett
  • 303-483-7163

Bret joined AMSR in 2012 and is factory trained by Sequal, Respironics, and Invacare. He says he has never had a more fulfilling job and loves to connect with people over the phone. Helping customers finding the best solution for them is his number one priority.

Aaron Searls AMSR Picture

Aaron Searls Oxygen Specialist

  • Email Aaron Searls
  • Call Aaron Searls
  • 303-483-7147

Aaron has been a dedicated member of the AMSR team since July 2014. Prior to that, he worked over 6 years in a fitness gym assisting with coaching, mentoring, and developing healthy living habits with people of all ages. Aaron loves rooting for the Colorado Avalanche and enjoys all things outdoors. He has a passion for helping others and is always looking to improve himself.

Stefanie Hughes AMSR Picture

Stefanie Hughes Oxygen Specialist

  • Email Stefanie Hughes
  • Call Stephanie Hughes
  • 303-483-7144

Stefanie joined AMSR in 2014. She is a Colorado native who comes from a medical background and was a Vision Therapist and Ophthalmic Technician for almost 10 years. She loves working with a company that makes customer care and customer service their number one priority! She enjoys spending time with her husband and two kids as well as nature hiking, biking and traveling.

Fritz Schneiderl AMSR Picture

Fritz Schneiderl Oxygen Specialist

  • Email Fritz Schneiderl
  • Call Fritz Schneiderl
  • 303-483-7135

Fritz, originally from Tulsa, Oklahoma, moved to Colorado in 1998. Fritz has been in the sales industry for over 15 years and has been a part of the AMSR family since April of 2016. When not at work he enjoys spending time with his wife and two kids as well as music, outdoors, and college football. (Go Oklahoma Sooners!)

Sean Lowe AMSR Picture

Sean Lowe Oxygen Specialist

  • Email Sean Lowe
  • Call Sean Lowe
  • 303-483-7145

Sean is originally from Louisiana but was born in Colorado Springs. He has over 10 years of experience in medical sales and his favorite part of his job is listening to customers and being a solution provider for something as important as oxygen! Outside of work, Sean likes to watch sports, run, and is an avid golf player and fan.

Laura Martinez AMSR Picture

Laura Martinez Oxygen Specialist

  • Email Laura Martinez
  • Call Laura Martinez
  • 303-483-7141

Laura, a Colorado Native, graduated from the University of Northern Colorado with a degree in Dietetics. Laura brings AMSR an impressive 3 years of experience in the DME (Durable Medical Equipment) field. Outside of work she enjoys hiking, biking, and spending time with her two children and dog.

Jacob Thurlo AMSR Picture

Jacob Thurlo Oxygen Specialist

  • Email Jacob Thurlo
  • Call Jacob Thurlo
  • 303-483-7143

Jacob, new to Colorado, moved here from Oregon, where he went to school for Exercise and Sports Science. He brings over 4 years of experience to our family here at AMSR. When not at work, Jacob enjoys weightlifting, rock climbing, and spending time with his dog and girlfriend.

Dee O’Kane AMSR Picture

Dee O’Kane Chat Specialist

  • Email Dee O’Kane
  • Call Dee O’Kane
  • 303-202-3027

Dee, originally from the Midwest, has lived and traveled throughout the country. She graduated from Xavier University and began working with AMSR in 2015. Outside of the office, Dee enjoys music, along with outdoor activates and spending time with family and friends.


Jack Bluni AMSR Picture

Jack Bluni Lead Rental Specialist

  • Email Jack Bluni
  • Call Jack Bluni
  • 303-483-7146

Jack moved to Colorado from Florida in August of 2014 where he attended college at the University of Central Florida. Jack brings 4 years of sales experience to the AMSR team. His favorite part of his job is when a customer calls in feeling somewhat overwhelmed and helpless, and by the end of their conversation they are happy, excited, and surprised by how easy renting a concentrator can be!

Linda Ganje AMSR Picture

Linda Ganje Rental Specialist

  • Email Linda Ganje
  • Call Linda Ganje
  • 303-483-7154

Linda joined AMSR in 2008 and has been factory trained by Sequal, Inogen, Respironics, Invacare, AirSep, Inova Labs and DeVilbiss. She enjoys educating people about the various oxygen concentrator options and assisting them in selecting the products that best fit their needs. She loves to see the joy and the freedom that oxygen concentrators bring to their lives.

Buy Backs

Kristina Maynard  AMSR Picture

Kristina Maynard  Buy Back Specialist

  • Email Kristina Maynard
  • Call Kristina Maynard
  • 303-483-7137

Kristina joined AMSR in September of 2015, choosing to relocate to Colorado from the West Coast. Thrilled to contribute to a locally owned company that dedicates itself to being preeminent in our industry. Outside the office, Kristina enjoys music, jewelry and vintage cars.

Shipping & Receiving

Mario Torres AMSR Picture

Mario Torres Warehouse Technician

  • Email Mario Torres
  • Call Mario Torres
  • 303-799-0013

Mario, a Colorado native, has over 2 years of experience in the shipping and receiving field. Outside of work he is attending college for Business and enjoys spending time with his friends playing soccer.

Bryn McGary AMSR Picture

Bryn McGary Warehouse Technician

  • Email Bryn McGary
  • Call Bryn McGary
  • 303-799-0013

Bryn moved from Arcadia California to Colorado in 1991 and has over 8 years of experience in the shipping and receiving field. Outside of work she enjoys hiking, camping, and spending time with her family, friends, and 8 year old Rottweiler Basset Hound, Mara.