@mamab5 Deep Oscillation Therapy is different than a pump device. I think your RN friend that mentioned a pump device is describing a pneumatic compression pump (eg. Intermittent pneumatic compression therapy).
https://en.wikipedia.org/wiki/Lymphedema
• Intermittent pneumatic compression therapy (IPC) utilizes a multi-chambered pneumatic sleeve with overlapping cells to promote movement of lymph fluid. Pump therapy should only be used in addition to other treatments such as compression bandaging and manual lymph drainage. Pump therapy has been used in the past to help with controlling lymphedema. In some cases, pump therapy helps soften fibrotic tissue and therefore potentially enable more efficient lymphatic drainage.
https://www.mayoclinic.org/diseases-conditions/lymphedema/diagnosis-treatment/drc-20374687
• Sequential pneumatic compression. A special sleeve connected to a pump inflates and deflates in cycles, gently moving lymph fluid away from the fingers or toes.