Therapeutic Cold Compress Device

เครื่องประคบเย็น

A cooling system and cold compress for easing pain after knee replacement surgery. A thermoelectric unit chills water that circulates through a wrap around the knee, holds the temperature steady and can run timed on-off cycles, replacing ice packs that have to be swapped by hand.

Type: Prototypes, Research & 3D Printing

The problem

Cold therapy eases pain after knee replacement well, but the usual methods are fiddly, hard to keep up and cannot hold a steady temperature, while the number of osteoarthritis patients grows with the ageing population.

What we built

The whole prototype was designed and built here. A thermoelectric module with its heat-rejection stack chills the water, a pump sends it through hoses to a gel wrap strapped around the knee, and a temperature sensor at the wrap tells the controller when to run so the wrap stays inside the set range. Temperature and timing are set from the screen and buttons on the unit. The 3D-printed enclosure is built in stacked sections that keep the cooling side apart from the electrics and control.

Outcome

Holds the wrap below 20 °C, the design target, in a 25 °C room
Three timed cooling cycles over 120 minutes, back inside the control band every cycle
23 patients recovering from knee replacement tried it in hospital and scored it 3.91 to 4.00 out of 4 on every question
22 of 23 strongly agreed that it works in practice and eases knee pain
A research prototype; user requests such as cooling both knees at once and more cooling power feed the next version