EnsoETM
Engineering Project (2018)
Product Development | Thermals | Silicone Molding
This project was done as a design exercise for our client attune medical, creators of the EnsoETM an active cooling device for maintaining core body temperature in unconscious patients. The product is inserted in the esophagus by a physician and then heated or chilled water is circulated through channels along the length of the device. The goal of this project was to remove the need for an external temperature probe to monitor the patient's temperature.
Modified Proximal Junction
Top: Modified Distal Tip
Bottom: Original Distal Tip
Design Changes
To meet our client's needs we redesigned the tip to integrate a thermistor at the far end. In order to accommodate this added probe the tip needed to be lengthened and channels were added to allow the wire to exit the device. Using the insulated properties of silicone I was able to calculate and verify with testing that extending the tip length by 2in would be sufficient to isolate the probe from the temperature of the water and sense core temperature within 1 C of the actual core temperature. The silicone coated wire ran though a central channel of the device where it exited at a molded junction.
Molding Development
In order to test these parts I needed to mold prototypes. For the modified distal tip I designed a four part mold that I could inject with a two part silicone and then cure. I went though multiple iterations of mold design and molding procedures to achieve my finished result. One of the major challenges faced was fully filling such a high aspect ratio part. To overcome this I tweaked vent sizes, volume injected and degas procedure.