Advisor(s)

Masoud Salehi

Abstract

Currently, hospitals need to constantly monitor hyper/hypothermic patients when trying to return a patient's core body temperature to safe value. The temperature automated blanket system (TABS) constantly monitors a patient's temperature, through a medical rectal probe (proven to be the most accurate way of reading a patient's core body temperature), and adjusts the heating/cooling blanket accordingly. The need for this product is evident by the fact that, currently, hospitals with non-automated systems designate a nurse to constantly monitor a patient, which is inconvenient for effective/efficient personnel use. Systems that automate the process of heating and cooling a patient do exist as complete packages, but these systems are large in size, require water, and are very expensive ($5,000 to $10,000). TABS is a cheap and smaller alternative to the large expensive packages that are available.

The blanket portion of the system uses the peltier effect to heat or cool the blanket to be placed on the patients. The peltier effect occurs when a current is passed across two dissimilar metals. In the case where a positive current is applied across the two dissimilar metals, one side of the peltier pad, or thermoelectric module (TEM), will heat and the other side will cool. When a negative, reversed current is applied across the same two dissimilar metals, the side that was heating will begin cooling. When placing a heatsink on the non-patient side of the TEM, you can draw heat away from the module allowing the cooling side to be controlled more effectively.

TABS integrates temperature sensors, a Programmable Logic Controller (PLC), heatsinks, peltier pads, and aluminum plates. During testing we found that using a generic Proportional Integral Derivative (PID) temperature control function would not suffice using the peltier effect. We handled the issue by making our own timing function for both heating and cooling activities, allowing the peltier units to be powered on for a given amount of time and then shut off; the heat transfer between both sides of the peltier pads was the cause for this need.

We made the user interface for the controller easy and useful for optimal friendliness and simplicity. We have a manual set point option, in addition to an automatic option, allowing a medical employee to set the optimal temperature they wish the patient to attain. Through research, we found that at different ages the average core body temperature differs by about 1 degree F give or take a degree. For automatic mode, we gave the user the option to select the age of the patient which has automatic set points in the program for each age range.

Date Accepted

5-2007

Publication Date

4-1-2007

Keywords

heating, cooling, blanket, hypothermia treatment, hyperthermia treatment

Degree Grantor

Northeastern University

Rights Holder

Chidinma Okebalama et al.

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