Miniature thermoelectric cooler

Abstract

A miniature thermoelectric cooling device for storing small amounts of thermally unstable substances, like drug vials with insulin for diabetic patients or protein based drugs for thrombolytic therapy, is disclosed. A solar energy collector coupled with a rechargeable battery is provided as the energy source. The miniature cooler is small enough to be belt-carried at all time by a person, whose life or health depends on the drugs. When switched to a heating mode, the thermoelectric device can temporarily elevate the temperature of the drug to a body temperature thus providing comfortable conditions for the injection. A combined solar-and-battery power supply allows keeping an article in the cooler at low temperatures around o'clock at all times during substantially long travels in hot or tropical conditions where even short term exposure to surrounding temperatures can destroy the potency of the drug.

What is claimed is:  
     
         1 . A miniature cooler comprising: 
 a storage compartment made of thermally insulating materials and having top and side walls with said top wall openably-connected to said side wall such that said top wall closes the compartment or allows access to the compartment;    a power supply including a photovoltaic collector panel and a rechargeable battery, said panel being externally attached to said compartment sidewall and electrically connected to said rechargeable battery, said photovoltaic collector being provided for generating to cool said compartment and to recharge said battery; and    a temperature control system comprising: 
 a thermoelectric unit imbedded in said top wall of the compartment, said unit having a hot end and a bottom end, said hot end of said unit facing upwardly and said cold end of said unit facing downwardly from said top wall, respectively;  
 a control unit operationally connected to the thermoelectric unit and the power supply, said control unit being provided for selectively turning said thermoelectric unit on and off; and  
 a temperature sensor placed inside the storage compartment and operatively connected to said control unit.  
   
     
     
         2 . The miniature cooler of  claim 1  wherein: 
 the storage compartment further additionally includes a Dewar flask, in which the articles to be stored are placed.  
 
     
     
         3 . The miniature cooler of  claim 1  wherein: 
 the volume of the storage compartment is less than 250 cc.  
 
     
     
         4 . The miniature cooler of  claim 1  wherein: 
 the power output of the solar battery is less than 10 W.  
 
     
     
         5 . The miniature cooler of  claim 1  wherein said thermoelectric unit comprises semiconductors connected electrically in series and thermally in parallel.  
     
     
         6 . The miniature cooler of  claim 5  wherein said semiconductors are made of bismuth telluride.  
     
     
         7 . The miniature cooler of  claim 5  wherein: 
 the storage compartment further additionally includes a Dewar flask, in which the articles to be stored are placed.  
 
     
     
         8 . The miniature cooler of  claim 5  wherein: 
 the volume of the storage compartment is less than 250 cc.  
 
     
     
         9 . The miniature cooler of  claim 5  wherein: 
 the power output of the solar battery is less than 10 W.  
 
     
     
         10 . The miniature cooler of  claim 5  and further comprising a belt for attachment of said cooler, said belt for wearing around the waist of a person.  
     
     
         11 . The miniature cooler of  claim 1  and further comprising a belt for attachment of said cooler, said belt for wearing around the waist of a person.