Magnetic apparatus

Abstract

An apparatus includes a magnetic apparatus that defines an actuation volume that is large enough to accommodate a sample, the magnetic apparatus including a magnet that is configured to create a magnetic field having a magnitude B in the sample when supplied with a DC current; at least one biological construct within the sample, the biological construct configured to change its status in response to a change in a property; and at least one magnetocaloric actuator coupled with the biological construct. A change in a characteristic in the actuation volume causes the property of the magnetocaloric actuator to change, which causes a change in the status of the biological construct.

What is claimed is: 
     
         1 . An apparatus comprising:
 a magnetic apparatus that defines an actuation volume that is large enough to accommodate a sample, the magnetic apparatus including a magnet that is configured to create a magnetic field having a magnitude B in the sample when supplied with a DC current;   at least one biological construct within the sample, the biological construct configured to change its status in response to a change in a property; and   at least one magnetocaloric actuator coupled with the biological construct;   wherein a change in a characteristic in the actuation volume causes the property of the magnetocaloric actuator to change, which causes a change in the status of the biological construct.   
     
     
         2 . The apparatus of  claim 1 , wherein the sample is a region of a live human body and the magnetocaloric property changes while the temperature in the live human body region is at a human body temperature. 
     
     
         3 . The apparatus of  claim 1 , wherein the change caused to the property of the magnetocaloric actuator occurs without causing a change in status of materials within the sample other than the at least one biological construct. 
     
     
         4 . The apparatus of  claim 1 , further comprising an energy supply connected to the magnet, wherein the magnet includes electrically conductive wire coils through which current from the energy supply is passed, wherein the energy supply provides the DC current supplied to the wire coils. 
     
     
         5 . The apparatus of  claim 1 , wherein the magnet is a superconducting magnet. 
     
     
         6 . The apparatus of  claim 1 , wherein the magnetic field magnitude B is greater than 0.5 Tesla or in a range of 1-20 Tesla. 
     
     
         7 . The apparatus of  claim 1 , wherein the magnetic apparatus is a magnetic resonance imaging apparatus. 
     
     
         8 . The apparatus of  claim 1 , wherein the magnetocaloric actuator includes a material selected from the group consisting of iron-rhodium, alloys of iron-rhodium, alloys of manganese arsenide, Heusler alloys, alloys of manganese-iron, and gadolinium. 
     
     
         9 . The apparatus of  claim 1 , wherein each magnetocaloric actuator is a spatially-separated particle having a size on the order of about 1-100 μm. 
     
     
         10 . The apparatus of  claim 1 , wherein:
 the biological construct is a thermally-sensitive biological construct;   the at least one magnetocaloric actuator is thermally coupled with the thermally-sensitive biological construct; and   a change in the magnitude B of the magnetic field supplied with DC current causes the temperature of the magnetocaloric actuator to change, which causes a change in the status of the thermally-sensitive biological construct.   
     
     
         11 . The apparatus of  claim 10 , wherein the magnetocaloric actuator is a magnetically manipulatable material that exhibits a transition between a first magnetic state and a second magnetic state in response to the change in the magnitude B of the magnetic field. 
     
     
         12 . The apparatus of  claim 11 , wherein the change in the magnitude of the magnetic field is substantially smaller than the magnitude B of the magnetic field. 
     
     
         13 . The apparatus of  claim 10 , wherein the magnetically manipulatable material exhibits the transition while the temperature in the sample is between 270 and 370 K. 
     
     
         14 . The apparatus of  claim 10 , wherein the at least one thermally-sensitive biological construct within the sample comprises an ion channel, and the ion channel has a status that is either closed or open. 
     
     
         15 . The apparatus of  claim 14 , wherein the ion channel is a transient receptor potential cation channel subfamily V member or a transient receptor potential cation channel subfamily M member. 
     
     
         16 . The apparatus of  claim 14 , wherein the ion channel is genetically engineered. 
     
     
         17 . The apparatus of  claim 10 , wherein each magnetocaloric actuator is a spatially-separated particle having a size that is large enough to retain heat long enough to cause the change in status in the adjacent thermally-sensitive biological construct. 
     
     
         18 . The apparatus of  claim 10 , wherein the magnetocaloric actuator temperature change ΔT is less than 20° C. for a change in magnitude of the magnetic field ΔB between 1-20 T. 
     
     
         19 . The apparatus of  claim 10 , wherein each magnetocaloric actuator thermally coupled with a first thermally-sensitive biological construct is distinct from each magnetocaloric actuator thermally coupled with a second thermally-sensitive biological construct. 
     
     
         20 . The apparatus of  claim 10 , wherein:
 an increase in the magnitude B of the magnetic field supplied with the DC current causes an increase in the temperature of the magnetocaloric actuator and an increase in the temperature of the thermally-sensitive biological construct; and   a decrease in the magnitude B of the magnetic field supplied with the DC current can cause a decrease in the temperature of the magnetocaloric actuator and a decrease in the temperature of the thermally-sensitive biological construct.   
     
     
         21 . The apparatus of  claim 10 , wherein:
 an increase in the magnitude B of the magnetic field supplied with the DC current causes a decrease in the temperature of the magnetocaloric actuator and a decrease in the temperature of the thermally-sensitive biological construct; and   a decrease in the magnitude B of the magnetic field supplied with the DC current can cause an increase in the temperature of the magnetocaloric actuator and an increase in the temperature of the thermally-sensitive biological construct.   
     
     
         22 . The apparatus of  claim 1 , wherein the sample is a living organism that is held at a physiological temperature to maintain the organism in a living state.