Magnetic field strength regulator for implant
AssigneeMedtronic, Inc.
InventorJohn J. Grevious
Life of this patent
Estimating the term…
Abstract
An efficient low cost means for regulating the output level of a magnetic field transmitter. A feedback coil tightly coupled to an output coil is designed to produce an output voltage just above the supply level for the output stage of the transmitter when the desired output level is achieved. The feedback sense coil tightly coupled to an output coil is designed to produce an output voltage just above a regulated power supply level for the output stage of the transmitting antenna until a desired output level is achieved. The feedback coil is diode coupled to the regulated power supply lines of the transmitter. When the output level increases above the regulation level the diodes begin to conduct returning energy to the supply and preventing further increase of the transmitting antenna signal.
Claims13
A medical device system, comprising:
- an implantable medical device having a receiving antenna;
- an external programmer means for transmitting information to a pacemaker including a transmitter, said transmitter in turn comprising:
- a transmitting antenna;
- means for supplying a radio frequency signal to said transmitting antenna to cause generation of a magnetic field;
- means for sensing strength of said magnetic field;
- and
- means responsive to said sensing means for variably loading said magnetic field to regulate said magnetic field strength, said loading means loads said magnetic field to restrict said field to a predetermined maximum level.
A medical device system, comprising:
- an implantable medical device having a receiving antenna;
- an external programmer means for transmitting information to a pacemaker including a transmitter, said transmitter in turn comprising:
- a transmitting antenna;
- means for supplying a radio frequency signal to said transmitting antenna to cause generation of a magnetic field;
- means for sensing strength of said magnetic field, said sensing means further comprises a sensing antenna;
- and
- means responsive to said sensing means for variably loading said magnetic field to regulate said magnetic field strength, said loading means further comprises means for allowing current flow through said sensing antenna in response to said magnetic field reaching a predetermined level.
A programmer for transmitting information to an implantable medical device by means of a transmitter, said transmitter in turn comprising:
- a transmitting antenna;
- means for supplying a radio frequency signal to said transmitting antenna to cause generation of a magnetic field;
- means for sensing strength of said magnetic field:
- and
- means responsive to said sensing means for variable loading said magnetic field to regulate said magnetic field strength, said loading means loads said magnetic field to restrict said field to a predetermined maximum level.
A programmer for transmitting information to an implantable medical device by means of a transmitter, said transmitter in turn comprising:
- a transmitting antenna;
- means for supplying a radio frequency signal to said transmitting antenna to cause generation of a magnetic field;
- means for sensing strength of said magnetic field, said sensing means further comprises a sensing antenna;
- and
- means responsive to said sensing means for variably loading said magnetic field to regulate said magnetic field strength, said loading means comprises means for allowing current flow through said sensing antenna in response to said magnetic field reaching a predetermined level.
A transmitter system for use in a programmer useful to communicate with an implantable medical device comprising:
- a transmitting antenna;
- a power supply means connected via an amplifier to provide power to encoded signal for transmission by said transmitting antenna,
- secondary antenna means for receiving transmission by said transmitting antenna and for controlling Q of said transmitting antenna by absorbing transmitted power.
Dependencies are inferred from the claim text.