FIELD

Embodiments herein relate to electrical stimulation devices and methods for the treatment of cancer. More specifically, the electrical stimulation devices and methods herein can include features related to measuring one or more electrical properties, including but not limited to impedance, polarization, capacitance, or voltage, at or near a site of a cancerous tumor.

BACKGROUND

A living organism is made up of a complex three-dimensional architecture of biological tissue including cells and extracellular matrix surrounded by intracellular and extracellular fluids. The intracellular fluid found inside of the cells of an organism is generally ionic, and includes various electrically active molecules such as ions, proteins, macronutrients, and nucleic acids. The extracellular fluid includes various fluids found outside of the cells of an organism. Examples of extracellular fluids can include the blood plasma, lymph, cerebrospinal fluid, ocular fluid, synovial fluid, and saliva, to name a few. The extracellular fluids are generally ionic in nature, and can include electrically active macronutrients such as ions, sugars, fatty acids, and metabolic waste products. The cell membranes of an organism include phospholipids and proteins, where the hydrophobic lipid tails are sandwiched between two layers of hydrophilic phosphate headgroups and various proteins associated therewith.

The biological tissue in a living organism has an electrical impedance when placed in an alternating electric field. The electrical impedance of the biological tissue of a living organism can depend on the tissue type, the health or diseased state of the tissue, and the frequency of the applied electric field. Electrical impedance of each type of biological tissue is determined by the cell type, intracellular fluid, and extracellular fluid composition for each specific tissue.

The electrically active molecules of biological tissues also give rise to dielectric properties within the biological tissues. When placed in an electric field, biological tissues can store electromagnetic energy due to the displacement of the positive or negative charges carried on the electrically active molecules therein. Displacement of the positive and negative charges within the biological tissue can result in a net polarization of the biological tissue.

SUMMARY

In a first aspect, a medical device for treating a cancerous tumor is included. The medical device can include an electric field generating circuit configured to generate one or more electric fields at or near a site of the cancerous tumor and control circuitry in communication with the electric field generating circuit, where the control circuitry can be configured to control delivery of the one or more electric fields from the electric field generating circuit. The control circuitry can cause the electric field generating circuit to generate one or more electric fields having a field strength selected from a range of from 0.25 V/cm to 1000 V/cm. The medical device can include one or more supply wires in electrical communication with the electric field generating circuit, where the one or more supply wires can each be in electrical communication with one or more supply electrodes. The one or more supply electrodes can be configured to deliver an electric field at or near the site of the cancerous tumor. The medical device can include one or more sensing wires in electrical communication with the control circuitry, where the one or more sensing wires can each be in electrical communication with one or more sensing electrodes. The one or more sensing electrodes can be configured to measure an impedance of the cancerous tumor at at least two different electric field strengths.

In a second aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the control circuitry is configured to generate at least a first electric field and a second electric field, and where the first electric field has a first electric field strength and the second electric field has a second electric field strength.

In a third aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the second electric field strength is greater than the first electric field strength.

In a fourth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the first electric field strength is selected from a range of from 0.1 V/cm to 2 V/cm and the second electric field strength is selected from a range of from 1 V/cm to 100 V/cm.

In a fifth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the medical device including a memory including one or more therapeutic parameter sets.

In a sixth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the control circuitry is further configured to implement the one or more therapeutic parameter sets to deliver a given therapy.

In a seventh aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the control circuitry is configured to modulate the one or more electric fields if the impedance at or near the site of the cancerous tumor changes by at least 5% during a therapy relative to an initial impedance at or near the site of the cancerous tumor at a beginning of the given therapy.

In an eighth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the one or more electric fields is modulated by increasing or decreasing the electric field strength.

In a ninth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the control circuitry can cause the electric field generating circuit to generate the one or more electric fields at frequencies selected from a range of from 10 kHz to 1 MHz at or near a site of the cancerous tumor.

In a tenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the control circuitry can be further configured to generate one or more electric fields by sweeping through a range of frequencies, where sweeping through a range of frequencies includes sweeping from a first frequency up to a second frequency and sweeping from the second frequency down to the first frequency, and where the second frequency is higher than the first frequency.

In an eleventh aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the range of frequencies includes a range of frequencies of from 100 kHz to 500 kHz.

In a twelfth aspect, a method for treating a cancerous tumor within a subject is included. The method can include implanting a medical device at or near a site of the cancerous tumor. The method can include applying at least two electric fields at or near the site of the cancerous tumor to deliver at least a first electric field having a first electric field strength and a second electric field having a second electric field strength using one or more supply leads each including one or more supply electrodes. The method can include measuring an impedance of the cancerous tumor at the at least two electric field strengths, where measuring an impedance includes using one or more sensing leads including one or more sensing electrodes. The method can include modulating a therapy according to at least one therapeutic parameter set if the impedance changes.

In a thirteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where modulating the therapy according to the at least one therapeutic parameter set includes modulating the one or more electric fields if the impedance at or near the site of the cancerous tumor changes by at least 5% during a therapy relative to an initial impedance measured at or near the site of the cancerous tumor at a beginning of the therapy.

In a fourteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the at least one therapeutic parameter set further includes modulating the one or more electric fields by increasing or decreasing a strength of the one or more electric fields.

In a fifteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where modulating the therapy according to the at least one therapeutic parameter set includes terminating the at least one therapeutic parameter set if the impedance falls outside of a predetermined range during the predetermined period of time.

In a sixteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where the one or more electric fields includes a field strength selected from a range of from 0.25 V/cm to 1000 V/cm.

In a seventeenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the method can include assigning the subject into a non-response to therapy category if a decrease in the impedance is measured over the predetermined period of time.

In an eighteenth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, the method can include assigning the subject into a response to therapy category if an increase in the impedance is measured over the predetermined period of time.

In a nineteenth aspect, a method for treating a cancerous tumor within a subject is included. The method can include implanting a medical device at or near a site of the cancerous tumor. The medical device can include applying one or more electric fields at or near the site of the cancerous tumor to deliver a therapy according to at least one therapeutic parameter set for a predetermined period of time, where applying the one or more electric fields includes using one or more supply leads each including one or more supply electrodes, where applying the one or more electric fields further includes applying one or more electric fields at at least two frequencies. The method can include measuring an impedance of the cancerous tumor during application of the one or more electric fields at the at least two frequencies, where measuring an impedance includes using one or more sensing leads including one or more sensing electrodes. The method can include modulating the therapy according to the at least one therapeutic parameter set if the impedance changes during the predetermined period of time.

In a twentieth aspect, in addition to one or more of the preceding or following aspects, or in the alternative to some aspects, where applying the one or more electric fields at at least two frequencies includes applying at least a first electric field at a first frequency and at least a second electric field at a second frequency.

This summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details are found in the detailed description and appended claims. Other aspects will be apparent to persons skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof, each of which is not to be taken in a limiting sense. The scope herein is defined by the appended claims and their legal equivalents.

