Haifa, Israel
Haifa, Israel

Time filter

Source Type

An apparatus for generating a sinusoid at a pre-set frequency f includes a DC power source with a controllable output voltage, a transformer, a power switch, a sequencer, and an output filter. The power switch is configured to apply the output of the DC power source to the primary of the transformer in either direction or to remain off based on control signals that are applied to its control input. The sequencer applies control signals to the control input in a choreographed sequence to form an oversampled version of a sine wave. The output filter is connected to the secondary of the transformer, and it passes the pre-set frequency f and attenuates frequencies above a cut-off frequency. In some preferred embodiments, the cut-off frequency is 3f and the transfer function of the output filter has a zero at 5f.


When electrodes are used to impose an electric field in target tissue within an anatomic volume (e.g., to apply TTFields to treat a tumor), the position of the electrodes can be optimized by obtaining electrical conductivity measurements in an anatomic volume and generating a 3D map of the conductivity directly from the obtained electrical conductivity or resistivity measurements, without segmenting the anatomic volume into tissue types. A location of the target tissue is identified within the anatomic volume, and the positions for the electrodes are determined based on the 3D map of electrical conductivity and the position of the target tissue.


Tumors can be treated with an alternating electric field. The size of cells in the tumor is determined prior to the start of treatment by, for example, biopsy or by inverse electric impedance tomography. A treatment frequency is chosen based on the determined cell size. The cell size can be determined during the course of treatment and the treatment frequency is adjusted to reflect changes in the cell size. A suitable apparatus for this purpose includes a device for measuring the tumor impedance, an AC signal generator with a controllable output frequency, a processor for estimating the size of tumor cells and setting the frequency of the AC signal generator based thereon, and at least one pair of electrodes operatively connected to the AC signal generator such that an alternating electric field is applied to the tumor.


Patent
Novocure LTD | Date: 2013-03-01

Cells that are in the process division are vulnerable to damage by AC electric fields that have specific frequency and field strength characteristics. The selective destruction of rapidly dividing cells can therefore be accomplished by imposing an AC electric field in a target region for extended periods of time at particular frequencies with particular filed strengths. Some of the cells that divide while the field is applied will be damaged, but the cells that do not divide will not be harmed. This selectively damages rapidly dividing cells like bacteria, but does not harm normal cells that are not dividing. Since the vulnerability of the dividing cells is strongly related to the alignment between the long axis of the dividing cells and the lines of force of the electric field, improved results can be obtained when the field is sequentially imposed in different directions.


Patent
Novocure Ltd | Date: 2013-03-01

Cells that are in the process division are vulnerable to damage by AC electric fields that have specific frequency and field strength characteristics. The selective destruction of rapidly dividing cells can therefore be accomplished by imposing an AC electric field in a target region for extended periods of time at particular frequencies with particular filed strengths. Some of the cells that divide while the field is applied will be damaged, but the cells that do not divide will not be harmed. This selectively damages rapidly dividing cells like bacteria, but does not harm normal cells that are not dividing. Since the vulnerability of the dividing cells is strongly related to the alignment between the long axis of the dividing cells and the lines of force of the electric field, improved results can be obtained when the field is sequentially imposed in different directions.


Patent
Novocure Ltd | Date: 2015-06-05

Cells that are in the process division are vulnerable to damage by AC electric fields that have specific frequency and field strength characteristics. The selective destruction of rapidly dividing cells can therefore be accomplished by imposing an AC electric field in a target region for extended periods of time at particular frequencies with particular filed strengths. Some of the cells that divide while the field is applied will be damaged, but the cells that do not divide will not be harmed. This selectively damages rapidly dividing cells like bacteria, but does not harm normal cells that are not dividing. Improved results can be obtained when the field is sequentially imposed in different directions.


A light generating circuit is implanted in a subjects body and aimed at a target region such as a tumor. A photosensitizer is introduced into the target region, and an AC electric field is induced in the region. The field causes the light generating circuit to generate light, which activates the photosensitizer; and at certain field strengths and frequencies, the field itself has a beneficial effect. The beneficial effects of the field and the activated photosensitizer are thereby obtained simultaneously.


Patent
Novocure Ltd | Date: 2013-03-08

An electrode for applying electric fields to a patient includes a plurality of ceramic elements (e.g., ceramic discs) that are designed to be positioned against the patients skin. Electrical connections are made to the ceramic elements (e.g., using a flex circuit). Temperature sensors (e.g., thermistors) are preferably provided at at least some of the ceramic elements to sense the temperature at the skin beneath the ceramic elements, so that appropriate action can be taken if an overtemperature condition is detected.


An apparatus or method for applying a therapeutic electric field to a target region of a patient, comprising: an AC signal generator (41) that generates an electric field; and a control signal generator (43, 44) that cyclically changes the direction of the electric field between a first direction for a first period of time (tl) and a second direction for a second period of time (t2).


Patent
Novocure Ltd | Date: 2016-08-08

Cells that are in the process division are vulnerable to damage by AC electric fields that have specific frequency and field strength characteristics. The selective destruction of rapidly dividing cells can therefore be accomplished by imposing an AC electric field in a target region for extended periods of time at particular frequencies with particular filed strengths. Some of the cells that divide while the field is applied will be damaged, but the cells that do not divide will not be harmed. This selectively damages rapidly dividing cells like bacteria, but does not harm normal cells that are not dividing. Since the vulnerability of the dividing cells is strongly related to the alignment between the long axis of the dividing cells and the lines of force of the electric field, improved results can be obtained when the field is sequentially imposed in different directions.

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