JP-2020526253-A5 -

Dates

Publication Date

20221212

Application Date

20180625

Description

In some embodiments, the system can calculate the amount of strain in response to determining that the electromagnetic field is strained. The amount of electromagnetic field strain is proportional to a change in one or more of the calculated metric values. In this embodiment, the system can calculate the amount of strain in the electromagnetic field based on one or more updated values calculated at a second time and one or more baseline values calculated at a first time prior to the second time. The system can encode an indication of the amount of strain and provide the encoded indication of the amount of strain to a display configured to display the encoded data. This allows the user to be notified of the amount of field strain. The user can then decide whether to use electromagnetic data navigation during surgery. The user can mount the electromagnetic field generator 110 to a holder, such as by attaching it to a bed rail. Using a guide provided by the electromagnetic tracking system, the user can rotate the electromagnetic field generator 110 so that all electromagnetic patch sensors 105 are positioned within the effective volume 400. To provide feedback via a display (e.g., via a touchscreen 26), the electromagnetic tracking system can determine the position of the electromagnetic patch sensors 105 relative to the electromagnetic field generator 110 based on one or more electromagnetic patch sensor signals generated by the electromagnetic patch sensors 105. The system can encode a representation of the position of the electromagnetic patch sensors 105 relative to the effective volume of the electromagnetic field. Encoding the representation of the position of the electromagnetic patch sensors 105 may include generating an image (or a series of images to form a video) in which the relative position of the electromagnetic patch sensors 105 relative to the representation of the effective volume is displayed. This encoding may further include encoding an image (or video) using an image or video codec so that the image is decoded and displayed by a display. The system can provide the encoded representation of the position to a display that displays the encoded data. In at least one embodiment, the system can encode a representation of the position of the electromagnetic patch sensor 105 for each of the first and second sub-volumes of the magnetic field generator. The second sub-volume is larger than the first sub-volume and surrounds the first sub-volume; therefore, in at least one embodiment, the second sub-volume can be a risky sub-volume of 415. The system can provide an encoded representation of the position of the electromagnetic patch sensor 105 for each of the first and second sub-volumes to a display, so that the user can reposition the electromagnetic patch sensor 105 within the first sub-volume by moving the electromagnetic field generator 110. In other implementations, the first and second sub-volumes can correspond to preferred sub-volume 405 and acceptable sub-volume 410. In these embodiments, the system can encode a user command to position the electromagnetic field generator 110 such that the electromagnetic patch sensor 105 is located within at least one of the first and second sub-volumes, and provide the encoded user command to the display. In some embodiments, it may be impossible to place all of the electromagnetic patch sensors 105 within an effective volume. For example, the electromagnetic field generator 110 may not be able to generate an effective volume large enough to accommodate all of the electromagnetic patch sensors 105 for a patient with a wide area of interest. In such embodiments, the system can encode a user command to position the field generator so that a predetermined number of electromagnetic sensors are placed within a first effective volume, and provide the encoded command to the display. For example, if three electromagnetic patch sensors 105 are used, the system can encode a command to the user so that at least two of the electromagnetic patch sensors 105 are placed within the effective volume. In one embodiment, the system can encode user commands to (1) place the first sensor of the electromagnetic sensor on the center of the patient's sternum, (2) place the second sensor of the electromagnetic sensor on the patient's left lateral eighth rib, and (3) place the third sensor of the electromagnetic sensor on the patient's left lateral eighth rib. Thus, before positioning the electromagnetic field generator 110, the system can provide the user with instructions for positioning the electromagnetic patch sensors 105. The system can provide the encoded user commands for positioning the first to third electromagnetic sensors on the patient to the display. In another embodiment, the system may be configured to receive input from the user, for example via a touchscreen 26, indicating that the second and third electromagnetic sensors cannot be positioned within the effective