IL295450A - Tracheotomy - Google Patents

Description

TRACHEOTOMY FIELD AND BACKGROUND OF THE INVENTION The present invention, in some embodiments thereof, relates to detecting a position inside a body lumen and, more particularly, but not exclusively, to detecting a position inside a Trachea. Tracheotomy is a surgical procedure by which a hole is made on the anterior of the neck to open up a direct airway through an incision made on the trachea. Tracheotomy is a common procedure for patients enduring prolonged mechanical ventilation. One of the two alternatives for performing this procedure is per-cutaneous tracheotomy. This method is based on the Seldinger technique. Several methods have been described to perform per-cutaneous tracheotomy, one of them involves introducing a needle into the trachea for example with the aid of fiberoptic bronchoscopy. International Patent Application Publication No. WO2009070616A2 describes "an integrated catheter placement system for accurately placing a catheter within a patient's vasculature is disclosed. In one embodiment, the integrated system comprises a system console, a tip location sensor for temporary placement on the patient's chest, and an ultrasound probe. The tip location sensor senses a magnetic field of a stylet disposed in a lumen of the catheter when the catheter is disposed in the vasculature. The ultrasound probe ultrasonically images a portion of the vasculature prior to intravascular introduction of the catheter. The ultrasound probe includes user input controls for controlling use of the ultrasound probe in an ultrasound mode and use of the tip location sensor in a tip location mode. In another embodiment, ECG signal- based catheter tip guidance is included in the integrated system to enable guidance of the catheter tip to a desired position with respect to a node of the patient's heart". International Patent Application Publication No. WO2019232398A1 "devices, systems, and methods for creating a percutaneous tracheostomy are described herein. A system can include an inflation assembly and a guidewire assembly. The inflation assembly can include an elongated tube, an inflatable member, and a magnetic member. The elongated tube can have a first end, a second end, and can define a lumen. The inflatable member can be coupled to the first end of the elongated tube and can be fluidically coupled to the lumen such that the inflatable member can receive fluid via the lumen. The magnetic member can be coupled to the first end of the elongated tube such that movement of the magnetic member can cause corresponding movement of the first end of the elongated tube. The first end of a guidewire of the guidewire assembly can include a coupling member, the coupling member configured to couple to the inflatable member such that translation of the elongated tube translates the guidewire assembly". SUMMARY OF THE INVENTION The following describes some examples of embodiments of the invention (an embodiment may include features from more than one example and/or fewer than all features of an example): Example 1. A system for identifying a skin penetration site for a tracheotomy procedure, comprising: a detection assembly configured to be placed in contact with a skin surface of a neck over a trachea, comprising: a frame surrounding at least partially at least one opening, wherein said frame comprises at least one skin contacting surface; at least one detector configured to detect a magnetic field generated by a magnetic field source positioned within the trachea; a control circuitry functionally coupled to said at least one detector, wherein said control circuitry is configured to determine a position of a skin penetration site in said skin surface, based on said detected magnetic field which is aligned with said magnetic field source. Example 2. A system according to example 1, wherein said control circuitry is configured to determine a position of said magnetic field source within said trachea based on said detected magnetic field. Example 3. A system according to any one of examples 1 or 2, wherein said position of said skin penetration site is aligned with said magnetic field source and/or with one or more locations within the trachea.

Example 4. A system according to any one of the previous examples, comprising an elongated guide having a magnetic portion, and wherein said magnetic field source detected by said at least one detector comprises said magnetic portion. Example 5. A system according to example 4, wherein said magnetic portion of said guide comprises a magnet or an electromagnet. Example 6. A system according to any one of examples 4 or 5, wherein said elongated guide comprises an elongated flexible shaft, and wherein said magnetic portion is positioned along said elongated flexible shaft. Example 7. A system according to example 6, wherein said elongated flexible shaft comprises a spacer surrounding at least partly said magnetic portion. Example 8. A system according to example 7, wherein said spacer is elastic. Example 9. A system according to any one of examples 7 or 8, wherein said spacer comprises elastic ribs. Example 10. A system according to any one of the previous examples, wherein said control circuitry is configured to determine a position of said magnetic field source in said trachea relative to said skin surface and/or relative to one or more borders of said frame. Example 11. A system according to any one of the previous examples, comprising a user interface configured to generate a human detectable indication, wherein said control circuitry signals said user interface to generate said human detectable indication with information regarding a position of said magnetic field source within the trachea and/or a position of said skin penetration site. Example 12. A system according to example 11, wherein said control circuitry is configured to signal said user interface to generate a human detectable indication with information regarding a distance of said magnetic field source from said skin surface. Example 13. A system according to any one of examples 11 or 12, wherein said user interface comprises at least two LED stripes, each is associated with a different side of said frame surrounding at least partly said at least one opening, and wherein said LED stripes are substantially perpendicular to each other. Example 14. A system according to any one of examples 11 to 13, wherein said user interface is positioned on a surface of said frame that is opposite to said skin contacting surface.

Example 15. A system according to any one of the previous examples, wherein said at least one detector comprises at least two spaced-apart sensors associated with said frame. Example 16. A system according to example 15, wherein said at least two spaced-apart sensors comprise at least 3 or at least 4 sensors. Example 17. A system according to any one of examples 15 or 16, wherein said at least two sensors comprise magnetic contactless proximity sensors. Example 18. A system according to any one of examples 15 to 16, wherein said frame is shaped as a polygon and wherein said at least two sensors are located at corners of said polygon. Example 19. A system according to any one of the previous examples, wherein said frame comprises at least two sides positioned at an angle of about 90 degrees relative to each other. Example 20. A system according to example 19, comprising a first movable guide coupled to a first side of said at least two sides and a second movable guide coupled to a second side of said at least two sides, wherein said first movable guide is configured to move relative to said first side and said second movable guide is configured to move relative to said second side, to indicate a position of said skin penetrating site on said skin surface. Example 21. A system according to example 20, wherein each of said first movable guide and said second movable guide comprises a portion of a channel, wherein each portion is slidable over a different movable guide of said first movable guide and said second movable guide to generate said channel in said position where the first movable guide and said second movable guide cross each other, and wherein said channel is shaped and sized to guide a skin penetrating tool to said skin penetration site. Example 22. A system according to example 21, wherein said skin penetrating tool comprises at least one of a syringe, a dilator, a tube, and a cannula. Example 23. A system according to any one of the previous examples, wherein said frame is bendable to conform to a curvature of said neck. 30 Example 24. A system according to any one of the previous examples, wherein said frame comprises at least one curved fastener having a curvature that fits a curvature of said neck and is configured to fasten said frame to said neck. Example 25. A system according to example 24 wherein said at least one curved fastener comprises two curved fasteners aligned relative to each other and coupled to opposite sides of the frame. Example 26. A system according to any one of examples 24 or 25, wherein said at least one curved fastener is coupled to said frame via at least one hinge, and is configured to move relative to said frame. Example 27. A system according to any one of the previous examples, wherein said at least one detector is located at said skin contacting surface of said frame. Example 28. A system according to any one of the previous examples, wherein a maximal width of said frame is in a range between 4 cm-20 cm. Example 29. A system according to any one of the previous examples, wherein said at least one opening is shaped and sized to allow access via said frame to a skin surface having an area size in a range between 25 cm and 625 cm .Example 30. A system according to any one of the previous examples, comprising a control unit having a housing coupled to said frame, and wherein said control unit comprises a power source and said control circuitry functionally coupled to said power source in said housing. Example 31. A system for navigating a dilator via a skin surface into a trachea, comprising: a guide comprising a magnetic portion, wherein said magnetic portion is shaped and sized to be positioned within the trachea ;a dilator; a control unit coupled to said guide and said dilator, configured to deliver electrical currents intermittently to said guide and to said dilator, wherein said electrical currents are sufficient to generate a first magnetic field by said guide magnetic portion and a second magnetic field by said dilator, a detection system comprising: at least one sensor configured to detect a magnetic field; a control circuitry functionally coupled to said at least one sensor, wherein said control circuitry is configured to determine a position of said dilator relative to said guide magnetic portion and/or a distance between said dilator and said guide magnetic portion based on signals generated by said at least one sensor. Example 32. A system according to example 31, comprising a user interface configured to generate a human detectable indication, wherein said control circuitry is configured to signal said user interface to generate said human detectable indication with information indicating a degree of proximity between said dilator and said guide magnetic portion based on said determined position and/or distance. Example 33. A dilator, comprising: an elongated body having a tapered distal section shaped and sized to penetrate through skin tissue into a trachea; a magnetic portion located at said tapered distal section. Example 34. A dilator according to example 33, wherein said elongated body comprises: an outer tubular portion having a long axis, a proximal end and a distal expandable end at said tapered distal section, wherein said outer tubular portion comprises a channel along said long axis; an inner portion having a proximal end and a distal end, configured to slide within said channel; wherein sliding of said inner portion into said outer tubular portion within said channel expands said distal expandable end of said elongated body. Example 35. A method for performing tracheotomy, comprising: inserting a guide having a magnetic portion into a trachea of a subject; detecting a magnetic field generated by said magnetic portion or changes thereof from outside the body; identifying a penetration site in a skin surface of a neck towards said trachea based on the detected magnetic field; performing tracheotomy via the identified penetration site. Example 36. A method according to example 35, wherein said performing tracheotomy comprises forming an incision at said penetration site and inserting a cannula through said incision into said trachea.

Example 37. A method according to any one of examples 35 or 36, comprising determining a position of said magnetic portion based on said detected magnetic field; and wherein said identifying comprises identifying said skin surface penetration site based on the determined position of said magnetic portion. Example 38. A method according to any one of examples 35 to 37, comprising: generating a human detectable indication indicating a position on said skin surface of said identified skin surface penetration site. Example 39. A method according to example 38, wherein said generated human detectable indication comprises information regarding a position of said skin surface penetration site in an x-axis and in a y-axis of a virtual plane overlapping with said skin surface. Example 40. A method according to any one of examples 35 to 39, comprising: determining a depth of said magnetic portion from said skin surface based on said detected magnetic field and generating a human detectable indication indicating said determined depth. Example 41. A method according to any one of examples 35 to 40, wherein said inserting comprises inserting said magnetic portion into an endotracheal tube positioned inside the trachea. Example 42. A method according to example 41, comprising: positioning said magnetic portion at a tracheotomy target location distally to said endotracheal tube; and wherein said identified penetration site is aligned with said target tracheotomy location. Example 43. A method according to any one of examples 35 to 42, wherein said tracheotomy comprises advancing a dilator having a magnetic portion via the skin surface penetration site into the trachea, and wherein said detecting comprises detecting a magnetic field generated by said dilator magnetic portion during said advancing, and wherein said method comprising determining a position of said dilator magnetic portion based on said detected magnetic field generated by said dilator magnetic portion. Example 44. A method according to example 43, comprising receiving a human detectable indication with information regarding a position of the dilator magnetic portion relative to the guide magnetic portion within the trachea and/or with information regarding a distance between the dilator magnetic portion and the guide magnetic portion. Example 45. A method according to any one of examples 35 to 44, comprising positioning a detection assembly configured to detect said magnetic field in contact with said skin surface prior to said inserting of said guide. Example 46. A method according to example 45, wherein said identifying comprises identifying said skin surface penetration site in a region of said skin surface accessible via an opening in said detection assembly. Example 47. A method according to example 45, wherein said performing tracheotomy comprises performing tracheotomy via said detection assembly opening. Example 48. A method according to any one of examples 45 to 47, wherein said positioning comprises positioning said detection assembly over a cricoid region of said neck. Example 49. A method for navigating a tool via a skin surface into trachea, comprising: generating a first magnetic field by a tool advanced through a skin surface into a trachea and a second magnetic field by a magnetic guide located within said trachea; detecting said first magnetic field and said second magnetic field by at least one sensor located outside the body; determining a position of said tool relative to said magnetic guide and/or a distance of said tool relative to said magnetic guide, based on said detected first magnetic field and said detected second magnetic field. Example 50. A method according to example 49, wherein said generating comprises generating said first magnetic field and said second magnetic field intermittently. Example 51. A method according to any one of examples 49 or 50, comprising generating a human detectable indication with information regarding said position and/or said distance. Example 52. A method according to example 51, comprising generating an alert signal if said distance is smaller than 5mm or if said tool contacts said magnetic guide. Example 53. A method according to any one of examples 49 to 52, wherein said tool comprises a dilator. Example 54. A tracheostomy method, comprising: advancing a dilator having a magnetic portion via an incision in a skin surface towards a trachea; receiving indications regarding a position of said dilator relative to a magnetic field source within the trachea and/or a distance between said dilator and said magnetic field source; dilating said dilator during said advancing or when said dilator is within said trachea; stopping said advancing if a tip of said dilator is within said trachea based on said received indications; introducing a tracheostomy tube via an inner lumen of said dilator into said trachea. Example 55. A method according to example 54, wherein said dilating comprising dilating a tapered outer portion of said dilator comprising an inner channel by introducing a movable inner portion into said channel. Example 56. A method according to example 55, comprising retracing said movable inner portion of said dilator to expose said inner channel prior to said introducing, and wherein said introducing comprises introducing said tracheostomy tube via said exposed inner channel into said trachea . Example 57. A method for detecting a distal tip of a tube within a trachea, comprising: advancing a magnet configured to generate a magnetic field within an inner lumen of a tube located within a trachea; positioning said magnet at a distal tip of said tube; detecting said magnetic field by at least one sensor located outside the body; determining a position of said tube distal tip within said trachea based on said detected magnetic field. Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. BRIEF DESCRIPTION OF THE DRAWINGS The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee. Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings and images. With specific reference now to the drawings and images in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. In the drawings: FIG. 1A is a flow chart of a process for determining a position of a magnet inside a body cavity, in order to generate a passageway from outside the body into the body cavity, according to some exemplary embodiments of the invention; FIG. 1B is a flow chart of a process for determining a penetration site through skin surface for performing tracheotomy, according to some exemplary embodiments of the invention; FIGs. 2A-2E are schematic illustrations describing detection of a magnetic field generated by a magnet positioned inside a body cavity to determine a skin penetrating site, according to some exemplary embodiments of the invention; FIG. 3A is a schematic block diagram of a detection assembly, according to some exemplary embodiments of the invention; FIG. 3B is a schematic illustration of a magnet guide, according to some exemplary embodiments of the invention; FIGs. 4A-4E are schematic illustrations of a detection assembly, according to some exemplary embodiments of the invention; FIG. 5 is a schematic illustration of a magnet guide, according to some exemplary embodiments of the invention; FIG. 6 is a flow chart of a Tracheotomy process performed using the detection system, according to some exemplary embodiments of the invention; FIGs. 7A-7H are schematic illustrations of a Tracheotomy process performed using the detection system, according to some exemplary embodiments of the invention. FIG. 8A is a flow chart of a tracheostomy process, according to some exemplary embodiments of the invention; FIG. 8B is a flow chart of a dilation process of a dilator, according to some exemplary embodiments of the invention; FIGs. 8C-8E are schematic illustrations of a magnetic dilator, according to some exemplary embodiments of the invention; and FIG. 8F is a schematic illustration of a system for generating a magnetic field, according to some exemplary embodiments of the invention. DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION The present invention, in some embodiments thereof, relates to detecting a position inside a body lumen and, more particularly, but not exclusively, to detecting a position inside a Trachea. Overview An aspect of some embodiments relates to detecting a position of at least one magnet located within a body cavity, for example a trachea. In some embodiments, a skin penetration site is identified based on the detected position of the magnet and/or based on a magnetic field generated by the at least one magnet, detected by at least one sensor, located optionally outside the body. In some embodiments, the identified skin penetration site is used for performing Tracheotomy from the skin and into the Trachea. In some embodiments, the identified skin penetration site is aligned with one or more locations within the Trachea that are targets for insertion of a tool, for example a cannula into the Trachea. In some embodiments, the identified skin penetration site is aligned with a position of the magnet inside the trachea that is a target site within the Trachea for insertion of the cannula. According to some embodiments, the skin penetration site is identified using a detection assembly positioned outside the body that is configured to detect a position of the magnet within the trachea and to identify the location of the skin penetration site on the skin surface. In some embodiments, the detection assembly delivers a human detectable indication which includes information regarding a vertical position and a horizontal position of the skin penetrating site, based on the detected position of the magnet. In some embodiments, the detection assembly is used to guide a needle or a tube via the skin penetrating site into the trachea. According to some exemplary embodiments, the detection assembly is used during at least one of, tracheotomy, tracheostomy, endoscopic gastrostomy, supra-pubic urinary catheter insertion and a proctologic procedure. A potential advantage of identifying a tissue penetrating site that is aligned with a target position within the trachea may be to increase the chances of reaching the trachea in a first attempt and/or to avoid crossing through the trachea, for example when the position of the trachea relative to the skin surface is not well established. According to some embodiments, the detection system is used to detect a position of a magnet introduced into an endotracheal tube. In some embodiments, the detection system is used to detect a position of a distal tip of the endotracheal tube, for example when the endotracheal tube is retracted within the trachea. In some embodiments, the detection system is used to detect and provide an indication regarding a depth of the magnet from the skin surface. A potential advantage of detecting a depth of a magnet, positioned inside the trachea, from the skin surface may be to prevent damage to a posterior tracheal wall during needle puncture during dilatation and/or during cannula insertion. A potential advantage of using the detection system and/or the detection assembly for accurately identifying a target penetration site in the skin, may be to reduce or prevent neck extension when changing a posture of the subject to a supine position, for example prior to percutaneous tracheotomy.

An aspect of some embodiments relates to determining a position of a tool inserted through the skin into a body cavity, for example into a trachea, relative to a magnetic field source located inside the body cavity. In some embodiments, the tool is a magnetic tool and comprises at least one magnetic portion. In some embodiments, the at least one magnetic portion of the tool comprises a permanent magnet. Alternatively, the magnetic portion of the tool comprises an electromagnet. In some embodiments, the magnetic field source located within the trachea comprises a magnet. Alternatively, the magnetic field source comprises an electromagnet. According to some embodiments, the magnetic portion of the tool generates a first magnetic field and the magnetic field source positioned in the trachea generates a second magnetic field. In some embodiments, the first magnetic field and the second magnetic field are generated intermittently, for example at different time periods. In some embodiments, the position of the tool relative to the magnetic field source in the trachea is determined based on the detection of the first magnetic field and the second magnetic field. In some embodiments, the first magnetic field and the second magnetic field are detected using a detection assembly, for example a detection assembly comprising a detection frame. According to some embodiments, an indication, for example a human detectable indication is generated with information regarding the proximity between the tool and the magnetic field source within the trachea and/or when the tool contacts the magnetic field source. In some embodiments, the indication comprises at least one alert signal. In some embodiments, the alert signal is a continuous signal optionally change in pitch and/or signal frequency, that correlates with a distance between the magnetic portion of the tool and the magnetic field source in the trachea. In some embodiments, when a distal end of the tool containing the magnetic portion contacts the magnetic field source, for example a magnetic portion of a magnet guide, a distinct audio indication is generated to specifically indicate the contact. In some embodiments, a distinct audio signal is generated when a distance between the tool and the magnetic field source is smaller than 5 mm, for example smaller than 3 mm, smaller than 2 mm or any intermediate, smaller or larger distance. According to some embodiments, the tool comprises a dilator, for example a solid dilator having a tapered body or a dilator that is configured to move between a non-dilated state and a dilated state. In some embodiments, the tool comprises a visualization tool, a cannula, a tube, a tracheostomy tube. In some embodiments, the magnetic portion of the tool is located at a distal tip of the tool. In some embodiments, the tool is electrically connected to a power source, for example to allow delivery of electrical currents to the tool for generating the magnetic portion. In some embodiments, a guide comprises the magnetic portion which serves as the magnetic field source within the trachea is connected to the power source, for example when the magnetic portion of the guide is an electromagnet. An aspect of some embodiments relates to a dilator, for example a dilator to be used in a tracheotomy or a tracheostomy procedures, comprising a magnetic portion. In some embodiments, the magnetic portion comprises a magnet, for example a permanent magnet, or an electromagnet. In some embodiments, the magnetic portion is located at a distal end of the dilator having a leading edge that is configured to penetrate into tissue. According to some embodiments, the dilator comprises an elongated tapered body, for example a solid tapered body. In some embodiments, the magnetic portion is located at a distal end of the tapered body, or at a distal end of a tapered portion of the body. According to some embodiments, the dilator comprises an outer portion having a tapered body or a distal tapered portion, and an inner portion which is slidable within a lumen of the outer portion. In some embodiments, sliding of the inner portion within the outer portion dilates the outer portion of the dilator, and the dilator moves from a non-dilated state to a dilated state. In some embodiments, removal or retraction of the inner portion of the dilator out from lumen of the outer portion, allows to use the lumen as a channel for a safe insertion of a tube, for example a tracheostomy tube via the dilator into the trachea. In some embodiments, the outer portion is dismantlable, and is configured to be dismantled in order to be removed out from the body, for example when the tracheostomy tube is within the trachea. In some embodiments, during dismantling the outer portion is peeled off. An aspect of some embodiments relates to determining a positon of a tube, for example an endotracheal tube, within the trachea. In some embodiments, a location of a magnet or a magnet portion associated with the tube, for example located within the tube, at the tube wall or on the tube surface, is determined from outside the body. In some embodiments, the magnet or the magnetic portion is located at the distal tip of the tube. According to some embodiments, the location of the tube, for example the location of the distal tip of the tube is detected from outside the body. In some embodiments, the location of the tube is detected by at least one sensor, for example at least 2, at least 3, at least 4 or any larger number of sensors, positioned outside the body. In some embodiments, the at least one sensor is configured to detect a magnetic field and/or changes in the magnetic field. According to some exemplary embodiments, the magnet is part of a magnet guide introduced into the tube. Optionally, the magnet is a magnetic portion of the magnet guide. In some embodiments, the magnetic portion of the magnet guide is centered within the endotracheal tube using one or more spacers, optionally surrounding the magnetic portion. In some embodiments, the magnet guide comprises at least one anchor, for example an expandable anchor, configured to anchor the magnet guide within the endotracheal tube, optionally, at the distal tip of the endotracheal tube. In some embodiments, positioning of the magnet at the distal tip of the tube allows, for example, to detect a position of the tube within the trachea, optionally from outside the body. A potential advantage of detecting a position of a distal tip of the endotracheal tube may be to monitor a retraction process of the endotracheal tube, for example to prevent loss of secured airway when a retraction distance of the endotracheal tube is too large. Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

Exemplary process for magnet detection According to some exemplary embodiments, identifying position of an organ, for example a body cavity, or a portion thereof relative to a location on a skin surface is important, for example to guide an object towards the body cavity or portion thereof, or to avoid the body cavity or the portion of the body cavity. In some embodiments, the object comprises a needle or any other skin penetrating object, used for example to generate a passage between the skin surface outside the body and the body cavity and/or for taking a tissue sample of the body cavity. In some embodiments, identifying the position of the body cavity allows, for example to avoid penetrating through unwanted tissue, for example nerve tissue and blood vessels, and/or penetrating into other unwanted organs. Reference is now made to fig. 1A, depicting a process for identifying a position of a magnet within a body cavity, according to some exemplary embodiments of the invention. According to some exemplary embodiments, a magnet is inserted into a body cavity, for example a lumen, of a subject, at block 102. In some embodiments, the magnet is inserted into the body cavity through an anatomical opening of the body, for example mouth, nostril, ear, anus, and/or an external urethral orifice. Alternatively, the magnet is inserted into the body cavity through a surgical opening, for example an opening formed in the body during a surgical process. According to some exemplary embodiments, at least one sensor configured to detect a magnetic field is positioned outside the subject body, at block 104. In some embodiments, the at least one sensor is placed in contact with the skin. In some embodiments, the at least one sensor is positioned outside the body and is optionally aligned with a target location within the body where the magnet is predicted to be located. Optionally, the at least one sensor is positioned near, for example in a close proximity, to a target location within the body where the magnet is predicted to be located. In some embodiments, the at least one sensor is positioned outside the body at a distance of up to 20 cm, for example up to 15 cm, up to 10 cm or any intermediate, smaller or larger distance from a predicted location of the magnet within the body. In some embodiments, a position of the at least one sensor outside the body is selected such that the target location of the magnet is within a detection range of the at least one sensor. In some embodiments, the at least one sensor comprises two or more sensors, which optionally allow detection of the magnet in an X-Y coordinate system, or in an X-Y-Z coordinate system. According to some exemplary embodiments, a magnetic field generated by the magnet is detected by the at least one sensor, at block 106. According to some exemplary embodiments, the magnet position is determined, at block 108. In some embodiments, the magnet position within the body cavity is determined. In some embodiments, the magnet position is determined within boundaries of a detection volume defined by the at least one sensor. According to some exemplary embodiments, a distance of the magnet within the body cavity from a reference location outside the body, is optionally determined at block 110. In some embodiments, the reference location is a location on the skin surface. In some embodiments, a depth of the magnet from the skin surface, for example from a reference location on the skin surface is determined at block 110. Alternatively, the reference location is a location of the at least one sensor. According to some exemplary embodiments, a passageway from outside the body to the body cavity is generated at block 112. In some embodiments, the passageway is generated based on the position of the magnet that was determined at block 108. Additionally or optionally, the passageway is generated based on the distance of the magnet determined at block 110. In some embodiments, the passageway is generated at block 112, for example in order to generate an airway between the body cavity and the outside of the body, for example the skin surface. Exemplary general process for determining tracheotomy site According to some exemplary embodiments, during tracheotomy an opening is formed through the front of the neck at a selected location on the skin surface, and into the trachea. In some embodiments, identifying a penetration site in the skin surface for performing the tracheotomy is important, for example to avoid damage to tissue of the neck and to tissue between the skin surface and the trachea. Additionally, or alternatively, identifying a penetration site in the skin surface for performing the tracheotomy is important, for example to make sure that the formed opening will reach the trachea and/or will avoid one or more tubes located in the trachea. Reference is now made to fig. 1B, depicting a general process for determining a skin penetration site for performing tracheotomy, according to some exemplary embodiments of the invention. According to some exemplary embodiments, a magnet is inserted into a trachea of a subject, for example a human subject, at block 120. In some embodiments, the magnet is introduced via a mouth of the subject into the trachea. Optionally, the magnet is advanced, for example controllably advanced to a target location within the trachea. According to some exemplary embodiments, a magnetic field generated by the magnet is detected at block 122. In some embodiments, the magnetic field is detected from outside the body. In some embodiments, the detected magnetic field is used to determine a position of the magnet within the trachea. Optionally, the detected field is used to determine a distance of the magnet from the skin surface. In some embodiments, the determined position and/or depth of the magnet is used to determine a position of the trachea or a target location within the trachea, relative to the skin surface. According to some exemplary embodiments, a penetration site through the skin surface towards the trachea is identified, at block 124. In some embodiments, the penetration site is identified based on the determined position of the magnet relative to the skin surface. Alternately or additionally, the penetration site is identified based on the position of the trachea or a target location within the trachea relative to the skin surface. In some embodiments, the identified penetration site is a site in the skin surface for forming tracheotomy. According to some exemplary embodiments, tracheotomy is performed via the identified penetration site, at block 126. In some embodiments, during tracheotomy, a cut is formed in the skin surface at the identified penetration site, followed by formation of a hole between the skin surface and the trachea. Alternatively, a needle is introduced via the identified penetration site into the trachea.

Exemplary tracheotomy site identification Reference is now made to figs. 2A-2E, depicting identification of a site for performing tracheotomy, according to some exemplary embodiments of the invention. According to some exemplary embodiments, for example as shown in fig. 2A, a magnet 202 is positioned within a body cavity 204, for example a trachea of a subject. In some embodiments, the magnet is positioned within at least one tube inserted within the body cavity 204. In some embodiments, the magnet generates a magnetic field 206, for example a three-dimensional magnetic field. According to some exemplary embodiments, at least two sensors, for example sensors 208 and 210 are positioned outside the body. In some embodiments, the at least two sensors 208 and 210 are sensors configured to detect a magnetic field or changes thereof. In some embodiments, the at least two sensors 208 and 210 define a three-dimensional detection volume 212. In some embodiments, the detection volume 212 comprises the magnet 202 position inside the body cavity and/or the magnetic field 206 generated by the magnet. In some embodiments, the position of the at least two sensors 208 and 210 is selected in order to include the magnetic field 2generated by the magnet 202 and/or the magnet 202 within the detection volume 212. According to some exemplary embodiments, for example as shown in fig. 2B, a position of the magnet 202 is determined in a X-Y plane 214 located outside the body, for example based on the detected electric field 206. In some embodiments, a position of the magnet 202 relative to each of the sensors 208 and 210 is determined, optionally in the X-Y plane 214. In some embodiments, the X-Y plane is located on the skin surface. According to some exemplary embodiments, for example as shown in fig. 2C. a position of the magnet 202 relative to a surface of the skin 216 is determined, based on the detected magnetic field 206 generated by the magnet 202. In some embodiments, the magnet 202 is positioned within the body 220, and a distance of the magnet 202 relative to a region outside the body, for example the X-Y plane, is determined, based on the detected magnet field 206. In some embodiments, a distance 218 between the skin surface 216 and the magnet 202 is determined, based on the detected magnetic field. Optionally, a depth of the magnet 202 within the body 220 relative to the skin surface 216 is determined, for example based on the detected magnet field. According to some exemplary embodiments, for example as shown in fig. 2D, a penetration site 219 in the skin surface 216 for performing tracheotomy is identified, for example based one the determined position of the magnet 202 within the body cavity 204. In some embodiments, the determined position of the magnet is used to plan a tracheotomy process, for example by identifying a skin penetration site that is aligned with the trachea and/or with a specific target location within the trachea, as previously determined based one the position of the magnet. According to some exemplary embodiments, for example as shown in fig.2E, tracheotomy is performed via the identified penetration site 219. In some embodiments, during the tracheotomy a channel 219 is formed between the identified penetration site 219 and the trachea 204. In some embodiments, the channel 219 is a hole formed by cutting the skin at the identified penetration site 219. Alternatively, the channel 219 is a channel formed by a needle inserted via the identified penetration site 219 into the trachea. Optionally, the needle is used for guiding a tube into the trachea. Exemplary penetration site detection system According to some exemplary embodiments, a detection system, for example a system for detecting a penetration site through the skin surface suitable for performing tracheotomy, comprises a detection assembly configured to be positioned outside a body of a subject, and a magnet guide comprising a magnet. In some embodiments, the magnet guide is configured to guide the magnet into a body cavity within the body of the subject. Optionally, the detection system is a kit which includes the detection assembly and the magnet guide. Reference is now made to fig. 3A, depicting a detection assembly, according to some exemplary embodiments of the invention. According to some exemplary embodiments, a detection assembly 3comprises a body 304, for example a curved or an angled body, surrounding at least partly one or more openings 306, for example a void between two ends of the body. In some embodiments, the body is shaped as an arc. Alternatively, the guide body 304 is shaped as an enclosed frame, surrounding the one or more openings 306. According to some exemplary embodiments, the body 304 is shaped and sized to be placed in contact with a skin surface, for example a skin surface in the neck area. In some embodiments, the body 304 comprises an adhesive, for example glue, on a skin contacting surface that is configured to be attached to the skin surface. In some embodiments, the body 304 is configured to conform to the curvature of the neck. In some embodiments, the body 304 is elastic, for example bendable. In some embodiments, the body 304 or the skin contacting surface if formed from a soft material. According to some exemplary embodiments, the body 304 comprises at least one sensor, for example two or more sensors 308 associated with the body 304. In some embodiments, the two or more sensors 308 are configured to detect a magnetic field and/or changes thereof. In some embodiments, the two or more sensors 308 are coupled to the body 304 in two or more spaced-apart locations, such that the one or more openings are located at least partly between the two or more sensors. According to some exemplary embodiments, the body 304 comprises at least one user interface 310, for example two or more user interfaces, configured to generate and deliver a human detectable indication, for example to a user of the detection assembly. In some embodiments, the at least one user interface 310 is configured to generate an audio and/or a visual indication. In some embodiments, the user interface 310 comprises at least one of, a speaker, a display, and one or more light emitting diodes (LEDs). In some embodiments, the user interface comprises a marker and/or a light projector. According to some exemplary embodiments, the detection assembly 302 comprises a control unit 312 coupled to the body 304. In some embodiments, the control unit 312 comprises a control circuitry 316, functionally coupled to the at least one sensor 308 and to the at least one user interface 310. In some embodiments, the control unit 312 comprises memory 320 functionally coupled to the control circuitry 316. In some embodiments, the control circuitry 316 receive signals from the two or more sensors 308 indicating a magnetic field within a detection range of the two or more sensors 308. In some embodiments, the control circuitry 316 calculates a position of a source of the indicated magnetic field, and signals the at least one user interface 310 to generate the human detectable indication with information regarding the position of the magnetic field source. In some embodiments, the control circuitry 316 calculates the position of the magnetic field source using at least one of, an algorithm, a formula, and a lookup table, stored in the memory 320. According to some exemplary embodiments, the control circuitry 3calculates the positon of the magnetic field source in a plane defined by the body 3and/or by the two or more sensors 308. In some embodiments, the control circuitry 316 calculates the position of the magnetic field source in an X-Y coordinate system, for example a X-Y coordinate system of the defined plane. In some embodiments, the control circuitry 308 calculates the position of the magnetic field source relative to the body 304 and/or relative to the location of the two or more sensors 308. According to some exemplary embodiments, the control circuitry 316 signals the at least one user interface 310 to generate the human detectable indication with information regarding at least one of, the position of the magnetic field source in the X-Y coordinate system, the position of the magnetic field source relative to the body 304, and the position of the magnetic field source relative to the location of the two or more sensors. According to some exemplary embodiments, the at least one user interface 3comprise two or more spaced-apart light indicators located on the body 304. In some embodiments, the control circuitry 316 signals the two or more light indicators to generate an indication regarding a position of the magnetic field source relative to each of the light indicators, for example in different axes of an X-Y coordinate system and/or in a plane defined by the two or more indicators. In some embodiments, a virtual intersection point of the light indications generated by the two or more light indicators indicates a position of the magnetic field source, for example in a plane defined by the two or more light indicators. In some embodiments, the virtual intersection point is located within the one or more openings 306 and optionally indicates a detected tracheotomy skin penetration site. According to some exemplary embodiments, the control unit 312 comprises a power source 318, for example a battery. In some embodiments, the power source 318 is a rechargeable power source. Alternatively or additionally, the power source 318 is a replaceable power source. According to some exemplary embodiments, the control unit 312 comprises a communication circuitry 322, configured to allow commination, for example wireless communication, with at least one additional device. In some embodiments, the at least one additional device comprises a cellular device or any other handheld device. In some embodiments, the control circuitry 316 signals the communication circuitry 3to send information to the additional device, for example to allow a user interface to generate a human detectable indication, indication a location of the detected penetration site. Alternatively or additionally, the control unit 312 transmits signals or indications thereof to the additional device and receives information from the additional device regarding a location of a penetration site. According to some exemplary embodiments, the detection assembly 302 which includes the body 304 and the control unit 312 is disposable. Alternatively, the body 304 is disposable, and the control unit 312 is reusable. According to some exemplary embodiments, for example as shown in fig. 3B, the detection system comprises a magnet guide 330, for example a stylet. In some embodiments, the magnet guide 330 comprises a magnet 332 coupled to a guiding shaft 334. In some embodiments, the magnet 332 is coupled, for example fixedly coupled, to the guiding shaft 334 between a distal end 333 of the guiding shaft 334 and a proximal end 335 of the guiding shaft 334 , for example to prevent detachment of the magnet 332 from the guiding shaft 334 within the trachea. In some embodiments, the magnet 332 is coupled to the distal end 333 of the guiding shaft 334. In some embodiments, the magnet 332 is positioned within the guiding shaft 334. According to some exemplary embodiments, the guiding shaft 334 is flexible, for example bendable. In some embodiments, the flexible guiding shaft 334 allows, for example, bending of the magnet guide 330 when the magnet guide 330 passes within a tube placed in the trachea. In some embodiments, the magnet guide 335 comprises one or more markings along the guiding shaft for indicating a length of the guiding shaft 334 from the proximal end 335 or from the distal end 333. 30 According to some exemplary embodiments, the magnet guide 330 optionally comprises at least one camera 336 coupled to the guiding shaft 334, and is located distally or proximally to the magnet 332. Exemplary detection frame assembly Reference is now made to figs. 4A-4D, depicting a detection frame assembly, according to some exemplary embodiments of the invention. According to some exemplary embodiments, a detection frame assembly 4comprises a detection frame 404 and a control unit 406 coupled to the detection frame via electrical wiring 408. In some embodiments, the detection frame 404 is shaped and sized to be placed on a neck of a subject. Optionally, at least a portion of the detection frame 404 is placed in contact with a skin surface of the neck. According to some exemplary embodiments, the detection frame 4comprising a frame body 410, surrounding an opening 412, which allows access to at least a portion of the skin surface when the detection frame 404 is placed in contact with the neck. In some embodiments, the detection frame 404 comprise at least 3 sides arranged in a polygon shape. In some embodiments, at least one side 414 and at least one additional side 416, of the at least 3 sides, are arranged in an angle 418 of about degrees therebetween. According to some exemplary embodiments, for example as shown in fig. 4B, the detection frame comprises at least 2 sensors, for example sensors 420, 421, 422, and 423 configured to detect a magnetic field or changes thereof. In some embodiments, each of the sensors is located on a different side of the polygon shape of the frame 404, or at an intersection between two sides of the polygon-shaped frame. In some embodiments, the sensors are associated with the frame 404, for example mounted on the frame, coupled to the frame, or positioned within the frame. In some embodiments, the sensors, for example sensors 420, 421, 422 and 423 comprise magnetic proximity sensors, for example magnetic contactless proximity sensors. In some embodiments, the sensors are configured to detect a magnetic object. According to some exemplary embodiments, for example as shown in fig. 4B, the frame body 410 comprises a first surface 424, for example a skin contacting surface, and at least one opposite surface, for example surface 426 shown in fig. 4A, facing a user of the frame, for example an expert using the frame, optionally prior to and/or during performing tracheotomy in the subject. According to some exemplary embodiments, the frame 404, for example the body 410 has a maximal length 437 in a range between 4 cm and 25 cm, for example in a range between 4 cm and 15 cm, 5 cm and 12 cm, 7 cm and 17 cm, 10 cm and 20 cm, or any intermediate, smaller or larger range of values. In some embodiments, the frame 404, for example the body 410 has a maximal width 435 in a range between cm and 25 cm, for example in a range between 4 cm and 15 cm, 5 cm and 12 cm, 7 cm and 17 cm, 10 cm and 20 cm, or any intermediate, smaller or larger range of values. According to some exemplary embodiments, the detection frame 402 comprises one or more user interfaces, configured to generate and deliver a human detectable indication with information regarding a location of a tracheotomy penetration site. In some embodiments, the one or more interfaces comprise at least two light emitting arrays, for example LED stripes 426 and 428 shown for example in figs. 4A and 4C. In some embodiments, the LED stripes are located on sides of the frame body 410, for example sides of the frame body that are substantially perpendicular to each other. As used herein the term "substantially perpendicular" refers to deviation of less than 20º from perpendicular alignment. In some embodiments, each of the LED stripes is located on a different side of the frame body 410. According to some exemplary embodiments, the sides of the frame body that are perpendicular to each other, for example sides 414 and 416 define a two dimensional plane. In some embodiments, a light indication in each of the LED stripes indicates coordinates of a penetration site in a single axis of the two dimensional plane. In some embodiments, a light indication in a first LED strip associated with side 416 indicates a distance of the penetration site from the side 414 that is perpendicular to side 416. Additionally, a light indication in a second LED strip associated with side 414 indicates a distance of the penetration site from side 416. According to some exemplary embodiments, the frame 402 comprises at least one display 430 for providing a visual indication with information regarding a distance of a detected magnet from the frame body 410. In some embodiments, the at least one display 430 providing a visual indication with information regarding a distance of a detected magnet from a plane defined by the frame body 410. According to some exemplary embodiments, the control unit 406 comprises a control circuitry, functionally connected to at least one sensor of the frame 404, for example sensors 420, 421, 422 and 423. Additionally, the control circuitry is functionally connected to at least one user interface of the frame 404, for example to the LED stripes 426 and 428 and/or to the display 430. In some embodiments, the control unit 406 comprises a power source, for example a battery. According to some exemplary embodiments, the frame 404 comprises one or more fasteners, configured to fasten the frame body 410 to the body part of a subject, for example to a neck of the subject. In some embodiments, the one or more fasteners are coupled to the frame body 410, optionally by a hinge. In some embodiments, the one or more fasteners are movable with respect to the frame body 410. According to some exemplary embodiments, the one or more fasteners comprise wings 432 and 434 coupled to the frame body 410 by hinges 436 and 438, respectively. In some embodiments, the wings 432 and 434 are curved towards a contacting surface of the frame body 410. In some embodiments, when the frame body 410 is placed in contact with the neck, the curved wings 432 and 434 surround at least partly the neck, for example to prevent lateral movement of the frame body 410. According to some exemplary embodiments, for example as shown in fig. 4D, a first light indication 440 from LED strip 428 indicates a distance of a penetration point, for example penetration point 442 from side 416. In some embodiments, a second light indication 444 from LED strip 426 indicates a distance of the penetration point 442 from the side 418. In some embodiments, a cross section between virtual lines passing through each of the light indications 440 and 444 mark a location of the penetration point 442. Reference is now made to fig. 4E depicting a detection frame having movable guides, according to some exemplary embodiments of the invention. According to some exemplary embodiments, the detection frame 4comprises one or more guides, for example two guides 450 and 452. In some embodiments, the guides are movable guides. In some embodiments, a guide slides over a first side of the frame and with respect to a different side of the frame that is perpendicular to the first side. In some embodiments, at least one side of the frame comprises a screw, aligned along the side of the window. In some embodiments, a guide is functionally coupled to the screw. In some embodiments, rotation of the screw moves the guide over the screw. In some embodiments, each of the movable guides comprises a window, for example window 454 configured to align the slide 452 with respect to an indication on the side 416, for example alight indication generated by the LED strip. In some embodiments, a crossing point between the guides, when each guide is aligned with a light indication of a LED strip marks a location of a penetration site. In some embodiments, the guides move independently. According to some exemplary embodiments, the detection frame 404 comprises a tubular guiding channel 454 formed from two portions, each portion is coupled to a different guide of the guides 450 and 452. In some embodiments, each portion of the tubular guiding channel slides over the guide to a selected location, in which the two portions are aligned to form the tubular guiding channel 454. In some embodiments, the channel is shaped and sized to guide a needle or a tube towards an identified penetration site on the skin surface. In some embodiments, an inner width, for example an inner diameter of the channel is larger than an outer diameter of the needle or the tube that is advanced towards an identified penetration site in the skin. According to some exemplary embodiments, the detection frame comprises at least two actuators, for example electric motors, each is associated with a single guide, for example a single guide of the guides 450 and 452. In some embodiments, the at least two actuators are configured to move the guides, either automatically by a control circuitry of the control unit, or based on signals inserted to the control unit using a user interface. Alternatively, a user of the detection frame moves the guides manually. Exemplary magnet guide According to some exemplary embodiments, a magnet guide is configured to allow insertion of a magnet in a safe way into a trachea of a subject, optionally within a tube positioned within the trachea. In some embodiments, at least one magnet is coupled to a rod, for example a flexible rod, between a distal end and a proximal end of the rod. Alternatively, the magnet is coupled to a distal end of the rod. Optionally, the rod is a cylindrical tube, and the magnet is positioned within the cylindrical tube.

In some embodiments, the rod is made from plastic. Optionally the magnet guide is disposable. Reference is now made to fig. 5, depicting a magnet guide, according to some exemplary embodiments of the invention. According to some exemplary embodiments, a magnet guide 502 comprises an elongated rod 504 and a magnet 506 coupled to the rod 504. In some embodiments, the magnet is integrated within the rod. According to some exemplary embodiments, the magnet guide comprises a spacer 508 coupled to the rod 504. In some embodiments, the spacer 508 is an elastic spacer. In some embodiments, in a relaxed state an outer width of the spacer is larger than the outer width of the rod 504. In some embodiments, the magnet 506 is positioned in the center of the spacer 508. In some embodiments, the spacer 5comprises two or more ribs, for example ribs 510 and 512. In some embodiments, the spacer 508 is configured position the magnet 506 at a distance from the trachea wall, for example to prevent navigation of a tube or a needle to the trachea wall. In some embodiments, the spacer 508 is used to centralize the magnet along or within the endotracheal tube, without tortuosity, for example without twisting of the magnet guide. In some embodiments, preventing twisting of the magnet guide within the endotracheal tube allows, for example, to determine an actual advancement distance if the magnet guide within the endotracheal tube for accurate placement of the magnet at the tip of the endotracheal tube optionally using length markings at the proximal end of the magnet guide. Exemplary tracheotomy According to some exemplary embodiments, the detection system comprising the detection frame and the magnet guide are used in a tracheotomy. In some embodiments, tracheotomy is a procedure which includes making of an incision on the anterior aspect of the neck and opening a passage into the trachea. Tracheotomy is a common procedure for patients enduring prolonged mechanical ventilation. In some embodiments, the tracheotomy procedure comprises per-cutaneous tracheotomy. Optionally, the per-cutaneous tracheotomy is performed using a bronchoscope.

Reference is now made to fig. 6 depicting using of the detection system during a per-cutaneous tracheotomy procedure, according to some exemplary embodiments of the invention. According to some exemplary embodiments, an expert, for example a physician decides to perform tracheotomy in a subject, at block 602. In some embodiments, tracheotomy is performed, for example, to generate an emergency airway access, to generate an airway access for prolonged mechanical ventilation, in cases where there is a functional or mechanical upper airway obstruction, and/or in situations where there is decreased clearance of tracheobronchial secretions. In some embodiments, an endotracheal tube is positioned within the trachea of the subject. According to some exemplary embodiments, a posture of a subject scheduled to undergo tracheotomy is optionally changed, at block 604. In some embodiments, the posture of the subject is optionally changed to a supine position with optionally a neck extension. According to some exemplary embodiments, a detection assembly, for example a detection frame is placed in contact with the skin at an anterior portion of the neck, at block 606. In some embodiments, the detection frame is positioned on the neck such that an opening of the detection frame allows access to a cricoid region of the neck. In some embodiments, for example as shown in fig. 7A, the detection assembly 702 is positioned over the cricoid region 704 of the neck. According to some exemplary embodiments, a magnet guide is introduced into the trachea, at block 608. In some embodiments, the magnet guide is introduced into the trachea via a mouth of the subject. In some embodiments, the magnet guide is introduced into an endotracheal tube positioned within the trachea. According to some exemplary embodiments, at least one indication regarding a position of the magnet within the body is received from the detection assembly at block 610. In some embodiments, the at least one indication comprises an indication regarding a depth of the magnet relative to the skin surface. In some embodiments, the indication is received by at least one user interface, for example at least one LED strip. In some embodiments, the at least one user interface comprises at least one vertical LED strip and at least one horizontal LED strip.

According to some exemplary embodiments, a magnet of the magnet guide is positioned at a distal tip of the endotracheal tube, at block 612. In some embodiments, the magnet is positioned at the distal tip of the endotracheal tube based on markings at a proximal end of the magnet guide indicating a length of the magnet guide or a distance of the markings from the position of the magnet. In some embodiments, the magnet guide is advanced within the tracheal tube until the markings at the proximal end of the magnet guide indicate that a distance of the markings from the magnet is substantially equal to the length of the endotracheal tube positioned inside the trachea, for example the distance of the markings deviates in less than 10% from the length of the endotracheal tube positioned inside the trachea. In some embodiments, the magnet guide is advanced into the endotracheal tube until the magnet is aligned with a distal tip of the endotracheal tube. According to some exemplary embodiments, the magnet guide and the endotracheal tube are retracted simultaneously within the trachea, at block 614. In some embodiments, the magnet guide and the endotracheal tube are retracted simultaneously within the trachea until the magnet is positioned at a cricoid level. In some embodiments, the detection assembly monitors the position of the magnet, optionally continuously. In some embodiments, the magnet guide and the endotracheal tube are retracted until the indication regarding the position of the magnet indicates that the magnet and the distal tip of the endotracheal tube are located at the cricoid level. According to some exemplary embodiments, the magnet is advanced distally to the endotracheal tube while the endotracheal tube distal tip remains at the cricoid level, at block 616. In some embodiments, the magnet guide is selectively advanced into the trachea, without moving the endotracheal tube. In some embodiments, the magnet is advanced to a distance of up to 10 mm distally to the distal tip of the endotracheal tube, at block 616. According to some exemplary embodiments, the magnet is positioned at a selected target site for tracheotomy within the trachea, at block 618. According to some exemplary embodiments, an indication is received from the detection assembly regarding a skin penetration site that is aligned with the position of the magnet and/or with the position of the selected target site within the trachea, at block 620. According to some exemplary embodiments, a needle is inserted into the skin at the skin penetration site, at block 622. In some embodiments, the needle is introduced via the skin penetration site and into the selected target site within the trachea. In some embodiments, the skin penetration site is located between the 2nd and rd tracheal rings or between the 2nd tracheal ring and the suprasternal notch. Optionally, the skin penetration site is located about 1 cm above the suprasternal notch. In some embodiments, the needle is inserted to a target location in the trachea that is located at a distance of at least 5 mm, for example, at least 10 mm, at least 15 mm, at least 20 mm, or any intermediate, smaller or larger distance distally to a tip of an endotracheal tube. According to some exemplary embodiments, an indication is optionally received regarding the position of the needle or the needle tip relative to the magnet, at block 624. In some embodiments, the indication includes information regarding the relative distance between the needle tip and the magnet. Alternatively, the indication includes information regarding a penetration depth of the needle relative to the detection assembly or relative to the skin surface. According to some exemplary embodiments, the needle is used to generate a stable airway between an external surface of the skin and the trachea, at block 626. In some embodiments, the needle is used to generate a stable airway, for example using a Seldinger technique. Reference is now made to figs. 7A-7H depicting a tracheotomy process for insertion of a needle into the trachea using the detection system, according to some exemplary embodiments of the invention. According to some exemplary embodiments, for example as shown in fig. 7A, a detection frame 702 is placed in contact with an anterior region of the neck, for example over a cricoid region 704. According to some exemplary embodiments, for example as shown in fig. 7B, a magnet, for example a magnetic tip 706 of a magnet guide 708 is positioned at a tip 710 of an endotracheal tube 712, positioned within a trachea 714. In some embodiments, the magnetic tip 706 is positioned at the tip 710 of the endotracheal tube 712, based on the tracheal tube known length and markings on the magnet guide. According to some exemplary embodiments, for example as shown in fig. 7C, the endotracheal tube 712 and the magnet guide are retracted simultaneously, for example until the magnetic tip 706 is positioned at a cricoid level. In some embodiments, for example as shown in fig. 7D, one or more indications, for example LED marks 714 and 716 generated by the detection frame 706 indicate that the magnetic tip 706 is at the cricoid level. According to some exemplary embodiments, for example as shown in fig. 7E, the magnet guide 708 is advanced into the trachea 714 and distally to the endotracheal tube distal tip 710, while keeping the endotracheal tube distal tip 710 at the cricoid level. In some embodiments, the magnetic tip 706 is positioned within the trachea 7at a desired target location for cannula insertion. In some embodiments, for example as shown in fig. 7F, the one or more indications, for example LED marks 714 and 7generated by the detection frame 706 indicate a location of a skin penetration site 715 that is aligned with the desired target location for cannula insertion within the trachea 714. In some embodiments, one of the LED marks, for example LED mark 7indicates a horizontal position of the skin penetration site 512, and a second LED mark, for example LED mark 716 indicates a vertical position of the skin penetration site 512. According to some exemplary embodiments, for example as shown in fig. 7G, a needle 718 is inserted into the skin at the skin penetration site 512 and into the a desired target location in the trachea 714. In some embodiments, for example as shown in fig. 7H, the detection frame delivers an indication 720 with information regarding the depth of the magnetic tip 706 from the skin surface. Alternatively, the indication 720 provides information regarding a penetration depth of the needle 718 into the throat. According to some exemplary embodiments, once the needle is at the desired target location for cannula insertion, a cannula is inserted into the trachea, for example using the Seldinger technique.

Exemplary dilator navigation According to some exemplary embodiments, at least one tool is introduced into the trachea, for example from outside the body, while monitoring a position of the tool relative to the trachea lumen and/or relative to at least one magnet located within the trachea. In some embodiments, the position of the tool is monitored using a detection assembly, for example the detection assembly 302 shown in fig. 3A, the detection assembly 402 shown in fig. 4A. In some embodiments, the positon of the tool is monitored based on a magnetic field generated by the at least one tool. In some embodiments, the position of the at least one tool is monitored based on a first magnetic field generated by the at least one tool and a second magnetic field generated by the magnet within the trachea. In some embodiments, the first and second magnetic field have different parameter values, for example different timing values. According to some exemplary embodiments, the at least one tool comprises a dilator introduced through a skin penetration site into the trachea, and is used to dilate a passage from the skin surface into the trachea to a width that allows introduction of a tracheostomy tube into the trachea. In some embodiments, the tracheostomy tube is inserted into the trachea after the removal of the dilator from the body of the subject. Alternatively, the tracheostomy tube is inserted through an inner lumen of the dilator into the trachea. Reference is now made to fig. 8A, depicting navigation of a tool, for example a dilator into the trachea, according to some exemplary embodiments of the invention. According to some exemplary embodiments, a needle is inserted into the skin at an identified skin penetration site, as described for example at block 622 in fig. 6. According to some exemplary embodiments, a guide wire is introduced into the trachea via the needle, at block 802. In some embodiments, the guide wire is introduced into the trachea via an inner lumen within the needle. According to some exemplary embodiments, the needle is removed at block 804. In some embodiments, the needle is removed while leaving the guide wire inside the trachea crossing through the skin penetration site into the trachea. According to some exemplary embodiments, a dilator is advanced into the trachea via the skin penetration site using the guide wire, at block 806. In some embodiments, the dilator is advanced into the trachea over the guide wire.

According to some exemplary embodiments, a tube, for example a tracheostomy tube is inserted into the trachea at block 808. In some embodiments, the tube is inserted into the trachea via an inner channel within the dilator. Optionally, the dilator is used to guide the tube into the trachea via the dilator inner channel. According to some exemplary embodiments, the dilator is removed at block 810. In some embodiments, the dilator is removed from the body of the subject, leaving the tube between the skin surface and the trachea. According to some alternative exemplary embodiments, a detectable dilator is advanced into the trachea using the guide wire, at block 812. In some embodiments, the detectable dilator is advanced into the trachea over the guide wire. In some embodiments, the detectable dilator comprises a magnet, for example a magnetic tip. In some embodiments, the detectable dilator is configured to generate a magnetic field from a source located at a distal tip of the dilator, for example a source located at a leading edge of the dilator. According to some exemplary embodiments, a subject, for example a subject performing the tracheostomy procedure optionally receives indication regarding a position of the dilator relative to the trachea and or skin surface, at block 814. Alternatively, the indications comprise information regarding a penetration depth or distance of the dilator from a skin surface or any anatomical or virtual landmark. In some embodiments, the indications comprise information regarding a relative distance of the dilator, for example a dilator tip from the trachea wall and/or from the trachea lumen. In some embodiments, the indications comprise a human detectable indication, for example a visual and/or an audio indication. According to some exemplary embodiments, the subject optionally receives indications regarding a position of the dilator relative to a magnet located within the trachea, at block 816. Optionally, the magnet is centered in the trachea. In some embodiments, the subject optionally receives indications, for example human detectable indications, regarding a position of the dilator tip relative to a magnet located within the trachea. According to some exemplary embodiments, the subject optionally receives indications regarding a distance between the dilator, for example the dilator tip, and a magnet within the trachea, at block 818. According to some exemplary embodiments, the indications comprise an alert signal generated for example by a detection frame. In some embodiments, the alert signal comprises a continuous or an intermittent signal, for example an audio signal. In some embodiments, changes in at least one parameter of the audio signal, for example change in pitch, volume, and/or frequency of the audio correlates with a distance between the detectable dilator and a magnetic guide located within the trachea. Optimally when the two magnets touch each other, a distinct alert signal, for example a distinct sound is generated and received indicating physical contact or close proximity smaller than about 4 mm between the two magnets. Reference is now made to fig. 8B, depicting dilator use, according to some exemplary embodiments of the invention. According to some exemplary embodiments, after a user receives one or more indications that the dilator tip is within the trachea, the dilator is dilated at block 820. In some embodiments, the dilator is dilated by introducing an inner movable portion of the dilator into an outer expandable portion of the dilator. In some embodiments, a distal end of the expandable outer portion is tapered, and the inner movable portion of the dilator has an outer width that is larger than an inner width of the outer portion, for example larger than an inner width of the expandable tapered outer portion. In some embodiments, insertion of the dilator inner portion into the dilator outer portion expands, for example dilates, the dilator outer portion. Optionally, insertion of the dilator inner portion into the dilator outer portion expands, for example dilates, the tapered part of the dilator outer portion. According to some exemplary embodiments, following dilation of the dilator, the movable inner portion of the dilator is removed, at block 822. In some embodiments, removal, for example retraction of the movable inner portion forms a channel via the dilator outer portion between the skin outer surface and the trachea. According to some exemplary embodiments, a tube, for example a tracheostomy tube is introduced via the dilator into the trachea, at block 824. In some embodiments, the tube is introduced into the trachea via the channel within the outer portion of the dilator. According to some exemplary embodiments, the dilator is disassembled, at block 826. In some embodiments, an outer portion of the dilator, surrounding the tube, is disassembled at block 826. In some embodiments, the dilator outer portion is disassembled by manipulating, for example rotating, breaking, and/or cutting a proximal end of the dilator located outside the body. According to some exemplary embodiments, the disassembled portions of the dilator are removed at block 828. In some embodiments, the disassembled parts of the dilator outer portion are removed from the body, leaving the tracheostomy tube within the body between the skin surface and the trachea. Exemplary dilator Reference is now made to figs. 8C-8E depicting a detectable dilator, according to some exemplary embodiments of the invention. According to some exemplary embodiments, a dilator, for example dilator 8comprises a body 832 having a proximal end 833 and a distal end 832 comprising a magnet, for example a magnetic distal end. In some embodiments, the body 832 is configured to move between a non-dilated state, for example as shown in fig. 8D, and a dilated state, for example as shown in fig. 8C. In some embodiments, in a non-dilated state, for example as shown in fig.8D, the distal end 834 is tapered. Alternatively, the outer portion 840 of a dilator is tapered. In some embodiments, the distal end 834 comprises a magnetic portion 836. In some embodiments, the magnetic portion comprises a magnet and/or is configured to generate a magnetic field when electrically connected to a power source. According to some exemplary embodiments, the dilator 830 comprises a handle 838 at the proximal end 833. Optionally, the handle 838 is functionally coupled to the body 832 at the proximal end 833. According to some exemplary embodiments, for example as shown in fig. 8D, the body 832 comprises an outer portion 840 having an inner lumen, and an inner portion 842 configured to slide within the lumen of the outer portion 840. In some embodiments, the outer portion is an expandable outer portion, configured to dilate in response to a force applied from within the inner lumen. In some embodiments, the inner portion 842 comprises a handle 844, optionally at a proximal end of the inner portion 842.

According to some exemplary embodiments, for example as shown in fig. 8D, in a non-dilated state, the tapered distal end 834 of the body 832, for example a tapered distal end of the outer portion 840, is shaped and sized to penetrate into the body, for example through the skin penetration site, optionally using the guide wire. In some embodiments, when the outer portion 840 is within the body, the inner portion 842 is advanced within the outer portion 840, and dilates the outer portion 840. In some embodiments, dilation of the outer portion 84 moves the dilator to a dilated state, for example as shown in fig. 8C. According to some exemplary embodiments, following dilation of the dilator, the inner portion 842 is retracted from the inner lumen of the outer portion 840, for example to allow insertion of a tracheostomy tube via the outer portion inner lumen into the trachea as described at block 808 in fig. 8A. According to some exemplary embodiments, for example as shown in fig. 8E showing a distal end 850 of a dilator in a dilated state, the inner portion 852 is positioned within an expandable outer portion. In some embodiments, for example as shown in fig. 8E, a distal tip of the inner portion 852 is magnetic, and comprises a magnet 856. Exemplary magnetic field generation According to some exemplary embodiments, a detectable dilator, for example a detectable dilator having a magnetic portion is used in combination with a magnet guide. In some embodiments, a detection assembly is configured to identify and to differentiate between the magnetic fields generated by the detectable dilator and the magnet guide. In some embodiments, differentiating between the two magnetic field allows, for example to associate a first magnetic field with the magnet guide and a second magnetic field with the dilator, and to optionally determine a position of the dilator relative to the position of the magnet. Reference is now made to fig. 8F, depicting a system for generating a magnetic field according to some exemplary embodiments of the invention. According to some exemplary embodiments, a dilator 870 comprising a magnetic distal end 872 is functionally coupled to a magnetic field generator 874. In some embodiments, the magnetic field generator 874 is electrically connected to a power source 878. In some embodiments, the magnetic distal end 872, is functionally coupled to a control circuitry 876. In addition, a magnet guide 880 comprising a magnetic portion 882 is functionally coupled to the magnetic field generator 874, for example to the control circuitry 876. In some embodiments, the magnetic field generator is in communication with the detection assembly 3 According to some exemplary embodiments, the magnet guide 880 is introduced into the trachea, for example as described at block 608 in fig. 6, and is used to identify a skin penetration site using a detection assembly. In some embodiments, during tracheostomy, for example as described in fig. 8A, the detectable dilator 870 is navigated into the trachea. In some embodiments, during the navigation of the dilator 870, the generator 874 delivers electrical currents to the magnetic distal end 872 and the magnetic portion 882 to generate a first magnetic field by the magnetic distal end 872 and a second magnetic field by the magnetic portion 882. In some embodiments, the control circuitry 876 controls the delivery of the electrical currents, for example to deliver the electrical currents intermittently between the magnetic distal end 872 and the magnetic portion 882. In some embodiments, intermittent delivery of electrical currents between the magnetic distal end 872 and the magnetic portion 882 allows for example to the detection assembly, for example detection assembly 302 to associate a first magnetic field detected by the assembly 302 with the magnetic distal end 872 of the dilator 870 and a second magnetic field detected by the assembly 302 with the magnetic portion 882 of the magnet guide 880 located within the trachea. In some embodiments, the detection assembly 302 is configured to deliver a human detectable indication based on the detection of the two magnetic fields indicating a position of the dilator 870, for example a position of the magnetic distal end 872 relative to the magnetic portion 882, and/or an indication regarding a distance between the magnetic distal end 872 and the magnetic portion 882. It is expected that during the life of a patent maturing from this application many relevant endotracheal tubes will be developed; the scope of the term endotracheal tube is intended to include all such new technologies a priori. As used herein with reference to quantity or value, the term "about" means "within  10 % of".

The terms "comprises", "comprising", "includes", "including", "has", "having" and their conjugates mean "including but not limited to". The term "consisting of" means "including and limited to". The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure. As used herein, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof. Throughout this application, embodiments of this invention may be presented with reference to a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as "from 1 to 6" should be considered to have specifically disclosed subranges such as "from 1 to 3", "from 1 to 4", "from 1 to 5", "from 2 to 4", "from to 6", "from 3 to 6", etc.; as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range. Whenever a numerical range is indicated herein (for example "10-15", "10 to 15", or any pair of numbers linked by these another such range indication), it is meant to include any number (fractional or integral) within the indicated range limits, including the range limits, unless the context clearly dictates otherwise. The phrases "range/ranging/ranges between" a first indicate number and a second indicate number and "range/ranging/ranges from" a first indicate number "to", "up to", "until" or "through" (or another such range-indicating term) a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numbers therebetween. 30 Unless otherwise indicated, numbers used herein and any number ranges based thereon are approximations within the accuracy of reasonable measurement and rounding errors as understood by persons skilled in the art. As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts. As used herein, the term "treating" includes abrogating, substantially inhibiting, slowing or reversing the progression of a condition, substantially ameliorating clinical or aesthetical symptoms of a condition or substantially preventing the appearance of clinical or aesthetical symptoms of a condition. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.

Claims (50)

1.WHAT IS CLAIMED IS: 1. A system for identifying a skin penetration site for a tracheotomy procedure, comprising: a detection assembly configured to be placed in contact with a skin surface of a neck over a trachea, comprising: a frame surrounding at least partially at least one opening, wherein said frame comprises at least one skin contacting surface; at least one detector configured to detect a magnetic field generated a magnetic field source positioned within the trachea; a control circuitry functionally coupled to said at least one detector, wherein said control circuitry is configured to determine a position of a skin penetration site in said skin surface, based on said detected magnetic field.

2. A system according to claim 1, wherein said control circuitry is configured to determine a position of said magnetic field source within said trachea based on said detected magnetic field.

3. A system according to any one of claims 1 or 2, wherein said position of said skin penetration site is aligned with said magnetic field source and/or with one or more locations within the trachea.

4. A system according to any one of the previous claims, comprising an elongated guide having a magnetic portion, and wherein said magnetic field source detected by said at least one detector comprises said magnetic portion.

5. A system according to claim 4, wherein said magnetic portion of said guide comprises a magnet or an electromagnet.

6. A system according to any one of claims 4 or 5, wherein said elongated guide comprises an elongated flexible shaft, and wherein said magnetic portion is positioned along said elongated flexible shaft.

7. A system according to claim 6, wherein said elongated flexible shaft comprises a spacer surrounding at least partly said magnetic portion.

8. A system according to claim 7, wherein said spacer is elastic.

9. A system according to any one of the previous claims, wherein said control circuitry is configured to determine a position of said magnetic field source in said trachea relative to said skin surface and/or relative to one or more borders of said frame.

10. A system according to any one of the previous claims, comprising a user interface configured to generate a human detectable indication, wherein said control circuitry signals said user interface to generate said human detectable indication with information regarding a position of said magnetic field source within the trachea and/or a position of said skin penetration site.

11. A system according to claim 10, wherein said control circuitry is configured to signal said user interface to generate a human detectable indication with information regarding a distance of said magnetic field source from said skin surface.

12. A system according to any one of claims 10 or 11, wherein said user interface comprises at least two LED stripes, each is associated with a different side of said frame surrounding at least partly said at least one opening, and wherein said LED stripes are substantially perpendicular to each other.

13. A system according to claim 10, wherein said user interface is positioned on a surface of said frame that is opposite to said skin contacting surface.

14. A system according to any one of the previous claims, wherein said at least one detector comprises at least two spaced-apart sensors associated with said frame.

15. A system according to claim 14, wherein said at least two spaced-apart sensors comprise at least 3 or at least 4 sensors.

16. A system according to any one of claims 14 or 15, wherein said at least two sensors comprise magnetic contactless proximity sensors.

17. A system according to any one of claims 14 to 16, wherein said frame is shaped as a polygon and wherein said at least two sensors are located at corners of said polygon.

18. A system according to any one of the previous claims, wherein said frame comprises at least two sides positioned at an angle of about 90 degrees relative to each other.

19. A system according to claim 18, comprising a first movable guide coupled to a first side of said at least two sides and a second movable guide coupled to a second side of said at least two sides, wherein said first movable guide is configured to move relative to said first side and said second movable guide is configured to move relative to said second side, to indicate a position of said skin penetrating site on said skin surface.

20. A system according to any one of the previous claims, wherein said frame is bendable to conform to a curvature of said neck.

21. A system according to any one of the previous claims, wherein said frame comprises at least one curved fastener having a curvature that fits a curvature of said neck and is configured to fasten said frame to said neck.

22. A system according to any one of the previous claims, wherein said at least one detector is located at said skin contacting surface of said frame.

23. A system according to any one of the previous claims, wherein a maximal width of said frame is in a range between 4 cm-20 cm.

24. A system according to any one of the previous claims, comprising a control unit having a housing coupled to said frame, and wherein said control unit comprises a power source and said control circuitry functionally coupled to said power source in said housing.

25. A system for navigating a dilator via a skin surface into a trachea, comprising: a guide comprising a magnetic portion, wherein said magnetic portion is shaped and sized to be positioned within the trachea ;a dilator; a control unit coupled to said guide and said dilator, configured to deliver electrical currents intermittently to said guide and to said dilator, wherein said electrical currents are sufficient to generate a first magnetic field by said guide magnetic portion and a second magnetic field by said dilator, a detection system comprising: at least one sensor configured to detect a magnetic field; a control circuitry functionally coupled to said at least one sensor, wherein said control circuitry is configured to determine a position of said dilator relative to said guide magnetic portion and/or a distance between said dilator and said guide magnetic portion based on signals generated by said at least one sensor.

26. A system according to claim 25, comprising a user interface configured to generate a human detectable indication, wherein said control circuitry is configured to signal said user interface to generate said human detectable indication with information indicating a degree of proximity between said dilator and said guide magnetic portion based on said determined position and/or distance.

27. A dilator, comprising: an elongated body having a tapered distal section shaped and sized to penetrate through skin tissue into a trachea; a magnetic portion located at said tapered distal section.

28. A dilator according to claim 27, wherein said elongated body comprises: an outer tubular portion having a long axis, a proximal end and a distal expandable end at said tapered distal section, wherein said outer tubular portion comprises a channel along said long axis; an inner portion having a proximal end and a distal end, configured to slide within said channel; wherein sliding of said inner portion into said outer tubular portion within said channel expands said distal expandable end of said elongated body.

29. A method for performing tracheotomy, comprising: inserting a guide having a magnetic portion into a trachea of a subject; detecting a magnetic field generated by said magnetic portion or changes thereof from outside the body; identifying a penetration site in a skin surface of a neck towards said trachea based on the detected magnetic field; performing tracheotomy via the identified penetration site.

30. A method according to claim 29, comprising determining a position of said magnetic portion based on said detected magnetic field; and wherein said identifying comprises identifying said skin surface penetration site based on the determined position of said magnetic portion.

31. A method according to any one of claims 29 or 30, comprising: generating a human detectable indication indicating a position on said skin surface of said identified skin surface penetration site.

32. A method according to claim 31, wherein said generated human detectable indication comprises information regarding a position of said skin surface penetration site in an x-axis and in a y-axis of a virtual plane overlapping with said skin surface.

33. A method according to any one of claims 29 to 32, comprising: determining a depth of said magnetic portion from said skin surface based on said detected magnetic field and generating a human detectable indication indicating said determined depth.

34. A method according to any one of claims 29 to 33, wherein said inserting comprises inserting said magnetic portion into an endotracheal tube positioned inside the trachea.

35. A method according to claim 34, comprising: positioning said magnetic portion at a tracheotomy target location distally to said endotracheal tube; and wherein said identified penetration site is aligned with said target tracheotomy location.

36. A method according to any one of claims 29 to 35, wherein said tracheotomy comprises advancing a dilator having a magnetic portion via the skin surface penetration site into the trachea, and wherein said detecting comprises detecting a magnetic field generated by said dilator magnetic portion during said advancing, and wherein said method comprising determining a position of said dilator magnetic portion based on said detected magnetic field generated by said dilator magnetic portion.

37. A method according to claim 36, comprising receiving a human detectable indication with information regarding a position of the dilator magnetic portion relative to the guide magnetic portion within the trachea and/or with information regarding a distance between the dilator magnetic portion and the guide magnetic portion.

38. A method according to any one of claims 29 to 37, comprising positioning a detection assembly configured to detect said magnetic field in contact with said skin surface prior to said inserting of said guide.

39. A method according to claim 38, wherein said identifying comprises identifying said skin surface penetration site in a region of said skin surface accessible via an opening in said detection assembly.

40. A method according to claim 39, wherein said performing tracheotomy comprises performing tracheotomy via said detection assembly opening.

41. A method according to any one of claims 38 to 40, wherein said positioning comprises positioning said detection assembly over a cricoid region of said neck.

42. A method for navigating a tool via a skin surface into trachea, comprising: generating a first magnetic field by a tool advanced through a skin surface into a trachea and a second magnetic field by a magnetic guide located within said trachea; detecting said first magnetic field and said second magnetic field by at least one sensor located outside the body; determining a position of said tool relative to said magnetic guide and/or a distance of said tool relative to said magnetic guide, based on said detected first magnetic field and said detected second magnetic field.

43. A method according to claim 42, wherein said generating comprises generating said first magnetic field and said second magnetic field intermittently.

44. A method according to any one of claims 42 or 43, comprising generating a human detectable indication with information regarding said position and/or said distance.

45. A method according to claim 44, comprising generating an alert signals if said distance is smaller than 5mm or if said tool contacts said magnetic guide.

46. A method according to any one of claims 42 to 45, wherein said tool comprises a dilator.

47. A tracheostomy method, comprising: advancing a dilator having a magnetic portion via an incision in a skin surface towards a trachea; receiving indications regarding a position of said dilator relative to a magnetic field source within the trachea and/or a distance between said dilator and said magnetic field source; dilating said dilator during said advancing or when said dilator is within said trachea; stopping said advancing if a tip of said dilator is within said trachea based on said received indications; introducing a tracheostomy tube via an inner lumen of said dilator into said trachea.

48. A method according to claim 47, wherein said dilating comprising dilating a tapered outer portion of said dilator comprising an inner channel by introducing a movable inner portion into said channel.

49. A method according to claim 48, comprising retracing said movable inner portion of said dilator to expose said inner channel prior to said introducing, and wherein said introducing comprises introducing said tracheostomy tube via said exposed inner channel into said trachea .

50. A method for detecting a distal tip of a tube within a trachea, comprising: advancing a magnet configured to generate a magnetic field within an inner lumen of a tube located within a trachea; positioning said magnet at a distal tip of said tube; detecting said magnetic field by at least one sensor located outside the body; determining a position of said tube distal tip within said trachea based on said detected magnetic field. Maier Fenster Patent Attorney G.E. Ehrlich (1995) Ltd. 35 HaMasger Street Sky Tower, 13th Floor Tel Aviv 6721407