WO2019084550A1

WO2019084550A1 - Easily applied neurological monitoring template

Info

Publication number: WO2019084550A1
Application number: PCT/US2018/058022
Authority: WO
Inventors: Shawn REGAN; Brian PETREE; Daniel Mccoy; Gabriel ORSINGER
Original assignee: Rhythmlink International, Llc
Priority date: 2017-10-27
Filing date: 2018-10-29
Publication date: 2019-05-02

Abstract

A template for neurological monitoring comprising bands, and bands in combination with resilient cords, that define an easily applied template. The present template may include electrodes or have holes for placing electrodes, with the electrode location designations printed at each electrode location. The template includes guides for positioning the template on the head of a patient so that it is symmetric front-to-back and side-to-side for consistent monitoring. When resilient cords are part of the interconnections of the templates electrode supports, the template will self-adjust, equalizing tension so that positions are proportional over a range of head sizes and shapes.

Description

EASILY APPLIED NEUROLOGICAL MONITORING TEMPLATE

TECHNOLOGICAL FIELD

[0001 ] This disclosure relates generally to neurological monitoring and, more specifically, to neurological monitoring templates and headsets.

BACKGROUND

[0002] Neurological monitoring may occur in the course of medical research and during surgical operations, as well as in exigent circumstances such as in emergency rooms, ambulances, and emergency rescue vehicles. Electrodes are attached to the patient's head and connected electrically to amplifiers for display of the patient's brain activity. Examples of such headsets and templates are disclosed ion US patents US8412303 and US9484012.

[0003] The electrodes are normally positioned at specific, pre-selected locations of the patient's head. The use of consistent locations provides an output that can be more easily compared to the monitoring results for that patient in prior and subsequent monitoring events, and from one person to another. FIG. 1 illustrates an example of a map of the relative locations of electrode position designations presented in appropriate spatial relationship with each other on the head of a patient. The figure shows the top of a head with the person looking toward the top of the figure. The left ear of the patient is on the left side of the figure and the right ear is on the right side of the figure. The number of electrodes and their actual positions may be different depending on the purpose of the neurological monitoring. However, consistency of placement is important for comparing results.

[0004] Technicians who perform neurological monitoring are well-trained to know standard electrode position locations and generally follow international standards for placement of electrode sets when and as appropriate. FIG. 1 is just such a standard set of electrode location designations.

[0005] At times, however, other medical personnel may need to initiate

neurological monitoring, particularly under medical emergencies, such as emergency room assistants and emergency medical technicians, who have less training in neurological monitoring and are operating under circumstances where time may be of the essence. The quality of the results may deteriorate accordingly, and make interpretation of the results more difficult and subject to error.

[0006] Exact measuring and marking of electrode locations on patients' heads is generally a resource-intensive process. It takes time and resources; particularly if the patient is also to undergo imaging procedures, which may require removal of the electrodes to avoid radio-frequency heating or the appearance of artifacts caused by metal in the MRI field. The use of a hospital room, an MRI room, or an emergency room for positioning and attaching - and detaching - electrodes, even for a few minutes, adds cost.

[0007] To facilitate correct placement of the electrodes, templates may be placed on the head of the patient. A template is device that acts as a physical map. conforming to the patient's head and which is marked to identify where electrodes are to be placed. A harness is a template that has the electrodes already in place. Templates and harnesses are typically made of straps that are sewn together to form a cap of sorts and may be available in different sizes.

[0008] Of course, the template or harness, in addition to being made with care and precision, are also to be put on the patient's head and oriented to serve as a map for electrode positions.

[0009] Another issue in neurological monitoring is connecting specific electrodes to the correct position on the scalp of the patient, or on a template to be placed on the patient's head, and then connecting that electrode cables to the right channels on the amplifier to capture the signals the electrode is sensing and be certain that an electrode is connected to the appropriate place on the patient's head and to the corresponding channel.

[0010] In certain neurological monitoring situations, placement of the electrodes in a symmetrical pattern on the patient's head is particularly important. A symmetrical electrode pattern can be described as an arrangement of electrodes that is divided into two identical subsets arranged in pre-designated spacings with respect to a nominal centerline, or imaginary plane, through the head of the patient so that the set of electrodes on one side is a mirror image of the set of the electrodes on the other side of that centerline or plane. Achieving symmetry can be difficult due to the non-uniformity and uniqueness of patient's head size or shape or both, or to injuries sustained, or to the conditions under which the nurse or emergency medical technician is operating and the position of the patient.

[001 1 ] Accordingly, an improvement in the process of quickly positioning and connecting electrodes to the scalp of a patient, especially for those with relatively little training and who may be working under emergency conditions, would be an advantage.

SUMMARY

[0012] The present electrode template simplifies the process of placing

electrodes on the head of a patient by providing a headset or template that is readily put into position and oriented. It includes alignment guides and, in some embodiments, elastic cords that help speed initial placement of the headset by causing it to curve into a three-dimensional template, and to assist in proper relative spacing regardless of variations in the head size of the patient. The alignment guides include a left and a right guide, and a front and back guide.

[0013] The present headset may also include electrodes, and may also have positions marked to designate the positions for receiving specific electrodes to assist in the electrode mapping process. Each position designation on the present template, in addition to being used to designate a place on the template for an electrode, also corresponds to a channel on a neurological monitoring amplifier. Use of the present template increases assurance that each electrical connector inserted into the amplifier is connected to the right electrode attached to the patient's scalp.

[0014] The present template fits on the patient's head easily because of its

construction. The use of a broad longitudinal band that follows the centerline of the head and plural lateral bands that each radiate laterally from the longitudinal band, and an alignment guide that can be centered and leveled on the nasion without measuring accelerates the placement by preventing twisting of the templates structural elements and providing broader, more stable and visible structural elements. There may also be two alignment guides on the sides of the template to facilitate alignment of the template left to right using auricular landmarks of the ears of the patient, such as the auricular holes. Between these easily identifiable locations: the centerline of the head, the nasion, and the designated auricular locations, the template can be positioned by sight. In addition, the use of resilient cords in one aspect of the disclosure to cause the longitudinal band and transverse band to curve into a three-dimensional template and enables the template to be self-adjusting so inter-electrode spacing is proportionate.

[0015] A feature of the disclosure is the template for positioning electrodes on the head of a patient for neurological monitoring. The template includes in one aspect of the disclosure a longitudinal band having a distal end and a proximal end, plural transverse bands perpendicular to the longitudinal band and attached to the longitudinal band and having distal ends. These wide, thin longitudinal and transverse bands are made of a flexible material, which may be made of solid or foamed plastic material, that bends but resist twisting and are formed into a cap that may then be easily adjusted so that it is level and straight.

[0016] In another aspect of the disclosure, the template also includes plural

resilient cords. Each cord is cut to a pre-determined length and then its two ends are attached, one end of the two cords to one end of the each of two transverse bands on the same side of the template. The ends of the cords may be attached to the ends of the transverse bands through holes in the transverse bands. The end of the cord is connected to itself to secure it to the transverse band. Two connectors are used for each cord, one on each end, and plural transverse bands require plural connectors and cords are connectored at their crossing points. Alternately, flexible cords could be attached with rivets, hooks, or other joining devices.

[0017] A feature of the disclosure is that the longitudinal band and the transverse bands are integral, being formed of one piece that is wide and long but thin so they have flexibility in one dimension and are resiliently flexible in that direction so as to spring back easily when bent but to resist bending and twisting in the other dimensions.

[0018] Another feature of the disclosure is that the longitudinal band and at least one of the transverse bands are integral.

[0019] A feature of the disclosure is that the template may include electrodes deployed symmetrically over the longitudinal band and the plural transverse bands.

[0020] A feature of the disclosure is that the longitudinal band and the plural transverse bands are marked with electrode position designations. A template that carries the location designation, Cz, for example, at the location on the patient's head where the Cz electrode is to be attached confirms to the user that the template is properly positioned.

[0021 ] Another feature of the disclosure is that the proximal end of the

longitudinal band has a first alignment guide for aligning the template with the nasion of a patient, and an additional alignment guides may be attached to transverse bands for adjusting the present template side to side by leveling it with respect to an auricular point such as the auricular holes.

[0022] These and other aspects of the disclosure will be readily apparent to those skilled in the art of templates and headsets from a careful reading of the following detailed description of the presently disclosed, easily applied, neurological monitoring template.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the figures,

[0024] FIG. 1 is chart showing standard 10-20 code placement positions for

neurological monitoring electrodes, according to the prior art;

[0025] FIG. 2 is a right side view of the present template for neurological

monitoring, according to an aspect of the disclosure;

[0026] FIG. 3 is a left side view of the template of FIG. 2, according to an aspect of the disclosure; [0027] FIG. 4 is a front view of the template of FIG. 2, according to an aspect of the disclosure;

[0028] FIG. 5 is a rear view of the template of FIG. 2, according to an aspect of the disclosure;

[0029] FIG. 6 is a top view of the template of FIG. 2, according to an aspect of the disclosure;

[0030] FIG. 7 is a front of the template of an alternative template, as applied to the head of a manikin, according to an aspect of the disclosure;

[0031 ] FIG. 8 is top front perspective view of the template of FIG. 7, as applied to the head of a manikin, according to an aspect of the disclosure;

[0032] FIG. 9 is top rear perspective view of the template of FIG. 7, as applied to the head of a manikin, according to an aspect of the disclosure;

[0033] FIG. 10 is left side view of the template of FIG. 7, the right side being

symmetric to the left side view, as applied to the head of a manikin, according to an aspect of the disclosure;

[0034] FIG. 1 1 , is a view of a lateral positioning guide for a head set according to an aspect of the disclosure; and

[0035] FIG. 12 is a detail of FIG. 1 1 , showing the markings on the ring, according to an aspect of the disclosure.

DETAILED DESCRIPTION

[0036] The present disclosure describes an improvement in templates for

neurological monitoring. The improved template is readily applied to a patient's head with consistency in placement from patient to patient and in a level and left- right symmetry in the electrode positions.

[0037] The proposed template would use one or more structures to aid in the positioning of two to 48 mounted electrodes.

[0038] Referring now to FIGS. 2-6, this disclosure teaches a template 10 that may also serve as an electrode harness when electrodes are included with template 10. Template 10 is shown without electrodes but may in the alternative carry electrodes. Each electrode position 14 may be marked with standard position designations so the specific electrode intended for that position may be attached at that location, to facilitate consistent connection of the electrodes on template 10 to the corresponding channels of a neurological amplifier (not shown).

[0039] As used herein, an electrode position designation - such as an

alphanumeric code, color, or number or combination thereof - uniquely specifies the location on the scalp of a patient where an electrode may be placed according to an electrode location plan. The plan may be a standard plan such as that shown in FIG. 1 , which is widely used in neurological monitoring, or a customized plan used by a research team, for example. The electrode location plan is a geometric arrangement for the electrodes to be placed on the head of a patient that meets the needs of a researcher, a neurosurgeon, or an

organization. Each electrode to be used, according to the particular plan, has a specific position designation.

[0040] The electrode position designations may be printed, stamped, or adhered to the template or attached via tags. They may be printed in ink that is easily machine or human readable. Additional information may optionally be included with the electrode position designation, such as the particular neurological monitoring amplifier channel.

[0041 ] The present template is used for applying electrodes to the head of a

patient so that the headset is symmetric with respect to the patient's head. Initial placement may be done by a technician, physician, nurse, emergency medical technician.

[0042] The present template simplifies the tasks of applying electrodes in a

symmetrical pattern. In particular, the system includes a template which may include electrodes and which template has features that simplify proper orientation of the template on the patient.

[0043] The symmetric placement of a template on the head of a patient is an important goal in neurological monitoring, particularly if a particular goal of the neurological monitoring is to determine if the patient has had a stroke and needs immediate treatment such an anti-coagulant, or is bleeding out and needs a tourniquet. Symmetrical placement is defined with respect to an imaginary centerline defined as a line running from the patient's nasion to the patient's inion across the crown of the head, which is the highest point when the head is held in its normal level position, and nominally bisects the patient's head between the right side and the left side. The head may be sub-divided into quarters between front and rear by an imaginary line that runs from the left auricular hole across the crown of the head to the right auricular hole.

[0044] FIG. 2- 6 illustrate the present template 10 in right side, left side, front, back and top views, respectively. The letter "N" next to the template 10 represents the nasion, which curved portion commonly called the "bridge" of the nose. The letter Ί" represents the inion, which is just below the bone at the back of the skull where the head curves inwardly.

[0045] Template 10 is made of longitudinal and transverse bands that are

broader than they are thick so that they do not tend to twist and which

assemblage of circumferential, central and lateral bands forms a template that is readily-fitted to the top of the head, much like a cap. A circumferential band 18 of the template 10, which may be a longer band than the others, provides the circumference for template 10. A central band 22 fits from the front of the head to the back along the axis of symmetry. Secondary, lateral bands 26, 30, and 34 run from the left ear to the right ear crossing second band 22 at right angles and join first band 18 on both sides of the patient's head. Circumferential band 18, central band 22 and lateral bands 26, 30 and 34, may be sewn together, glued, or molded or fabricated in one piece.

[0046] Template 10 has a shape that may fit a patient's head if template 10 is the same size or a size similar to that of the patient's head, and it is easy to use. There may be more than template 10, each one fitting a range of sizes, such as a large, medium and a small size. Template 10 is also shown with no electrodes in place, that is, template 10 is not a harness as herein defined. Once template 10 is placed on the head of the patent, electrodes (not shown in FIGS. 2-6) are attached to the patient's head at each of the electrode positions 14 for monitoring to begin.

[0047] FIGS. 7-10 show a different aspect of the disclosure, namely, a template 38 made of bands and resilient cords. The cords may be made of natural or man-made rubber, elastic woven material, or resilient plastic.

[0048] Template 38 also has electrodes 42 attached at the locations appropriate for monitoring. The number of electrodes 42 will depend on the procedure; the number visible on template 38 presents one simple example, of an electrode plan that may be suitable for detecting strokes.

[0049] Template 38 has a longitudinal band 46, which is the longest band and runs from the nasion 44 at the bridge of the nose, best seen in FIG. 7, to the inion 50 at the top of the neck (best seen in FIG. 9, across the top of the head 52. Four transverse bands 56, 60, 64, and 68, best seen in FIG. 10, extend

transversely to the sides of longitudinal band 46 and extend to generally converge toward the ears of the patient when longitudinal band 46 is placed on the curved centerline of head 52. Transverse band 56 runs across the patient's forehead just above the nasion 44. Transverse band 60 runs across the front top part of the patient's head 52. Transverse band 64 runs across the rear top part of the patient's head 52. Transverse band 68 runs across the back of the patient's head 52.

[0050] As best seen in FIG 10, a first cord 96 runs from transverse band 56 to transverse band 64, and a second cord 100 runs from transvers band 60 to transverse band 68. Connectors 108 are used to secure cords 96, 100, to transverse bands 56, 64, and 60, 68, respectively, and another connector 108 is used to secure cord 96, 100, to each other at a crossing point 1 12. Cords 96, 100, and connectors 100 pull template 38 into a three-dimensional curved shape of a template.

[0051 ] Additional or fewer transverse bands and additional longitudinal bands may be used; template 38 with four transverse band is shown as an example.

[0052] Longitudinal band 46 and transverse bands 56, 60, 64, and 68 may be made as separate pieces then joined in any convenient manner or may be integrally formed; that is, they all may be cut from a single piece of material such as a sheet of flexible plastic.

[0053] Longitudinal band 46 and transverse bands 56, 60, 64, and 68 have three dimensions, including a length, a width and a thickness. The smallest dimension is the thickness of a band; the largest dimension is the length of a band, and the width is the intermediate-sized dimension. It will be appreciated that longitudinal band 46 and transverse bands 56, 60, 64, and 68 will bend most easily about the axis defined by their largest dimension and will resist being bent about their smaller and smallest dimensions. Accordingly, the shape of transverse bands 46, 56, 60, 64, and 68 resists twisting better than a band with a circular cross- section, for example. Resistance to twisting is a feature of the disclosure both with respect to template 10 and template 38, because twisting resistance helps to prevent deformation of template 10 and correspondingly tends to assure the person applying the template to the patient in the correct orientation with respect to the patient's head.

[0054] Longitudinal band 46, the longest one, follows the centerline of the head.

The shorter, transverse bands 56, 60, 64, and 68, extend laterally from each side of longitudinal band 46 and tend to point toward the ears of the patient when applied to the patient's head. Transverse band 56 may initially be too far forward or too far backward when first applied, for example. A guide 70 on a first end 72 of longitudinal band 46 will move toward nasion when template 38 is then adjusted appropriately forward or rearward while on head 52 of the patient.

[0055] The person who is fitting template 38 onto head 52 of the patient may be able to tell by looking at the patient wearing template 38 whether template 38 is centered left to right, that is, whether longitudinal band 46 follows an imaginary centerline in the middle of head 52 or not. Optionally, and as seen in FIGS. 1 1 and 12, a guide 78 may be added to an additional transverse band 82 (not shown in FIGS, 7-10) that extends downward from the highest point, or crown, of head. Guide 78 may be formed as a loop 86 to encircle the ear for stability or simply be a small rod. Guide 78, as seen in FIGS. 1 1 and 12, has marks 80 on it, which will be near the ears 94 of the patient when positioned so that the positions of the marks can be compared to the closest common features of the ears 94, such as the auricular hole 92 that is the entrance to the ear canal or to the bone 94 just forward of the auricular hole, or other features of the ears. Marks 80 on guide 78 will assist the user to make fine adjustments of template 38 a little to the left side of the patient or to the right in order to center template 38 on head 52.

[0056] The front-to-back alignment uses the nasion 44 as a landmark; the side- to-side alignment uses the ears as landmarks. The term landmark is used metaphorically to indicate an easily located physical feature on the head of a human being. In particular, a landmark may be a particular feature that is common to human beings, such as ears, noses, bumps on the back of the head. The electrode positions on the transverse bands 56, 60, 64, and 68 are established by a network of cords 100, each one attached to two transverse bands 56, 60, 64, 68. Cords 100 are resilient so that they tend to equalize the tension among themselves. They are self-adjusting with respect to the spatial relationships among the rings 104 to which they are connected, thereby holding the rings in place in proportion to the lengths of cords 100 on the patient wearing template 38. Importantly, there is no need to measure the distances between electrode positions to determine the location of an adjacent electrode or to consider whether the size of the template. Cords 100 adjust resiliently to patient head size and shape and equalize the tension between rings 104

[0057] Template 38 is symmetric and easily and quickly placed on the head of a patient and to enable neurologic measurement and the side-to-side alignment is based on center the headset, the patent's ears are used to determine left-to-right symmetry and the patient's nasion and inion are used to determine front-to-back symmetry. Attached to the headset on each side is a loop that is put over the ear, one loop over each ear. Each loop has markings on it to make it easy to see the position of the loop with respect to an arbitrary feature of the patient's ear.

[0058] A feature of the disclosure is a system for applying electrodes to the head of a patient, said system comprising a headset having plural electrode positions indicated on it; and at least one guide attached to the headset. The at least one guide corresponds to a landmark on the head of the patient. When the headset is applied to the head of the patient and adjusted with respect to the patient's head the at least one guide is aligned with that landmark. Then, the plural electrodes positions are oriented with respect to the head.

[0059] A neurological monitoring template comprises a template dimensioned to fit onto the head of human above the nose and the ears. The template has plural positions for electrodes, each of which positions is in a pre-determined location and spaced apart from each other position. Each of the positions has a predetermined marker associated with it that corresponds to and identifies the predetermined electrode position designation for an electrode.

[0060] Another feature of the disclosure is that the at least one alignment guide may be a nasion guide, a left auricular guide and a right auricular guide, an inion guide or more than one. Each alignment guide may carry one or more markers to assist in matching a landmark on the patient's head with the alignment guide.

[0061 ] A feature of the disclosure is that the pre-determined marking on the

longitudinal and transverse bands may include an alphabetical letter and either a number or the letter z and which may selected from the group consisting of Fp1 , Fp2, F7, F3, Fz, F4, F8, T3, C3, Cz, C4, T4, T5, P3, Pz, P4, T6, 01 , and 02.

[0062] Another feature of the disclosure is that the pre-determined marker may be a tag containing the electrode position designation pre-attached to the template, or the electrode position designations may be printed or stamped on the template.

[0063] Another feature of the disclosure is that the template may be made of flexible bands and resilient cords that are connected to define a web.

[0064] A feature of the disclosure is that the number of predetermined positions may be a standard set or a custom set with any number and arrangement of pre- designated electrode position designations carried on the template.

[0065] These and other features and their advantages will be apparent to those skilled in the art of neurological monitoring from a careful reading of the detailed descriptions of preferred embodiments accompanied by the drawings. Many modifications and substitutions may be made in the foregoing detailed description without departing from the spirit and scope of the disclosure, which is defined in the appended claims.

Claims

WHAT IS CLAIMED IS:

1 . A template for neurological monitoring, said template comprising:

a longitudinal band having a proximal end and an a distal end;

plural transverse bands extending laterally from said longitudinal band, said plural transverse bands including

a first transverse band having a first distal end, and

a second transverse band spaced apart from said first transverse band and having a second distal end; and

plural cords including a cord of said plural cords having

a first end of said cord attached to said first distal end of said first transverse band, and

a second end of said cord attached to said second distal end of said second transverse band,

wherein said cord of said plural cords bends said proximal end of said

longitudinal band and said distal end of said longitudinal band into a three-dimensional curved template.

2. The template of claim 1 , wherein said plural transverse bands are integral with said longitudinal band.

3. The template of claim 1 , wherein said longitudinal band and said plural transverse bands have positions for electrodes.

4. The template of claim 3, wherein said positions are marked for specific electrodes.

5. The template of claim 1 , further comprising electrodes deployed on said longitudinal band and said plural transverse bands.

6. The template of claim 1 , wherein said longitudinal band and said plural transverse bands are wider than they are thick.

7. The template of claims 1 , wherein said cords are resilient.

8. The template of claim 1 , wherein said proximal end of said longitudinal band includes an alignment guide.

9. The template of claim 8, wherein said alignment guide is alignable with a nasion.

10 The template of claim 8, wherein said alignment guide is alignable with an auricular landmark.

1 1 . The template of claim 1 , further comprising plural connectors operable to fasten said cord to said first distal end of said first transverse band and to said second distal end of said second transverse band.

12. The template of claim 1 , wherein said longitudinal band has a left side and a right side, and wherein said template further comprises four transverse bands on said left side and four transverse bands on said right side of said longitudinal band.

13. The template of claim 12, wherein said plural cords include four cords, a first pair of cords of said four cords on said left side and a second pair of cords on said right side.

14. The template of claim 13, where said first pair of cords cross to connect a first transverse band with a third transverse band and a second transverse band with a fourth transverse band.

15. The template of claims 14, further comprising a connector connecting said first pair of cords at their crossing point.