Patent Application
20200029848
The present application relates to electrodes, and more specifically to the attachment of electrodes to a patient. In particular, a method and apparatus are described for preparing the skin on a patient's scalp for attachment of electrodes, such as for performing an electroencephalogram.
Electroencephalography, or EEG, is a method of recording electrical activity in the brain. In particular, EEG measures voltage fluctuations resulting from ionic current within the neurons of the brain. Typically, an EEG is performed by attaching electrodes to the patient's scalp (the anatomical area bordered by the face in the front, and by the neck at the sides and back). Once attached, it is possible to measure voltage fluctuations over time.
EEG has been used for various forms of medical diagnosis including epilepsy. For purposes of studying brain function, EEG has several advantages over other techniques. For example, costs may be lower, equipment is significantly less bulky than other types of equipment, temporal resolution is very high, subject movement may not affect results, the test is silent, claustrophobia is not an issue, high-intensity magnetic fields are not required, radioactivity is not required, and testing is fairly noninvasive.
Performance of an EEG comprises the following steps: supplying electrodes, preparing the scalp for electrode placement (often using a form of light abrasion to reduce impedance), and placing the electrodes on the scalp using a conductive paste or gel. Each step will now be described separately.
Electrodes are supplied with each attached to an individual wire. The electrodes are supplied in the form of cups that are available in different metals. Silver/silver chloride or gold cup electrodes may desirably be used due to their recording properties. These materials are desirable because they have low impedance.
In one example of the prior art, the head is measured according to the international 10/20 system of electrode placement. Electrode placement locations can then be marked using a grease pencil. Instructions for measuring the head based on the international 10/20 system of electrode placement are known to one of ordinary skill the art and will not be repeated here.
Prior to attaching the cups to a patient's scalp, the skin must be prepared. An abrasive solution may be used to lower impedance of the electrode connection. Thus, an abrasive prep (hereafter “prep”) is used to clean the area where the electrode will be applied. The objective is to remove oils and dried skin from the location where the electrodes will be attached. In addition, a slight abrasion of the skin allows for low impedance. Various solutions are commercially available for performing abrasive prep and are sold under various trade names including NUPREP, LEMON PREP, and SKIN PURE. Typically, a cotton tipped applicator is used to apply a small amount of prep to the location where each electrode placement location has been marked. Such a cotton tipped applicator may be or resemble a cotton tipped swab sold under the trade name QTIP. Such swabs (as described by Wikipedia) include one or two small wad(s) of cotton wrapped around one or both end(s) of a short rod made of wood, rolled paper or plastic. Using the cotton tipped applicator, prep may be wiped several times in one direction over that spot. The goal of this procedure is to remove dead skin cells and oils and to slightly abrade the skin.
Next, each electrode cup is filled with conductive paste. Conductive paste allows each cup to be adhered to the scalp. The conductive paste also ensures that the contact impedance of the electrode—skin interface is reduced. Examples of conductive paste are sold under several trade names including TEN20 and ELEFIX. Each cup is then pressed onto each location that was prepared with the prep using downward pressure. The electrodes may then be covered with gauze or cotton. Frontal electrodes may be secured using medical tape. Sometimes, the electrode wires are secured together in order to reduce or eliminate artifacts from the recording.
Each electrode is then plugged into the EEG machine. By doing so, each electrode is connected to an input of a differential amplifier in order to amplify the voltage being measured.
The voltages are subsequently recorded. Sometimes “activation” procedures may be used including strobe lights, eye closure, mental activity, hyperventilation, etc. Each EEG signal can then be stored and filtered for display.
A method of attaching electrodes to a patient, the method comprises the steps of providing a squeezable member having a hollow interior, wherein a skin abrasive solution is in the interior, wherein the squeezable member includes a restrictive member having a restrictive opening for restricting flow of the skin abrasive solution out of the squeezable member, and a tip through which the solution leaving the restrictive member exists the squeezable member; squeezing the squeezable member; scrubbing skin portions of the scalp of the patient with the tip; and attaching electrodes to the skin portions of the patient's scalp.
The prior art method of applying prep has several problems which makes the process undesirable. As previously explained, prep is applied to a patient's scalp through the use of a cotton tipped applicator or swab. The cotton tipped applicator is dipped into a container of prep, and then the cotton tipped applicator is rubbed on locations on the patient's scalp.
As the prep goes from location to location on the patient's scalp, it is desirable to keep the cotton tipped applicator saturated with prep. Thus the technician applying the prep repeatedly moves his/her hand back and forth: dipping the applicator into a solution of prep and then rubbing the applicator on the patient's scalp in various locations.
There are problems with this procedure, namely the time needed to apply the prep and the possibility of applicator breakage.
Because the technician is moving the applicator back and forth between the solution of prep and the patient's head, time is lost in the process of moving between the patient's head and the solution of prep. This can be particularly inconvenient for a patient. For example, if a patient is a child, or the patient is an adult with a disability such as a learning disability, the patient might be impatient or potentially frightened by the process of being prepared for an EEG recording. In one example, the patient may have difficulty sitting still. In another example, if the patient is very upset, the patient can start to cry, and/or can be very agitated with the result of frequent head movements. With any type of head movement, application of prep onto a patient's head can become very challenging. Thus a technician will attempt to apply prep on a patient's head as quickly as possible. If the technician is continuously moving his/her hand back and forth between the patient's head and a solution of prep, this process of hand movement increases the amount of time needed to apply prep to all the locations on a patient's head, and/or creates unnecessary delays between applying prep to each location on the patient's head.
Breakage of the applicator is another concern. An applicator may be comprised of wood (as opposed to other materials) because of low cost as well as sufficient structural strength. In other words, the cotton tipped applicator needs to be sufficiently strong so that a technician can apply pressure on to the patient's head while grasping the applicator. This pressure may be needed in order to slightly abrade the skin in order to lower the impedance of the electrode connection. Unfortunately, if a technician applies too much pressure, then the applicator might break, with the result that a sharp point is formed, and that is possibly pointing towards the patient's head. Even if a technician is “perfect” in the amount of pressure being applied, if the patient suddenly jerks his/her head in the wrong direction, and with sufficient force, the jerking motion may result in the applicator snapping in half. Again, this may result in a dangerous situation where a technician is left holding only a portion of the applicator, with a sharp end facing towards the patient's head.
Accordingly, in an exemplary embodiment of the present invention, squeezable member 100 is provided as shown in
In one embodiment, sidewalls 109 of body 102 are flexible. This flexibility enables body 102 to be squeezed from opposite sides as shown by the exemplary and illustrative opposing arrows that are illustrated in
Squeezable member 100 includes applicator 210. Applicator 210 may include a tip that includes materials to provide comfort to a patient when applicator 210 is in contact with skin layer 110. Thus, applicator 210 may be comprised of a sponge-like material. Alternatively, applicator 210 may have a hard interior and an exterior softer than the hard interior. Exemplary exterior is formed of textiles or fabrics. Details regarding applicator 210 are described below.
Squeezable member 100 may also include optional restrictive member 106. Restrictive member 106 may provide some form of restriction as liquid within hollow interior 104 flows through applicator 210 and onto skin layer 110. Details regarding restrictive member 106 are also provided below.
In operation, squeezable member 100 is provided. Also, squeezable member 100 may be provided with abrasive prep in hollow interior 104. In another embodiment, squeezable member 100 is provided empty and is then filled with abrasive prep. Abrasive prep is sold under several brand names such as NUPREP, LEMON PREP, and SKIN PURSE. Squeezable member 100 may be inverted into the position shown in
As a result of gravity, and/or squeezing of body 102, prep is now introduced onto skin layer 110. Using for example a back-and-forth motion, applicator 210 may be rubbed on skin layer 110 in order to clean skin layer 110 with the abrasive prep that has come out of body 102. In one embodiment, the actions of 1) allowing abrasive prep to flow out of body 102 and 2) rubbing applicator 210 on skin layer 110, occur concurrently. In another exemplary embodiment, flow of abrasive prep out of body 102 and rubbing of skin layer 110 by applicator 210 occur sequentially (i.e. allow abrasive prep to flow out of body 102, subsequently rub skin layer 110 with applicator 210, repeat). Alternatively, a combination of the above steps may occur in which rubbing of skin layer 110 and exiting of abrasive prep from body 102 first occurs simultaneously, then occurs sequentially, etc.
In one exemplary embodiment, squeezable member 100 is supplied in a closed container and filled with abrasive prep prior to being received for patient use. In this exemplary embodiment, the technician removes squeezable member 100 from packaging, preps a patient head for EEG recording, and when done simply disposes of squeezable member 100. In another exemplary embodiment, squeezable member 100 is refillable, and applicator 210 is replaceable. Thus for example, prior to use, squeezable member 100 is provided empty, squeezable member 100 is filled with abrasive prep, applicator 210 is rubbed on a patient's skin layer 110 while abrasive prep is concurrently and/or sequentially exiting squeezable member 100, and after patient preparation is complete, applicator 210 is discarded or sterilized. Squeezable member 100 is then refilled with abrasive prep, and either applicator 210 is attached to body 102 prior to further patient use, or previously-used applicator is sterilized and subsequently attached to body 102. Several exemplary embodiments will now be provided in order to illustrate both methods of operation.
In the embodiment shown in
Tip 216 may be oval-shaped as shown in the figure, although this is merely exemplary. Tip 260 may be manufactured using various exemplary manufacturing processes including injection molding and blow molding. Tip 216 may include a hollow interior and a plurality of small sized openings from which abrasive prep exits tip 216. Furthermore, tip 216 may be covered with a soft (or compressible) member 218 in order to reduce friction between tip 216 and skin layer 110. An exemplary layer may be cotton, although other fibers are also contemplated including polyester type fibers. Tip 216 is mounted to a base that includes restrictive member 214. Restrictive member 214 includes restrictive opening 220 through which abrasive prep flows. Restrictive opening 220 may have a diameter which is smaller (or much smaller) then the diameter of tip 216. The small diameter of restrictive opening 220 restricts the rate at which abrasive prep flows into tip 216 and towards skin layer 110. Because the diameter of restrictive opening 220 is smaller than the diameter of tip 216, this feature may need to be addressed during the manufacturing process. Thus, for example after tip 216 is manufactured using injection molding, it may be desirable to manufacture applicator 210 as identical bisymmetrical halves that are bonded (or fused) together during the manufacturing process.
As previously explained, applicator 210 is attached to body 102 using various methods that include and are not limited to a threaded attachment, a friction attachment, a tongue and groove attachment, etc. Also, in another exemplary embodiment, applicator 210 and body 102 are manufactured so that applicator 210 and body 102 are integrated into a single piece. As previously explained, if injection molding is used as the form of manufacturing, it may be desirable to form squeezable member 100 is two separate identical bisymmetrical pieces that are bonded/fused together during the manufacturing process.
Body 102 includes body opening 204. When squeezable member 100 is inverted, abrasive prep flows out of hollow interior 104, through body opening 204, through restrictive opening 220, into tip 216, and through cover 218 before coating skin layer 110.
Prior to performing an EEG on a patient, squeezable member 100 is supplied having body 102 with hollow interior 104. Abrasive prep (a skin abrasive solution) may either be included in the hollow interior 104 or added to hollow interior 104 prior to use. Squeezable member 100 includes applicator 210 having tip 216 (at the end of applicator 210) through which the prep exits squeezable member 100. The squeezable member includes a restrictive member, either in body 102 or applicator 210. In the example shown in
Squeezable member 100 may be squeezed to assist in the flow of prep out of squeezable member 100.
As (or after) prep flows onto the patient's scalp, skin portions of the patient's scalp are scrubbed with tip 216. Scrubbing may be accompanied by pressure against the patient's scalp. In one embodiment, pressure is applied to the scalp in a direction orthogonal to direction in which squeezable member 100 is squeezed. In another embodiment, squeezable member 100 is used to apply pressure at an angle that is not exactly orthogonal to the patient's scalp, but the pressure has an orthogonal pressure vector component.
Electrodes are then attached to the patient's scalp at the locations where the patient's scalp was scrubbed.
During use, if prep is not already in hollow interior 104, then prep is added to hollow interior 104. Adding prep to hollow interior 104 may be performed as follows: Applicator 210 may be unfastened from body 102, prep is poured into hollow interior 104, and applicator 210 may be reattached to body 102. Applicator 210 that is reattached to body 102 is either an applicator 210 that was previously detached from body 102 or a new applicator 210.
Squeezable member 100 may thus be provided as a kit, with body 102 and a plurality of applicators 210. In this manner, each applicator 210 that is used may be discarded and replaced with a new (and clean and/or sterile) applicator 210.
The above explanation is with regard to the embodiment shown in
Compressible tip 240 sits within applicator 210 and rests on restrictive member 222. Restrictive member 222 may be one of a plurality of restrictive members 222 that extend inwardly from the inner walls of applicator 210. While restrictive member 222 extends inwardly from the inner walls of applicator 210, the location of one restrictive member 222 relative to another may result in spaces therebetween, thus allowing abrasive prep to flow to those spaces. Alternatively, restrictive member 222 can be another shape such as a disk with a central opening. The disk may be adhered to the interior of applicator 222. Adhering of restrictive member 222 within applicator 210 may be via chemical bonding, bonding during the manufacturing process, or a tongue and groove configuration. Compressible tip 240 may be held in place within applicator 210 with a friction hold, adhesive, and/or it may rest on restrictive member 222. Applicator 210 includes sidewalls in which compressible tip 240 is inserted.
During actual operation, abrasive prep flows through body opening 204 of body 102, through restrictive opening 220, through compressible tip 240 and onto skin layer 110. Furthermore, while
When opposing pressure is applied to body 102, prep within hollow interior 104 is pressed against seal 250, causing seal 250 to open. As opposing pressure (or even pressure from one side) against body 102 is increased, seal 250 increases the size of its opening to allow more prep to flow therethrough. Without opposing pressure exerted against body 102, seal 250 remains closed and therefore prep is prevented from flowing past seal 250, through compressible tip 240, and onto skin layer 110.
As disclosed in U.S. Pat. No. 5,664,705, seal 250 may be comprised of a plurality of members that are attached to each other during manufacturing in order to maintain prep within body 102. Score lines may separate the individual valve members. Upon application of pressure while body 102 is squeezed, the valve members open, separating from each other along the score lines. In an exemplary embodiment, score lines may be cut deepest at the apex allowing the valve members to easily separate.
U.S. Pat. No. 5,664,705 discloses that the body is manufactured as a plurality of different members that are bonded (or fused) together during the manufacturing process. This is merely exemplary.
At step 1002, a squeezable member may be provided. For example, squeezable member 100 may be provided. In some exemplary embodiments, abrasive prep is included within the squeezable member. At step 1004, portions of skin layer 110 may be scrubbed. In the preferred embodiment, the portions of skin layer are on the scalp, i.e. located on a person's head. Step 1004 may be accompanied by other steps. One exemplary step that may accompany step 1004 includes the step of inverting the squeezable member so that it is inverted, so it is facing downwards and is in contact with the patient's skin. Furthermore, another exemplary step that may be included is the step of squeezing the squeezable member from opposite sides in order to assist with the dispensing of abrasive prep from the squeezable member. As previously described, squeezing and scrubbing may occur simultaneously, may occur serially (one after the other), or may occur in some combination thereof. At step 1006, electrodes are attached to the patient's skin so that, for example, EEG recording may commence. At step 1008, the squeezable member may be discarded. If the squeezable member is discarded at step 1008, then processing proceeds to step 1002 at which a new squeezable member is provided. Alternatively, if the squeezable member includes a removable retainer, then at step 1010 the removable retainer is removed. At step 1014, solution, namely abrasive prep, is added to the squeezable member. At step 1012, the retainer is replaced onto the squeezable member. Processing then proceeds to step 1004 where skin portions of yet another patient may be scrubbed.
While several embodiments described above include structure for opening and resealing squeezable member 100, in several embodiments squeezable member 100 is supplied with prep already included therein and with a resealable opening for refilling squeezable member 100 after the prep has exited.
In the aforementioned description, numerous details are set forth. It will be apparent, however, to one skilled in the art, that the disclosure may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the disclosure.
Whereas many alterations and modifications of the disclosure will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description, it is to be understood that any particular implementation shown and described by way of illustration is in no way intended to be considered limiting. Therefore, references to details of various implementations are not intended to limit the scope of the claims, which in themselves recite only those features regarded as the disclosure.
