Patent Application
20230122254
This application claims priority to Netherlands national patent application serial number 2029404, filed Oct. 14, 2021, the entirety of which application is incorporated by reference herein.
The present invention relates to dermatomes. In particular, the invention relates to dermatomes having single use parts that are releasably connectable to a reusable part.
Dermatomes as such are known. Dermatomes are used to harvest skin grafts from a human or animal body. The skin graft can then be used to treat wounds, for instance burn wounds, at which no skin or damaged skin may be present. Normally, skin is harvested from the person to be treated. Accordingly, such a grafting process is called autografting.
In general dermatomes consist of a handle and a head, wherein the head comprises a blade which in most cases is driven by some kind of drive means. Blades are single use. Accordingly, the dermatome head comprises a receiving structure for receiving and holding the blade at a certain position. The head further comprises a guide surface, which in use of the dermatome slides across the skin of the donor. A position of the blade with respect to the guide surface, which is called the blade height or cutting height, defines the position of the blade with respect to the surface of the skin when the dermatome is used. Accordingly, a thickness of the skin grafts is determined by said blade height. In order to allow a user, such as a doctor, to select a desired thickness for the skin grafts, dermatomes may be provided with a blade height adjustment mechanism, which moves the receiving structure in order to move the blade with respect to the guide surface.
Although the existing dermatomes are satisfactory to some extent, a need for improvement remains. In particular, dermatomes that allow blade height adjustment are notoriously hard to clean due to their many, possibly small, movable parts. Accordingly, such dermatomes pose a serious health risk through a possible lack of hygiene, which could lead to e.g. cross contamination or which could facilitate infections of the skin graft and the wound to be treated, and/or of the donor site, the donor site being a part of the body from which the skin graft is taken.
The invention aims to address this issue, by providing a dermatome solution which does not pose the same health risks.
The aim is achieved by a kit of replaceable dermatome blade units, comprising at least a first blade unit and a second dermatome blade unit, wherein each dermatome blade unit comprises a blade support, comprising connecting means for releasably attaching the dermatome blade unit to a handle and/or a dermatome head, and a dermatome blade attached, preferably movably, to the blade support, wherein for each dermatome blade unit a distance in a first direction normal to a main surface of the dermatome blade between the dermatome blade and the connecting means is defined as an attachment height, wherein the attachment height of the first dermatome blade unit is larger than the attachment height of the second dermatome blade unit.
Since the attachment height of the first and second dermatome blade unit differs, the blade height when the dermatome blade units are connected to a dermatome differs between the two dermatome blade units. Accordingly, the blade units can be used to produce skin grafts of different thicknesses. At the same time, the added complexity of a blade height adjustment mechanism in the head of the dermatome is avoided. Accordingly, the dermatome may be easier to clean, thereby reducing health risks.
The invention stems in part from the realization that a health advantage may be achieved by moving complexity from the dermatome head to the blade unit, since the blade unit is single use and the dermatome head needs to be cleaned for reuse. Accordingly, less complex parts need to be cleaned.
Moreover, since the blade height and thus the graft thickness is defined by the blade unit, it is no longer possible inadvertently select a wrong setting on the dermatome, which may occur e.g. during use when a set height adjustment mechanism fails and changes the blade height setting unexpectedly. According to the invention, failure of the height adjustment can be avoided, which may reduce a chance of medical errors. Additionally or alternatively, the blade height used can be easily reviewed before and even after using the dermatome by checking the blade unit used. Accordingly, the grafting operation becomes less error prone and more traceable.
It is noted that the blade and the blade support or parts thereof may be integrally made, i.e. they may be formed of the same, single part. As an alternative, they may be made of different parts, which are optionally movable with respect to each other. In particular, the blade may comprise a metal, whereas the blade support may comprise at least one plastic part.
A relatively elegant design of the dermatome blade unit may be achieved if the dermatome blade unit is connectable to a head of a dermatome, which may be reusable. As explained above, the dermatome head may accordingly be easier to clean.
However, the invention also finds application in case the dermatome blade unit is comprised by a dermatome head, which may thus be replaceable and/or single use in its entirety. In that case, the enhanced traceability and reduced chances of medical errors remain important advantages achieved through the invention.
It is noted that it is not strictly necessary to provide blade units having a different attachment height. Some advantages of the invention as described herein may be achieved with dermatome blade units having the same or similar attachment heights.
In an embodiment of the kit, the blade support comprises a cover and a clamping element, the blade being interposed between the cover and the clamping element.
Interposing the blade between a cover and clamping element may allow securely holding the blade, especially when allowing movement of the blade with respect to the cover and/or clamping element. The cover may at the same time be used to cover a bottom of the dermatome head. Moreover, the blade units according to this embodiment may be relatively easy to produce.
It is noted prior art dermatomes also include a cover, in order to at least partly cover the dermatome blade, and other (moving) parts of the dermatome. Such covers are fixed to the dermatome head using e.g., bolts. By including the cover in the dermatome blade unit, additional complexity is removed from the dermatome, which may therefore be cleaned more easily.
The connecting means may be fixed to or may be part of one or both of the clamping element and the cover. In particular, the connecting means are an integral part of the cover. In that case, the clamping element may be used to lock the blade in place on the cover. The clamping element may be connected to the cover via a clamping connection, for instance as described below. However, it is also possible to connect the clamping element to the cover in some other way, as long as the blade is kept in place. As such, the clamping element need not necessarily clamp. In fact, the clamping element may therefore also be replaced by a locking element or some other component.
There is also the possibility that the blade support only comprises one of a cover and a clamping element. For instance, the blade support may comprise a cover and no clamping element. In that case the blade would be held by the cover, optionally in combination with another component of the dermatome, such as a component of the dermatome head. Another option is that the blade support comprises a clamping element, or some other kind of element fixing the dermatome blade, wherein said element optionally cooperates with a part of the dermatome, such as a blade cover attached to the dermatome head, in order to (movably) keep the dermatome blade in its place.
In another embodiment of the kit, a thickness of the cover and/or the clamping element varies from the first to the second dermatome blade unit, in order to provide a corresponding difference in attachment height.
The difference in attachment height results in, as described before, a difference in slice thickness when the blade units are used on a dermatome. By varying the thicknesses of the cover and/or clamping element the attachment height may be varied relatively elegantly. Moreover, the clamping element and/or cover may form a sliding surface for the blade at the desired attachment height. By varying the thickness of the respective component(s), the slide surface may be disposed on the desired height. Moreover, when the thickness of the respective component(s) is used to define the attachment height, it may be clearly visible from the blade unit which attachment height it provides.
In another embodiment of the kit, a total thickness of the cover and the clamping element and the dermatome blade of each dermatome blade unit is defined in the first direction, and wherein the total thickness of the first dermatome blade unit is equal to the total thickness of the second dermatome blade unit.
Accordingly, all blade units have the same total thickness, regardless of their respective blade heights. As such, it may be relatively easy to integrate blade units with different blade heights in a dermatome or dermatome head.
An alternative would be to only vary the thickness of the cover or the clamping element, in particular the one component comprising the connection means, while keeping the clamping element at the same thickness for every dermatome blade unit, while still alternating the difference in attachment height. In this alternative, the single thickness component, e.g., the clamping element or the cover, may benefit from mass production.
In yet another embodiment of the kit, one of the cover and the clamping element comprises male connecting units and the other of the cover and the clamping element comprises corresponding female connecting units, the male and female connecting units being configured to engage each other in order to lock the clamping element in place with respect to the cover.
By locking the clamping unit in place with respect to the cover, the blade may be held securely between the two. Using male and corresponding female connecting units may be a practical way to provide the desired locking action, although alternatives may also be used.
The male connecting units may comprise one or more pillars, extending from in particular the cover. The female connecting units may comprise apertures or recesses, in particular in the clamping element. The apertures or recesses and the pillars may be shaped so as to allow introduction of the pillars into the apertures or recesses under plastic deformation of the pillars and/or apertures or recesses, thereby clamping the apertures or recesses onto the pillars. As such, a clamping connection between the cover and the clamping element may be made.
The cover may be provided with one or more stops, for instance at the pillars, for engaging the clamping element. The one or more stops may be placed so that when the clamping element engages the stop(s), the cover and clamping element together define a suitable receiving space for the blade. The stop(s) may be arranged so that the blade has a certain play in a direction from the clamping element to the cover and vice versa, so as to allow movement of the blade in a direction transversal to the mentioned direction. Of course the stop(s) may alternatively or additionally be arranged on the clamping element.
In another embodiment of the kit, the dermatome blade of each dermatome blade unit is moveable with respect to the respective blade support in a direction substantially parallel to a direction in which a cutting edge of the dermatome blade extends.
This movement of the blade, which is transversal with respect to the grafting direction causes the blade to cut more easily into or through the skin. Accordingly, less force needs to be produced when grafting and/or cleaner cuts may be made. Moreover, allowing motion of the blade with respect to the blade support allows to keep the blade support stationary with respect to the dermatome and/or dermatome head. As such, the dermatome or dermatome head may be designed more elegantly, as no or little moving parts are needed.
In yet another embodiment of the kit, each dermatome blade comprises an engagement surface, configured for engagement by drive means of a dermatome for moving the dermatome blade with respect to the blade support.
Motion of the blade, for instance that described in the preceding paragraphs, may be realized by engaging the blade by the drive means to this engagement surface.
When the blade unit is attached to the dermatome head, and a handle is attached to the head, the drive means arranged in the handle may engage directly on the engagement surface of the blade unit. Accordingly, the head can be kept free of driving and/or driven components, so that the head can be designed relatively elegant and/or with few components. Accordingly, the head may be more easy to clean.
In accordance therewith, the handle may comprise a drive means. The drive means may comprise an output. The head may comprise a through feed for the output of the drive means to run towards the blade unit. The blade unit may comprise the aforementioned engagement surface. The output of the drive means may therefore engage on the blade unit through the head, without actually requiring components of the head to be part of the drive train. It is of course possible to, as an alternative, provide a coupling as part of the head, which receives input from the output of the drive means and engages on the engagement surface of the blade unit. This however complicates design of the dermatome head.
The capability to drive the blade unit with the drive means in the handle directly, is especially advantageous when the blade unit and/or the head can be decoupled/detached from the handle and from each other. In such a case, the head and handle may be combined as desired, for instance by selecting a desired width of the head. Yet the head and the handle may be cleaned relatively easily when the head is detached from the handle.
In another embodiment of the kit, the engagement surface is formed by an aperture and/or recess in the dermatome blade.
Via the aperture and/or recess the blade can be pushed in a direction parallel to the plane of the blade, while motion of the blade in a direction normal to the plane may be decoupled from motion of the drive means in that direction. Accordingly, unwanted vibrations and/or motion in the normal direction may be at least partially avoided.
In yet another embodiment of the kit, each blade support comprises a guide surface for guiding the dermatome blade unit across skin during use of the respective dermatome blade unit in a dermatome.
The guide surface may allow smooth movement of the dermatome over the skin, for instance at a well defined height, and therefore give better control when using the dermatome.
The guide surface of the blade unit may be flush with an additional guide surface of the dermatome head.
As the guide surface defines the position of the dermatome with respect to the skin, the position of the connecting means with respect to the guide surface of the blade unit and/or the dermatome head may vary from dermatome blade unit to dermatome blade unit, in correspondence with the attachment height. As such, the varying attachment height may also be described as a varying distance from blade to guide surface, as seen in a thickness direction of a skin graft to be cut. The thickness direction can be inferred from the orientation and position of the guide surface and the blade, and may for instance be substantially normal to a plane of the blade.
In yet another embodiment of the kit, each dermatome blade unit comprises a removable blade protector, removably fixed to the blade support, preferably to the cover thereof, for example via a breakable connector.
The blade protector may be used to prevent inadvertent access to the blade for instance during storage, transport or mounting of the blade unit to the dermatome. As such, the blade may be protected from objects which could detriment its sharpness and/or a user may be protected from being cut by the blade. Additionally or alternatively, the blade protector may reduce the possibility of the dermatome blade damaging a packaging, such as a sterile packaging, thereby reducing the chance of such optionally sterile packaging failing.
As an alternative to a breakable connecting, a snap-fit connection may be used.
In one alternative, the snap fit connection may be arranged so that after removal of the blade protector, it cannot be replaced. Accordingly, the snap fit connection, or any other connection type used, may be a single disconnect connection. It is noted that the blade protector may alternatively or additionally be removably fixed to the clamping element, or to the blade support in general.
In another alternative, the snap fit connection may be arranged to allow reconnecting the blade protector, thereby allowing safe disposal of the dermatome blade unit.
In case the blade protector is fixed using a breakable connection, the blade protector may be made integrally with the component to which it is removably fixed. Alternatively, also in the case of using another type of connection, the blade protector may be manufactured as a separated component, which is removably fixed to the blade support, the cover and/or the clamping element after manufacturing.
A breakable connection may be combined with a snap-fit connection, wherein the blade protector may be removed from the blade before use by breaking the breakable connection, and replaced using the snap-fit connection for safe disposal after use.
The invention also relates to a dermatome blade unit as described above. The blade unit may have any features described hereabove, such as those described in relation to the kit of dermatome blade units, by themselves or in any suitable combination.
The invention also relates to a dermatome comprising a handle and a dermatome head attached to the handle, the dermatome head comprising a guide surface for guiding the dermatome head across skin in use of the dermatome, a dermatome blade unit as described in the previous paragraph, wherein the dermatome blade unit is attached releasably to the dermatome head using the connecting means of the dermatome blade unit and corresponding connecting means of the dermatome head.
Accordingly, a dermatome is obtained which may cut skin grafts of different thicknesses depending on which dermatome blade unit is used. Such a dermatome has the additional advantage that it is relatively easy to clean, as the dermatome head may be kept relatively elegant. In particular, no moving parts are needed in order to set the cutting height. In fact, the cutting height may be varied by selecting a suitable blade unit.
In a practical embodiment of the dermatome, the connecting means of the dermatome head are stationary with respect to the guide surface of the dermatome head. Accordingly, the thickness of the skin graft can be varied only by the attachment height of the blade unit used. Moreover, when the connecting means are stationary with respect to the guide surface, no added complexity is needed for a blade height adjustment mechanism.
In another embodiment of the dermatome, the dermatome head is attached releasably to the handle.
Releasing the dermatome head, may make cleaning the dermatome relatively easy. Moreover, using releasable dermatome heads allows selecting dermatome heads for suitable purposes, for instance for selecting a grafting thickness or grafting width. Accordingly, the dermatome heads may be designed relatively simply, because it is no longer required that a dermatome head allows for different thicknesses and/or widths. Due to the simple design, cleaning may be even more easy. Additionally or alternatively, the simple design may allow using the dermatome head in its entirety as a single use product at relatively low cost.
It is noted that the same or similar advantages may be achieved using a dermatome as described herein but without the blade unit as described herein. Instead, any suitable blade may be used, for instance one permanently connected to the dermatome head, or a replaceable blade as is known from the prior art.
In yet another embodiment of the dermatome, the handle is provided with a drive mechanism for driving a dermatome blade of a dermatome blade unit attached to the dermatome head in a direction transversal to a grafting direction of the dermatome. The drive mechanism is an example of a drive means as mentioned above.
By providing the drive mechanism in the handle, the dermatome head may be kept relatively elegant and/or simple. As such, the dermatome head may be easier to clean and or less costly to replace. The drive mechanism may be a motor.
If no dermatome blade unit is used, the drive mechanism may be used to drive another type of blade of the dermatome.
In yet another embodiment of the dermatome, the handle of the dermatome comprises at least one battery in an embodiment of the dermatome. Practically, the battery may be used to power the drive mechanism.
Accordingly, the head of the dermatome may be kept relatively simple.
As an alternative, the drive mechanism may be powered by an external power source, such as a pneumatic power source or an electric power source. To this end, the drive mechanism may comprise a suitable power input, such as a pneumatic power input or an electric power input.
The drive mechanism is an example of a drive means introduced above.
The invention also relates to a kit of parts of a dermatome as described above, and a further dermatome head, the further dermatome head is releasably attachable to the handle in order to replace the dermatome head, wherein a width of the dermatome head as defined in the direction transversal to the grafting direction is larger than a width of the further dermatome head as defined in the direction transversal to the grafting direction.
Using such a kit of parts, a user may select a different dermatome head to achieve a desired width of the skin graft made by moving the dermatome in the grafting direction. By using dermatome heads of different width, skin grafts of the required size may be cut with a relatively simple dermatome head, which may thus be cleaned relatively easily or which may be discarded and replaced at relatively low costs.
The dermatome head and/or the further dermatome may have any of the above-described features of the dermatome head, alone or in any suitable combination.
The invention also relates to a dermatome head as described above, for instance in relation to the dermatome or the kit of parts of a dermatome and the further dermatome head, and a dermatome blade unit as described above.
The components of the kit of parts may have any of the above-described features, alone or in any suitable combination.
The invention will be further elucidated with reference to the attached drawings, in which:
Throughout the figures, like elements will be referred to using like reference numerals. Like elements across different embodiments will be referred to using reference numerals increased by 100 (one hundred).
Although the invention has been described above with reference to specific embodiments and examples, the invention is not limited thereto. Instead, the invention is also defined by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2029404 | Oct 2021 | NL | national |
