GB2520620A

GB2520620A - Improved medical device

Info

Publication number: GB2520620A
Application number: GB1417888.3A
Authority: GB
Inventors: Tsong Yun Kwong
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-10-09
Filing date: 2014-10-09
Publication date: 2015-05-27
Anticipated expiration: 2034-10-09
Also published as: GB201317895D0; GB2520620B; GB201417888D0

Abstract

A tendon hammer comprising a hammer head and a shaft 3, in which the shaft 3 is pivotally mounted on the hammer head. There is provided a recess in the hammer head. The reflex hammer further comprises a collar mechanism 4 which slides on an end of the shaft 3, the collar mechanism 4 sliding into and out of a locked position where it sits in the recess so as to lock the hammer head in position relative to the shaft 3, the recess being of a size to accommodate the collar mechanism 4. The hammer head may comprise a layer of plastic material on a metal weight, the metal weight being attached to a base portion. The shaft 3 may be telescopic.

Description

IMPROVED MEDICAL DEVICE

This invention relates to a medical device used, typically but non-exclusively, for neurological examination.

Doctors often USC a multitude of instruments to perform neurological examinations, in particular a tendon hammer is used to elicit reflexes in the body. Throughout the last years, there have been a large variety of designs for the hammer. There has been a round headed Queen Square hammer. typicafly this is made of an aciyhc shaft and a circular head attached to elicit the reflex. The head is typically a circular disc with a rubber ring around it so when in contact with the patient, it does not cause too much discomfort.

There have been efforts to make the hammer more compact. These attempts have ranged from; having shorter shafts, having a screw on/screw off head so the head is fufly detachable, to having a separate "port" on the side of the shaft to attach the head.

More recently a retractable form of the Queen Square became available, which has a telescopic shaft (such as is available with part number 112-220 from AMG Medical Inc., of Montreal, Canada). The head is in a parallel plane to the shaft; however, the shaft does not lie in the same plane, To use this hammer, the user must tilt the head so that the head becomes perpendicular to the shaft. I have appreciated that one of the issues that have come from continued use of the hammer is the head becomes loose and so does not remain in a perpendicular plane when in use. By virtue, the user must then change the position they hold the hammer so that the head does not give way when in use. Because of the way this hammer has been constructed, there is a pin and pivot that allows for a 90 degree angle change. If user swings the hammer in the same plane as the pivot and especially when the pivot becomes loose over time, the hammer head wifl collapse with the force, Another issue of the retractable tendon hammer is that the head and the shaft are equally weighted and so the user must use a greater moment of force to elicit a reflex compared to the classica' Queen Square hammer.

According to a first aspect of the invention. there is provided a tendon hammer comprising a hammer head and a shaft, in which the shaft is pivotafly mounted on the hammer head, and in which there is provided a recess in the hammer head, the tendon hammer further comprising a coflar mechanism which slides on an end of the shaft, S the collar mechanism sliding into and out of a locked position where it sits in the recess so as to lock the hammer head in position relative to the shaft, the recess bcing of a size to accommodate the collar.

\\Te therefore disc'ose an invention that provides a solution to lock the tendon hammer head in position in relation to the shaft, which solves the issue of the head becoming loose and also does not restrict the user in holding the hammer in a certain way, We also disclose a more compact version of the tendon hammer where the head and the shaft are in the same p'ane.

The end of the shaft is typically the closcst end of thc shaft to thc hcad. Thc cnd may have grooves. typicafly two grooves, formed therein, the grooves preventing rotational motion of the coflar mechanism relative to the shaft but aflowing the collar mechanism to slidc into and out of the locked position. The grooves may have a lcngth, which is less than a length of the shaft, typically significantly less, thc collar mechanism may only bc able to slidc along thc lcngth of the groovcs.

Thc rcccss will typically bc of complementary outlinc to thc collar mcchanism.

The shaft may be telescopic, Typicafly, it wifl comprise a plurality of cylindrical portions of increasing diameter. A penultimate cylindrical portion of the shaft may be provided with the grooves, A final cylindrical portion of the shaft may be mounted on the hammer head and be pivotally mounted to thc penultimate portion, typically through a rod that is also mounted in the hammer head.

The hammer head will typically be generafly planar; for example, it may be disc-shaped. As such, when the collar mechanism is in the locked position, the hammer head may be pcrpcndicular to the length of thc shaft. The hammer head may also have a storage position, in which the collar mechanism is not in the ocked position and the hammer head is cop'anar, or at kast parallel, with the kngth of the shaft, Having the shaft coplanar with the hammer head in the storage position can allow the hammer to occupy a single flat plane, which can mean that it is easier to store than prior art hammers.

The hammer head may comprise a meta' weight with a construct, typicaflv of plastic S materiaL on a first side thereof and a base on the other side thereof Especiafly where the central construct is of plastic material, this allows for cheaper manufacture, whilst still having sufficient mass.

The weight may be annular, such as a washer, or may comprise a C-shaped body of uniform diameter and height.

The weight of the hammer head is such that a centre of mass of the tendon hammer is closer to the hammer head than to the end of the shaft. typicafly measured in the locked position; typically, the distance of the centre of mass from the hammer head along the shaft will be less than 50%. 25% or 10% of the length of the shaft. This replicates a classic Queen square hammer and means that less moment force is required to deliver a reflex.

According to a second aspect of the invention, we provide a tendon hammer head comprising a metal weight with a construct, typically of plastic material, on a first side thereof and a base on the other side thereof, Especiafly where the central construct is of plastic material, this allows for cheaper manufacture, whilst still having sufficient mass.

According to a third aspect of the invention, there is provided a method of using the hammer of the first aspect of the invention, the method comprising taking the hammer in the storage position, rotating the hammer head to be perpendicular to the shaft, and sliding the collar mechanism to sit in the recess, so as to be in the locked position, Thns, the hammer can be converted from the storage position to the locked position ready for use, The method may also comprise extending the shaft. where the shaft is telescopic.

The method may comprise subsequently sliding the collar mechanism out of the recess and pivoting the head to be parallel or cop'anar with the shaft, The method may also S comprise collapsing the telescopic shaft, There now follows, by way of example only, description of an embodiment of the invention. describcd with rcference to the accompanying drawings, in which: Figure la shows a front elevation of a tendon hammer in accordance with an embodiment of the invention; Figure lb shows a side elevation of the tendon hammer of Figure Ia; Figure 2a shows a rear elevation of the tendon hammcr of Figure Ia; Figure Zb shows the same view as Figure 2a, without the shaft; Figure 2c shows a perspective view of thc tendon hammer of Figure la from the underside, with the shaft perpendicular to the hammer head; Figure 3a shows a perspective view of the penultimate section of the shaft of the tendon hammer of Figure Ia; Figures 3b and 3c show side and front elevations of the end of the shaft of the tendon hammer of Figure la, showing the pivoting mechanism; Figure 4a shows an exploded perspective view of the hammer head of the tendon hammer of Figure Ia; Figure 4b shows a perspective view of the pivoting mechanism of Figures 3b and 3e. together with the mounting rod; and Figure 5 shows a perspective view of the coflar mechanism of the tendon hammer of Figure la, The accompanying drawings show a tendon hammer iii accordance with an embodiment of the invention. In Figure la, the tendon hammer is shown with a shaft 3 attached to a hammer head 2. A ring of soft material I is provided, traditionally made of rubber, however can be made of other soft material in the case of latex allergy. Figure lb shows the head 2 and the shaft 3 in the same plane as each other.

The head 2 itself has a cavity to receive the shaft 3 and that allows the shaft 3 and head 2 to be in the same plane. To be able to do this, there is a recess in the hammer head 2 and rubber ring 1 that accommodates the shaft 3, Figures 2a to 2c of the accompanying drawings show this more clearly. Figure 2a is a back view of the head 2. The hammer further comprises a collar mechanism 4 that allows the head 2 to be locked into position, and when the collar 4 is used, it is pushed upwards into a recess 5 in the head, which is of a size that can accommodate the collar 4, Figure 2b shows the shaft perpendicular to the head; it can be seen that there is a recess 5 in the head 2 that collar 4 sits in when it is not being used. Figure 2c is a side on profile view with the shaft 3 at 90 degrees to the head 2. A mechanism 7 connects the shaft 3 to the hammer head 2. It is a solid bar preferably made from metal, that transverses through the centre of the head 2 at a back panel of the tendon hammer head 2.

Figure 3a shows the end of the tendon hammer shaft, which allows the collar mechanism 4 to slide up and down. Typically, telescopic shafts have cylindrical portions of increasing diameter. In the penultimate portion of the shaft, we disclose a modification in which two grooves 8 allow the collar 4 to slide up and down and also not rotate around the shaft 3. This modification therefore keeps the collar 4 in a single fixed plane with the head 2 and allows the head 2 to slide up and down of a fixed distance.

Figure 3c shows the pivot mechanism of the shaft, which is positioned at the tip at the end of the shaft 3. that allows 90 degree movement of the head relative to the shaft, and which is comprised of a central screw (9) that allows that movement of axis. It also has a mechanism that allows it to be held in each position and the head is used to move that mechanism in that 90 degree angle. Figure 3b is a straight on profile of the end of the tendon hammer shaft.

Tendon hammer heads are typically solid metal round constructs which give the head the necessary mass. In Figure 4a, we show a different construction of the tendon hammer head, as a means of reducing cost and giving weight. It also provides a method of attaching itsdfto the shaft. The hammer head comprises a p'astic (but not limited to such material) construct 10, a metal disc I I such as a washer, which gives the hammer weight and may be curved and a base of hammer head 12, with the central rod 7 running through. Though not shown, there is an indent in the plastic base 12 that allows the rod 7 to pass through the centre to provide an attachment to thc shaft 3. The base also provides the central recess 5 that allows the coflar space 4 to move up into the tendon hammer head 2 and so allow the locking mechanism to function. Figure 4b shows how the central rod 7 and end of tendon hammer shaft 3 are connected.

An ahernative variation of the metal weight I I is to provide instead a C-shaped metal weight of uniform diameter and height. This allows the head to be more uniform in shapc and easicr to manufacture.

Though a met& washer 11 is used here to give the head mass, other methods can be considered such as having cubes of metal used to give weight.

It is also envisaged that the weight of the hammer head 2 is in such a proportion to be heavier than the shaft so that the centre of mass of the product is closer to the head; typically, it would be quite close to the head. This is important because it replicates a classical Queen Square hammer and so that less moment force needs to be delivered to elicit a reflex.

In Figure 5, we further show the collar mechanism 4 which holds the head in position.

It is envisaged that for the tendon hammer to be used. the user firstly flips the hammer head 2 to a 90 degree angie, and then raises the collar 4 up to lock the head. This can be done in one simultaneous smooth action rather than two separate steps. The user then extends the telescopic shaft 3 to give the hammer its full length, When the user has finished examining, the user can close the hammer by doing it in two ways: 1, To pull the coflar 4 down and then flip the head 2 so that is in the same plane as the shaft; 2. By directly pulling down on the head 2 and using the low friction between coflar 4 and the hammer head 2, the collar can be automaticafly pushed down.

The collar 4 is constructed or preferably made of a light weight material that has a S central hole 14 that aflows the shaft 3 to pass through but &so has spines 13 that allows it fit into the grooves S on the tendon hammer shaft 3. The spines 13 are such as size to allow the collar to enter the recess S in the hammer head 2 and also to let the collar 4 clear hammer head 2 when the user has finished using thc hammer.

It is envisaged that the head 2 is tilted to a 90 degree position perpendicular to the shaft 3, and then user can push the collar 4 into an indentation 5 in the hammer head 3, which then hold the tendon hammer head in position. When the user has stopped using the hammer. they shde the collar 4 down and then can fold the hammer head 2 into position. The collar 4 could be made of a material that if the user decides to flip the head 2 without pulling down the collar 4. the friction co-efficient will automatieafly slide down the grooves 8 and so aflowing the hammer head 3 to be pulled down.

Though this document refers to a Queen Square hammer, it is not limited to such design but also includes Tomahawk. Babinski. Troemer hammers etc. It is also envisaged that a penelip can also be added to the shaft, so that the tendon hammer can be carried like a pen in a pocket.

This invention maybe produced in any colour or colour combination used in the device, \7%'hile the preferred embodiment has been described using specific terms, this is purely for illustrative purposes. It is to be understood that the descriptions are not limited to that described in this document, It will be apparent to those of ordinary skilled in the art that various modifications, substitutions, omissions and changes may be made without departing from the spirit of the present invention. As such, it is intended they wifi fall in the scope of the invention.

Claims

CLAIMS1 A tendon hammer comprising a hammer head and a shaft, in which the shaft is pivotafly mounted on the hammer head, and in which there is provided a recess in the S hammer head, the tendon hammer further comprising a collar mechanism which slides on an end of thc shaft, the collar mechanism sliding into and out of a locked position where it sits in the recess so as to lock the hammer head in position relative to the shaft, the recess being of a size to accommodate the collar mechanism.
2, The tendon hammer of claim 1, in which the end has grooves, typically two grooves, formed therein, the grooves preventing rotational motion of the collar mechanism relative to the shaft but allowing the collar mechanism to slide into and out of the locked position.
3. The tendon hammer of claim 2, in which the grooves have a length, which is less than a length of the shaft, typically significantly less, the collar mechanism only being able to slide along the length of the grooves.
4, The tendon hammer of any preceding claim, in which the recess is of complementary outline to the collar mechanism.
5. The tendon hammer of any preceding claim, in which the shaft is telescopic.
6, The tendon hammer of claim S as dependent on claim I. in which the shaft comprises a plurality of cylindrical portions of increasing diameter, with a penultimate cylindrical portion of the shaft being provided with the grooves.
7. The tendon hammer of claim 6, in which a final cylindrical portion of the shaft may be mounted on the hammer head and be pivotally mounted to the penultimate portion, typically through a rod that is also mounted in the hammer head.
8. The tendon hammer of any preceding claim, in which. when the collar mechanism is in the locked position, the hammer head is perpendicular to the length of the shaft.
9. The tendon hammer of any preceding clainL in which the hammer head has a storage position, in which the collar mechanism is not in the locked position and the hammer head is coplanar with the length of the shaft.
10. 11, 13 or 14 as those claims depend from claim 9. the method comprising taking the hammer in the storage position, rotating the hammer head to be perpendicular to the shaft, and sliding the collar mechanism to sit in the recess, so as to be in the locked position.16. The method of claim 15, in which the tendon hammer is in accordance with claim 5. the method also comprising extending the shaft.17, The method of claim 16, in which the shaft is extended simultaneously with the sliding of the collar mechanism into the recess.I S. The method of any of claims IS to 17, comprising subsequenfly sliding the collar mechanism out of the recess and pivoting the head to be paralld or coplanar with the shaft, 19, The method of claim I S as dependent from claim 16, comprising collapsing the telescopic shaft.20, A tendon hammer substantially as described herein with reference to and as illustratcd in the accompanying drawings.

10, The tendon hammer of any preceding daim, in which the weight of the hammer head is such that a centre of mass of the tendon hammer is closer to the hammer head than to the end of the shaft.

11, The tendon hammer of an' preceding daim, in which the hammer head comprises a metal weight with a construct, typically of plastic material, on a first side thereof and a base on the other side thereof, 12. A tendon hammer head comprising a metal weight with a construct, typically of plastic material, on a first side thereof and a base on the other side thereof 13. The tendon hammer of claim I I or the tendon hammer head of daim 12, in which the weight is an annular disc.14, The tendon hammer of claim 11 or the tendon hammer head of claim 12, in which the weight comprises a C-shaped body of uniform diameter and height.15. A method of using the tcndon hammer of claim 9 or any of claims