Dental simulation machine

A dental simulation machine including a support having a support surface for engagement by a finger of a user to support a hand of the user, the support surface being moveable between a plurality of positions.

FIELD OF THE INVENTION

The present invention relates to a dental simulation machine.

BACKGROUND TO THE INVENTION

Machines to simulate dentistry techniques for training purposes are known and include, for example, the Simodont machine manufactured by the applicant. These machines implement virtual reality technology to allow a student to practice various dentistry procedures. The simulation machines generally comprise a display screen which outputs 3D images for viewing by the user wearing 3D glasses. Positioned below the display screen is at least one hand piece (e.g. a physical simulated dentist tool) which is fixed to the machine by a mechanism comprising a series of linkages and electric motors. The relative position of the hand piece (as it is moved by the user) and the force applied by a user is measured as the user conducts a dentistry operation (for example, drilling into a tooth) on a virtual 3D model of a tooth, set of teeth or jaw. The hand piece simulates a dentist's drill and provides haptic feedback to the student as the student performs their drilling.

Dental simulation machines provide a simulation environment for trainee dentists before they are required to perform the same techniques on a real, rather than a virtual, tooth. Patient safety is very important. The more realistic the training environment the smoother the student's transition from practicing on the dental simulation machine to performing dentistry on a real patient.

Typically, the 3D model is artificially constructed. Different models are designed for different training requirements and situations—for example, a particular model may be of a chipped tooth (which the student is required to fix in a simulated training scenario). Other models may exhibit other characteristics or combinations of characteristics according to the needs of dentistry training programs.

An example of a supporting platform for training tactility in a virtual/actual dentistry operation is described in Chinese patent publication number CN101719322A. The supporting platform described in CN101719322A includes a lower tooth assembly having a ring member in which a user's index finger is inserted. The portion of a user's index finger having the proximal phalanx (the portion of the index finger a ring would sit on) is held within the ring member and the inner surface of the ring member supports the ring portion of the user's index finger. The ring member is mounted on the lower tooth assembly via a piston and locating pin, and thus the ring member is spaced apart from a plane defined by the tooth assembly. The inner surface of the ring member is positioned significantly above the plane defined by the tooth assembly.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a dental simulation machine including a support having a support surface for engagement by a finger of a user to support a hand of the user, the support surface being moveable between a plurality of positions.

The support surface may be an upper support surface. The support surface may form a top face of the support. The support surface may be an outer facing surface of the support. The support surface may be provided at an upper end of the support.

According to a further aspect of the present invention there is provided a dental simulation machine including a support having a support surface for engagement by a finger of a user to support a hand of user, the support surface having a support surface area of less than 250 mm2, preferably less than 200 mm2, preferably less than 150 mm2, preferably less than 100 mm2.

DETAILED DESCRIPTION

A dental simulation machine is shown generally atFIG. 1. The machine100is used by students of dentistry to practice dentistry using virtual reality technology. A student sits on a chair (not shown) facing viewing screen101. Hand rest102defines, generally, an area in which the student operates a dentistry hand piece108, such as a dentist's drill. Power button105provides machine on/off functionality and height adjustment switch106allows the user to adjust the height of a position of the machine100, including hand rest102and viewing screen101. Viewing screen101displays virtual 3D moving images whose movements correspond with movement of a hand piece108(which generally resides within area of hand rest101) by a student. The student views the images on viewing screen101wearing passive 3D glasses. Mouse104allows the user of the machine to adjust the relative position and orientation of the images on viewing screen101in three dimensions. Foot pedal107facilitates control of operation of a simulated drill (or other powered dentistry tool).

The machine100also comprises training screen103(which may be a touch sensitive screen) which is used by the student to access information relevant to their training, such as training programs, individual lessons, scoring and marking data, mentor comments, and to review previous training material. While a simulation process is being performed, the images displayed on viewing screen101are also output to training screen103to allow an onlooker to view the student's use of the machine.

When using certain dentistry tools when performing dentistry work on a patient, such as a dental mirror, the dentist simply holds the mirror in the appropriate place, the end of the mirror may rest on part of the patient's mouth, for example it may rest on the inside of the cheek of the patient and therefore may be steadied by the inside of the cheek.

However, certain other tools, for example a dentist's drill needs to be held by the dentist and manipulated by the dentist. When using the drill the dentist tends to find support for their hand within the patient's mouth close to where the burr is operating on the tooth in question. In particular, the dentist may rest a finger of the hand holding the dentist's drill on a tooth adjacent the tooth being worked on or on a gum, or on part of the jaw.

As will be appreciated, using an adjacent tooth or a gum or part of the jaw as a prop, or for support only provides such support over a small localised area.

Prior art dental simulation machines have provided relatively large relatively flat surfaces against which an operator of the dental simulation machine can rest their hand. However, such relatively large relatively flat surfaces are not representative of the inside of a patient's mouth.

The present invention provides a more realistic environment on a dental simulation machine by providing a relatively small support surface for engagement by a part of a finger, for example an end or a tip or an edge of an end or a tip of a little finger or a ring finger or a middle finger, of a user of the dental simulation machine. By supporting the end or the tip of the finger of the user, the hand of the user is in turn supported. Such a discreet relatively small support of the dental simulation machine provides a more realistic environment when training. In particular, the support surface may be of a size similar to the surface of a tooth of a patient which a dentist might use to prop off when performing on a patient. The support surface may be of a size similar to a part of a gum or a part of a jaw which the dentist might use to prop off when performing on a patient.

Thus the support surface may have a support surface area of less than 250 mm2, or less than 200 mm2, or less than 150 mm2, or less than 100 mm2.

With reference toFIGS. 3, 4 and 5there is shown the hand rest102together with support10. The hand rest102is generally U-shaped having a first arm30connected to a second arm31by an arcuate section32. The support10is connected to the first arm30at region33. The first arm30includes a recess34.

A further support20is connected to the second arm31at region35. The second arm31includes a recess36.

Support10comprises a generally elongate body11having an upper support surface12at an end thereof. In other words, the support surface12is provided on a top face of the support10. The support surface12provides an outer facing support surface at an upper end of the support10. The further support20includes a corresponding generally elongated body21with a further upper support surface22at an end thereof. In other words, the support surface22is provided on a top face of the support20. The support surface22provides an outer facing support surface at an upper end of the support20.

The support10is pivotally mounted via a pivot13to the hand rest102at region33.

The further support20is pivotally mounted via a pivot23to the hand rest102at region35.

A detent14is operable to hold the support10, and hence the support surface12in each of the deployed positions shown inFIG. 4, 6, 7and a stored position (not shown in respect of support10).

A detent24is operable to hold the further support20, and hence the further support surface22in a plurality of deployed positions not shown but corresponding to those of support10shown inFIGS. 4, 6 and 7and also in a stored position as shown inFIG. 4.

The detent24includes a rib or ribs (not shown) on the second end25of the generally elongate body which selectively engage in recesses37,38or39to enable the further support20to be held in any one of the three deployed positions corresponding to the deployed positions of support10shown inFIGS. 4, 6 and 7. The detent also holds the further support20in the stored position as shown inFIG. 4.

The pivot23includes a pivot pin23A having an axis A about which the further support20can rotate. The generally elongate body21is biased by a bias device (for example a spring not shown) in a first direction B. The bias device ensures that the detent keeps the further support20in either the stored position or any of the deployed positions as appropriate. The detent can be disengaged by moving the further support20in a direction opposing the spring, i.e. in the direction of arrow C, thereby disengaging the detent and allowing the further support to move to an alternate position.

As can be seen fromFIG. 4, the further support20is mounted on an inside of the U-shape. As best seen fromFIG. 3the pivot pin23A is accessible from the outside of the U-shape. In particular the user presses on the pivot pin23A in the direction of arrow C with his or her finger to disengage the detent to allow the further support20to be moved to a desired position.

The support10also includes a pivot pin13A having an axis (in this case the same axis A as pivot pin23A). Accordingly, movement of support10between the three deployed positions shown inFIGS. 4, 6 and 7and the stored position (not shown) is similar to that of movement of the further support20between its corresponding positions.

Turning toFIG. 2, this shows a view of what the user of the dental simulation machine10might see through the viewing screen101. The user will be able to see a virtual simulated gum50with virtual simulated teeth51,52,53and54. The user will also be able to see a virtual simulated drill55having a virtual simulated drill burr56. As will be appreciated the virtual simulated features shown inFIG. 2represent the equivalent features on an actual patient and an equivalent drill and burr used by an actual dentist.

The dental simulation machine includes a hand piece in the form of a physical simulated dentist's tool for example a physical simulated drill (108) which, when grasped by a user of the dental simulation machine will feel to that user like an actual drill. A user of the dental simulation machine may grasp or hold the hand piece108like a pen, with the hand piece108held between the user's thumb and index finger (forefinger). The hand piece108may be rested on the elongate edge of the user's middle finger. A simulated dentist's tool provides haptic feedback to the student or the like as the student performs their drilling.

In an example, the support surface12is a physical simulated part of a patient. It is relatively small. In particular its size is such that it is only possible for a student to rest part of a finger, for example an end or a tip or an edge of an end or a tip of a finger such as a little finger or a ring finger or a middle finger, on the support surface12and this better represents the type of support available for a dentist when operating on a patient. For example, the support surface12is of a size similar to that of a patient's tooth which the dentist may use to prop against. Whilst an entire gum of a patient is significantly bigger than the support surface12, in view of the limited space available in a patient's mouth, and in view of the size of the dentist's hand, it is not possible for the dentist to support their hand off the entire gum line of a patient. Rather in practice it is found that only relatively small parts of the gum line can be used by a dentist to support their hand. In practice, a dentist may only be able to rest an end or a tip or an edge of an end or a tip of the little finger or an end or a tip or an edge of an end or a tip of the ring finger or an end or a tip or an edge of an end or a tip of the middle finger against a correspondingly small part of the gum line and accordingly the support surface12is a good physical representation of that part of the gum line against which a dentist might rest a part, in particular an upper part, for example an end or a tip or an edge of an end or a tip, of a finger, for example a little finger or a ring finger or a middle finger for support.

The row of teeth on a patient's lower jaw define a plane. When a dentist drills a hole in one of the teeth in the row, he or she may (as described above) rest a part of his or her little finger or ring finger or middle finger on another of the patient's teeth in the row. Before drilling, the tip of the drill starts out at or slightly above the plane defined by the row of the patient's teeth. During drilling, the tip of the drill drills down below the plane defined by the patient's teeth. During drilling, the drill may drill into the patient's tooth by a desired amount, typically 0.5 to 1.0 centimetres, i.e. the drill may extend below the plane of the patient's teeth by approximately 0.5 to 1.0 centimetres.

Similarly, the dental simulation machine provides a physical support surface12that simulates a tooth that is one of a virtual simulated row of teeth. The physical simulated tooth defines a virtual plane of the virtual simulated row of teeth. The user rests a part of his or her little finger or ring finger on the support surface12. Prior to simulated drilling, the user holds a physical simulated drill (the hand piece108) such that the virtual simulated burr56of the virtual simulated drill55visible by the user in the viewing screen101is at or slightly above the virtual plane defined by the support surface of the physical simulated tooth. During drilling, the simulated burr56of the simulated drill55extends below the virtual plane defined by the physical simulated tooth by approximately 0.5 to 1.0 centimetres according to the procedure that is simulated on the dental simulation machine, thus providing a more realistic environment on a dental simulation machine.

Note that whilst in the above examples the support surface12represents a physical simulation of part of a patient, it need not represent any part of the patient. Thus, there is a skill involved in learning to prop a hand against a relatively small feature by resting an end or a tip or an edge of an end or a tip of a little finger or a ring finger or a middle finger on a relatively small feature. This skill can be learnt by using support surface12without the need for support surface12to represent a part of the patient. Once the skill of propping a hand by resting an end or a tip of a finger off a small feature has been learnt, then the further skill of propping a hand by resting an end or a tip of a finger off a small feature positioned as found in a patient's mouth can be learnt by arranging the support surface to represent a physical simulation of a part of a patient.

Whether or not the support surface12represents a physical simulation of part of a patient, the support surface12may or may not be represented in a view as seen through the viewing screen101by the student.

However in a preferred embodiment, the support surface12may be represented in the view as seen through the viewing screen101by the student.

By way of example arranging the apparent position of the virtually simulated teeth and gum shown inFIG. 2appropriately with respect to the hand rest102, then the support surface12when positioned as shown inFIG. 7represents a physical simulation of virtual tooth54.

In this example, the virtual simulated gum and teeth are as shown inFIG. 2. The student holds the physical simulated drill (the hand piece,108) in his/her right hand. The student may hold the physical simulated drill like a pen, with the physical simulated drill held between the thumb and index finger (forefinger) of the student's right hand. The hand piece may be rested on the elongate edge of the middle finger of the student's right hand. Accordingly, the virtual simulated drill55and burr56will appear as shown inFIG. 2. Under these circumstances a dentist operating on a patient might wish to rest the end or the tip of the little or small or ring or middle finger of their right hand on an actual tooth the equivalent of virtual simulated tooth54in order to drill into an actual tooth the equivalent of virtual simulated tooth53. Under these circumstances the support10and support surface12would be positioned as perFIG. 7so as to represent virtual simulated tooth54and hence the user of the dental simulation machine would be able to support the end or tip of his or her little or ring or middle finger on support surface12which would feel as if it were correctly positioned with respect to the other viewed components, in particular with respect to the virtual simulated drill55, virtually simulated burr56and the virtually simulated tooth53being worked on.

In a further example, the user of the dental simulation machine may wish to work on virtual simulated tooth53but may wish to hold the physical simulated drill108in his/her left hand. The user may hold the physical simulated drill like a pen, with the physical simulated drill held between the thumb and index finger (forefinger) of the user's left hand. The hand piece may be rested on the elongate edge of the user's middle finger. Under these circumstances a dentist might want to prop the end or the tip of his/her little or small or ring or middle finger of his or her left hand on an actual tooth the equivalent of virtual simulated tooth52. One option would be to reposition the virtual simulated features as shown inFIG. 2such that the position of the support surface12as found inFIG. 7now corresponds with virtual simulated tooth52. Alternatively, the support10and hence support surface12can be moved to the position shown inFIG. 6where the support surface12now corresponds to the position of virtual simulated tooth52and therefore provides a physical simulation of virtual simulated tooth52.

If then the user of a dental simulation machine wishes to work on virtual simulated tooth52and hold the drill in his/her right hand, then either the support surface can remain in the same position (i.e. as perFIG. 6) and the model can be moved such that support surface corresponds with the virtual simulated tooth53or alternatively the model can remain in the same position and the support10and support surface12can be moved to the position shown inFIG. 4wherein the support surface12corresponds with virtually simulated tooth53.

In particular, it will be appreciated that by providing three deployed positions of support surface12which represents three physical simulations of three teeth allows for supporting of an end or a tip of a finger and hence a hand when working on any of four virtual simulated teeth. This saves having to move the model every time a different virtual simulated tooth is to be worked on.

The further support20and further support surface22enable simulation of the right hand side of a patient's jaw in a similar manner.

As will be appreciated, with the support10orientated as shown inFIG. 4, a student's finger may rest entirely on the top circular surface. For example, an end or a tip of a student's little or ring or middle finger may rest entirely on the top circular surface. With the finger rest orientated as shown inFIG. 6then a student's finger may rest partially on part of the circular end surface and partially on part of the cylindrical surface immediately adjacent the circular end surface. For example, an edge of an end or a tip of a student's little or ring or middle finger may rest partially on part of the circular end surface and partially on part of the cylindrical surface immediately adjacent the circular end surface. With the support10position as shown inFIG. 7, then a student's finger may rest in part on part of the circular end of the support and in part on an opposite part of the cylindrical surface of the support10immediately adjacent the circular end surface. For example, an edge of an end or a tip of a student's little or ring or middle finger may rest in part on part of the circular end of the support and in part on an opposite part of the cylindrical surface of the support10immediately adjacent the circular end surface.

It will be appreciated that, with the hand piece of the dental simulation machine held or grasped like a pen, with the hand piece held between the user's thumb and index finger (forefinger), and the end or tip of the user's little finger supported on either support surface12or support surface22, the hand piece can be moved in a full range of motion in the lateral, up-down and fore-aft directions.

However the support is orientated, and under all circumstances the student's finger, for example an end or a tip of the student's finger, rests on a relatively small area and this provides a more realistic dental simulation machine.

As will be appreciated, whether the support is orientated as inFIG. 4orFIG. 6orFIG. 7, the support surface is provided towards an end of the body.