GB2305858A - Tape for measurement of body contour - Google Patents

Abstract

A tape includes a longitudinal abutment surface to allow guidance of a probe of a line digitiser across a irregularly shaped object such as a human foot. The tape can have an L-shaped cross-section or a groove to guide the probe. The tape is flexible and is brought into close contact with the body. A support arrangement comprises an arch 51 of relatively rigid tape guiding tape not in contact with a body. The arch is normally hinged with respect to location feet 53 secured to a surface upon which a body is located.

Description

DIGITISER TAPE The present invention relates to digitiser tape and similar arrangement for use with pen-type digitiser to facilitate digitisation of three-dimensional bodies such as a foot.

Pen-type line digitisers are reasonably well-known and an example of a currently available system is the Microscribe-3D manufactured by Immersion Corp. of 2158 Paragon Drive, San Josh, California, U.S.A. Such line digitisers comprise essentially a pen-like manipulator probe connected to a processor unit capable of determining with a fair degree of accuracy the XYZ co-ordinate position of the tip of the pen-like element. Thus, by movement of the pen-like projection about a body and periodic polling or manual plotting of positions about that body it is possible to create a three-dimensional digitised map or data set corresponding to the shape of that surveyed body.

This digital map can be used as a basis for computer-aided design manipulation and/or to enable moulding of a cast.

Furthermore, in the area of orthopaedic footwear it will be possible if a digital map could be accurately created of a patient's foot then that map could be used in order to determine the appropriate shoe last upon which to create remedial or simply appropriately comfortable footwear for the patient.

It will be appreciated that in order to appropriately determine the digital map of a body such as a foot which has a relatively slippery skin surface that the pen must be controlled as it passes over the body. Unfortunately, with a pen-like projection it is extremely difficult to draw the pen in a straight line or consistently across the body, the pen tends to drift as a result of the slopes inherent in human foot.

It is an objective of the present invention to provide a device capable of enhancing the accuracy of data acquisition by a pen-type line digitiser in respect of awkward or slippery bodies.

In accordance with the present invention there is provided a digitiser tape for use with a pen-type line digitiser in respect of bodies such a human foot, the tape including at least one abutment surface and being flexible to enable the tape to be wrapped around at least a substantial part of a body, the abutment surface providing a steady edge along which the pen of a line digitiser can be drawn to allow persistent digitisation of that body.

Preferably, the tape has either an L-shaped or a groove in its cross-section.

Preferably, the tape is securely fixed at one end and securably fixable at the other end upon a suitable board to support the body. The securely fixed end of the tape may be mounted upon a swivel-type device to allow adjustment in the tape position whilst the securably fixable end may include a buckle to allow the tape to be secured.

Preferably, the tape is approximately 15 mm wide and has an abutment surface with a height of at least 2 mm above the tape and is resilient to lateral force presented by the pen probe of the line digitiser.

Preferably, the abutment surface is kept substantially perpendicular to the body surface when wrapped around it.

According to an alternative embodiment of the present invention there is provided a digitiser arrangement comprising a tape arch suspended between location fee, the arch being designed to overspan a body to enable a pen probe of a line digitiser to be held steady whilst run along the edge of said arch in contact with a body, the feet (53) providing resilient location of the arch in use but enabling adjustment of the arch about the body as required to enable the arch to span appropriate segments of the body therebelow.

Embodiments of the present invention will now be described by way of example only with reference the accompanying drawing in which: Figure 1 is a schematic perspective view of a foot with a tape wrapped around it; Figure 2 is a plan view of a first embodiment of the present invention; Figure 3 is a cross-section of the tape illustrated in Figure 2; Figure 4 is a cross-section of an alternative embodiment of the invention; Figure 5 is a front view of the digitiser arch n accordance with the invention; and, Figure 6 is an end view of the arch shown in Figure 5.

Figure 1 is a schematic illustration of a foot (1) located upon a support surface (2) with a tape (3) in accordance with the present invention wrapped around a substantial part of the foot (1). The tape (3) is securely fixed upon the (unseen) far side of the foot (1) and extends in close contact with the foot (1) to a securable buckle bar (4) upon the other side of the foot (1). Tape (3) is in close contact with the foot (1) and thus readily assimilates the shape of the foot (1).

The tape (3) may be placed by a user such as an orthologist against salient features such as bunions or other protrusions on the foot (1) in order that more close digitisation of those features can be achieved. Such location of the tape (3) is achieved by provision at the fixed end of the tape of a swivel to allow alteration of angle and attitude etc. of the tape (3).

The securable end of the tape can be held using a buckle as illustrated or using any other appropriate technique including hook and fleece materials (Velcro), adhesive tape, locking pins etc. Alternatively, the tape could be adhesive on one side and thus applied to appropriate parts of the foot (1).

In Figure 2 a plan view of a first embodiment of the tape (3) is illustrated. The tape (3) is essentially a band of flexible material having a groove (5) located centrally in the example shown. However, it will be appreciated that the groove (5) could be located to one side of the tape (3). The groove (5) essentially provides two abutment surfaces (6) which create a track along which a pen probe element of a line digitiser can consistently run. It is more important that the groove (5) provides a smooth and steady track across a body such a foot (1) rather than the actual location of the abutment surfaces (6) in the tape (3). The line digitiser processor means simply correlates XYZ position as the pen is moved along the abutment surfaces (6) and these XYZ positions are accumulated to provide a digital map of the foot (1).

Obviously several segments of the foot (1) must be interrogated by the pen of the line digitiser to enable an appropriate digital map to be achieved. The tape (3) ensures that the spacing of these segments can be more consistently achieved and the bumps and irregularities in a badly formed foot (1) for example do not create slippage, fall-off or other factors which may lead to a depletion of interrogated digital data in these most important areas of the foot (1). The tape (3) essentially provides a steady for the pen probe of the line digitiser to assist the operator to interrogate the foot (1) more accurately.

The tape (3) can be constructed as illustrated in Figure 3 from a base layer (7) upon which further cheek strips (8,9) are adhered to create the abutment surfaces (6) which act to guide and trace the pen probe of a line digitiser. As indicated previously the bottom surface (10) of the base layer (7) can be made adhesive to enable it to be stuck to the body or foot (1) in appropriate parts for interrogation. Thus, the strip (3) may be similar to a elongated plaster adhered to a protrusion in the foot (1) to enable the line digitiser to pass over that feature in order to determine its shape.

Figure 4 illustrates an alternative tape (11) in accordance with the present invention. This tape (11) has a contact layer (12) with a protruding edge (14) to give the tape (11) effectively an L-shaped cross-section. The edge (14) provides an abutment surface against which the pen element of the line digitiser may be drawn to provide a steady when interrogating a body in contact with the layer (12). It will be appreciated that the edge (14) should be substantially rigid whilst the tape (11) as with tape (3) is flexible enough to allow wrapping about at least a substantial part of the body such as a foot (1).

It has been found that an abutment surface of at least 2 mm height is sufficient to enable a pen element of a line digitiser to be held steady against a body by the tape (3).

It will be understood that there is a balance between providing sufficient height in the abutment surface to ensure adequate steadying of the pen whilst retaining flexibility in the tape (3), the higher the abutment surface the greater the steadying effect. However, this may be detrimental in terms of tape flexibility.

It will be understood that the tape in accordance with the present invention may be made of fabric, rubber or plastic material. Furthermore, the tape could be extruded or as illustrated in Figure 3 be constructed using several adhered components (7,8,9).

In Figure 5 an embodiment of the present invention is described in which a tape is rigid as compared to previous tapes (3,11). The tape is essentially rigid and may be an arch of thick leather or plastic or even metal. The arch (51) is held about hinges (52) between the arch (51) and respective locating feet (53). The arch (51) extends over a body and provides along its respective edges a guide against which the pen of a line digitiser may be run or guided to provide a consistent sweep of a body beneath the arch (51). The arch (51) is not in contact with the body but may be hinged such that the guiding edge is in contact.

The feet (53) can be adhered to a base surface (55) upon which the body is located by a range of attachment techniques including magnetism or Velcro fleece and hook material or adhesive etc. Thus, the position of the arch (51) is widely variable about a body located upon the surface (54) and allows the arch (51) to be arranged in a wide range of attitudes and relationships with regard to the surface and thus the steady edge of arch (51) can be arranged to be about any desired segment of a body held upon the surface (54).

Figure 6 illustrates the arrangement shown in Figure 5 in end projection. It can be seen that the hinge (52) is a simple pin which allows arcuate movement as exemplified by the arrowheads. It will be appreciated that the extent of this arcuate movement may be limited by end stops (not shown) located in the feet (53).

Claims (11)

Claims:

1. Digitiser tape for use with a pen probe-type line digitiser in respect of bodies such as a human foot, the tape including at least one abutment surface and being flexible to enable the tape to be wrapped around a substantial part of a body, the abutment surface providing a steady edge along which the probe pen of a line digitiser can be drawn to allow consistent digitisation of a body.

2. Digitiser tape as claimed in Claim 1 wherein the tape has an L-shaped cross-section.

3. Digitiser tape as claimed in Claim 1 wherein the tape includes a groove to provide the abutment surface.

4. Digitiser tape as claimed in Claim 1, 2 or 3 wherein the tape is at least 15mm wide and has an abutment surface having a height of at least 2 mm above the tape which is resilient when wrapped around a body.

5. Digitiser tape as claimed in any preceding Claim wherein the abutment surface is kept substantially perpendicular to the body surface when wrapped around it.

6. Digitiser tape as claimed in any preceding Claim wherein the tape is adhesive on at least one surface to allow the tape to be adhered to the body.

7. A digitiser arrangement comprising a tape arch suspended between location fee, the arch being designed to overspan a body to enable a pen probe of a line digitiser to be held steady whilst run along the edge of said arch in contact with a body, the feet (53) providing resilient location of the arch in use but enabling adjustment of the arch about the body as required to enable the arch to span appropriate segments of the body therebelow.

8. An arrangement as claimed in Claim 7 wherein the arch is secured to the feet by hinge elements which allow the arch to rotate with respect to these feet.

9. An arrangement as claimed in Claim 7 or 8 wherein the feet are secured to a surface upon which a body is located using magnetism or fleece and hook material (Velcro) or adhesive.

10. Digitiser tape substantially as hereinbefore described with reference to Figures 1 to 4.

11. Digitiser arrangement substantially as hereinbefore described with reference to Figures 5 to 6.