WO2007073214A1

WO2007073214A1 - A transducer interface system

Info

Publication number: WO2007073214A1
Application number: PCT/NZ2006/000337
Authority: WO
Inventors: Donald Michael Graham; Shane Richard Leath
Original assignee: Donald Michael Graham; Shane Richard Leath
Priority date: 2005-12-22
Filing date: 2006-12-21
Publication date: 2007-06-28

Abstract

A transducer interface system including a flexible bladder containing a fluid, a mounting element locating the flexible bladder and an ultrasonic transducer so that the ultrasonic waves of the transducer pass through the bladder before reaching a target material. The mounting element is configured to include a first and a second section where the second section includes an aperture which allows a portion of the bladder to extend beyond an outer surface of the second section.

Description

A TRANSDUCER INTERFACE SYSTEM

STATEMENT OF CORRESPONDING APPLICATIONS

This application is based on 'the Provisional specification filed in relation to New Zealand Patent Application Number 544422, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This invention relates to a transducer interface system.

In particular, the present invention may provide a transducer interface system including a flexible, fluid-filled, bladder used as a stand-off material for an ultrasonic transducer.

BACKGROUND ART

Characterising the internal properties of materials without employing invasive processes is useful in many applications. The internal layer of a muscle might be studied without cutting, fruit may be checked for defects without harming it, and live animals may be studied to measure fat and/or muscle depth and shape, or to determine skeletal or physiological development of the animal.

Multi-layer materials often comprise soft and flexible tissue which can be difficult to characterise. Scanning systems such as traditional contact based scanning system can place pressure on the outside of a multi-layer target material, deforming or damaging the material to be measured.

Ultrasonic transducers can be used to characterise the internal elements of biological articles with many layers. For example, they can be used to characterise the internal organs and muscle layers of animals or the internal characteristics of fruits.

A common ultrasonic transducer uses a wand type apparatus which a user must place in contact with a target article to be measured. However, this arrangement can create problems. To provide a good physical contact with the target, pressure needs to be applied to the transducer, and therefore to the target. This pressure can deform the target. This may be unimportant if the desired measurements to be taken are deeply internal such as measuring internal organs. However, if the layer to be measured is close to the surface, deforming this surface during measurement can alter the results obtained.

The user also has to consider each measurement taken with a transducer separately, as contact with different areas of an article necessitates a change in the way the transducer is placed. This is an impediment to automation as measurements are not consistent and are difficult to compare directly.

In ultrasonic characterisation systems it is necessary to achieve good physical contact and acoustic coupling with items having curved or irregular surfaces, while minimising deformation of the item which is to be measured. To do this a stand-off material is often used which may mould to the shape of the item to be measured.

Traditional stand-off materials such as gel used on animals with skin, cannot be used on material which is to be consumed as food. Gels can contaminate foods, and strict safety regulations deem that any substance applied must be satisfactorily removed afterwards. Furthermore it is desirable to avoid adding any material that may act as a medium for promoting microbial growth. Any material added may also assist in growth of any existing microbial bacteria and limit the shelf life of a product. Examples of such materials to be consumed as food include fruit or animal carcasses without skin, such as lamb or beef. Thus, for safety and customer requirements, no gel or similar stand-off material should be applied to these articles; if these are applied, extra processing is then needed to remove the substance.

Characterising carcasses and their distribution of fat is an important process for the meat packaging industry. Providing a way of optimising high value cuts from each animal is important. If a carcass can be characterised readily, then processes that optimise high value cuts can be made by an automated system without errors caused by abnormally shaped animals.

To currently characterise a carcass, carcasses are weighed and the weight is used to determine in which way a carcass should be butchered. Large, medium, and small carcasses are placed in groups and these groups are then uniformly butchered depending on their classification. However, if a carcass contains a large amount of fat, then it may be placed in a group with large animals, even though the amount of meat on the carcass may be relatively small.

Therefore, an improved way of characterising the carcasses that takes into account their fat percentage and/ or meat percentage and/or bone percentage would be of an advantage.

No two animals are identical, so applying a standard cut plan to a group of carcasses will necessarily result in a variation of the shape, size and/or percentage of fat and meat in each cut. If a user optimizes the leg cuts for example, the set of resulting forequarter cuts is likely to vary significantly.

An improved method of sorting carcasses to minimize the overall variation of cuts would be preferred.

One way of more accurately assessing the make up and proportions of a carcass is to use ultrasonic scanning methods to determine the depth of fat and/or meat layers and/or bone structure of the carcass at indicative anatomical points. In this method, an ultrasonic transmitter and receiver can be used with the electrical output from the ultrasonic receiver being used to determine the depth of fat on a carcass.

An ultrasonic transducer emits ultrasonic waves, and the reflection of these waves at a boundary between the fat and the meat and the bone can be used to determine the amount of fat on the carcass at a key anatomical indicator point. This is because fat and the meat and the bone have different ultrasonic reflection properties.

However, this method doesn't produce highly accurate results as pressure from the transducer deforms the fat and meat layers of the carcass. Each measurement must be considered individually and the system tuned by hand to a transducer operator's preference. This prevents automation as an operator is needed for each measurement.

An improved stand-off material which provides an effective interface between the transducer and a surface to be measured, without deforming the surface or underlying structures, or applying any substances such as gels to the surface would be an advantage. This material may preferably allow automation and improved readings from the transducer system.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term 'comprise' may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided a transducer interface system which includes,

a flexible bladder configured to contain a fluid, and

a mounting element configured to locate the flexible bladder with respect to an ultrasonic transducer so that ultrasonic waves transmitted by the ultrasonic transducer pass through the bladder before reaching a target material.

Preferably a target material may be a flexible multi-layer surface of any kind. Preferably this surface may be a surface of a biological article, such as fruit, a live animal or animal carcass.

The present invention may provide a transducer interface system which is preferably used in conjunction with a target material to characterise that material. Preferably the target material may be a carcass of an animal, such as a lamb or beef carcass. Preferably this carcass may be made out of a combination of fat and meat and bone. Alternatively, the transducer interface system may be used in other applications such as characterising fruit, vegetables, or other materials, biological or otherwise.

Reference throughout the specification will be made to a target material being a carcass. However, those skilled in the art should appreciate that other target materials may be characterised through use of the present invention, and any reference throughout the specification to the above only should in no way be seen as limiting.

The present invention provides a transducer interface system which may be used to characterise a multi-layer target material without deforming that material. Preferably the transducer interface system may be used to characterise layers of the target material close to the surface. It is these layers which may deform significantly when pressure is applied, thus reducing the accuracy of measurements taken.

Alternatively, the interface provided may be used to determine where bone is situated within a carcass, characterise the growth of a live animal, or perform any other similar characterisation operations.

Preferably an ultrasonic transducer is an element that turns electrical energy into ultrasonic energy waves and vice versa. An ultrasonic transducer may be a component that incorporates an ultrasonic transmitter and receiver. This component may be a standard ultrasonic transducer as is readily available and commonly used in a number of ultrasonic testing applications.

Preferably the flexible bladder may be provided by a material which has a thickness of less than half a wavelength of the waves emitted and received by the ultrasonic transducer.

Ultrasonic transducers may produce waves with a wavelength of anywhere between 0.09mm and 1.9mm. The wavelengths may be set based on the imaging requirements of the system.

In a preferred embodiment of the present invention, the ultrasonic transducer may emit and receive ultrasonic waves with a wavelength of 0.2mm to 0.4mm the thickness of the material of the flexible bladder may then be approximately 0.1mm or less.

A comparatively thin material may minimise reflections at the interface of the bladder and the fluid contained in the bladder, and the bladder and the surface of the carcass. Preferably the thin flexible bladder may also be strong enough to withstand internal pressure from the fluid and external pressure from the carcass being measured.

Preferably the bladder may be made from an appropriate polymer which has all the properties listed above. Alternatively, the bladder may be provided by any other material, such as membrane, for example leather or a sausage skin, which may also be thin, strong, and flexible.

Reference throughout the specification will be made to the flexible bladder being made of a polymer. However, those skilled in the art should appreciate that other materials may be used, and reference throughout the specification to the above only should in no way be seen as limiting.

Preferably the flexible bladder may be filled with a fluid which has similar acoustic properties to the material to be measured. If the material to be measured is a layer of fat on a carcass, then the fluid may have the similar acoustic properties as the fat to be measured, such as its reflection, transmission and diffraction characteristics. This allows the ultrasonic waves from the transducer to be substantially unimpeded as they pass through the bladder fluid and into the material to be measured.

Preferably if the material to be measured initially has a layer of fat, then this fluid may be a fat. This allows a minimum reflection between the standoff bladder, and the fat layer. This reduces signal noise when the ultrasonic waves initially hit the target material. Minimising the change in acoustic properties gives less noisy data, thus providing a clearer picture of the internal elements of the target material.

Alternatively the fluid may be an oil which has similar acoustic properties as the fat. In a preferred embodiment, the bladder may be filled with a mixture of fat and oil to provide a fluid that has similar acoustic properties to the fat in the target material, but is still fluid. Fat alone may cause problems due to solidification.

Alternatively, the bladder may be filled with other fluids such as water, air or any other fluid which allows ultrasonic waves to be transmitted through the fluid. If the flexible bladder is filled with fluids which do not have the same acoustic properties as the layer to be measured, then further processing may be needed to remove extra reflections and noise from the data gathered.

Reference throughout the specification will be made to the flexible bladder being filled with oil. However, those skilled in the art should appreciate that other fluids may be used, and any reference throughout the specification to the above only should in no way be seen as limiting.

According to another aspect of the present invention there is provided a mounting element for a transducer which includes,

a first section adapted to locate a transducer, and

a second section adapted to house a bladder in contact with a transducer located by the first section,

wherein the second section includes an aperture which allows a portion of the bladder to extend beyond an outer surface of the second section of the mounting element.

Preferably a mounting element for a transducer may allow the flexible bladder and the ultrasonic transducer to lie in contact with one another.

Preferably the mounting element may be made of metal. Alternatively, the mounting element may be made of any material which strong enough to locate an ultrasonic transducer and a flexible bladder, without interfering with the measuring properties of the ultrasonic transducer. Examples of material such as this may be plastic, wood, ceramic, or any other type of material which has those properties listed above.

Preferably, the first section locates an ultrasonic transducer. Preferably this transducer is located by enclosing the transducer inside the first section of the mounting element.

Preferably the first section may be such a shape that the ultrasonic transducer can lie within the mounting element without substantial movement. This may be achieved by having recess shaped complementary to the transducer in the mounting element for the transducer to lie in. . Alternatively it may be achieved in other ways, such as the whole mounting element being a size small enough that pressure from the area of the mounting element over the transducer keeps the transducer in place. Alternatively the first section may be configured in any other way which connects the ultrasonic transducer to the second section, such as including clips, straps or other connection means to contain the transducer.

Preferably, the second section is configured to house a bladder in contact with a transducer. The first section may include an aperture which is complementary to an aperture in the second section.

Preferably, the first and second sections may be connected without any separating walls between the two sections. This may mean that one side of each section is open, and therefore the transducer and flexible bladder can be located in direct contact with each other.

Preferably the second section may include an aperture which allows a portion of the bladder to extend beyond the outer surface of the mounting element. Preferably the second section may deform the bladder, and allow the bladder to be compressed in the housing where the bladder is located. This forces a portion of the bladder out through the aperture. Preferably this aperture holds the extended portion of the bladder taut. This ensures that when ultrasonic waves are transmitted through the bladder surface, this surface has an even thickness throughout, and the material's surface does not introduce interference or noise to the transducer data recorded. The extended portion of the bladder may preferably be placed against the carcass when the transducer system is in use.

As the bladder is flexible, this allows it to be placed against a range of surfaces without needing to change the alignment of the mounting element. This means that the characterisation data reading and resulting ultrasonic image recorded of each carcass can use the same calibration of transducer, and therefore the results may be reliably compared to one another. These results may be used in determining which farms, or even animals, breed animals with a large proportion of desired characteristics.

The present invention may provide many potential advantages over the prior art.

The transducer system provided may preferably be used on a carcass processing production line. This allows carcasses to be characterised quickly and easily in a uniform fashion. This can lead to improved automation of carcass characterisation systems and optimise cut plan calculations.

The present invention uses a flexible bladder as a stand-off material in a transducer interface system. Preferably the present invention may be used to characterise animal carcasses.

The present invention allows a transducer to contact a carcass without deforming the surface of the carcass. This system may allow improved automation of meat packaging process and other carcass characterising operations and therefore improved time and cost savings throughout this process.

BRIEF DESCRIPTION OF DRAWINGS Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 shows a characterisation image as created when using a prior art transducer interface system, and

Figure 2 shows a characterisation image created when using the present invention when configured in accordance with a preferred embodiment.

Figures 3a, 3b, and 3c show side views of a transducer interface system provided in accordance with a preferred embodiment.

BEST MODES FOR CARRYING OUT THE INVENTION

Figure 1 shows a characterisation image created using a prior art transducer system, and Figure 2 shows an output characterisation image taken using a transducer interface system as configured in accordance with a preferred embodiment of the present invention.

Figure 1 shows a rigid stand-off interface (1a) engaged with the transducer in a prior art system. As the stand-off is rigid, the surface measured (2a) is shown as following the curvature of the stand-off. This creates excess noise, and the interface between the fat (3a) and the muscle (meat) (4a) is lost in this noise. There are also added reflections (5) due to lack of a suitable stand-off material.

By contrast, Figure 2 also shows a transducer and stand-off interface (1 b) provided in accordance with a preferred embodiment of the present invention. The stand-off is provided by a flexible bladder, thus the curvature of the carcass's surface (2b) is retained, and one can clearly see where the fat layer (3b) is situated. Also shown is enhanced fat detail throughout the muscle (4b). Figures 3a and 3b show side cut away views of the present invention configured in accordance with a preferred embodiment. Figure 3c shows a closed side view of the present invention configured in accordance with Figures 3a and 3b.

These figures show a transducer interface system (6), including a flexible bladder (7) which contains a fluid, a mounting element (8) which locates the flexible bladder (7) with respect to a transducer (11 ). The mounting element includes a first section housing a transducer (9), and a second section (9A) which houses a bladder (7) in contact with the transducer (11 ). The second section (9A) includes an aperture (10) which allows a portion of the bladder (7) to extend beyond this outside surface of the mounting element.

The transducer is used to characterise a target material. The target material is placed against the portion of the flexible bladder (7) which is extending from the aperture (10) in the mounting element (8). Ultrasonic waves are then sent from the transducer (11) through the flexible bladder (7) onto the target material and reflections from these waves are received by the transducer. Electrical signals proportional to the received waves are then sent to a processing means where a characterisation image is created.

The bladder section projected out through the aperture is pulled taut as it is stretched through the aperture. This creates a consistent shape and form for the bladder projection to contact the target material. The length of the bladder applied is preferably the same length as the transducer to prevent noise from the edges of the transducer's range appearing on the data received. The consistency of this shape, and therefore the transducer readings allows the interface system to be used in an automated production line. Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

WHAT WE CLAIM IS:

1. A transducer interface system which includes,

a flexible bladder configured to contain a fluid, and

a mounting element configured to locate the flexible bladder with respect to an ultrasonic transducer to allow ultrasonic waves transmitted by the ultrasonic transducer to pass through the bladder before reaching a target material.

2. A transducer interface system as claimed in claim 1 wherein the target material is a flexible multi-layer material.

3. A transducer interface system as claimed in claim 1 or claim 2 wherein the target material is an animal carcass.

4. A transducer interface system as claimed in any one of claims 1 to 3 wherein the flexible bladder is provided by a material which has a thickness of less than half a wavelength of the waves emitted and received by the ultrasonic transducer.

5. A transducer interface system as claimed in any one of claims 1 to 4 wherein the bladder is formed from a polymer.

6. A transducer interface system as claimed in any one of claims 1 to 5 wherein the fluid contained by the bladder is an oil.

7. A transducer interface system as claimed in any one of claims 1 to 5 wherein the fluid contained by the bladder is a fat.

8. A mounting element for a transducer which includes,

a first section adapted to locate a transducer, and

a second section adapted to house a bladder in contact with the transducer located by the first section,

9. A mounting element as claimed in claim 8 wherein the flexible bladder and the ultrasonic transducer lie in contact with one another.

10. A mounting element as claimed in any one of claims 8 or 9 wherein the transducer is enclosed inside the first section of the mounting element.

11. A mounting element as claimed in any one of claims 8 to 10 wherein the first section has a complementary shape to that of the transducer.

12. A mounting element as claimed in any one of claims 8 to 11 wherein the first and second sections are connected without any separating walls between the two sections.

13. A mounting element as claimed in any one of claims 8 to 12 wherein the second section deforms the bladder.

14. A mounting element as claimed in any one of claims 8 to 13 wherein the bladder is compressed in the mounting element.

15. A mounting element as claimed in any one of claims 8 to 14 wherein the aperture of the second portion holds the extended portion of the bladder taut.

16. A transducer interface system as herein described with reference to and as illustrated by the accompanying figures and/or examples.

7. A mounting element as herein described with reference to and as illustrated by the accompanying figures and/or examples.