The present disclosure generally relates to methods and devices for the repair of ultrasound probes used in medical and industrial applications.
Ultrasound techniques are commonly used in a variety of medical specialties such as obstetrics, gynecology, radiology, cardiology, and surgery. They are commonly used in the medical field to perform a variety of useful functions, such as diagnosis of cardiovascular disease, classifying lesions as being malignant or benign, guiding biopsy procedures, and clarifying a variety of conditions effecting pregnant women and their fetuses. In industry, ultrasound techniques are used to perform nondestructive testing, the purpose of which is to detect defects that may occur either during the manufacturing process or after a part has been used (such as fatigue cracks, stress corrosion cracks, or simple corrosion). Such tests are typically performed in the aviation, transportation, and energy generation industries.
An ultrasound probe is generally used to generate and detect acoustic waves. Such probes may be either handheld or mounted on fixed or moving platforms, but they all are comprised of a regular arrangement of multiple ultrasound transducers, commonly referred to as an array. The array contains many individual transducers (128 or 256 or more) aligned in a regular pattern; each transducer has individual circuitry and leads constituting an element of the array. The arrays are commonly referred to as 2D arrays, 1.5D arrays, linear arrays, curvilinear arrays, and phased arrays, depending upon the geometric arrangement of the elements in the array. The active portion of the transducer is a piezoelectric material, which may be comprised of a ceramic such as PZT (lead-zirconate-titanate) or a single crystal such as PMN-PT (lead-magnesium-niobate/lead-titanate). Acoustic matching layers are also included as parts of the array element to improve the transducer efficiency and bandwidth by better matching the high acoustic impedance of the hard, dense ceramic to the relatively low acoustic impedance of tissue.
Ultrasound probes are highly sensitive instruments that can be easily damaged. For example, a technician may accidentally drop the probe during use or strike the probe against an examination table or other hard surface. The probe may also be damaged if it is improperly stored or transported. Finally, the probe may be damaged if chemicals that are used while the probe is being applied, cleaned, or disinfected are not chosen properly or used incorrectly. Some types of damage to the probe, such as damage to the cable or cracks in the probe's protective casing, can be readily repaired.
However, the transducer array, sometimes referred to as the acoustic stack, is very difficult to repair. Removal of a damaged element or elements involves very precise control of the removal tools in order to prevent further damage to adjacent good elements. Furthermore, the damaged element or elements must be removed in such a way as to prevent misalignment of adjacent good elements by the weakening of the backing, or substrate, upon which all the elements are supported, as by undercutting, frictional melting, and the like. New elements replacing the damaged elements must be very precisely placed back into position. When the new elements are in place, they must be precisely aligned with the other elements in the array. All these operations require very sophisticated and precise techniques performed either by highly trained personnel or by expensive computerized numerical control (CNC) machines that are precisely aligned relative to the damaged elements or to the remaining good elements. Such repair could be performed by the original equipment manufacturer in order to obtain a ready supply of form/fit/function replacement parts. However, when the life cycle costs of such repair are considered, it may be more cost effective for the original equipment manufacturer to simply replace the array in its entirety.
Therefore, since damaged elements are small and difficult to work with, it is difficult to replace them individually leading to the entire acoustic stack being generally discarded. This may be an expensive proposition because the probes themselves are quite expensive.
As can be seen, there is a need for a method to inexpensively repair a probe in a cost effective manner, so that non-catastrophic damage that may degrade the performance of the probe does not result in a replacement of the transducer array, thereby extending the operational life of the probe. Thus, repair of damaged probes is a paramount economic issue for commercial concerns that use such probes on a regular basis. There are approximately 250,000 ultrasound probes in use today in the United States. Probes have an average lifetime of three years. This means that 80,000 probes require repair or replacement each year. The average repair or exchange price of a probe may range from about $3,500 to about $20,000 at current prices. If a method were provided to repair probes having non-catastrophic damage, a significant portion of these costs could be saved.
A method is provided for the repair of a damaged array containing elements. The method comprises the following steps, which may not be performed in this order: identifying a first section of elements in the damaged array, wherein the damaged section contains a first number of contiguous elements and all damaged elements in the damaged array are in the first section; identifying a second section in a donor array, the second section having a second number of contiguous good elements that is not less than the first number; removing the first section from the damaged array to leave a repair site within the damaged array; removing the second section from the donor array; and affixing the second section to the repair site of the damaged array.
A method is further provided for the repair of a damaged array containing elements. The method comprises the following steps, which may not be performed in this order: determining a first section of the damaged array within which all of the damaged elements may be located; removing the first section of the damaged array to create a repair site; providing a donor array; identifying a second section of the donor array having a number of undamaged elements equal to the number of damaged elements contained in the first section of the damaged array; removing the second section from the donor array; preparing the second section from the donor array to have a profile that mates to the profile of the repair site; attaching the second section from the donor array to the damaged array at the repair site; aligning the elements of the second section with the remaining elements in the damaged array; repairing electrical connections between the second section and the damaged array; and testing the array for proper operation.
A repaired acoustic array is further provided. The repaired acoustic array comprises good elements from a damaged array and a donor array and may be produced by the previously described methods.
A method is further provided for the partial repair of a damaged ultrasound array. The method comprises the following steps, which may not be performed in this order: identifying a first section of elements in the damaged array, wherein the first section contains a first number of contiguous elements and all damaged elements in the damaged array are in the first section; identifying a second section in a donor array, the second section having a sufficient number of good elements to make the damaged array operable and useful; removing the first section from the damaged array to leave one or more repair sites within the damaged array; removing the second section from the donor array; and affixing the second section to the repair site of the damaged array.
These and other features, aspects, and advantages set forth in the present disclosure will become better understood with reference to the following drawings, description, and claims.
The following detailed description is of the best currently contemplated modes of carrying out the methods set forth in the present disclosure. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the methods disclosed herein, since the scope of the present disclosure is best defined by the appended claims.
Broadly, the current disclosure includes methods for replacing a damaged section of elements in an array stack (the recipient array) with a good section of elements taken from a donor array stack, where the good section of elements generally conforms in size and shape to the damaged section. The disclosure includes methods for aligning the donated array section with the recipient array in the areas of mechanical attachment, electrical attachment, and overall performance. In practice, the good section of elements may preferably be taken from a donor array manufactured by the same manufacturer as the recipient array so that the electrical characteristics, material properties, acoustic properties, and general construction readily conform to that of the receiving array.
The recipient array may have one or more damaged sections therein so that it either does not function at all or else it functions at a degraded level. The term “degraded” is taken to mean that some elements may function normally and some elements may not perform according to the specifications of a normal element, so that the overall performance characteristics of the overall array do not match those of a standard array as it comes from the factory. Each damaged section is identified as a section of contiguous elements in the array which may in turn contain one or more damaged elements. The damaged elements may be adjacent to one another or may have intervening good array elements therebetween. In principle, it is desirable to minimize the number of damaged sections by judicious choice of the damaged and good elements for inclusion in the identification of a damaged section. If the number of damaged sections is minimal, then the probability of having to rework the array due to an improper repair is minimized. However, any number of damaged sections may be identified without departing from the scope of the present disclosure.
Also disclosed herein are methods that generally provide for removing a section of contiguous elements from the recipient array, where the removed section contains damaged elements (and therefore a damaged section); selecting a section of contiguous elements from a donor array, where the donated section contains a sufficient number of good elements to make the array functional; and inserting the donated section from the donor array into the gap left by the removed section in the recipient array. The present disclosure also includes methods for aligning, testing, and verifying the repaired array to ensure that it exhibits the same electrical, acoustic, and physical characteristics as a generic array manufactured by the original equipment manufacturer.
Use of the disclosed methods may permit damaged arrays to be repaired without incurring the cost of a new replacement array and discarding the old array. The probe may thus be kept in operational condition for several years in a relatively inexpensive manner. In addition, parts of expensive damaged arrays may be recycled by re-using them as donor arrays whenever it becomes uneconomical to repair them using the disclosed method, in order to provide contiguous operational portions for other damaged arrays. The donor array may also be used to repair multiple recipient arrays, as well as repair other damaged parts of recipient probes, such as cables and connectors. This may reduce waste and the unnecessary manufacture of replacement array parts.
While the disclosed method may be described in terms of repairing an acoustic stack for an ultrasound probe, it may be used in the repair of similar, array-like structures in which small elements, typically on the order of 100-500 microns, are supported on a substrate in a monolithic or unitary arrangement, without departing from the scope of the present disclosure. In the detailed description that follows, it should be understood that although the discussion will focus on the repair of a single damaged section of an array, the disclosed method may be used for the repair of any number of damaged sections in an array without departing from the scope of the present disclosure.
Referring to
Although the acoustic stack is shown in
Each element may have leads for connection to an external system that may be used to control the operation of the elements and to detect signals that may be provided by the elements. The elements may be independent, in the sense that they may be individually activated, or fired, in various time sequences and various power levels, according to the particular application. Furthermore, the signals that the elements may provide may be received, weighted, and analyzed according to different algorithms. The leads from the piezoelectric crystals may be attached to flex circuits, or “flexes,” which may consist of individual traces on flexible circuit boards that conduct signals to and from the piezoelectric crystals to external systems (
Referring now to
In order to repair the recipient array 210, the section containing the damaged elements must be removed and replaced by a section containing good elements. While it is ideal to always replace a damaged section with a section containing only good elements, it is also possible to replace a damaged section with a section containing a sufficient number of good elements to make the probe operable and useful (i.e., partial repair).
According to
Referring again to
Referring now to
As shown in
Referring now to
When the surfaces of both the repair site 255 and the good section 252 are suitably prepared, the good section 252 may be installed within the repair site 255 as by epoxy, gluing, welding, heat treatment, or other similar technique, while ensuring that the top surfaces 270 containing the individual elements are themselves aligned mechanically, acoustically, and electrically with each other. The good section 252 may be temporarily fixed in place to allow for a preliminary alignment operation. In one embodiment, such an alignment operation may comprise the actions of inserting the good section 252 and the undamaged section 214 of the recipient array 210 into a jig or form having the general shape and profile of an operational array configuration. Such an operation may permit physical alignment of the elements from the good section 252 and the undamaged section 214 of the recipient array 210. The good section 252 and the undamaged section 214 of the recipient array 210 may then be permanently set in place by the use of a bonding agent or some other agent that may affix the two sections together into a monolithic array and fill the area between the two sections so that the alignment may be maintained. In another embodiment, the good section 252 may be more rigidly “tacked” to the undamaged section 214 of the recipient array 210 by a discrete number of bonding agent portions, so that the repaired array 260 may be removed from the form, electrically connected to test instrumentation (as by wiring harnesses, for example), and adjusted to ensure that the elements are electrically, acoustically, and physically aligned. When such alignment is established, the sections may be permanently affixed to one another according to the previously described procedure. In still another embodiment, the use of the jig or form may be omitted and physical alignment accomplished by visual and manual means. The number of elements in the good section 252 may be chosen so that, after installation, the total number of elements in the repaired array 260 is identical to its original number of elements before the repair process was initiated.
Referring now to
A damaged section 312 may be identified for replacement by a good portion of a donor array 350 (
A donor section 352 may be identified within the donor array 350 (
The donor section 352 may be inserted within and against the recipient array part 314 (
As shown in
Referring now to
Referring now to
The candidate array may be considered as a unit and a set of damaged sections of the array may be identified according to a set of repair criteria, according to the block designated as 520. The set of damaged sections may be established by numerous methods. One such method would be to assign each damaged element to a damaged section containing only that damaged element. Then sections that are contiguous may be combined to reduce the number of damaged sections. Then, if two adjacent damaged sections are separated by N good elements therebetween (where N is a criterion for repair), then those adjacent damaged sections along with any intervening undamaged elements may be combined into a single section containing both damaged and undamaged elements, all of which are contiguous. The process may continue until a limit is reached, e.g. the number of sections equals one and the section does not comprise the entire array. Other methods may be contemplated without departing from the scope of the present disclosure.
A determination may be made as to whether the candidate array is to be repaired or discarded, according to the block labeled 530. Another criterion may be established to make this determination. For example, the criterion may be that if the number of elements contained in the set of damaged sections is greater than one half the number of elements in a good array, then the array would be discarded or used as another donor array for the repair of other recipient arrays. As another example, if the number of damaged sections in the set is less than the value of M (where M is a second criterion for repair, which may or may not be equal to N), then the candidate array may be designated as repairable. Other criteria may be used to make the determination without departing from the scope of the present disclosure.
If the determination is made to repair the candidate array, then it becomes a recipient array. A set of donor sections from one or more donor arrays for use as candidates for replacing the damaged sections may be identified within a stock of donor arrays that are on-hand, according to the block labeled 540. The repair facility within which the repair is made may have a collection of new and/or damaged arrays from which donor sections containing only good elements may be identified and removed. Occasionally, a completely new array may be ordered from the original equipment manufacturer for use as a donor array. Each donor section thus selected may be matched with a corresponding damaged section, so that the number of elements in the donor section is greater than or equal to the number of elements in the corresponding damaged section. This limitation may allow the number of elements in the good donor sections to be reduced, as by removal and discarding, so that the total number of active array elements in a repaired array is the same as the total number of active array elements in a new array.
The damaged sections may be removed from the recipient array, according to the block designated as 550. Removal may be accomplished with or without the prior removal of flex circuits attached to the array. The designated donor sections may be removed from the one or more donor arrays, according to the block designated as 560. The remaining portions of the recipient array and each of the donor sections may be prepared so that the donor sections may be inserted into and/or affixed to the remaining recipient array, according to the block designated as 570.
The donor sections may be aligned with the elements of the recipient array and attached thereto, according to the block designated as 580. Alignment may be accomplished either manually through use of forms or jigs, or electrically through use of test instrumentation, or through other means within the scope of the present disclosure. When the array has been thus repaired, it may be assembled back into the probe from which it originated, and the probe along with the array may be further tested, according to the block designated as 590. Such testing may ensure that the probe, and thus the array, is a valid form/fit/function repair for the original equipment manufacturer's probe/array. If the repair is not valid, the repair process as shown in
The present disclosure has been described with reference to flowchart illustrations and/or block diagrams of methods and apparatus (systems), according to embodiments disclosed herein. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented in any order that accomplishes the goal of restoring an acoustic array to normal operation. The present disclosure is not necessarily limited to the steps in the order as presented, but should be construed to include all reasonable variations of step order that accomplish the desired goal.
From the foregoing, it will be understood by persons skilled in the art that a method for the repair of an ultrasound probe device has been provided. While the description contains many specifics, these should not be construed as limitations on the scope of the present disclosure, but rather as an exemplification of the preferred embodiments thereof. The foregoing is considered as illustrative only of the principles of the present disclosure. Further, because numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the present disclosure to the exact methodology shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the present disclosure. Although this disclosure has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and numerous changes in the details of the method may be resorted to without departing from the spirit and scope of the present disclosure.
Number | Date | Country | |
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61021730 | Jan 2008 | US |