WO2016137399A1

WO2016137399A1 - Method and apparatus for biological soft tissue measurement

Info

Publication number: WO2016137399A1
Application number: PCT/SG2016/050092
Authority: WO
Inventors: Ee Hoon Constance TEO; Pang Cheng David LAU; Chee Kong Chui; Chin Boon CHNG; Rong Wen; Chin Heng Matthew CHUA
Original assignee: National University Of Singapore; Singapore Health Services Pte Ltd
Priority date: 2015-02-25
Filing date: 2016-02-25
Publication date: 2016-09-01

Abstract

A biomedical method and device for measuring a channel within soft tissue is provided. The method includes the step of inserting a micro-wire having a measurement scale having clearly defined markings at predefined intervals through soft tissue into a channel within the soft tissue until one of the clearly defined markings is positioned at a first side of the channel and the micro-wire traverses the channel. The method also includes the step of determining the length of the channel from the measurement scale on the micro-wire.

Description

METHOD AND APPARATUS FOR

BIOLOGICAL SOFT TISSUE MEASUREMENT

PRIORITY CLAIM

[0001] This application claims priority from United States Provisional Patent Application No. 62/120,431 filed on February 25, 2015.

TECHNICAL FIELD

[0002] The present invention generally relates to methods and apparati for biological soft tissue measurement and more particularly relates to methods for micro- wire marking for biomedical applications.

BACKGROUND OF THE DISCLOSURE

[0003] Micro-wires have been employed in various biomedical applications like angiograms, oral braces and stenting. The current methods of micro-wire marking include ink coating, mechanical machining and precision micro-laser engraving. Biomedical ink deposition is one of the cheapest and widely employed means of marking. However, the increase in wire size thickness and the potential for chipping to occur from cyclic bending limit the reliability of such ink deposition methods.

[0004] Direct mechanical machining of markings on a micro-wire is extremely difficult due to the flexible nature of the wire. A motorized rotatable clamp is needed for such machining in order to achieve a uniform marking around the wire. This approach, however, lacks precision due to the cantilever effect and the compromising of the mechanical integrity of the wire.

[0005] Finally, the use of micro-laser engraving is a costly method to mark micro- wires. This method also presents risks of having surface feature deformation and/or poor finishing. In addition, the annealing effect might also compromise the mechanical properties of the micro-wire making it more prone to failure during biomedical application.

[0006] Thus, what is needed is a method and apparatus for micro-wire marking for biomedical applications which at least partially overcomes the drawbacks of present approaches and provides a more reliable method and apparatus for biological soft tissue applications. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.

SUMMARY

[0007] According to at least one embodiment of the present invention a method for fabricating a micro-wire for accurate measurement during biomedical applications is provided. The method includes the steps of providing a first wire as a core wire, coiling a second wire around the core wire as a coil sleeve to form the micro-wire into a guidewire, and marking the coil sleeve at predefined intervals to provide an accurate measurement scale on the guidewire for biomedical applications.

[0008] According to an additional embodiment of the present invention a biomedical method for measuring a channel within soft tissue is provided. The method includes the step of inserting a micro-wire having a measurement scale having clearly defined markings at predefined intervals through soft tissue into a channel within the soft tissue until one of the clearly defined markings is positioned at a first side of the channel and the micro-wire traverses the channel. The method also includes the step of determining the length of the channel from the measurement scale on the micro-wire.

[0009] According to a further embodiment of the present invention a device for micro-wire biomedical applications is provided. The device includes a medical instrument and a control panel. The medical instrument includes a disposable transparent catheter, a light emitting diode (LED) marked core, and a motorized tube driving system, the motorized tube driving system including a motor, a guide screw, and a controller. The control panel is coupled to a distal end of the disposable transparent catheter and displays measurement parameters and a tube working length. The control panel is responsive to a user activation to forward signals to the controller for extending the disposable transparent catheter and simultaneously rolling the LED marked core into the disposable transparent catheter such that the LED marked core operates as a core wire and inner brace and LED lights evenly distributed along the LED marked core allow measuring a length between any two points along the disposable transparent catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to illustrate various embodiments and to explain various principles and advantages in accordance with a present embodiment.

[0011] FIG. 1 depicts side planar view of a marked micro-wire for biomedical applications in accordance with a present embodiment. [0012] FIG. 2 illustrates an enlarged side planar view of ink deposition on a coiled guidewire in accordance with a variation of the present embodiment.

[0013] FIG. 3, comprising FIGs. 3 A and 3B, depicts side planar views of different micro-wire marker patterns produced by laser engraving in accordance with variations of the present application, wherein FIG. 3A depicts a micro-wire band pattern and FIG. 3B depicts a micro-wire wave pattern.

[0014] FIG. 4, comprising FIGs. 4A and 4B, depicts a side planar view of a micro- wire multiple strand combination in accordance with another variation of the present embodiment, wherein FIG. 4A depicts the completed multiple strand micro-wire and FIG. 4B depicts the multiple strand micro-wire during formation.

[0015] FIG. 5 illustrates a side planar view of a single color measurement scale on a micro-wire for applications in trachealesophageal (TEP) procedures in accordance with a variation of the present embodiment.

[0016] FIG. 6 illustrates a side planar view of a guidewire and an additional biomedical measurement device for TEP procedure applications in accordance with a further variation of the present embodiment.

[0017] And FIG. 7 illustrates a side planar view of a method for manufacture of a marked biomedical micro-wire device in accordance with another variant of the present embodiment using a light emitting diode (LED) marking guidewire core.

[0018] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been depicted to scale.

DETAILED DESCRIPTION

[0019] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description. It is the intent of the present embodiment to present a medical guidewire with visually detectable markers for location of two points and for measuring the distance between them. A standard medical guidewire is modified to include an accurate set of measurement scales.

[0020] Patients who have undergone total laryngectomy (TL) lose their ability to voice. To restore their ability to speak, trachealesophageal puncture (TEP) speech is typically used for voice restoration. To enable TEP speech, a surgical procedure is required to first create a fistula between the esophagus and the trachea, after which a one-way voice prosthesis can be inserted to enable air to be diverted from the trachea into the esophagus and out through the mouth. This surgical procedure is traditionally performed as a primary procedure during TL, but recent advancements in techniques has demonstrated the benefits of performing TEP as a secondary procedure within an outpatient office-based setting.

[0021] In accordance with a present embodiment, a method for fabrication of a marked micro-wire which can circumvent limitations of current fabrication methods results in a marked micro-wire which can accurately measure tissue thickness and enable a clinician to select an appropriate voice prosthesis for a patient during TEP. The present method is not limited to TEP and can be applied to other biomedical applications involving invasive measurement of a length of a channel.

[0022] The marked micro-wire fabricated in accordance with the present embodiment can be used in transnasal esophagoscopy (TNE) guided TEP together as a measurement and insertion device (MAID) to aid in the measurement and insertion of a voice prosthesis at the time of TEP. TEP MAID in accordance with the present embodiment enables the dual capability of (a) measuring the length of the fistula created for appropriate voice prosthesis selection, and (b) maintaining the fistula opening, so as to enable the insertion of the voice prosthesis at the time of TEP. This is made possible by the incorporation of a measurement scale on the body of the canula that is introduced simultaneously during the dilation process of the Seldinger method, allowing the distance between the posterior tracheal wall and the anterior tracheal wall to be accurately measured.

[0023] In accordance with the present embodiment, fabrication of a modified guidewire (i.e., a marked micro-wire) with a measurement scale embedded along the length of the guidewire at a predefined position (i.e., a marked micro-wire) also ensures fabrication of a consistent and uniform external diameter of the guidewire. This marked guidewire is inserted just after the initial needle puncture and is used to (a) enable serial dilation of the fistula, (b) prevent the creation of false tracts during the process, and (c) immediate measurement of the fistula length at the time of the needle puncture. Feature (c) can be used to accurately determine the fistula length.

[0024] Referring to FIG. 1, a side planar view 100 of a marked micro-wire 102 for biomedical applications in accordance with a present embodiment is depicted. A scale 104 on the guidewire consists of an initial three millimeter marking 106 at its distal end for location of the anterior tracheal wall followed by multiple markings 108 at two millimeter intervals. The diameter of a conventional medical guidewire is one millimeter. With a coil sleeve covering the core wire of a guidewire, it is difficult to produce a measurement scale on its surface. The scale 104 depicts a possible scheme for immediate visual identification and location of the positions of both the posterior tracheal wall and the anterior tracheal wall. The markings 108 in the scale 104 can utilize a color scheme with a separate external color coded chart to be used as a reference to identify the length between the posterior tracheal wall and the anterior tracheal wall.

[0025] Thus, utilizing the marked micro-wire 102 during TNE guided TEP, the measurement of the fistula length after insertion can be carried out in the following way: (i) Locate the anterior esophageal wall by aligning the proximal end of the first three millimeter marking 106 with the anterior esophageal wall. This can be carried out visually (as in TNE) or by non-invasive methods such as ultrasound imaging or computed tomography (CT). (ii) Locate the posterior tracheal wall visually through stoma by identifying the marking that is aligned with it.

[0026] The present embodiment addresses a technical problem of providing a medical guidewire with visually detectable markers for location of two points and for measuring the distance between them. A standard medical guidewire is modified to include an accurate set of measurement scales. The diameter of conventional medical guidewire is one millimeter. With a coil sleeve covering the core wire of a guidewire, it is difficult to produce a measurement scale on its surface. In order to produce readable markers on the surface of the medical guidewire to estimate appropriate prosthesis size, there are various methods which can be utilized.

[0027] One common method of marking a medical device is ink deposition. However, applying ink to the irregular surface of coiled guidewires increases the external diameter and increases the potential for chipping to occur from cyclic bending stresses. In accordance with the present embodiment, an additional machining process uses centerless grinding to grind the guidewire at desired intervals before ink deposition in order to compensate for the added thickness and ensure a constant external diameter. Referring to FIG. 2, an enlarged side planar view 200 depicts ink deposition on a coiled guidewire 202 in accordance with the present embodiment. A first wire 204 serves as a core wire for inner bracing of the guidewire and a second wire 206 is coiled around the first wire 204 as a coil sleeve to form the guidewire. Prior to depositing the ink 208 on the coil sleeve at predefined intervals to provide an accurate measurement scale on the guidewire for biomedical applications, the second wire 206 is grinded at the predefined intervals to a depth 210 in order to compensate for the added thickness of the deposited ink 208 to ensure a constant external diameter.

[0028] Another common method of marking uses a laser marking system to produce comprehensive marker patterns without undermining device strength and guiding functions. In accordance with present embodiments, two types of marker patterns and their laser manufacturing methods are described.

[0029] As shown in FIG. 3A, a side planar view 300 depicts a marking laser machine 302 with a laser head 304 being used to engrave continuous band-pattern scales along a guidewire 306. Position calibration of the guidewire 306 with respect to the laser head 304 is achieved by a three-dimensional platform which is controlled by the marking laser machine 302. In order to keep the guidewire 306 straight and fixed during the laser marking process, both ends of the guidewire 306 are clamped (not shown) while the marking laser machine 302 moves from one end of the guidewire 306 to the other end of the guidewire 306 to engrave the measurement scale along the axial direction. The width of the band pattern and depth of the marker is controlled by the marking laser machine 302. For each band pattern, the clamping heads of the laser platform rotate (as indicated by an arrow 308) around the shaft axis 310, enabling the band pattern to be distributed evenly around the guidewire 306.

[0030] Referring to FIG. 3B, a side planar view 320 depicts a micro-wire 322 wave pattern made by moving the laser head (not shown) along the shaft axis 324 while rotating the shaft at the same time to produce the wave patterns 326. The control function (e.g., a trigonometric function) of the wave pattern making could be imported via a user interface of the marking laser which can coordinate the shaft's axial and rotational motion.

[0031] In accordance with a further embodiment of marked micro-wire fabrication, the marking process is integrated into the coiling process. FIG. 4, comprising FIGs. 4 A and 4B, depict side planar views 400, 450 of a micro- wire multiple strand combination in accordance with this further embodiment of present application. The view 400 depicts a completed multiple strand micro-wire 402 including a core wire 404 and a coil sleeve 406 and the view 450 depicts a multiple strand micro-wire 402 during a coiling step of the formation. Referring to the view 450, a base coil wire 452 is led into a coiling mechanism 454 and coiled around the core wire 404 (as indicated by an arrow 456) for a certain length while a marking wire 458 is fed in at preset intervals. The base coil 460 forms the external surface structure of the multiple strand micro-wire 402 which guarantees the required strength and flexibility of the micro- wire 402. The marking coil 462 can be made with different materials which have distinct colors or textures as compared to the base coil 460 for distinguishing predetermined intervals defined by the marking coil 462.

[0032] Instead of a color scheme for identification of the position of both the anterior esophageal wall and the posterior tracheal wall during a TEP procedure, a single colored measurement scale could be used. FIG. 5 depicts a side planar view 500 of a single color measurement scale 502 on a micro-wire 504 for applications in TEP procedures in accordance with the present embodiment. A length L_t 506 is the entire length of the measurement scale. As L_t 506 is known and predefined, a prosthesis length can be calculated by Equation 1 : L_t - 2*n (1) where Lt is the entire length of the measurement scale and n is a number of marking intervals not covered by tissue from proximal marking. Referring to FIG. 6, a side planar view 600 of a further biomedical measurement device for TEP procedure applications in accordance with the present embodiment uses an additional device 602 with a scale on its outer surface which can additionally be included. The device 602 can be used with a guidewire 604 to measure a prosthesis length by subtracting a length L₂ 606 from a length Li 608.

[0033] Referring to FIG. 7, a side planar view 700 of a method for manufacture of a marked biomedical micro-wire device 702 in accordance with the present embodiment using a light emitting diode (LED) marking guidewire core 704 is depicted. The biomedical micro-wire 702 manufactured in accordance with the depicted method is for use in a medical instrument which includes a disposable transparent catheter 706, the LED marked core 704, and a motorized tube driving system 708 consisting of a motor 710, a guide screw 712 and a controller 714. A control panel 716 displaying measurement parameters and tube working length is attached on a distal end 718 of the guidewire device 702. When a user activates a button on the control panel 716 to extend the guidewire, the guidewire (which is the disposable transparent tube 706) rolls out of a wire storage box 720. At the same time, the LED marked core 704 rolls into the transparent guidewire 706 to work as a core wire and inner brace. Since the LED lights are evenly distributed along the LED marking tube 704, measurement of the length between any two points along the guidewire 706 can be achieved by measuring the lit LEDs which can be controlled by the control panel 716. [0034] Thus, it can be seen that the present embodiment in its multiple variations can provide an improved robust method and apparatus for micro-wire marking for biomedical applications which at least partially overcomes the drawbacks of present approaches and provides a more reliable method and apparatus for biological soft tissue applications. The present embodiment presents a medical guidewire with visually detectable markers for location of two points and for measuring the distance between them. In addition, a method for fabrication of a marked micro-wire in accordance with the present embodiment which can circumvent limitations of current fabrication methods results in a marked micro-wire which can accurately measure tissue thickness and enable a clinician to select an appropriate voice prosthesis for a patient during TEP. Further, the present method is not limited to TEP and can be applied to other biomedical applications involving invasive measurement of a length of a soft tissue channel.

[0035] While exemplary embodiments have been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should further be appreciated that the exemplary embodiments are only examples, and are not intended to limit the scope, applicability, operation, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of steps and method of operation described in the exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.

Claims

CLAIMS What is claimed is:

1. A method for fabricating a micro-wire marking for accurate measurement during biomedical applications comprising:

providing a first wire as a core wire;

coiling a second wire around the core wire as a coil sleeve to form the micro- wire into a guide wire; and

marking the coil sleeve at predefined intervals to provide an accurate measurement scale on the guidewire for biomedical applications.

2. The method in accordance with Claim 1 wherein the marking step comprises depositing ink for ink deposition marking of the coil sleeve, the method further comprising prior to the marking step an additional step of centerless grinding of the coil sleeve at the predefined intervals in order to compensate for added thickness of ink deposited during the step of ink deposition marking to ensure a constant external diameter of the guidewire.

3. The method in accordance with Claim 1 wherein the marking step comprises: positioning the guidewire at a calibrated position with respect to a marking laser;

clamping both ends of the guidewire; and

moving the marking laser from one end of the guidewire to another end of the guidewire to engrave the measurement scale at the predefined intervals along an axial direction of the guidewire by laser marking continuous band-pattern scales at the predefined intervals of the coil sleeve.

4. The method in accordance with Claim 3 wherein the moving step comprises moving the marking laser head along the guidewire while simultaneously rotating the guidewire to produce wave patterns at the predefined intervals along an axial direction of the guidewire.

5. The method in accordance with Claim 1 wherein the coiling step and the marking step are performed simultaneously the coil sleeve comprises a base coil wire and a marking wire and wherein the simultaneous steps of coiling and marking the guidewire comprises coiling the base coil wire around the core wire for certain lengths while coiling the marking wire thereinto at the preset intervals, the marking wire being distinguishable from the base coil wire.

6. The method in accordance with Claim 5 wherein the marking wire has a distinct color as compared to the base coil wire.

7. The method in accordance with Claim 5 wherein the marking wire has a distinct texture as compared to the base coil wire.

8. The method in accordance with Claim 1 wherein the core wire is a light emitting diode (LED) marked core, and wherein the coil sleeve is a transparent guidewire sleeve, and wherein the marking step comprises extending the transparent guidewire sleeve in situ while simultaneously inserting the LED marked core into the transparent guidewire sleeve to act as a core wire and inner brace while providing lightable LEDs at the predefined intervals to provide the accurate measurement scale on the guidewire.

9. The method in accordance with Claim 1 wherein the first wire is a predefined length.

10. The method in accordance with Claim 1 wherein the diameter of the guidewire is substantially one millimeter.

11. The method in accordance with Claim 1 wherein the marking step comprises marking the coil sleeve with an initial marking at three millimeters and further markings at the predefined intervals to provide an accurate measurement scale on the guidewire for trachealesophageal puncture (TEP) applications, wherein the predefined intervals are substantially two millimeters from one another and wherein the initial marking is for location of an anterior tracheal wall during the TEP application.

12. The method in accordance with Claim 1 wherein the marking step comprises marking the coil sleeve colored markings at the predefined intervals to provide an accurate measurement scale on the guidewire for biomedical applications, wherein the colored markings comprise a plurality of distinctly different colored markings and wherein a user color code chart can be referenced during the biomedical application to determine a length.

13. A biomedical method for measuring a channel within soft tissue comprising: inserting a micro-wire having a measurement scale having clearly defined markings at predefined intervals through soft tissue into a channel within the soft tissue until one of the clearly defined markings is positioned at a first side of the channel and the micro-wire traverses the channel; and

determining the length of the channel from the measurement scale on the micro-wire.

14. The method in accordance with Claim 13 wherein the biomedical method is a trachealesophageal puncture (TEP) and wherein the channel is a fistula opening between an patient's esophagus and the patient's trachea.

15. The method in accordance with Claim 14 wherein the inserting step comprises a transnasal esophagoscopy (TNE) guided inserting of the micro-wire.

16. The method in accordance with Claim 14 wherein the determining step comprises determining a length of the fistula opening for selection of an appropriate voice prosthesis.

17. The method in accordance with Claim 14 wherein the inserting step comprises inserting the micro-wire into the fistula opening until a predetermined end of a predetermined one of the clearly defined markings aligns with an anterior esophageal wall end of the fistula opening.

18. The method in accordance with Claim 17 wherein the inserting step comprises visually viewing when the predetermined end of the predetermined one of the clearly defined markings aligns with the anterior esophageal wall end of the fistula opening.

19. The method in accordance with Claim 17 wherein the inserting step comprises non-invasively viewing when the predetermined end of the predetermined one of the clearly defined markings aligns with the anterior esophageal wall end of the fistula opening.

20. The method in accordance with Claim 19 wherein the step of non-invasively viewing comprises viewing by a non-invasively viewing method selected from the group comprising ultrasound imaging or computed tomography imaging.

21. The method in accordance with Claim 17 wherein the determining step comprises determining the length of the channel in response to locating a position of one of the clearly defined markings which aligns with an posterior tracheal wall end of the fistula opening.

22. The method in accordance with Claim 20 wherein locating a position of one of the clearly defined markings which aligns with an posterior tracheal wall end of the fistula opening comprises visually viewing through stoma the posterior tracheal wall end of the fistula opening to identify the one of the clearly defined markings that is aligned with it.

23. A device for micro-wire biomedical applications comprising:

a medical instrument comprising: a disposable transparent catheter;

a light emitting diode (LED) marked core; and

a motorized tube driving system comprising:

a motor;

a guide screw; and

a controller; and

a control panel coupled to a distal end of the disposable transparent catheter and displaying measurement parameters and a tube working length, the control panel responsive to a user activation to forward signals to the controller for extending the disposable transparent catheter and simultaneously rolling the LED marked core into the disposable transparent catheter such that the LED marked core operates as a core wire and inner brace and LED lights evenly distributed along the LED marked core allow measuring a length between any two points along the disposable transparent catheter.