U.S. patent application number 14/983696 was filed with the patent office on 2016-06-30 for coatings for surgical instruments.
The applicant listed for this patent is DePuy Synthes Products, Inc.. Invention is credited to Sean Selover, Dayananda Sukadhare.
Application Number | 20160186307 14/983696 |
Document ID | / |
Family ID | 55299728 |
Filed Date | 2016-06-30 |
United States Patent
Application |
20160186307 |
Kind Code |
A1 |
Sukadhare; Dayananda ; et
al. |
June 30, 2016 |
COATINGS FOR SURGICAL INSTRUMENTS
Abstract
A coated medical instrument can include a first layer bonded to
a metal substrate surface of a medical instrument, a second layer
bonded to the first layer, and a third layer disposed on the second
layer, The first layer comprises chromium (Cr), hafnium (Hf),
titanium (Ti), and/or niobium (Nb). The second layer comprises a
nitride, oxide, carbide, carbonitride, or boride of chromium (Cr),
hafnium (Hf), niobium (Nb), tungsten (W), titanium (Ti), aluminum
(Al), zirconium (Zr), and/or silicon (Si). The third layer
comprises a nitride, oxide, carbide, boride, oxynitride,
oxycarbide, or oxycarbonitride of chromium (Cr), hafnium (Hf),
niobium (Nb), tungsten (W), titanium (Ti), aluminum (Al), zirconium
(Zr), and/or silicon (Si). Methods for making coated medical
instruments are also disclosed herein.
Inventors: |
Sukadhare; Dayananda;
(Bayside, NY) ; Selover; Sean; (Westport,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DePuy Synthes Products, Inc. |
Raynham |
MA |
US |
|
|
Family ID: |
55299728 |
Appl. No.: |
14/983696 |
Filed: |
December 30, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62097755 |
Dec 30, 2014 |
|
|
|
Current U.S.
Class: |
428/623 ;
204/192.15; 204/192.38 |
Current CPC
Class: |
A61L 27/306 20130101;
C23C 14/0641 20130101; A61L 2/232 20130101; C23C 14/022 20130101;
A61L 31/082 20130101; C23C 14/083 20130101; C23C 14/0068 20130101;
A61L 2420/08 20130101; A61L 2430/38 20130101; C23C 14/0089
20130101; C23C 14/325 20130101 |
International
Class: |
C23C 14/06 20060101
C23C014/06; C23C 14/00 20060101 C23C014/00; C23C 14/58 20060101
C23C014/58; C23C 14/08 20060101 C23C014/08; C23C 14/32 20060101
C23C014/32; C23C 14/02 20060101 C23C014/02 |
Claims
1. A coated medical instrument comprising: a first layer bonded to
a metal substrate surface of a medical instrument, the first layer
comprising chromium (Cr), hafnium (Hf), titanium (Ti), and/or
niobium (Nb); a second layer bonded to the first layer, the second
layer comprising a nitride, oxide, carbide, carbonitride, or boride
of chromium (Cr), hafnium (Hf), niobium (Nb), tungsten (W),
titanium (Ti), aluminum (Al), zirconium (Zr), and/or silicon (Si);
and a third layer disposed on the second layer, the third layer
comprising a nitride, oxide, carbide, boride, oxynitride,
oxycarbide, or oxycarbonitride of chromium (Cr), hafnium (Hf),
niobium (Nb), tungsten (W), titanium (Ti), aluminum (Al), zirconium
(Zr), and/or silicon (Si).
2. The coated medical instrument of claim 1, wherein: the first
layer is 0.01 to 1.0 microns thick; the second layer is 1.0 to 5.0
microns thick; and/or the third layer is 0.01 to 5.0 microns
thick.
3. The coated medical instrument of claim 1, wherein the first
layer comprises metallic Cr, Hf, Ti, or Nb or a nitride or oxide of
Cr, Hf, Ti, or Nb.
4. The coated medical instrument of claim 1, wherein the second
layer comprises a nitride or oxide of Cr, Hf, Nb, W, Ti, Al, Zr, or
Si.
5. The coated medical instrument of claim 1, wherein the third
layer comprises Ti.
6. The coated medical instrument of claim 1, wherein the third
layer is blue, grey, or black.
7. The coated medical instrument of claim 1, wherein the metal
substrate surface is stainless steel.
8. The coated medical instrument of claim 1, wherein the second
layer has a monoblock, multilayered, or gradient structure.
9. The coated medical instrument of claim 1, wherein: the first
layer comprises metallic Cr and the second layer comprises a
nitride or oxide of Cr; the first layer comprises metallic Hf and
the second layer comprises a nitride or oxide of Hf; or the first
layer comprises metallic Nb and the second layer comprises nitride
or oxide of Nb.
10. The coated medical instrument of claim 9, wherein the nitride
or oxide of Cr, Hf, or Nb comprises a gradient.
11. The coated medical instrument of claim 1, wherein the coated
medical instrument is corrosion resistant.
12. A method for manufacturing a coated medical instrument
comprising: depositing a first layer on a metal substrate surface
of a medical instrument by vapor deposition, the first layer
comprising chromium (Cr), hafnium (Hf), titanium (Ti), and/or
niobium (Nb); depositing a second layer on the first layer by vapor
deposition, the second layer bonded to the first layer, and the
second layer comprising a nitride, oxide, carbide, carbonitride, or
boride of chromium (Cr), hafnium (Hf), niobium (Nb), tungsten (W),
titanium (Ti), aluminum (Al), zirconium (Zr), and/or silicon (Si);
and depositing a third layer on the second layer by vapor
deposition, the third layer comprising a nitride, oxide, carbide,
boride, oxynitride, oxycarbide, or oxycarbonitride of chromium
(Cr), hafnium (Hf), niobium (Nb), tungsten (W), titanium (Ti),
aluminum (Al), zirconium (Zr), and/or silicon (Si).
13. The method of claim 12, wherein at least one of the layers is
deposited by an arc process or a combination of an arc and sputter
processes.
14. The method of claim 12, wherein at least one of the layers is
deposited at a temperature of 180 to 1,000.degree. F.
15. The method of claim 12, further comprising a reactive plasma
surface cleaning-conditioning process before depositing at least
one of the first, second, and third layers.
16. The method of claim 12, further comprising external cleaning
the metal substrate surface before depositing the first layer.
17. The method of claim 12, further depositing the second layer
using an arc and sputter process, thereby depositing a gradient in
the second layer.
18. The method of claim 12, further comprising depositing the first
and second layers in a first vapor deposition chamber and
depositing the third layer in a second vapor deposition
chamber.
19. The method of claim 12, further comprising cleaning and
conditioning a surface of the second layer using a plasma cleaning
technique before depositing the third layer.
20. The method of claim 12, wherein the coated medical instrument
is corrosion resistant.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application No. 62/097,755, filed on Dec. 30, 2014 and entitled
"Coating for Surgical Instruments," which is hereby incorporated by
reference in its entirety.
FIELD
[0002] The present application relates to coatings and methods for
forming the same, for example, coatings for a surgical
instrument.
BACKGROUND OF THE INVENTION
[0003] There are many types of surgical instruments used to perform
surgical procedures in hospitals or other medical facilities.
Overtime, these surgical instruments can experience wear and/or be
damaged. For example, medical personnel such as doctors and nurses,
often repeatedly handle a surgical instrument during a given
surgical procedure. At the same time, the surgical instrument can
be exposed to air and various bodily fluids which can cause
spotting, staining, and/or corrode the instrument. After a surgical
procedure has been completed, the instruments are typically cleaned
and sterilized so that they can be reused for a subsequent surgical
procedure.
[0004] While hospitals and/or the individual physicians can reduce
costs by cleaning and reusing surgical instruments, the cleaning
and sterilization processes can shorten an instrument's useful
life. A surgical instrument is typically formed from one or more
metals (e.g., stainless steel). Stainless steel is commonly used to
produce surgical instruments and is a metal alloy that generally
includes iron, carbon, chromium, nickel, manganese, silica, and
other metals. Stainless steel and many other metals/metal alloys
are likely to corrode from normal use. Protracted and repeated
handling of a metal instrument can cause a metal instrument to
corrode more quickly, as can cleaning and/or sterilization
processes.
[0005] Conventional surgical instruments formed from metal are not
easily identifiable because they generally have the same silver
color. During a surgical procedure, it is important for a surgeon
and other medical personnel to identify and distinguish between
multiple types and/or sized instruments placed on a surgical tray.
The selection of the correct instrument should be made quickly as a
delay could increase the duration of the procedure and the
associated risks to the patient. However, surgical instruments are
typically made from stainless steel and tend to have a similar
color, making it difficult for medical personnel to quickly and
easily visually identify and select the desired instrument.
[0006] Accordingly, there is a need for durable,
corrosion-resistant, and easily identifiable surgical
instruments.
SUMMARY OF THE INVENTION
[0007] Coated surgical instruments are described which utilize
coatings to improve the corrosion-resistance and/or impart other
desirable properties to the instrument (e.g., color, appearance).
An uncoated surgical instrument can be formed from a variety of
materials, such as varying grades of stainless steel. The
instrument can be coated with one or more layers of material and/or
material gradients. The composition, thickness, and technique for
forming each layer can be selected to impart a specific property on
the instrument, such as to improve the instrument's corrosion
resistance. A corrosion-protection layer, for example, can have a
higher resistance to corrosion than the untreated instrument, e.g.,
uncoated stainless steel. By way of example, a surgical instrument
can be coated with two or more layers, such as a base layer and
corrosion-protection layer/gradient. In some embodiments, the
instrument can have a top layer deposited onto the
corrosion-protection layer and this outer layer can have a
distinctive color so that a user can more easily visually identify
the instrument.
[0008] Methods for depositing coatings onto a surgical instrument
are also described. Distinct coating sequences can be carried out
using any combination of vapor deposition and coating systems. The
methods can generally begin by pre-cleaning the uncoated/untreated
instrument prior to depositing coatings or material gradients.
While the techniques for coating the instrument can vary, in one
example, a first vapor deposition system can be used to
sequentially deposit the first metal layer and the
corrosion-protection layer onto the surgical instrument and a
second vapor deposition system can be used to deposit a third,
outer layer onto the metal compound layer/gradient. The
manufacturing methods herein can provide greater flexibility in
selecting and depositing particular coatings and/or material
gradients onto a surgical instrument.
[0009] In various aspects, a coated medical instrument comprises a
first layer bonded to a metal substrate surface of a medical
instrument, a second layer bonded to the first layer, and a third
layer disposed on the second layer. The first layer comprises
chromium (Cr), hafnium (Hf), titanium (Ti), and/or niobium (Nb).
The second layer comprises a nitride, oxide, carbide, carbonitride,
or boride of chromium (Cr), hafnium (Hf), niobium (Nb), tungsten
(W), titanium (Ti), aluminum (Al), zirconium (Zr), and/or silicon
(Si). The third layer comprises a nitride, oxide, carbide, boride,
oxynitride, oxycarbide, or oxycarbonitride of chromium (Cr),
hafnium (Hf), niobium (Nb), tungsten (W), titanium (Ti), aluminum
(Al), zirconium (Zr), and/or silicon (Si).
[0010] In various aspects, a method for manufacturing a coated
medical instrument comprises depositing a first layer on a metal
substrate surface of a medical instrument by vapor deposition,
depositing a second layer on the first layer by vapor deposition,
and depositing a third layer on the second layer by vapor
deposition. The first layer comprises chromium (Cr), hafnium (Hf),
titanium (Ti), and/or niobium (Nb). The second layer comprises a
nitride, oxide, carbide, carbonitride, or boride of chromium (Cr),
hafnium (Hf), niobium (Nb), tungsten (W), titanium (Ti), aluminum
(Al), zirconium (Zr), and/or silicon (Si). The third layer
comprises a nitride, oxide, carbide, boride, oxynitride,
oxycarbide, or oxycarbonitride of chromium (Cr), hafnium (Hf),
niobium (Nb), tungsten (W), titanium (Ti), aluminum (Al), zirconium
(Zr), and/or silicon (Si).
[0011] The first layer can be 0.01 to 1.0 microns thick; the second
layer can be 1.0 to 5.0 microns thick; and/or the third layer can
be 0.01 to 5.0 microns thick. The first layer can be about 0.01,
0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 microns
thick. The first layer can be 0.01 to 0.1, 0.1 to 1.0, 1.0 to 2.0,
2.0 to 3.0, 3.0 to 4.0, or 4.0 to 5.0 microns thick. The second
layer can be about 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0
microns thick. The second layer can be about 1.0 to 2.0, 2.0 to
3.0, 3.0 to 4.0, or 4.0 to 5.0 microns thick. The third layer can
be 0.01 to 5.0 microns thick. The third layer can be about 0.01,
0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0,
2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 microns thick. The third layer can
be about 0.01 to 0.1, 0.1 to 1.0, 1.0 to 2.0, 2.0 to 3.0, 3.0 to
4.0, or 4.0 to 5.0 microns thick.
[0012] The first layer can comprise metallic Cr, Hf, Ti, or Nb or a
nitride or oxide of Cr, Hf, Ti, or Nb. The first layer can be
metallic Cr, Hf, Ti, or Nb. The first layer can be a nitride of Cr,
Hf, Ti, or Nb. The first layer can be an oxide of Cr, Hf, Ti, or
Nb.
[0013] The second layer can comprise a nitride or oxide of Cr, Hf,
Nb, W, Ti, Al, Zr, or Si. The second layer can be a nitride of Cr,
Hf, Nb, W, Ti, Al, Zr, or Si. The second layer can be an oxide of
Cr, Hf, Nb, W, Ti, Al, Zr, or Si.
[0014] The third layer can comprise Ti. The third layer can be a
nitride, oxide, carbide, boride, oxynitride, oxycarbide, or
oxycarbonitride of titanium (Ti).
[0015] The third layer can be blue, grey, or black.
[0016] The metal substrate surface can be stainless steel.
[0017] The second layer can have a monoblock, multilayered, or
gradient structure (e.g., a gradient structure formed by utilizing
different metal targets, power settings within the system and/or
gas, gas mixtures and ratios).
[0018] The coated medical instrument can include: a first layer
that comprises metallic Cr and a second layer comprises a nitride
or oxide of Cr; a first layer that comprises metallic Hf and a
second layer that comprises a nitride or oxide of Hf; or a first
layer that comprises metallic Nb and the second layer comprises
nitride or oxide of Nb. The nitride or oxide of Cr, Hf, or Nb can
comprise a gradient structure.
[0019] The coated medical instrument can be corrosion resistant
(e.g., in normal, saline, and/or aqueous environments).
[0020] The coated medical instrument can be a spine surgical
instrument. The coated medical instrument can be a spinal
implant.
[0021] At least one of the layers can be deposited by an arc
process or a combination of an arc and sputter processes.
[0022] At least one of the layers can be deposited at a temperature
of 180 to 1,000.degree. F. The deposition temperature can be about
180, 200, 300, 400, 500, 600, 700, 800, 900, or 1,000.degree. F.
The deposition temperature can be about 180 to 200, 200 to 300, 300
to 400, 400 to 500, 500 to 600, 600 to 700, 700 to 800, 800 to 900,
or 900 to 1,000.degree. F.
[0023] The method can include a reactive plasma surface
cleaning-conditioning process before depositing at least one of the
first, second, and third layers. The method can include a reactive
plasma surface cleaning-conditioning process before depositing all
three of the first, second, and third layers. The method can
include a reactive plasma surface cleaning-conditioning process
before depositing the first and third layers.
[0024] The method can include an external cleaning of the metal
substrate surface before depositing the first layer.
[0025] The method can include depositing the second layer using an
arc and sputter process, thereby depositing a gradient in the
second layer.
[0026] The method can include depositing the first and second
layers in a first vapor deposition chamber and depositing the third
layer in a second vapor deposition chamber.
[0027] The method can include cleaning and conditioning a surface
of the second layer using a plasma cleaning technique before
depositing the third layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The invention will be more fully understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0029] FIG. 1A illustrates a gradient or one mono-block coating
structure.
[0030] FIG. 1B illustrates a multi/nanolayer stack coating
structure.
[0031] FIG. 2 illustrates am exemplary coating chamber.
[0032] FIG. 3 illustrates different types of targets.
[0033] FIG. 4 is a flow chart for a multi-chamber coating
process.
[0034] FIGS. 5A-F illustrate example coatings and their thicknesses
test results.
[0035] FIGS. 6A-F illustrate example coatings and their
Rockwell/Diamlar Benz test results.
DETAILED DESCRIPTION
[0036] Certain exemplary embodiments will now be described to
provide an overall understanding of the principles of the
structure, function, manufacture, and use of the devices and
methods disclosed herein. One or more examples of these embodiments
are illustrated in the accompanying drawings. Those skilled in the
art will understand that the devices and methods specifically
described herein and illustrated in the accompanying drawings are
non-limiting exemplary embodiments and that the scope of the
present invention is defined solely by the claims. The features
illustrated or described in connection with one exemplary
embodiment may be combined with the features of other embodiments.
Such modifications and variations are intended to be included
within the scope of the present invention.
[0037] Coated surgical instruments are described which utilize one
or more layers of coating to improve the corrosion-resistance
and/or impart other desirable properties to the instrument. An
uncoated surgical instrument can be formed from a variety of
materials, such as varying grades of stainless steel. The
instrument can be coated with one or more layers of material. For
example, one or more layers of material and/or material gradients
can be deposited onto an outer surface of the instrument. The
composition, thickness, and technique for forming each layer can be
selected to impart a specific property on the instrument, such as
to improve the instrument's corrosion resistance. A
corrosion-protection layer, for example, can have a higher
resistance to corrosion than the untreated instrument, e.g.,
uncoated stainless steel. By way of example, a surgical instrument
can be coated with two or more layers, such as a base layer and
corrosion-protection layer/gradient. In some embodiments, the
instrument can have a top layer deposited onto the
corrosion-protection layer and this outer layer can have a
distinctive color so that a user can more easily visually identify
the instrument.
[0038] Methods for depositing coatings onto a surgical instrument
are also described. Distinct coating sequences can be carried out
using any combination of vapor deposition and coating systems. The
methods can generally begin by pre-cleaning the uncoated/untreated
instrument prior to depositing coatings or material gradients.
While the techniques for coating the instrument can vary, in one
example, a first vapor deposition system can be used to
sequentially deposit the first metal layer and the
corrosion-protection layer onto the surgical instrument and a
second vapor deposition system can be used to deposit a third,
outer layer onto the metal compound layer/gradient. The
manufacturing methods herein can provide greater flexibility in
selecting and depositing particular coatings and/or material
gradients onto a surgical instrument.
[0039] Techniques for Pre-Cleaning an Instrument
[0040] Prior to depositing a coating onto an instrument, an
untreated instrument can be subjected to a pre-cleaning process
that will prepare the surface for receiving one or more
layers/gradients. At least one of the following methods can be used
for providing a substrate having a clean surface (e.g., capable of
electrical conduction): compressed air blow-off, chemical cleaning,
electrolytic cleaning, grinding, polishing, tumbling, blasting,
solvent degreasing, and ultrasonic cleaning. As will be
appreciated, other known cleaning techniques can be used to prepare
the substrate of the instrument.
[0041] Coating Structure
[0042] Any number of coatings can be deposited onto a surgical
instrument to improve one or more of the performance and/or other
characteristics of the instrument.
[0043] As illustrated in FIGS. 1A and 1B, a coated medical
instrument 110, 120 comprises a first layer 112, 122 bonded to a
metal substrate 111, 121 surface of a medical instrument, a second
layer 113, 123 bonded to the first layer, and a third layer 114,
124 disposed on the second layer. The metal substrate surface can
be steel, or more particularly a stainless steel (e.g., surgical
grade stainless steel).
[0044] The first layer 112, 122 comprises chromium (Cr), hafnium
(Hf), titanium (Ti), and/or niobium (Nb). The second layer 113, 123
comprises a nitride, oxide, carbide, carbonitride, or boride of
chromium (Cr), hafnium (Hf), niobium (Nb), tungsten (W), titanium
(Ti), aluminum (Al), zirconium (Zr), and/or silicon (Si). The third
layer 114, 124 comprises a nitride, oxide, carbide, boride,
oxynitride, oxycarbide, or oxycarbonitride of chromium (Cr),
hafnium (Hf), niobium (Nb), tungsten (W), titanium (Ti), aluminum
(Al), zirconium (Zr), and/or silicon (Si).
[0045] In some examples, the first layer can comprise metallic Cr,
Hf, Ti, or Nb or a nitride or oxide of Cr, Hf, Ti, or Nb. The first
layer can be metallic Cr, Hf, Ti, or Nb. The first layer can be a
nitride or oxide of Cr, Hf, Ti, or Nb. The second layer can
comprise a nitride or oxide of Cr, Hf, Nb, W, Ti, Al, Zr, or Si.
The second layer can be a nitride of Cr, Hf, Nb, W, Ti, Al, Zr, or
Si. The second layer can be an oxide of Cr, Hf, Nb, W, Ti, Al, Zr,
or Si. The third layer can comprise Ti. The third layer can be a
nitride, oxide, carbide, boride, oxynitride, oxycarbide, or
oxycarbonitride of titanium (Ti).
[0046] As described in connection with the experimental examples
below, the coated medical instrument can include: a first layer
that comprises metallic Cr and a second layer comprises a nitride
or oxide of Cr; a first layer that comprises metallic Hf and a
second layer that comprises a nitride or oxide of Hf; or a first
layer that comprises metallic Nb and the second layer comprises
nitride or oxide of Nb. The nitride or oxide of Cr, Hf, or Nb can
comprise a gradient structure.
[0047] The first two layers can impart corrosion resistance to the
coated medical instrument. The third layer may also impart
corrosion resistance and/or color (e.g., blue, grey, or black) to
the coated medical instrument.
[0048] The layers can have a mono block, gradient, and/or layered
structure. For example, the second layer 113 can be a monoblock or
gradient structure. Alternatively, the second layer 123 can be a
layered structure. Although not expressly illustrated in FIGS. 1A
and 1B, a first and/or third layer can have a gradient or layered
structure. As will be understood by those skilled in the art,
gradient structures can be formed, e.g., by utilizing different
metal targets, power settings within the system and/or gas, gas
mixtures and ratios.
[0049] In another example, a surgical instrument can include a base
(e.g., first) layer and a middle (e.g., second) layer. The base
layer can be deposited onto a surface of a pre-cleaned instrument,
as mentioned above, and the middle layer can be deposited onto the
base layer. These two layers can improve the corrosion resistance
of the instrument. The base layer can be a metallic layer of
Chromium (Cr) or Niobium (Nb) which can be deposited by a vapor
deposition method followed by a middle layer which can be a metal
nitride, carbide, carbo-nitride, or boride. The middle layer can
include at least one of the following metals, Chromium (Cr),
Hafnium (Hf), Niobium (Nb), Tungsten (W) and Zirconium (Zr), and
the metals may be in a compound form.
[0050] A top layer, such as a third layer in the case of coatings
that include a base layer and middle layer, can be deposited onto
one or more corrosion-resistant layers and this layer can impart a
distinctive color to the instrument. The top layer can include at
least one of the following metals including Chromium, Hafnium,
Niobium, Tungsten, Zirconium, Aluminum (Al), Silicon (Si), and
Titanium (Ti). The structure of this coating may be a carbide,
nitride, carbo-nitride, oxy carbo nitride, oxy nitride, oxy
carbide, or boride, of any of the metals named above. For example,
the top layer can be a pre-determined shade of black (or another
color such as blue or grey).
[0051] The thickness of the layers can also vary. The first layer
can be 0.01 to 1.0 microns thick; the second layer can be 1.0 to
5.0 microns thick; and/or the third layer can be 0.01 to 5.0
microns thick. The first layer can be about 0.01, 0.05, 0.1, 0.2,
0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 microns thick. The first
layer can be 0.01 to 0.1, 0.1 to 1.0, 1.0 to 2.0, 2.0 to 3.0, 3.0
to 4.0, or 4.0 to 5.0 microns thick. The second layer can be about
1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 microns thick. The
second layer can be about 1.0 to 2.0, 2.0 to 3.0, 3.0 to 4.0, or
4.0 to 5.0 microns thick. The third layer can be 0.01 to 5.0
microns thick. The third layer can be about 0.01, 0.05, 0.1, 0.2,
0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5,
4.0, 4.5, or 5.0 microns thick. The third layer can be about 0.01
to 0.1, 0.1 to 1.0, 1.0 to 2.0, 2.0 to 3.0, 3.0 to 4.0, or 4.0 to
5.0 microns thick. In another example, the base layer/gradient can
be in the range of about 0.1-1 micron thick, the middle layer can
be in the range of about 1-5.0 microns thick, and the top layer can
be in the range of about 0.1-5.0 microns thick.
[0052] As will be described in greater detail below, the layers of
material can be deposited onto the surgical instrument using
various techniques. For example, in one embodiment, the layers can
be deposited using a vapor deposition method with the base and
middle coats deposited onto the instrument in a first vapor
deposition device and the final top coat layer being deposited onto
the instrument using a second vapor deposition device.
[0053] Vapor Deposition Techniques for Coating an Instrument
[0054] In various aspects, a method for manufacturing a coated
medical instrument comprises depositing a first layer on a metal
substrate surface of a medical instrument by vapor deposition,
depositing a second layer on the first layer by vapor deposition,
and depositing a third layer on the second layer by vapor
deposition.
[0055] FIG. 2 illustrates an exemplary vapor deposition device 200
that can be used to deposit one or more layers/gradients of metal
coating onto a surgical instrument. The vapor deposition device
coating chamber 201 can be used in a square shaped, rectangular
shaped, octagonal shaped, or a simple bell jar shaped, made from
stainless steel. The coating system can have arc sources and/or
sputter sources (illustrated here as target sources 202) positioned
at strategic locations of the walls and the system can have planar,
round, or studded targets of standard sizes. The targets can be of
a single metal composition or studded or pre-alloyed with binary or
ternary alloys of different metals or compounds of Chromium,
Hafnium, Tungsten, and Niobium, Zirconium, Aluminum, Silicon and
Titanium, as shown in FIG. 3. The deposition device 200 also
includes radiant heaters 203, gas line 204, pump line 205 to create
a vacuum, and a substrate holder 207 (e.g., which can be rotated 1
to 10 RPM, or any other rotational value or range discussed
herein).
[0056] Although vapor deposition device 200 is presented as an
example for illustrative purposes, one skilled in the art will
understand that the invention can be implemented in various other
vapor deposition devices in view of the disclosure provided
herein.
[0057] As discussed above, the method can include a reactive plasma
surface cleaning-conditioning process before depositing at least
one of the first, second, and third layers. The method can include
a reactive plasma surface cleaning-conditioning process before
depositing all three of the first, second, and third layers. The
method can include a reactive plasma surface cleaning-conditioning
process before depositing the first and third layers. The method
can include an external cleaning of the metal substrate surface
before depositing the first layer.
[0058] The in situ etch process can include a glow discharge
process utilizing Hydrogen or Argon plasma or an arc-triggered glow
discharge process using Argon, Hydrogen, and Nitrogen, or a
combination thereof. The substrate can be capable of being rotated
and electrically biased. The bias for the arc coating system can be
a DC bias or a pulsed DC bias or a combination thereof. Appropriate
power sources can be used for arc or magnetron sputtering. The arc
system utilized can be a filtered arc method utilizing a magnetic
array of filters in situ the chamber to attain cleaner and denser
coatings.
[0059] At least one of the layers can be deposited by an arc
process or a combination of an arc and sputter processes. For
example, a method of applying a vapor deposited coatings in an
environment where the deposition process used may be predominantly
a cathodic arc method or a combination of a cathodic arc and
sputter processes can include applying the various layers in two
distinct systems at temperatures in the range of about
180-1000.degree. F. More particularly, the deposition temperature
can be about 180, 200, 300, 400, 500, 600, 700, 800, 900, or
1,000.degree. F. The deposition temperature can be about 180 to
200, 200 to 300, 300 to 400, 400 to 500, 500 to 600, 600 to 700,
700 to 800, 800 to 900, or 900 to 1,000.degree. F. The method can
be performed using the above mentioned arc/sputter systems to
produce a coating architecture of a specific thickness and formed
from specific compounds.
[0060] The sputter technique used can be of reactive sputter type.
Where the metal is sputtered, the compound can be formed on the
instrument surface using one or more gasses such as Argon,
Nitrogen, Acetylene, Oxygen, or Methane.
[0061] A combination of different source target compositions within
the said process can be used as one of the elements to obtain the
desired coating architecture on the instrument. The two vapor
coating devices can make use of various gasses using at least one
of the following gasses to enable formation of the metal compound
on the instrument: Argon, Nitrogen, Methane, Acetylene and
Oxygen.
[0062] The vapor device systems shown have arc sources and sputter
sources at strategic locations on the walls of the coating device.
The arc sources can be a planar target 300 or a round target 301 of
standard sizes or a studded target 302 with two different metals,
as illustrated in FIG. 3. The targets can be a single metal type,
binary, or ternary alloys or compounds of the metals, Chromium,
Hafnium, Niobium, Tungsten, Silicon, Aluminum, or Titanium. The
studded targets can include two metals press fitted into each
other.
[0063] A method of applying a coating on spinal instruments can
include pre-cleaning the surface of the instrument, as detailed
above, before loading the instrument onto fixtures that are in turn
loaded into a series of vacuum systems for different stages
(layers) of the coating. An internal surface etch process can be
used to enhance adhesion the base metal coat or subsequent layers
can be deposited over each other using a glow discharge or ion
bombardment process that allows for a surface cleaning-etching
process that enables a superior adhesion of the coating to the
substrate.
[0064] A method of achieving said coating architecture-sequence can
involve a two step coating sequence or coating operations. The two
coating steps in the two different devices that deposit the bottom
and middle layers and the top layer will involve pre-cleaning
before coating via an external cleaning method.
[0065] The in situ etch process may include a glow discharge
process utilizing Hydrogen or Argon plasma or an arc triggered glow
discharge arc process using Argon, Hydrogen and Nitrogen or a
combination thereof. The bias for the arc coating system may be a
DC bias or a pulsed DC bias or a combination thereof. Radiant
heaters can be used to heat the instrument to a temperature in the
range of about 180-1000.degree. F., or a different temperature
range or value discussed herein.
[0066] A method of achieving a said coating architecture-sequence
can involve a two-step coating sequence or coating operation. The
two coating steps can be carried out in the two different
devices--one that coats the first and middle (second) layer and the
second that coats the top (third) layer. Between the two steps
there can be physical transfer of thee substrates between the two
devices and can involve a pre-cleaning step before the top layer
coating is applied.
[0067] Different fixturing methods can be used for the type of
product utilizing metallic masking wherever required. The scope of
fixturing may utilize a single, double or even triple planetary for
uniform deposition in either the arc or sputter systems. Rotational
speeds in the range of about 1 to 10 RPM, or lower, e.g., 0.2-10.0
RPM, can be utilized for etching/coating/cooling sequences. For
example, a rotation speed can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8,
0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 RPM. A rotation speed can be
in the range of 0.2 to 1, 1 to 2, 2 to 3, 3 to 4, 4 to 5, 5 to 6, 6
to 7, 7 to 8, 8 to 9, or 9 to 10 RPM.
[0068] An exemplary overall process 400 of coating a surgical
instrument is shown in FIG. 4. The process 400 utilizes two
reaction chambers (referred to as chamber 1 and chamber 2).
[0069] In step 401, an instrument is received for coating/cleaning.
For example, one or more surgical instruments can be loaded onto
the fixtures and can be stacked for pre-cleaning. Step 402 of
(first) pre-cleaning can be achieved by at least one of the several
methods described above such as compressed air blow offs, chemical
cleaning, electrolytic cleaning, grinding, polishing, tumbling,
blasting, solvent degreasing and other forms of ultrasonic cleaning
using various solvents and solutions.
[0070] In step 403, an instrument is loaded onto fixtures and in
step 404 the fixtures are loaded into vapor coating device 1 (the
first coating chamber). For example, after pre-cleaning is
complete, the instrument(s) can be loaded in pre-designed
orientations for coating. Areas of the instrument that may require
masking can be masked using predesigned fixtures.
[0071] Once the loading is complete, the coating device can be
considered ready for the next step of loading for the purposes of
conditioning and coating. The overall process can include a pump
down cycle to create a vacuum within the coating system and the
tools are next subjected to pre heating in the presence of radiant
heaters. Once a satisfactory level of vacuum is reached, the
radiant heaters within the system can be turned on to preheat the
substrate (e.g., instrument+fixtures).
[0072] Conditioning of the substrate inclusive pre cleaning and
etching of the substrate surface (e.g., instruments+fixtures) can
be carried out by creating a plasma using a target and at least one
of argon, hydrogen, and oxygen. At least one target (e.g., Cr or
Ti) can be used.
[0073] Etching can be carried out using one of many gasses or
combinations. At least one of the following gasses can be used,
including Argon, Hydrogen, and Nitrogen. The etching process can be
a plasma process where the surgical instruments are biased and the
arc is stuck with the target and the biased tool using any/or all
of the gasses named above. During etching, the instruments in the
fixtures are rotated in the vapor device in the range of about 1-10
RPM, or another rotational value or range disclosed herein.
[0074] Step 405 includes coating the instrument (coating process 1,
for the first and second layers). Coating in vapor coating device 1
can be accomplished using an arc process or a sputter process under
predetermined conditions of target compositions, configurations and
orientations to the tool presenting themselves in the chamber. The
process can utilize at least one of Argon, Nitrogen, methane,
acetylene and oxygen, but multiple gases can be used in tandem. The
coating can use a straight DC bias or a pulsed DC bias. Different
targets subject to electrical charging can have different chemical
compositions and can be used together with other targets or at
different stages of the coating sequence. Adequate electromagnetic
filtering can be utilized during the coating sequence to avoid
un-ionized metal droplets from contaminating the coating on the
tool. During coating, the surgical instruments can be heated to
facilitate uniform coating on the instrument, but should not be
heated high enough so as to soften or otherwise damage the
structural integrity of the surgical instrument. Once the surgical
instrument is coated to satisfy the coating architecture described
above, the electrical circuits and the gasses are switched off and
the tools cooled. After the temperature of the instrument has
decreased to about 120.degree. F. (or lower), the instrument(s) can
be removed from the chamber/coating device 1 (step 406).
[0075] In step 407, the instrument is received from stage 1
coating. The surgical instruments can then be pre-cleaned (step
408) and loaded onto fixtures (step 409). The fixtures are the
loaded into vapor coating device 2 (a second chamber) in step 410.
The pre-cleaning may include at least one cleaning method selected
from the group consisting of compressed air blow-offs, chemical
cleaning, electrolytic cleaning, grinding, polishing, tumbling,
blasting, solvent degreasing and other forms of ultrasonic cleaning
using various solvents and solutions.
[0076] Pre-etching of the surfaces of the pre-coated instrument as
received from vapor deposition device 1 can be performed using a
plasma cleaning technique, similar to the methods used in vapor
deposition chamber 1. The basic structure of the vacuum chamber can
be similar to vapor device 1 in terms of target types, locations,
etc., but may include the ability to form additional compounds of
the third layer of the invention on the tools, such a nitride,
oxide, carbide, boride, oxynitride, oxycarbide, or oxycarbonitride
of chromium (Cr), hafnium (Hf), niobium (Nb), tungsten (W),
titanium (Ti), aluminum (Al), zirconium (Zr), and/or silicon (Si).
The third layer can provide a distinctive color coating.
[0077] In step 411, the instrument is coated with a third layer
according to the invention. After the coating is complete, the
instrument can be removed from the coating chamber (step 412) and
packaged (optional, not shown).
[0078] Corrosion Testing
[0079] In various embodiments, the coated medical instrument is
corrosion resistant. Corrosion resistance can be tested and/or
quantified by methods known in the art. A corrosion test can be a
pass/fail test, for example a tester can conduct a visual
inspection for corrosion with any visually detected corrosion
considered a failed test (e.g., not corrosion resistant) and an
absence of visual corrosion considered a passed test (e.g.,
corrosion resistant). Corrosion resistance can be measured using
conditions that replicate or simulate clinical sterilization and/or
use. Corrosion resistance can be corrosion resistance in normal,
saline, and/or aqueous environments.
[0080] One example corrosion test is as follows:
[0081] Materials: 1. coated medical instruments or test coupons
(e.g., produced according to the invention, illustrated in Example
1); 2. cleanser, such as Steris Instru-Klenz Alkaline Instrument
Cleaner (108608), diluted to twice the recommended concentration
(2%); and 3. a brush, such as a toothbrush (Oral-B Soft 30).
[0082] Methods: Autoclave the test coupons for one cycle, check for
corrosion. Soak test coupons in Steris Instru-Klenz solution for 10
minutes, rinse in water, then scrub surface for 1 minute. Autoclave
the sample 25 times and check for corrosion after the 5th and 25th
cycles. Soak test coupons in Steris Instru-Klenz solution again,
rinse in water, then scrub surface for 1 minute. Autoclave 50 more
times, check for corrosion (e.g., by visual inspection) after the
25th and 50th cycles.
EXAMPLES
Example 1
Corrosion Resistant Layer Preparation
[0083] Stainless steel coupons having a CrN thin film coating (Cr
first layer, CrN second layer), CrN thick film coating (Cr first
layer, CrN second layer), NbO coating (Nb first layer, NbO second
layer), HfO coating (Hf first layer, HfO second layer), HfN coating
(Hf first layer, HfN second layer), and NbN coating (Nb first
layer, NbN second layer) were prepared according to the methods
described above. The CrN thin film and CrN thick film coatings (Set
Nos. 1 and 3) were produced using reactive cathodic arc (RCA)
technology. The NbO, HfO, HfN, and NbN coatings (Set Nos. 2 and
4-6) were produced using reactive magnetron sputtering (RPMS or
suputtering) technology.
TABLE-US-00001 TABLE 1 Six example coatings according to the
invention. Coating composition CrN Thin CrN Thick film film NbO HfO
HfN NbN Technology RCA RCA RPMS RPMS RPMS RPMS Set # 1 3 2 4 5 6
17-4 Nom X X X X X X 17-4 Low X X X X NA X 17-4 High X X X X X X
420 Nom X X X X X X 420 Low X X X X X X 420 High X X X X X X 465
Nom X X X NA X X 465 Low X X X X X X 465 high X X X X X X
[0084] In Table 1, nom, low high, refer to the intensity of bead
blast pressures used on coupons to generate different surfaces on
the coupons that were subjected to the first round of coatings.
Example 2
Sample Analysis
[0085] Table 2 shows the results of sample analysis for the coating
compositions shown in Table 1. The Calotte tester used a
destructive tester for approximate coating thickness measurement on
flat coupons (results summarized below). The Rockwell Diamler Benz
test is a destructive coating adhesion/spalling test on flat
coupons (results summarized below). The La wave tester is a modulus
(elasticity) tester using laser induced acoustic waves (results
summarized below).
[0086] The data in Table 2 shows that the advantageous properties
of certain example coatings according to the invention. The HF
values show generally good adhesion and spalling resistance.
TABLE-US-00002 TABLE 2 Coupon sample analysis for the coating
compositions shown in Table 1. Coating Type La Wave on Calotte
Rockwell/Diamlar witness( Si) on S304 Benz Test on S304 Youngs
witness Spalling/Adhesion Density Modulus Thickness level indicator
(g/Cm.sup.3) ( GPA) CrN (Thin) 3.8 HF-1 6.2 320 CrN (Thick) 7.3 HF
2-3 6.2 218 NbO 3 HF2-3 4.5 95 HfO 4.8 HF-4 11.4 131 HfN 3 HF 1-2
13.1 242 NbN 3.4 HF 2 6.7 169
Example 3
Coatings Thickness Analysis
[0087] FIGS. 5A-F illustrate example coatings and their thicknesses
test results. FIG. 5A illustrates a CrN thin film having a
thickness of 3.8 .mu.m (this and other thicknesses in FIGS. 5A-F
indicated and the pairs of arrows). FIG. 5B illustrates a CrN thick
film having a thickness of 7.3 .mu.m. FIG. 5C illustrates a NbO
coating having a thickness of 3.0 .mu.m. FIG. 5D illustrates a HfO
coating having a thickness of 4.8 .mu.m. FIG. 5E illustrates a HfN
coating having a thickness of 3.0 .mu.m. FIG. 5F illustrates a NbN
coatings having a thickness of 3.4 .mu.m.
Example 4
Coatings Adhesion and Spalling Analysis
[0088] FIGS. 6A-F illustrate example coatings and their
Rockwell/Diamlar Benz test results. FIG. 6A illustrates a CrN thin
film having an adhesion/spalling of HF1. FIG. 6B illustrates a CrN
thick film having an adhesion/spalling of HF2-3. FIG. 6C
illustrates an NbO coating an adhesion/spalling of HF2-3. FIG. 6D
illustrates an HfO coating having an adhesion/spalling of HF4. FIG.
6E illustrates an HfN coating having an adhesion/spalling of HF1-2.
FIG. 6F illustrates an NbN coatings having an adhesion/spalling of
HF2. The coatings show good lamination, with the CrN thin film and
HfN coating having the relatively most robust coating under the
given test conditions. (Data from Table 2 and discussed in Example
2 above.)
[0089] The instrument disclosed herein can be used in surgery, for
example as spine surgical instruments and spinal implants. While
the instruments disclosed herein may be generally described in the
context spinal surgery, it will be appreciated that they can be
used with any human or animal implant, in any of a variety of
surgeries performed on humans or animals, and/or in fields
unrelated to implants or surgery.
[0090] A person of ordinary skill in the art will appreciate
further features and advantages of the invention based on the
above-described embodiments and objectives. Accordingly, the
invention is not to be limited by what has been particularly shown
and described, except as indicated by the appended claims or those
ultimately provided. All publications and references cited herein
are expressly incorporated herein by reference in their entirety,
and the invention expressly includes all combinations and
sub-combinations of features included above and in the incorporated
reference.
* * * * *