PTAB affirms anticipation of tourniquet by cable tie since tie is capable of "safe occlusive pressure"

Takeaway: The Applicant appealed a claim to a tourniquet including "the block body and cuff cooperate to provide safe occlusive pressures to both sides of the target digit." The Examiner rejected as anticipated by a cable tie used with telecom cable: the range of pressures exerted by the cable tie  included "safe" pressure, and this capability was enough for anticipation. The Applicant argued that the reference cable tie was made of high-tensile thermoplastic and had a loop tensile strength over 250 pounds. The Applicant entered expert affidavits by two surgeons attesting that this cable tie "was not suitable for use as a digit tourniquet." The Board adopted the Examiner's reasoning and affirmed the rejection.

Details:
Ex parte Warburton
Appeal 2011-011302; Appl. No. 11/222,956; Tech. Center 3700
Decided  January 18, 2013

The application on appeal was directed to a tourniquet for a finger or toe. The application included several independent apparatus claims of differing scope, as well as a method-of-use claim.



One of the independent claims on appeal read: 

     1. A single-use disposable digital tourniquet, comprising:
a substantially rigid block support body defining a curved digit contact outer surface and an opposing outer surface ...the support body comprising first and second spaced apart cuff channels sized and configured to receive a cuff therethrough,
     wherein the first and second cuff channels extend ... such that, in position, a cuff extends out of the first and second channels of the block body ...
     wherein the block body and cuff cooperate to provide safe occlusive pressures to both sides of the target digit ...
(Emphasis added.) 

In the early rounds of prosecution, the Examiner used a series of prior art tourniquet references to reject the claims. The Applicant amended the claims several times to distinguish over these tourniquet references.

In the fifth Office Action, a new reference, Dyer, appeared. Dyer described a cable tie assembly used to space apart a telecom cable and a metal support. The Examiner used Dyer to reject all the claims, including some that had been indicated as allowable in previous Office Actions.

Dyer's cable tie is shown below left, and an embodiment of the Applicant's claimed torniquet is shown on the right.

The Examiner asserted that Dyer's cable tie anticipated all the independent apparatus claims. Dyer was also used as a primary reference in a § 103 rejection of the sole independent method claim.

The Applicant amended independent apparatus claim 1 to recite "wherein the block body and the cuff cooperate to provide safe occlusive pressures to both sides of the target digit." The specification taught that "the minimum finger occlusion pressure is a function of the circumference of the finger and the patient's systolic blood pressure." The specification also included a table of target pressures vs. cuff widths, and incorporated by reference a journal article about finger tourniquets. The Applicant argued that Dyer did not teach "desired target/safe occlusive  pressures and/or [is] simply not configured to support the digit in the manner required for appropriate digit tourniquet use."

Along with the response, the Applicant filed § 1.132 Declarations by two surgeons. The surgeons asserted that Dyer's cable tie was not suitable for use as a digit tourniquet, and that they would not look to the field of cable ties for information about a medical instrument.

The Examiner maintained the anticipation rejection and provided further explanation:

[T]he amount of pressure provided by the device of Dyer depends solely on the amount of tension applied to the strap as it is pulled through the cable tie head and how far the strap is pulled through the cable tie head. Therefore, the device of Dyer is capable of providing various amounts of pressure to an object held between the cable tie head and the strap ... Simply because the material provides a large loop tensile strength ... does not render the strap incapable of providing a safe occlusive pressure as the strap could be left more or less slack around an object to provide a desired pressure.
(Emphasis added.)

In response to the Applicant's argument that Dyer did not "teach" the safe occlusive pressure limitation, the Examiner noted Dyer (an issued patent) was presumed to be enabled. Finally, the Examiner critiqued the declarations, contending that their statements about the maximum pressure the device is capable of applying "does not factually prove that the device is incapable of producing a smaller pressure."

The Applicant appealed. Elaborating upon earlier arguments, the Applicant explained that Dyer taught a tie wrap made of high-tensile thermoplastic and having a loop tensile strength over 250 pounds. In fact, Dyer suggested a particular crystalline plastic (DELRIN®) described as having "metal-like" properties. Thus, "this would not appear to be a material that forms a cuff for providing safe occlusive pressures to a target digit (i.e., without causing nerve or tissue damage." (Emphasis in original.)

Responding to the Examiner's point about presumed enablement, the Applicant argued that enablement in Dyer should be assessed with respect to cable ties, not tourniquets.

Dyer does not describe any mechanism that could provide this [safe occlusive pressure] feature; rather, Dyer teaches that the strap is inserted without any regard to the degree of tension of the objects held under the strap, and that the strap cannot be "backed out" or withdrawn to reduce this tension.  Thus, Appellant strongly asserts that Dyer does not contain adequate disclosure such that a person of ordinary skill in the art could make and use the claimed digital tourniquet having block body and cuff that cooperate to provide safe occlusive pressure to both sides of a target digit.

The Examiner's Answer focused on the capability of Dyer's structure. According to the Examiner, the "safe occlusive pressures" limitation was intended use, meaning Dyer's cable tie did anticipate because it was capable of applying the claimed pressures. Furthermore, the Answer noted that "the Rule 132 affidavits do not discuss the claimed invention providing 'safe occlusive pressures' and only discuss the block and strap providing occlusive pressure." (Emphasis added.)

The Applicant filed a Reply Brief with extensive rebuttal of the Examiner's positions. With regard to affidavits, the Reply Brief indicated specific paragraphs in the affidavits that referred to "safe, even and/or controlled occlusive pressure." The Reply Brief then asserted that the "Examiner's blanket statements that cable ties ... can provide a safe, even and/or controlled pressure cannot outweigh evidence to the contrary in the form of statements by expert surgeons."

Addressing intended use, the Reply Brief asserted that "safe occlusive pressures ... are provided by structural aspects of the claimed tourniquet such as the geometry of the support body and the cuff and the cooperating nature of these two components." (Emphasis added.)

Finally, commenting on the capabilities of Dyer's cable tie, the Reply Brief quoted from selected passages in Dyer to show that Dyer's "strap is inserted without any regard to the degree of tension on the objects" and "cannot be backed out or withdrawn to reduce this tension." As a result, Dyer does not "adequately describe" the claimed structural features that cooperate to function in the claimed manner.

The Board affirmed the anticipation rejection of claim 1 and explained as follows:

We note that the term “safe” is a relative term that is not otherwise defined by the Specification. In this regard, we agree with the Examiner’s logic that “the pressure provided by the strap of the device of Dyer depends solely upon the tension applied to the strap and the amount of strap pulled through the cable tie head” and that the device of Dyer is capable of applying pressure that would fall  within the range of pressure deemed safe for use as a digit tourniquet. Evidence supplied by Appellant in the form of expert opinion does not prove that the device of Dyer is incapable of supplying safe pressures. Accordingly, we conclude that the Examiner did not err in concluding that claim 1 is anticipated by Dyer.

My two cents: Imagine the Applicant's frustration at overcoming three tourniquet references, only to be blocked by a cable tie! Now, the Applicant did win on some other claims, but that's a topic for another post.

I give points to the Applicant for an organized prosecution. With each round, the Applicant elaborated on his own previous arguments and also addressed points brought up by the Examiner in the last paper. However, the Applicant loses points  – and more importantly, loses the appeal – for not hearing the Examiner on the most important issue: the claim language read on the cable tie's capability of generating a "safe" pressure. This issue was identified early on, and both sides generated a lot of paper discussing it. Even so, it appears that at some level, the Applicant just didn't get it.

Turning now to what might have been rather than what did happen, I wondered how the Applicant could have overcome the Dyer rejection. Is the root issue the meaning of "safe occlusion pressure"? The Board did suggest "safe" is broad. Or is intended use the root issue?

One way of looking at this is that the Dyer's high-strength cable tie strap can be used to apply a range of pressures, with Applicant's "safe" pressure in between. The reference therefore anticipates. If that's the issue, language about limiting the pressure should overcome. But I can't tell if this limiting aspect is how the Applicant really understood his invention, because the spec doesn't use the word limit or anything like it.

I've also thrown by the semi-structural "cooperate" limitation. Does the block body really have anything to do with the limit or safe pressure function? It's just the cuff, isn't it?

I might try something like "cuff adapted to safely limit," then argue it's not intended use, and instead conveys information about the type of structure. And the structure in Dyer – a high-tensile strap – is simply not one that operates to limit pressure to a safe value.

If the Examiner/Board insists on reading "adapted to" as intended use (satisfied by mere capability in the reference structure), I think maybe you're still okay. The high-tensile strap isn't really even capable of limiting pressure to a safe value. Sure, it's capable of producing safe pressure. Sure, it's capable of limiting pressure, since it will break at some point – but that's way past the safe value. 

The spec did mention "safe", "even", and "controlled" pressures, but didn't focus on this aspect, and didn't even use the word "limit." Probably because the Applicant focused on distinguishing over other tourniquets, not cable ties. And that's clearly a challenge with rejections like this: amending to describe a feature that's implicit in the description when read in context by a POSITA – yet isn't specifically described in any detail in the spec.

What does appear to be important is a related feature: structure to let the user know when the target pressure has been reached. This function is provided by a deformable member extending across the cuff channel. The material and specific design of the deformable member is chosen to yield or break when particular target is reached, producing tactile or audible feedback. This feedback tells the user to stop pulling on the cuff.

This deformable member was recited in some of the original dependent claims, and was also in two of the claims that had rejections reversed by the Board.