STATEMENT OF THE CASE

(Reprinted from the opinion of the Board)

The Specification states that prior art devices for inhalation of powdered medicaments are “dominated by inhaler devices that are activated by some mechanical means of activation” (Spec. 3:6-7), although Appellants described in a previous patent a device that senses airflow via an acoustic element, such as a microphone, which outputs signals that control a high frequency vibrator (id. at 3:10-15). “However, this acoustic sensor flow does not have the ability to detect the direction of the flow of air” (id. at 3:17-18).

The Specification states that the “present invention provides an improvement over the prior art inhalation devices such as our aforementioned U.S. Patent No. 6,152,130. The present invention provides a directional acoustic flow sensor to operate the inhaler.” (Id. at 4:2-4.) The Specification states that, in one embodiment, “the microphone element 8 produces noise signals 48 in response to detected airflow” (id. at 7:23 to 8:1).

When breathing commences, signal 48 will have an instantaneous voltage offset, relative to the voltage when there is no breathing, due to the change of the pressure in [the] air flow passage. . . . At the instant when breathing commences, the difference between these two signals represents the
direction of the breathing, whether it is an inhalation or exhalation.

(Id. at 9:23 to 10:7.)
Claims 20, 22-27, 29, and 39 are on appeal. Claim 20 is the only independent claim:

20. An air inhalation device for delivering medicament from a container to a user, said device comprising:
an acoustic controller, said acoustic controller including an acoustic sensing element configured to detect noise from free air flow into and through the device and to generate signals based on said detected noise, and a circuit for processing said signals to identify a direction and amplitude of said airflow; and
a high frequency vibrator separate from said acoustic sensing element and coupled to said container for inducing said medicament from said container into said air flow when said processed signals identify inhalation by said user, wherein a direction of said airflow is identified by said circuit by measuring an instantaneous voltage offset generated by said acoustic sensing element.

The Examiner has rejected all of the claims on appeal under 35 U.S.C. § 103(a) as obvious based on Abrams and Haveri (Answer 3). The Examiner finds that Abrams discloses a device meeting most of the limitations of claim 20 (id. at 3-4) but “is silent as to the controller determining a direction of the airflow by measuring an instantaneous voltage offset” (id. at 4).

The Examiner finds that “Haveri discloses a similar inhaler with a vibrating element that has a piezoelectric sensing element (56) that produces signals to identify airflow direction based on an instantaneous admittance value,” and also discloses that “admittance is related to current and voltage by Ohm's law” (id.). The Examiner concludes that it would have been obvious “to modify the controller of Abrams to also determine airflow direction as taught by Haveri in order to more accurately ensure that the patient was inhaling when the medicament was released to avoid wasting medicament” and to determine direction from the voltage because it “can be directly determined from the admittance” (id.).

Appellants argue that “Haveri determines direction of airflow using gas pressure that compress and stretch a piezoelectric element” (Appeal Br. 12), and that Haveri's system cannot be successfully combined with Abrams' system because “[b]oth Abrams and claim 20 function not from a direct pressure drop within the system, but use a microphone or fluid pressure transducer to detect [ ] the noise created by airflow within a device open to the atmosphere inhalation air flow. Haveri uses a direct pressure drop system.” (Id. at 14.) Appellants argue that the control logic that the Examiner finds in Haveri can only be initiated within a pressurized system. . . . Appellants' claimed invention is not a pressurized system, and Abrams does not teach a pressurized system. Thus, it is clear that the control logic of Haveri is incompatible with the systems of claim 20 and Abrams. (Id. at 15.)

We agree with Appellants that the Examiner has not persuasively shown that the combined disclosures of Abrams and Haveri would have made obvious the device of claim 20. Both Abrams and claim 20 require a system with an acoustic sensing element, such as a microphone, to detect air flow (Abrams, col. 2, ll. 18-26) or both air flow and direction (claim 20). Haveri discloses a nebulizer for use in a breathing circuit that includes a ventilator (Haveri, col. 5, ll. 7-9, 21-22). The ventilator can provide all or part of the patient's breathing gases, or the patient can breathe spontaneously through the breathing circuit (id. at col. 5, ll. 31-40). Haveri's nebulizer includes a “ring-like vibrating element 56 . . . mounted to the upper surface of plate 50” (id. at col. 6, ll. 60-61). Haveri states that element 56 can be made of a piezoelectric material, which has the property of changing its dimensions when electrically energized (id. at col. 6, ll. 61-65). Thus, “high frequency alternating electrical energization . . . causes the piezoelectric element 56 to alternately contract . . . to a radially decreased state . . . and then expand to a radially increased state” (id. at col. 8, ll. 56-64), along with attached plate 50 (id. at col. 8, l. 64 to col. 9, l. 9).

This vibration causes droplets of liquid medicament to be released into the airstream to be inhaled by the patient (id. at col. 9, ll. 10-23). Haveri discloses that “a piezoelectric element can also convert mechanical energy to electrical energy. This characteristic is used in [Haveri's] invention to obtain information about the breathing gases in the breathing circuit 2, and particularly the pressure of such gases.” (Id. at col. 9, ll. 29-33.) “This pressure will vary significantly during inhalation and exhalation conditions in breathing circuit 2. For example . . . [w]hen the patient breathes spontaneously, . . . breathing circuit pressure will decrease during inspiration and increase during expiration.” (Id. at col. 9, ll. 35-45.)

Pressure changes in breathing circuit 2 cause plate 50, and attached piezoelectric element 56, to bend either toward or away from the airflow passage (id. at col. 9, l. 53 to col. 10, l. 8). “The deflections of the piezoelectric element 56 . . . result in a change in the dipole moment of the piezoelectric material forming the element 56. This causes a voltage to be generated in the element 56.” (Id. at col. 10, ll. 21-24.) This voltage can then “be used to electrically measure the mechanical strains in element 56 caused by the external forces applied to the piezoelectric element 56 resulting from breathing gas pressures in breathing circuit 2 acting on plate 50” (id. at col. 10, ll. 31-35).

Haveri discloses that the signal from piezoelectric element 56 can be analyzed to determine whether the mechanical loading on the element is tensile or compressive (id. at col. 15, ll. 6-35) and that, based on the type of loading and whether the patient is breathing spontaneously or with assistance from the ventilator, “the direction of gas flow in [the] patient limb 10 can be determined” (id. at col. 15, ll. 41-42). “By detecting the direction and pressure of the breathing gas flow in breathing circuit 2 . . . , and providing this information to control unit 4 it is possible for the control unit 4 to initiate and halt the atomization of the drug to coincide with the breathing of the subject” (id. at col. 16, ll. 20-25).

The Examiner reasons that in Haveri's system, a fluctuating diaphragm (56) [ ] is used to determine the direction of airflow for helping to control the release of medicament. Since microphones (such as that found in Abrams) use a fluctuating diaphragm to convert analog noise signals to digital signals, the only modification to Abrams needed to read on the instant invention is changing the control logic to also determine direction of airflow from the fluctuating diaphragm as taught by Haveri. (Answer 6.)

We conclude that the Examiner's rejection is not supported by a preponderance of the evidence of record. As discussed above, Haveri's system determines the direction of airflow (inhalation or exhalation) based on changes in air pressure in the system sensed by a piezoelectric element. Haveri describes the detected pressure as “pressure of the breathing gas flow in breathing circuit 2” (Haveri, col. 16, ll. 20-21). Haveri's description of its system as including a breathing circuit having one end (patient limb 10) connected to the patient and the other end (inhalation limb 5 and exhalation limb 7) connected to a ventilator (id. at col. 5, ll. 18-30) supports Appellants' position that Haveri's nebulizer is connected to a closed, pressurized system.

The Examiner has not pointed to evidence or provided persuasive technical reasoning to show that inhalation and exhalation by a patient would have a  similar effect on the air pressure in Abrams' inhaler as it does in Haveri's nebulizer. In addition, the Examiner has not provided evidence or persuasive technical reasoning to support her position that [a]s a person inhales or exhales air past the diaphragm in Abrams's microphone, the diaphragm flexes one way or an opposite way depending on if the air is moving in a first direction (inhalation) or a second direction (exhalation). The amplitude of those fluctuations is measured to determine flow amplitude and the direction of the fluctuations is used to determine the flow direction in the same manner as taught by Haveri. (Answer 7.)

As discussed above, Haveri's system uses a piezoelectric element that is deformed either inwardly or outwardly, relative to the airflow passage, by a change in air pressure (Haveri, col. 9, l. 53 to col. 10, l. 8) and the type of loading (compressive or tensile) is determined and used together with the breathing mode to determine the direction of airflow (id. at col. 15, ll. 6-42). The Examiner has not shown that the vibrating diaphragm of a microphone, as used by Abrams, is capable of providing the output necessary to carry out the analysis used in Haveri's system; e.g., an indication of compressive or tensile loading that could be used to distinguish increased pressure from decreased pressure in the airflow passage. The Examiner therefore has not supported the position that “[t]here is nothing in either reference suggesting that the control logic of Haveri is incompatible with Abrams” (Answer 7), such that “[t]he simple and predictable modification of Abrams's control logic would then result in the instant invention” (id. at 8).

SUMMARY

We reverse the rejection of claims under 35 U.S.C. § 103(a) based on Abrams and Haveri.