[The IPKat] What do sex toys and patent law have in common?

[Claire Gregg]

What do sex toys and patent law have in common?

 Dr Claire Gregg Wednesday, October 08, 2025 - #patents, Claire Gregg

A stimulating new decision from the Australian Federal Court explores the intersection of sex toys and patent law, highlighting important issues regarding the construction and infringement of "when used" claims, as well as clarity and sufficiency of claims limited by result under Australian law.

Background

The decision in EIS Gmbh v LELO Oceania Pty Ltd (Liability Trial) [2025] FCA 1111 concerns a patent owned by EIS for the Satisfyer Pro and Satisfyer Pro 2, devices for clitoral stimulation. Claim 1 defines:

A compression wave massage device when used on the clitoris, comprising:

… a drive device configured to generate a change of the volume of at least one cavity between a minimal volume and a maximum volume such that in at least one opening a stimulating pressure field is generated,

wherein the cavity is formed by a single chamber

and the ratio of the volume change to the minimal volume is not below 1/10 and not greater than 1.

EIS sued LELO for infringement by the sale of its own clitoral stimulation products (Sona, Sona 2, Enigma, and Sila) in Australia. LELO counterclaimed for invalidity on grounds including lack of clarity, sufficiency, and support, and also alleged unjustified threats and misleading or deceptive conduct by EIS.

Construction of "when used"

A key construction issue in EIS related to the term "when used", which was introduced during examination to replace the non-limiting term "for" to overcome objections of lack of novelty and inventive step. The experts agreed that the claim preamble provides a description of the function of the device, but EIS contended that the subsequent integers of the device are not referable to its function, i.e., the claim is to a standalone device having the recited claim integers.

Downes J disagreed, stating "the claim is for a device which, when used on the clitoris, functions as a compression wave massager device with the features identified in [the claim integers]". Her Honour considered that "when used" conferred a narrowing limitation on the claims and to construe the claims as contended by EIS would effectively read out the words "when used" and impermissibly recast the claims in their previously non-limiting "for use" form. Thus, properly construed, the claims are for a compression wave massager device which has particular features when used on the clitoris.

Internal validity of claims limited by result

"When used" Kat

Much of the decision hinged on the feature of the claims that the volume change ratio (VCR) is not below 1/10, which was considered a limitation by result. Australian courts have previously emphasised that clarity and sufficiency are especially important for result-limited claims, as the specification must enable the skilled reader to determine whether the result is achieved.

In a relatively rare finding of lack of clarity by an Australian court, Downes J found that claim 1 (and the remainder of the claims by virtue of their dependency on claim 1) lacks clarity. In this regard, her Honour accepted expert evidence that the VCR defined in the claims is an imprecise and ambiguous proxy for measuring pressure and did not account for critical variables such as the starting position of the membrane, the presence and anatomical variation of the clitoris, or the exchange of air or fluid during use. As the method of measuring VCR in a laboratory setting does not reflect real-world use, a skilled person could not reliably determine if a device falls within the claim.

For the same reasons, Downes J found that all claims also lack sufficiency because the specification does not enable a skilled person to make the claimed device having the claimed VCR without undue burden. The lack of experimental data in the specification to justify the claimed VCR also led to a finding of lack of support.

Infringement

In relation to assessing infringement of "when used" claims, Downes J accepted that an alleged infringing device need not be measured when in use, but the patentee nonetheless must establish that all claim features are present when the product is in use. As there was insufficient information in the specification for a skilled person to determine whether a VCR integer is satisfied by the LELO products, and the boundaries of the claims are unclear, it could not be established that LELO’s products infringe the claims.

Despite finding that the claims are not infringed, Downes J was not satisfied that EIS's communications, including press releases and notifications to retailers and online platforms, constitute unjustified threats or misleading or deceptive conduct. Relevantly, the assessment of both grounds involves consideration of how the relevant communications would be perceived by a reasonable recipient. As her Honour considered EIS's communications to be statements of opinion or belief, and would be perceived as such by a reasonable recipient, LELO's claims of unjustified threats and misleading or deceptive conduct failed.

Concluding remarks

The EIS decision provides important guidance on the construction and infringement of "when used" claims. Compared to "for use" claims, which indicate the mere suitability of a product for a recited application, the "when used" limitation narrows the claim scope and requires all claim features to be present during use. To establish infringement, an alleged product must similarly take all the claim features when in use.

The decision also highlights the importance of clearly defining the invention and teaching a skilled person how to perform it. This is particularly important in claims limited by result, in respect of which a skilled person must be able to determine whether the result has been achieved.

 

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