Medical Treatment Claims for Medical Devices

One of the most contentious areas in patent protection internationally are claims to methods of medical treatment. Such claims are only possible in two countries – Australia and the US.

The aspects most often discussed in the debate relate to direct surgical or medical treatment, pharmaceutical dosage regimes, and diagnostic techniques practised directly on the human body.

In practice, to obtain effective protection for some medical devices, it is important to obtain some protection for the device as used, or where appropriate, for aspects of how the device interacts with the user. For instance, where the device is used to facilitate a service, the major economic benefit may not reside in the cost of the device itself, but in the improvement it provides to the service. One example is an improved reagent delivery cartridge, to speed up a process and improve safety. Another is where an active implanted medical device uses measurements within the body to calibrate or modify the stimuli which are delivered. In this case, the device may have the same cost, and the same components, but the software is modified to provide an altered operation mode.

In many other countries, claims to a method of medical treatment are expressly prohibited. For example, in India, China, Japan and Europe, such methods are included in a list of subject matter which is expressly excluded from patent protection. Given the restrictions, how can protection for these aspects be achieved?

Part of an effective response is to understand the rationale behind the prohibition. In general terms, the argument relates to a general principle that permitting the monopolisation of medical and surgical techniques would not be in the public interest. The specific instances raised include:

  • hindering medical research by restricting the free flow of knowledge;
  • exposing medical practitioners to personal liability for, e.g., performing life saving procedures; and
  • enabling patentees to control access to medical procedures, so as to take a general public service and place it in the hands of only those who can afford to pay.

The first reason is common to all patenting, applies in any case to pharmaceuticals which are routinely patented, and is not specific to methods of medical treatment. Combining the last two, the guidelines operated by major patent offices generally are centred around the work of the medical professional, so that the claim must not cover the actual delivery of therapy, or the work normally carried out by medical practitioners. Hence, claims directed straight at ‘A method of treating medical condition X wherein device Y is deployed as follows …’ are doomed to failure.

What is required is an analysis of the technical and business processes concerned, to isolate patentable aspects. It is protection of sometimes incidental, sometimes pre-patient or internal methods, which can provide some degree of protection. There is no substitute for a careful analysis and strategy process prior to drafting claims and the patent specification, taking these factors into account. This may result in a patent that looks misdirected to the medical practitioners and product developers, because it will necessarily not focus on what is happening to the patient directly, but it is how to achieve a claim which can be negotiated through the patent office policies and statutory restrictions.

It is important to appreciate that the restriction does not prevent obtaining a patent for a medical device as such. Hence, patents to mechanical, electrical, electronic or materials aspects of devices can be obtained in any jurisdiction. It is when the issue is one of processes within the devices, or that use devices, that a problem arises. While there are no hard and fast rules, some useful approaches include:

  • A focus on processes internal to the device, with no therapy delivered. For example, the method may receive sensor data, apply an algorithm, and modify a table of data. The data is what is used to determine therapy values, but that step is not claimed.
  • Consider the steps required to take a device from a latent state to a state ready for use. These will be carried out in the clinic, and are preparatory to any actual treatment, so can be claimed.
  • Claims can be directed to hardware components ‘adapted to be used’ in a process, or in some cases even to ‘when used’, to import at least some of the constraints of the process, if that helps with patentability.
  • Consider aspects of the product design that are required to make it suitable for a particular purpose. If you can protect any use of a device which could be used in a process, even if these are less significant technically, then this may provide effect use protection.

Of course, the field is much more open in the U.S. and Australia, however, the application of these approaches in addition to more direct method of treatment claims will only improve the effective scope of the patents obtained. The situation in the U.S. is somewhat under challenge, as there is a pending appeal to the US Supreme Court in Mayo v. Prometheus, dealing partly with these issues, in which oral argument was heard in December.

As in all patent drafting, careful strategic analysis and a solid understanding of business models is critical to obtaining effective, and hence valuable, IP rights.

by Peter Franke

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