Chapter excerpt from the ebook MedTech IP: Lessons and Strategies for Success - view all chapters here.
Computer-assisted methods may be used during various medical treatments, including surgery. At first sight it might be thought that such methods are excluded from patent protection as being methods of treatment of the human body by surgery or therapy.
However, by careful drafting of patent claims it is possible to avoid these exclusions. This applies both to methods which use computer-assisted devices to collect data from a patient, for example using a sensor, and to methods which use computers to assist doctors in making decisions based on processing of the collected information, for example during surgery.
In particular, when drafting claims in this area it is important to avoid steps which include physical activities which might be regarded as surgical steps.
Let's take a look at an example, and learn from an exceptional entrepreneur at the same time...
In 1982 a 15 year old boy in Bavaria, Germany was given his first home computer, a Commodore 64. The boy's name was Stefan Vilsmeier. Although primitive by today's standards, the 8-bit Commodore 64 was one of the first home computers to be widely used, due to affordable mass-production.
On receiving his computer, Stefan set about teaching himself computer programming, and developed an interest in generating 3D graphics on the computer. When he turned 16 he wrote a book on generating 3D graphics on the Commodore 64, and presented the book to a publisher.
Stefan asked the publishing agency, "For a new book, what is the maximum number of books you have ever sold?" They said the maximum number of books sold was 17,000. Stefan said, "OK, in that case for sales over 15,000 I want double royalties, and for sales over 20,000 I want triple royalties." Not expecting to exceed their record sales of 17,000, the publishing agency agreed to Stefan's proposal.
Stefan's book became a best-seller in its category, selling over 50,000 copies in its first year, bringing him US $75,000 in royalties. In today's money that equates to over US$ 170,000.
In 1989, aged 19, Stefan enrolled at the Technical University of Munich, Germany, to study Computer Programming and Medical Technology. However, the success of his book had secured him other opportunities to work on computer-related imaging projects, and left little time for studying theory. After just 20 days on campus as a computer science student, Stefan dropped out and founded Brainlab AG in his parents' home to focus on digitizing surgery.
Stefan was still only 19 years old when he founded Brainlab AG using the proceeds of his book sales based on computer graphics on the Commodore 64 computer. Today Brainlab AG has evolved into an international leader in medical technology, employing around 2,000 people in 20 offices around the globe. The company has installed intelligent software and intuitive hardware for use in surgery, radiotherapy and digital operating room integration in over 5,600 hospitals worldwide.
In the previous chapter we considered one of the foundational patent decisions relating to computer-implemented MedTech. That decision related to the computer control of X-ray apparatus. We will now consider a much more recent decision which also relates to the use of computers and X-ray apparatus.
On 13 February 2014 Brainlab AG filed International Patent Application No. PCT/EP2014/052829 for a method of positioning a medical structure. The invention could be used, for example, to allow a surgeon to more accurately position a hip replacement relative to a patient's pelvis. Figure 1 of the patent application is reproduced below.
In case you are wondering why this is important, accurate positioning of hip replacements is important because otherwise the patient can be left with a slight difference between the effective length of one leg and the other!
The patent application related to a computer-implemented data processing method for assisting the positioning of a first medical structure relative to a second medical structure, for example the positioning of a medical implant or surgical instrument relative to a bony structure of a patient.
Given Stefan's background in generating 3D images from the age of 15, it is not surprising that this invention also relates to 3D images. In fact, the invention compares 3D image information (obtained by a surgeon) with 2D image information (obtained for example from an X-ray image), in order to allow the surgeon to more accurately position a hip replacement or other structure.
The invention took advantage of the fact that a surgeon may better judge the patient's individual anatomy, and may thus plan a surgical operation more easily, on the basis of two-dimensional projection images such as x-ray images, rather than on the basis of image-free navigation techniques alone, directly on the patient's body.
In one example of the invention, an x-ray image of the pelvis is taken and the positions of two particular points, respectively assigned to the first and second medical structures (called the base point and the reference point in the application) are determined. The distance between these two points in a predetermined direction within the 2D plane of the image is calculated. For example, as shown in Figure 1 above, these points may be easily identifiable points of the pelvis and of a cup implant to be implanted.
The surgeon is then able to palpate the patient's anatomy and the hip implant in 3D using a pointer instrument tracked by a medical tracking system. This allows the actual positions of these two particular points in the three-dimensional anatomical space to be received by a computer.
Finally, the distance between the two points within the three-dimensional anatomical space, when projected onto the X-ray plane, is calculated and compared with the distance previously determined in the two-dimensional X-ray image.
This provides the surgeon with correspondence information describing whether or not these two directional distances correspond. With this information, it is possible for the surgeon to verify the correct positioning of the hip replacement relative to the pelvis.
Unfortunately the examining division at the EPO refused the patent application, arguing, among other things, that the claims were directed to subject-matter excluded from patentability under Article 53(c) EPC.
You will recall from Chapter 2 on Surgery and Diagnosis that Article 53 of the European Patent Convention (EPC) states that European patents shall not be granted in respect of:
(c) methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body...
Claim 1 of the patent application contained a step which effectively included the step of the surgeon using the navigated pointer instrument to palpate the patient's anatomy to allow the computer to "acquire" the 3D positional data mentioned above. The examining division considered this to be a surgical step, and thus to be excluded as a method for treatment of the human body by surgery.
Was it possible to overcome this objection? As we shall see, Brainlab AG were able to make a small amendment to claim 1 which was to prove decisive. They amended the step of "acquiring...three-dimensional position data" to "receiving, at the processor" the three-dimensional positional data.
Brainlab AG appealed against the refusal of the patent application, and the decision of the appeal board issued on 9 August 2022 as T 2136/19.
The appeal board stated:
5.1 Claim 1 of the main request is directed to a data processing method "to be executed by a computer". All the method steps recited in claim 1 are explicitly defined as being carried out at or by a digital processor of a computer. These steps are limited to receiving some data at the processor (for example, receiving image data such as data defining an x-ray image) and to determining, by the processor, some data on the basis of other data (for example, calculating directional distances on the basis of position data).
5.2 In particular, the step of "acquiring, by the computer, three-dimensional position data comprising position information describing the position of the base point (3) and the reference point (4) in three-dimensional anatomical space, in particular relative to the first medical structure (1)", which the examining division had identified as encompassing the surgical step of using a navigated pointer to palpate the patient's anatomy (point 12.3 of the decision under appeal), has been replaced with the step of "receiving, at the processor," this three-dimensional position data.
The Board acknowledges that the three-dimensional position data may well be acquired by palpating the patient's anatomy, thus by a step of a surgical nature; however, by virtue of the amendment above, the step of acquiring the position data itself is not part of the claimed method.
The appeal board noted that the claimed method was for "assisting" a surgeon to position medical structures. However, as explained in the patent description, this assistance was achieved only by providing the surgeon with the correspondence information (i.e. the correspondence between the 2D and 3D measurements) determined in the last step of the method. The appeal board noted that positioning the medical structure was not a step of the claimed data processing method.
The appeal board stated, "More generally, claim 1 does not recite any method step defining or encompassing a physical activity or action that constitutes a method step for treatment of a human or animal body by surgery or therapy. ..... The claimed method is strictly limited to a purely "passive" data processing method which is carried out entirely and exclusively within a computer without causing any effect on the patient's body as a result. It is irrelevant that the claimed method may be performed after or even iteratively during a surgical intervention on the body, as described in the description. In any event, there would be no functional link between the claimed method and any effects of a surgical or therapeutic nature that would occur during this intervention. Therefore, in the absence of such a functional link, the claimed method as such does not qualify as a method for treatment of the human or animal body within the meaning of Article 53(c) EPC (with regard to the requirement of a "functional link", see G 1/07, point 4.3.2 of the Reasons).
The appeal board therefore concluded that the invention did not fall under the exception to patentability of Article 53(c) EPC.
The appeal board also allowed a separate independent claim for a computer program directed to the method of claim 1, to a program storage medium on which this program was stored, and to a computer running or configured with the program.
This example shows how the exclusion under Article 53(c) EPC relating to methods for treatment by surgery or therapy can be avoided for computer implemented MedTech inventions by careful wording of the claims to avoid physical activities which might be regarded as surgical steps.
Brainlab AG has now filed several thousand patent applications worldwide, of which over 1,000 have already been granted. Clearly patents are of key importance to Brainlab AG in the computer implemented MedTech sector.
Stefan Vilsmeier is still the CEO of Brainlab AG, which he founded in 1989 at the age of 19. Despite his remarkable story of success, starting with the book he wrote at age 16, in a recent interview Stefan said he is actually "the shyest person he knows, and completely introvert".
Stefan explained that he has created a "pretty cool" headquarters in Munich which receives about 1,000 groups of customers every year, and creates a real "experience" for their customers. The building includes a former airport control tower surrounded by a 240,000 square foot facility containing advanced operating rooms where they can demonstrate their technology, and a hall which can seat 440 people. The acoustics in the hall are so good that it is used six times per year for performances by the Munich Philharmonic Orchestra and the Munich Opera Company!
Stefan said the building also has "Germany's best gym" and a company restaurant, complete with its own pastry chef, to help attract the best employees to work at Brainlab. The top four floors of the former airport tower, now a listed building, are now "Munich's coolest party zone", which is used both for Brainlab's internal parties and rented out 20 times a year for external parties. Stefan said it is so expensive to rent out that they tell people it is also "Munich's most expensive party location"! He said it is maybe the most profitable part of Brainlab!
The story of how Brainlab grew into a world-leading MedTech company from the book of a 16 year old boy is one of the most remarkable MedTech success stories I have come across. Clearly, Stefan has maintained the entrepreneurial skills which allowed him to negotiate such a good deal with the publishing agency at the age of 16, as there is surely no other MedTech company in the world which also enjoys revenue from opera performances and a prestigious party location in an airport tower!
We shall return to the story of BrainLab AG in the final chapter.
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