3.9.2 Cases where method steps define additional devices and/or specific data processing means 

Where a method claim includes steps defined as being carried out by devices other than generic data processing means, a corresponding device and/or computer program claim may need more than a mere reference to the method claim as in formulations (i)-(iv) in F‑IV, 3.9.1 to fulfil the requirements of Art. 84 (see also F‑IV, 3.8). Furthermore, if not all the features of the method claim are reflected in claims in other categories referring to the method, said claims in other categories have to be construed and examined separately with respect to novelty and inventive step.

In particular in applied fields such as medical devices, measuring, optics, electro-mechanics or industrial production processes, method claims frequently involve steps of manipulating or interacting with technical physical entities by using computer control. These method steps may not always be fully performed by the computer and the method claim may recite specific technical means for carrying out some of the steps. In such a case, defining a computer program claim as in F‑IV, 3.9.1(iii) will normally lead to an objection under Art. 84 if the step carried out by the specific technical means cannot be carried out by a generic data processing means (see Example 1 below). An objection under Art. 84 may also arise if the claims do not define which steps are carried out by the data processor or by the additional devices involved, as well as their interactions. The same applies if specific data processing means (e.g. a particular parallel computer architecture) are required as opposed to the generic data processing means described in F‑IV, 3.9.1.

On the other hand, if the method claim defines the further processing, by generic computational means, of data received from specific technical means, such as sensors, it is not necessary that the computer or computer program claims referring to the method comprise those specific technical means. In this case the specific technical means recited in the method are not required for carrying out the method steps and formulations as in F‑IV, 3.9.1 may be appropriate (see Example 2 below).

Finally, as is the case for any essential feature, if the specific technical means are essential for defining the invention, they have to be present in all the independent claims. Whether or not a feature is essential is decided according to the principles defined in F‑IV, 4.5 and subsections, taking due account of implicit features (F‑IV, 4.5.4).

Example 1

1. A method of determining oxygen saturation in blood in a pulse oximeter, comprising: 

– receiving in an electromagnetic detector first and second electromagnetic radiation signals from a blood-perfused tissue portion corresponding to two different wavelengths of light; 

– normalising said electromagnetic signals according to steps A, B and C to provide normalised electromagnetic signals; 

– determining oxygen saturation based on said normalised electromagnetic signals according to steps D and E. 

2. A pulse oximeter having an electromagnetic detector and means adapted to execute the steps of the method of claim 1. 

3. A computer program [product] comprising instructions to cause the device of claim 2 to execute the steps of the method of claim 1. 

4. A computer-readable medium having stored thereon the computer program of claim 3. 

Remarks: In this example, the method claim comprises a step which is defined as being executed by specific technical means (the electromagnetic detector in a pulse oximeter). A computer program claim making reference only to the method would lack clarity because such a program could not be executed e.g. on a general-purpose computer which does not have a pulse oximeter with an electromagnetic detector. Therefore, the computer program claim should be defined as being executed on the pulse oximeter with an electromagnetic detector (by referring to the device of claim 2) rather than only referring to the method claim 1.

Example 2

1. A computer-implemented method of determining oxygen saturation in blood, comprising: 

– receiving data representing first and second electromagnetic radiation signals acquired by an electromagnetic detector from a blood-perfused tissue portion corresponding to two different wavelengths of light; 

– normalising the data representing said electromagnetic signals according to steps A, B and C to provide normalised data; 

– determining oxygen saturation based on said normalised data according to steps D and E. 

2. A data processing apparatus comprising means for carrying out the method of claim 1. 

3. A computer program [product] comprising instructions which, when the program is executed by a computer, cause the computer to carry out the method of claim 1. 

4. A computer-readable medium having stored thereon the computer program [product] of claim 3. 

Remarks: In this example the invention lies in the further processing of acquired data for determining the oxygen saturation in blood. The data can be received for example from a data file storing data previously acquired by the electromagnetic detector. Such a method can therefore be carried out by generic data processing means, for example in the form of a desktop computer. It does not specify the electromagnetic detector as a required feature for receiving the input data. Hence, the device claim defined by reference to the method claim does not need to include the pulse oximeter or an electromagnetic detector either. Furthermore, the computer program claim can be executed on a general-purpose computer and not on a specific device in contrast to the case in Example 1. As a result, the formulations as in F‑IV, 3.9.1 are appropriate for claims 2-4 of Example 2.