IP-2024-000024 - [2025] EWHC 492 (IPEC)

The background section of the specification provides an indication of the acknowledged prior art and the nature of the inventive concept intended by the patentee. It explains that although advances had been made in lithotripsy, there had been little progress in removing the stone fragments.

Paragraph [0003] says that great strides have been made in the treatment of patients suffering from a stone, but not in every aspect of treatment:

The specification describes known techniques for removal and concludes the background section by saying:

Paragraph [0017] says that use of the invention goes beyond the treatment of kidney and other stones and that it may also be used for tissue ablation and morcellation. Morcellation is the cutting of tissue into smaller pieces to allow removal.

Figure 10 shows an embodiment of the invention:

Among the key components is the obturator 90, shown separately on the right. Another is the sheath 20. The sheath is in two parts, proximal (the upper part as represented in the figure) and distal. The sheath may be rigid, semi-rigid or flexible and has a length of about 15 to 65cm. There is a side arm 50 emanating from the proximal sheath. This is connected by tubing 70 to a negative pressure system 120 via a collection container 80. At the proximal end of the proximal part of the sheath is a flexible cap 100 which is releasably secured to the sheath.

In use the obturator is inserted into the proximal end of the sheath and extends beyond the distal end. Figure 16 largely illustrates this arrangement, although not showing the obturator 90 extending beyond the end of the sheath. This is part of Figure 16:

The assembly as a whole is marked 10 (which includes the negative pressure system and the collection container, not shown here). The two parts of the sheath 20, the proximal sheath and the distal sheath are marked 30 and 40 respectively. Also shown is an optional side arm 60.

Just visible in Figure 16 but not marked is a slit in the side arm 50. This is shown in plan view in Figure 14:

The slit in the side arm is marked 110. The surgeon can increase the suction pressure of the system by covering the slit with his or her finger and decrease the pressure by wholly or partly uncovering the slit. 23 represents the lumen of the sheath, 53 is the lumen of side arm and 63 is the lumen of the optional side arm 60.

The specification explains how the product claimed would be used in the typical instance of treating a patient suffering from a kidney stone using lithotripsy. The obturator is introduced into, and then secured to, the proximal end of the sheath. The function of the obturator is to allow the surgeon to manoeuvre and guide the sheath more easily. The distal end of the sheath is thereby introduced into the patient’s body. This could be via the ureter or percutaneously, i.e. through an incision in the skin. The distal end of the sheath is positioned close to the stone. The obturator is disengaged from the sheath and removed. A flexible cap is attached to the proximal end of the sheath to block air access. The side arm is connected, via a collection container, to the negative air pressure system. A scope is inserted into the sheath at the proximal end, through the flexible cap and into the patient. The scope is used to visualise the stone. The negative pressure system is activated. Lithotripsy is performed on the stone. The stone fragments created are drawn by the suction effect from the site of the stone via the gap between the endoscope and the sheath lumen, or alternatively through the entire sheath lumen after the endoscope has been retracted. The fragments move into the side arm and then along a connecting tube into the collection container.