“These are the longest and thought to be the most dangerous step in the procedure due to the use of pulses of ultrasound that may lead to inadvertent ruptures of the posterior lens capsule, posterior dislocation of lens fragments, and potential damage anteriorly to the corneal endothelium and /or iris and other delicate intraocular structures…A variety of surgical maneuvers employing ultrasonic fragmentation and also requiring considerable technical dexterity on the part of the surgeon have evolved…These are all subject to the usual complications associated with delicate intraocular maneuvers (Gimbel, Chapter 15: Principles of Nuclear PhacoEmulsification, in Cataract Surgery Techniques Complications and Management 2nd Ed. Edited by Steinert et al, 2004, 153-181, incorporated herein by reference).”
‘These are only two examples, Other pulse energy duration times, focal spot sizes and threshold energy levels are possible.’
‘The laser 10 and controller 12 can be set to locate the surface of the capsule and ensure that the beam will be focused on the lens capsule at all points of the desired opening. Imaging modalities and techniques described herein, such as for example, Optical Coherence Tomography (OCT) or ultrasound, may be used to determine the location and measure the thickness of the lens and lens capsule to provide greater precision to the laser focusing methods, including 2D and 3D patterning. Laser focusing may also be accomplished using one or more methods including direct observation of an aiming beam, Optical Coherence Tomography (OCT), ultra-sound, or other known ophthalmic or medical imaging modalities and combinations thereof.’
‘In addition, these and other 2D and 3D patterns may be used in combination with OCT to obtain additional imaging, anatomical structure or make-up (i.e., tissue density) or other dimensional information about the eye including but not limited to the lens, the cornea, the retina and as well as other portions of the eye.’
‘The techniques described herein may be used to perform new ophthalmic procedures or improve existing procedures, including anterior and posterior capsulotomy, lens fragmentation and softening, dissection of tissue in the posterior pole (floaters, membranes, retina), as well as incisions in other areas of the eye such as, but not limited to, the sclera and iris.’
"Each case will depend upon the description in the patent, but there is no basis in law or logic for including within the concept of "a person skilled in the art", somebody who is not a person directly involved in producing the product described in the patent or in carrying out the process of production." iii) The skilled addressee has practical knowledge and experience of the field in which the invention is intended to be applied. He/she (hereafter "he") reads the specification with the common general knowledge of persons skilled in the relevant art, and reads it knowing that its purpose is to disclose and claim an invention. iv) A patent may be addressed to a team of people with different skills. Each such addressee is unimaginative and has no inventive capacity. v) Although the skilled person/team is a hypothetical construct, its composition and mind-set is founded in reality. As Jacob LJ said in Schlumberger at [42]: " ... The combined skills (and mindsets) of real research teams in the art is what matters when one is constructing the notional research team to whom the invention must be obvious if the patent is to be found invalid on this ground." " ... The combined skills (and mindsets) of real research teams in the art is what matters when one is constructing the notional research team to whom the invention must be obvious if the patent is to be found invalid on this ground."
‘what problem does the invention aim to solve?’
‘The Skilled Engineer would not have any knowledge of the treatment of cataracts and so would not have the idea to modify Freedman to perform treatment of the lens, nor would the Skilled Engineer regard it as within their competence to make any decisions about whether to consider modifying the device of Freedman to treat eye tissue other than the cornea. I understand that Mr Benjamin will be considering, in his report, this question from the perspective of an ophthalmic surgeon.’ ‘… - the Skilled Engineer would not have any knowledge of the treatment of cataracts, nor would the Skilled Engineer consider it within their competence to make any decisions about modifying Mühlhoff to perform any other procedure. Again, I understand that Mr Benjamin will be considering, in his report, this question from the perspective of an ophthalmic surgeon.’
‘I do not believe the court in General Tire was seeking to address factual circumstances like those said to arise in this case. In principle the common general knowledge of a skilled person must be capable of including contradictory ideas on a topic, always assuming that information reaches the standard for common general knowledge. The existence of a defined area of doubt and uncertainty does not mean that, in principle, such knowledge is not part of the common general knowledge. An example, referred to by Ono, was in the judgment of Floyd J in Regeneron v Genentech[2012] EWHC 657 (Pat) e.g. at paragraph 67 and the conclusion at paragraph 88 (upheld by the Court of Appeal at[2013] EWCA Civ 93 , paragraph 22). Merck submitted the evidence in Regeneron was much stronger than the evidence in this case. The submission about evidence does not alter the point of principle.’
"156. … Common general knowledge has both positive and negative aspects. I have so far considered under this topic, as is customary, only positive aspects of the knowledge with which the skilled addressee is to be imbued. In my view in certain cases (and I believe this to be one of them), negative aspects of knowledge must in approximation to reality, play their part. At the priority date of the Patent, I believe that such was the 'mindset' within the vacuum cleaner industry, no notional, right-thinking addressee would ever have considered the viability of purifying dirt-laden air from a vacuum cleaning operation, other than by means of using a bag or bag and final filter. For present purposes, the addressee is nonetheless deemed to have been presented with (in effect) three items of prior art wherein it is proposed to clean dirt-laden air by means not of bags but by cyclonic action alone. He is also assumed to take some interest in them however inimical the proposals may be to his likely way of thinking at the time. In terms of its impact on the issue of obviousness, I believe that this negative thinking which as Mr Kitchin suggested amounted to prejudice, would at least have caused the addressee to regard modification to any of these prior art proposals with considerable reserve if not overt scepticism. This likelihood must, I consider, be given due weight. In my view of the matter, I cannot think that any of the cited prior art would ex facie be likely to have lead the addressee at the relevant date with any enthusiasm to effect the often substantial changes which would bring these proposals within a claim of the Patent: see para 153. My view in this regard is bolstered (but not precipitated) by Mr Dyson’s evidence of what actually happened when he tried to interest the industry in Dyson I."
‘Probably the most important 60 seconds of any phaco operation is the time spent in creating a central and circular rhexis of the correct size. It sets the stage for the rest of the operation.’
“There is one of these complications above all others that warrants more detailed discussion because of its particular importance, and that complication is a radial tear-out (Fig. 7.5)…We can describe it as a radial extension of the capsulorhexis tear. This gives an acronym (RECT) that phonetically describes its potential effect (i.e. wrecked) on the surgical outcome”
‘In particular, as I described in paragraphs 107 to 114, the use of ultrashort pulse lasers (picosecond and femtosecond lasers) to cut lens capsule and tissue inside the lens would have been known to the Skilled Engineer.’
‘Owing to their large collateral tissue effects, nanosecond ophthalmic photodisruptors have mainly been used to create explosive tears in surgical targets far from delicate structures. The best example of such an application is posterior capsulotomy, performed to disrupt the opacity that develops in the optical path behind the plastic intraocular lens, after cataract surgery (Steinert and Puliafito, 1985). In contrast the localised effects of femtosecond disruption described in the previous section permit its use as a highly precise cutting tool. To be used in this manner, essentially as a remote-controlled scalpel, individual laser pulses must be placed contiguously creating a postage stamp effect that results in incisional planes within the tissue. These planes can be placed in any or any orientation to create horizontal vertical or oblique incisions (Fig 1). Tissue targets that are transparent to the laser wavelength allow optical breakdown to occur at any depth or location without affecting tissue outside the photodisruption zone. For targets in the eye, this generally restricts laser wavelengths of the visible and near infrared. The only limitation to creating arbitrary incision planes is that they must be written from the deepest portion of the tissue to the shallowest coma because static gas bubbles that persist in tissue shadow the laser if the focus is moved to a plane below previously produced bubbles. Using a femtosecond laser with high pulse repetition rates (in the kilohertz range) and a computer-controlled scanning optical delivery system, localised micro photodisruptions can be placed in a contiguous fashion to produce incisions of any shape to produce high precision tissue separations. Complex shapes can also be created by intersecting these resection planes.’
‘OCT: In the years leading up to the Priority Date, and since the launch of the first commercial OCT systems (for imaging of the retina) in the 1990s, OCT technology had improved markedly, enabling higher resolution imaging and more precise and accurate measurements of the relative positions of structures in the eye. A range of different OCT-based imaging and measurement systems were launched in quick succession in the late 1990s and early 2000s from Zeiss and others, including the first OCT systems designed for biometry and imaging of the whole eye and anterior segment (as opposed to focusing on the retina). At the Priority Date, OCT would have been regarded as a highly promising imaging technique that now offered appreciably better axial resolution, precision and accuracy than competing technologies around that time, and that was continuing to improve.’
‘Usually, a helium-neon laser is used as an aiming beam. The surgeon first focusses this laser on the posterior capsule and then adds the cutting Nd;YAG laser beam as shown in Fig 4.6 by pressing a footpedal. Typically pulse durations of 30ns, pulse energies of up to 5mJ and focus diameters of 50-100 µm are used. With these laser parameters, local power densities exceeding 10 10 W/cm 2 are achieved, leading to the phenomenon of optical breakdown as described in Sect. 3.4. After having placed several line cuts, the posterior membrane opens like a zipper as illustrated in Fig. 4.7. The whole procedure can be controlled through a slit lamp. The surgeon’s eye is protected by a specially coated beamsplitter.’
‘Another laser treatment of the lens is the fragmentation of its interior rather than using ultrasonic exclusively [fn3: Laser fragmentation can significantly reduce the amount of necessary phaco time]. For this kind of treatment, picosecond laser pulses are advantageous, because they are associated with a lower threshold energy for the occurrence of optical breakdown if compared with nanosecond pulses. Thus more energy can be converted to the ionising process itself. In figure 4.8 the fragmentation of a human lens is shown which was obtained by using a picosecond Nd:YLF laser. The surgeon steadily moves the focus of the laser beam without injuring the capsule. During this treatment it is important to choose a pulse energy well above the threshold of optical breakdown because otherwise all laser energy will be absorbed by the retina and other tissues lying underneath.’
‘To create cuts inside the lens, the focus of the laser beam has to be scanned inside the lens tissue. Therefore the beam can be positioned by a two mirror galvano-scanner in the x-y plane with an operating range of nine millimetres in diameter and a resolution of better than one micron. To achieve a translation in the direction of propagation, a micro translation stage can change the distance between the scanner and the focusing optics on the one side and the fixation unit on the other by moving the treated eye or just the lens within a sub-micron resolution (figure 3). This fixation unit consists either of a glass plate that aplanates the cornea surface surrounded by a suction ring, that fits to the curvature of the treated eye or of a much smaller suction mask optimised in size for extracted pig lenses. The focusing optic is a f-theta-optic with a 75 mm focal length optimized for 780 nm wavelength and fs pulses. So, the laser can be focused to a minimal spot size of around 5 µm, as proved i.a. with a scanning knife-edge method. With this scanning and translation system it is possible to locate the focus and thus the optical breakdown region in any desired 3-dimensional pattern inside lens tissue with an accuracy of one micron.’
‘The task for the party attacking the patent on the ground of obviousness is to show how the skilled person would arrive at the invention claimed from the disclosure of the prior art. If the invention claimed is, as it is here, a simple idea, then it is correct that this simple idea is the target for the obviousness attack. That does not mean, however, that the court is entitled to assume that the skilled person takes a different approach to the prior art, stripping out from it detail which the skilled person would otherwise have taken into account, or ignoring paths down which the skilled person would probably be led: see the passage from Pozzoli cited above. The nature of the invention claimed cannot logically impact on the way in which the skilled person approaches the prior art, given that the prior art is to be considered without the benefit of hindsight knowledge of the invention.’
‘Laser surgery methods include ophthalmic procedures, dental procedures and irradiation of tissue for hemostasis, photodynamic destruction of forms of tumors, removal of epidermal growths and abnormalities and for the ablation of atherosclerotic plaques. Lasers have been used in surgical procedures to cut tissue and to immediately coagulate the cut. Lasers have been used to control bleeding during surgical removal of burn wound eschar and in surgery on highly vascularized organs such as the liver. Typically in laser surgery, heat generated by the laser is harnessed to destroy tissue. While thermal effects are commonly used in medical surgical methods, other nonthermal effects are utilized as well. Photons from laser beams can drive chemical reactions, break atomic bonds that hold molecules together or create shock waves to achieve various surgical objectives. Biomedical applications include such tasks as unclogging obstructed arteries, breaking up kidney stones, clearing cataracts and altering genetic material.’
‘Most laser surgical methods utilize the laser heat effect. If the wavelength of light from the laser is matched very closely with the absorption band of the target structure, the laser light will be absorbed by, and therefore damage only that structure. The heat effect of the laser can be extremely selective and precisely controlled. However, in many surgical methods, it is difficult or impossible to choose an irradiating wavelength that will damage target tissue without affecting surrounding tissue. The absorption wavelength of target tissue may not be known or cannot be determined because of turbidity of tissue or other reasons. The absorption band of target tissue may not be distinguishable from the absorption wavelength of surrounding tissue.’
‘The method can comprise projecting an interference light beam onto a multilayer target of biological tissue, detecting the interference light beam reflected by the multilayer target to provide an interferogram, evaluating the multilayer target on the basis of the interferogram, and controlling the laser treating of the biological tissue according to the evaluating step.’
‘The cornea is sensitive and delicate. The size and thickness of corneas vary from patient to patient. In performing a radial keratotomy, the length, width, depth and spacing of incisions must be precisely controlled in order to accomplish the desired object of improving vision without damaging the eye. The laser surgery devices 14, 64 and procedures illustrated in the Figures can control ablating of tissue to perform a radial keratotomy with high-intensity laser light by precise positioning of the laser beam and maximum absorption of the beam over a precise area and depth of incision.’
‘In another procedure, an absolute distance to the target of biological tissue (for example the distance between the ablating laser 52 and the surface of the cornea 12 can be determined by the procedure described with reference to Figs 3 and 4.’
‘The processor 48 can be a computer that determines the location and size of tumours or of cornea tissue and incisions and ablation using the information from the interferometer of figure one or figure three or a combination. Based on such information the computer can determine the total power intensity, pulse duration and repetition rate and position of a light guide for irradiation laser 56 the computer can provide real time information graphic representation of structures such as a cornea along with information relating to the progress of ablation such as information on tissue destroyed or incised.’ ‘In another embodiment, ablation is concurrently controlled by detecting the extent of incision. Cornea ablation by ablating beam 58 is controlled by detecting the extent of the incision with the interference beam during ablation and simultaneously controlling ablating beam 58. The power intensity, pulse duration and repetition rate and focus of the beam 58 can be concurrently adjusted according to a comparison with the incisions previously determined by the surgical model of the ablating plan. The cornea ablation can be controlled by using the ablating beam 58 by intermittently emitting a measuring pulse that determines the extent of incision and compares the extent to the surgical model. The power intensity, pulse duration and repetition rate and focus of the beam 58 can be controlled from the comparison.’
‘If a plasma is generated at a tissue interface, which could also be located within a tissue structure by all means, there is tissue ablation from the interface. Therefore, this is then referred to as photoablation. The case where a plasma bubble separates previously connected tissue layers is usually referred to as photodisruption. For the sake of simplicity, all such processes are subsumed here by the term optical breakdown, i.e. this term includes not only the actual optical breakdown but also the effects in the tissue resulting therefrom.’
‘As a measurement beam, the laser beam 80 brings about a laser-induced signal S at the real measurement point MP depending on the properties of the tissue, said signal being received by a detector 78 via the detection beam path (not illustrated in any more detail). The detected laser radiation-induced signals S are fed from the output of the detector 78 to the input of a memory unit 79 and stored in the memory unit 79 together with the coordinates (x', y', z') of the captured associated measurement points MP'. In a comparator unit 81 connected to the output of the memory unit 79, the laser radiation-induced signals S are compared to thresholds S^ stored there. [0151] As a result, this selects the measurement points that should be impinged by the treatment laser beam as targets once the energy reducer 7 has been removed. As a result, the treatment regime is determined. The coordinates of these selected captured measurement points MP' are transmitted to the control device 75 and are available for driving the deflection device 72 and the focusing device 73.’
‘Alternatively, any of the above-described measurement principles can be used.’
‘OCT would not generally provide signals in the same coordinate system as the treatment laser for all three dimensions (X, Y and Z) even if the same light source is used. In OCT the depth measurement is fundamentally an interferometric measurement. The measurement of signals from different depths is made by sweeping the mirror in the reference arm (in the case of time-domain OCT) or by processing the optical spectrum reflected from the entire axial length through the tissue (in the case of Fourier domain OCT). This measurement is not related to the axial position of a focal point within the sample. Even if the same deflection device was used in the measurement and treatment phases (so that there was correlation in the X-Y plane), there would be no correlation between the depth measurement provided by the OCT and the depth of treatment laser focusing in the tissue.’ iv) Professor Mrochen responded in his third report. He agreed that the z-coordinate in OCT is determined, at least in part, by interferometric measurement, but he did not agree that this meant that OCT could not be used in the fifth embodiment. He went on to say that whilst in OCT the z-co-ordinate is derived from the position of the reference mirror (in time domain OCT) or processing of the optical spectrum (in Fourier domain) and not solely the position of the focussing lens (which determines the axial position of the focal point of the laser within the sample), that does not mean that they use a different coordinate system that would need to be spatially registered. He said the SE would be able to set up the system such that the z-coordinate, derived (at least in part) by interferometric measurement during the OCT measurement step, was used to position the focussing lens to ensure the laser was targeted to the correct z depth during the treatment step. v) Professor Mrochen also responded by referring to the teaching in Mühlhoff at [0098] and [0099] as disclosing that the axial resolution of an OCT device may be improved by using a high numerical aperture and sweeping the focal point of the OCT measurement beam through different axial depths of tissue. He said in this technique, there is a relation between the focal point of the OCT measurement beam and the z-coordinate of the measured signal. vi) In the course of cross-examination, Counsel put to Professor Mrochen ‘Professor Bouma tells me that the Z co-ordinate OCT is determined entirely by interferometric measurement. Do you agree?’
‘Other obvious targets include the rest of the transparent ocular tissues (lens, capsule, and vitreous) as well as surgical procedures in translucent tissues such as the sclera. In the lens, potential applications under investigation include tissue cutting and removal for cataract and/or restoration of accommodation. …..’
‘The biggest limitation of the current laser systems is the challenge of denser cataracts. Given the rapidly evolving refinements and advances made in the technology to date, however, it is likely that this problem will be overcome. What does the future hold? Perhaps, by making ultra-small incision cataract surgery a reality, laser cataract surgery has opened the door to true endocapsular surgery. Maybe the probes of the future will allow for anterior capsule puncture, and on completion of lens removal, perhaps the capsular bag will be reinflated with an injectable lens, allowing for the preservation of accommodation. One can only guess at the directions this rapidly advancing technology will take, but one thing is sure: lasers are expanding the frontier of cataract surgery.’