AmberBlog

Remember the 1980’s? Big hair and Duran Duran? The 1980’s was also the era of the invention of MS-DOS, the Apple Macintosh, Windows, the first cellphones, and Prozac. But what were the leading patents from this era?

Users of AmberScope should be familiar with AmberScore, our patent ranking system. AmberScore considers such factors as as the number of forward and backward citations, the strengths of the citation connections, the age of the patent and the number of recent forward citations to come up with an overall score for the influence of the patent. AmberScore values are normalised as well, in such a way so that the average granted US patent less than 20 years old has an AmberScore value of 1.0 So an AmberScore value of 2 for a US patent is twice as good as the average granted patent, and so on.

AmberScore is based on our experience of ranking patents using Network Patent Analysis, and considering the limitation of other means of ranking patents. It is designed to be a simple to use and easy to understand predictor of patent quality.

In a three part series of blogs, we will consider the 10 most influential patents of each of the three last decades in order to illuminate some of the key technology trends over this period (note that in this top 10 list, we will exclude family members from a patent already in this list). So what were the top ten patents from the 1980s?

1) Leading our list (and in fact with the highest AmberScore value in our entire database) is US4733665 "Expandable intraluminal graft, and method and apparatus for implanting an expandable intraluminal graft" (filed 1985), originally filed by Expandable Grafts Partnership. This patent covers an expandable graft which can be used to dilate blocked blood vessels and so help deal with the consequences of heart disease. US4733665 has an AmberScore value of 347, which may reflect its 26 backward citations and 2,174 forward citations.

2) In second position is US4800159, Process for amplifying, detecting, and/or cloning nucleic acid sequences (1986). This patent is concerned with genetic engineering, and has just 3 backward citations, 1003 forward citations, and an AmberScore value of 206. Originally filed by Cetus Corporation, its last  listed owner is Roche Molecular Systems.

3) In third position, with an AmberScore value of 176, is US4886062 Intravascular radially expandable stent and method of implant  (1987), to Medtronic.  This is another device for unblocking blood vessels. This patent had 12 backward citations and has 1237 forward citations.

4) Heart disease was clearly a big focus in the 1980s, because the 4th most influential patent was US4800882 to Cook Incorporated, Endovascular stent and delivery system (1987), which refers to a wire stent used for clearing blood vessels. This patent has 12 backward citations and 1237 forward citations, and an AmberScore value of 167.

5) But this is not the only Cook Incorporated patent for a stent in the top ten list, as in 5th position in US4580568, covering a Percutaneous endovascular stent and method for insertion thereof (1984). This patent has 9 backward citations and 1144 forward citations, and a AmberScore value of 164.

7) The last of the stent related patents in this top ten list is US4655771 Transluminally placed expandable graft prosthesis (1983). Originally filed by Charles Dotter and now owned by Cook Corporation, this patent has 11 backward citations, 898 forward citations, and an AmberScore value of 158.

8) Moving from stents (I learnt more than than I ever suspected I would know about stents after writing the above section), in 8th position is US4799156 to Strategic Processing Corporation, which is for an Interactive market management system (1986). Essentially, this is a patent for e-commerce, including the ability to run multiple transactions in parallel, a central system and validation process. This patent has 10 backward citations, 1400 forward citations, and an AmberScore value of 137.

9) Genetic engineering re-enters this list in 9th position, via US4816567, Recombinant immunoglobin preparations (1983), filed by Genentech. As readers would recognise, a 'recombinant immunoglobin' is a genetically modified antibody, with many potential applications in treating diseases. This patent has 8 backward citations and 2425 forward citations, and an AmberScore value of 135.

10) And in 10th position is something is a patent for something that many of us might have at home, namely an inkjet printer. US4740796 to Canon covers Bubble jet recording method and apparatus in which a heating element generates bubbles in multiple liquid flow paths to project droplets (1986), or the process of creating the droplets printed onto paper in inkjet printing. This patent has 14 backward citations and 1944 forward citations, and an AmberScore value of 134.

So there is the final list - Six patents for inventions related to clearing blocked blood vessels, two for genetic engineering, and a patent each for e-commerce and an inkjet printer. As a matter of interest, the next 10 patents include more patents for stents, but also patents for securities trading, semi-conductors and a further patent for genetic engineering. But as will be seen in Part 2, the equivalent list for the 1990s sees a big move towards the electronic age - including a patent for a slot machine.

Appendum - Relationship between AmberScore and forward citation count

Sharp eyed readers would have noted that these patents all had very high forward citation counts, which is used as an indicator of patent quality by many analysts. However there was not a perfect correlation, with the 9th and 10th ranked patents having the highest and third highest forward citation count respectively. Readers might ask:

1. How can this be?, and;
2. Why not just use forward citation count as a patent quality indicator?

If we answer these questions in reverse, there does seem to be a shared view among many patent analysts that while forward citation count is important, by itself forward citation count is not a complete measure. Other analysts supplement forward citation count with other measures such as those based on: 

• prosecution measures such as the number of family members, renewal history etc
• litigation measure, such as whether the patent have been litigated
• internal measures, such as the number of inventors, breadth of patent codes.

Each of these measures has their limitations, such as

• prosecution measures can be affected by corporate decisions more to do with commercial strategy than patent quality
• litigation measures can be limited in that many high quality patents are not litigated - competitors may recognise a good patent when they see one, and just keep away from it
• internal measures may only have a weak correlation with patent quality

Based on significant experience with NPA studies, Ambercite instead prefers to use advanced network measures (such as AmberScore), which take into account forward and backward citations, and the citations to these citations etc. This based on the model that influential and important patents are not only connected to many patents, but many of its connections are connected to other influential patents, and many of these connections are strong - all of this reflecting a patent area of high concentration ('patent thicket') and hence high likely value.

Or in people terms, it is not just how many professional contacts you have, but how strong these connections are and who these people are connected to.

And this helps explain why AmberScore did not rank the top ten patents in the same order as forward citation count - it is not just how many people you know, but how well you know them, and how up to date your friendships are.

Would you like to use Amberscore to predict the influence of patents you are interested in? Further details of how to use AmberScore are found here.

All of us like to think that we are rational thinkers, so it was great to read the recently published bestseller "Thinking Fast and Slow" by the Isreali/American winner of the 2002 Nobel Prize for Economics, Daniel Kahneman. Kahneman explores in a very interesting and readable way a whole list of reasons why our thinking and decision is so often flawed, and I would recommend this book to anyone.

One of the more thought provoking parts of the book was the dangers and limitations of experts.  According to Kahneman, experts (and all of us probably think we are experts) have their place, but this place needs to be recognised, namely in peforming reasonably repetitive tasks where the rest of us benefit from their experience and underlying knowledge. For this reason we visit a doctor for an operation, and employ a patent attorney to draft a patent.

However experts can also suffer from over-confidence, and in some tests have been shown to perform worse than non-experts (particularly crowds of non-experts), particular where they rely on their intuition (the underlying theme of the book is that intuition is not the same thing as thinking - and in fact can give you misleading outcomes). But this tendency to use intuition can be reduced though the use of even rudimentary formulas or algorithms when making expert assessments, as this helps structure your thinking.

When reading this part of the book, I was reminded of a typical competition judging sheet. Judges might be asked to rate contestants on a series of categories, and then the categories scores are added up and perhaps weighted - as opposed to the judges simply picking a favourite contestant. By introducing this simple algorithm, any subconscoius bias in the judge is reduced and the most worthy contestant is more likely to be chosen.

So how does this relate to patents? Part of the role of an (expert) patent analyst is assessing patents, and this can be a very complex task. But according to Kahneman, the provision of formulas or algorithms may help matters as it helps us think about patents in a more structured manner. This may be one reason why many analysts use forward citation count to help them assess patent quality and importance, perhaps with other criteria such as family size, along with some other measures. Here at Ambercite we are developing an alternative predictor of patent quality, namely patent influence, which we believe is superior to forward citation or family size count. But regardless, we would suggest that any reasonable numerical predictor of patent quality, including forward citation count, is probably better than no measure at all, particularly if this means that the 'expert' ends up relying on their unstructured inituition instead.