The M-1160 Fukuyama-Yoshitomi type nucleus dividing cobra-shaft spatula was developed for the purpose providing maximum prevention against the development of complicated symptoms such as post operative corneal edema, corneal opacity and aphakic bullous keratopathy caused by serious impacts of nucleus fragments produced in the ordinary course of phaco surgery against the corneal endothelium.
This innovating spatula not only divides and separates lens nucleus but also has function of holding the nucleus fragments securing from pressing against corneal endothelium.

Because hooks now in use and spatulas for nucleus dividing and separating have single shaft, it is difficult for them to hold the nucleus fragments. Dr. Fumiaki Yoshitomi from Dazaifu City was the first to think that it would be easier to manipulate a nucleus and fragments if hooks or spatulas have parallel double shafts.

It was in July 2002 that Dr. Fumiaki Yoshitomi gave us a suggestion to make the shaft of the M-136 Divide Boy (Tokuda type nucleus dividing spatula) S-shaped. It was difficult to stabilize a shape of shaft in S-shaped. Therefore, we designed and produced a prototype with a lightening-shaped shaft, however it turned out to be a failure.
It was difficult to manipulate because it scratches the incised port in inserting into the anterior chamber. It also was less effective in holding nucleus fragments than expected.
Then, we tried to hold nucleus fragments by attaching an oval "scoop" to a shaft connected to a dividing spatula. However, a plate-shaped "scoop" couldn't hold the nucleus fragments steadily because it blocked off the outlet for liquid and air.

As the experiment revealed that an oval-shaped loop with middle of straight shaft near the dividing spatula instead of an oval "scoop" improved stability, we made a prototype with that shaft. However, it was too big to insert into the anterior chamber through a 1.5mm incision. For the purpose of deciding an appropriate size, we developed and made improved prototypes.
The shaft with oval-shaped loop could be more easily inserted through an incision and was more effective in holding nucleus fragments. While there was no problem in manipulating it in the direction of almost six o'clock from the 12 o'clock inside a capsule, its oval part did not obtrude out of incision as well as being no obstacle to surgery as it came closer to the 12 o'clock position.
Based on the ideas of Dr. Makoto Fukuyama from Ohmuta City who made investigational uses of the prototype, we modified it more delicate in size. In June 2003, we made a final prototype that could be inserted into the anterior chamber through 1.5mm incision and manipulated better in a capsule. One year after, the development was completed.

On June 25 2003, Dr. Fumiaki Yoshitomi and Dr. Makoto Fukuyama jointly applied for a patent and we, Inami & Co., Ltd., applied for the design registration.
In October 2003, Dr. Funatsu from Shunam City, Yamaguchi Prefecture asked for the development of a cobra-shaped shaft to the M-136N Nagahara type Phacochopper. Many people from Nagahara, Yoshitomi, Oshika and Oki used this newly modified product to prove its effectiveness.
This equipment was introduced by the ophthalmologic magazine Japanese Journal of Ophthalmic Surgery 17F369-370,2004. Its advantages were reported to the 28th General Meeting of the Japan Ophthalmologic Surgery Society held in Osaka in January 2005 and was favorably reviewed.