By concepts, it is a multitasking switch. See: http://www.google.co.th/search?hl=th&sa=X&ei=ma3ETZS5H82JrAf...

while using the Omronoperatingmaschine during your work.

not sure, but that's how I understand it.
の手元。。。。irritates me a bit.

---- Here is a site that I found regarding the ながらスイッチ (OMRON).

http://www.nc-net.or.jp/mori_log/detail.php?id=165669
Question: ながらスイッチ（ＯＭＲＯＮ）というのがありますが、
他社で類似品を探しています。ご存知の方がいれば教えてください。

Answer: 回答(1) [関係者] [自信あり]
オムロンは↓ですね
http://www.fa.omron.co.jp/product/family/304/index_p.html
でも、製品として完成された「ながらスイッチ」はオムロン以外では見つかりません

●質問者からのお礼
回答ありがとうございます。参考にします。

--- I found a glossary (Six Sigma Glossary) below which contains the example sentence that I've provided. It calls the ながらスイッチ a "Nagara Switch" and goes on to describe it. It seems to be unique to OMRON.

:
[DOC] PROPOZYCJA PROGRAMU
File Format: Microsoft Word - Quick View
Nagara Switch (nagara suicchi): Specially designed switch that can be activated with the swipe of the operator's hand to allow the operator to activate ...
www.polishsixsigmaacademy.pl/.../Lean Six Sigma Glossary.do... -