Page 439 - Handbook of Biomechatronics

The Artificial Pancreas 433

Fig. 14 Mill Hill portable insulin infusion pump developed in 1976. (Science and Society
Picture Library.)

syringe-based wearable infusion pump. The pump rapidly gained acceptance
from a wide range of medical specialties including chemotherapy, neonatol-
ogy, and endocrinology, so in 1976 Kamen founded AutoSyringe, Inc., to
manufacture and market the pumps. By the time this was sold to Baxter, it
included the first insulin pump. This was followed in the early 1980s with
the Auto-Syringe AS6C pump with a variable delivering speed. Typical
pumps from that time are shown in Fig. 15.
As the number of pump users and companies manufacturing pumps
increased, disadvantages of the technology became apparent. Batteries did
not last for more than a few days and some pumps had expensive insulin res-
ervoirs. In addition having a needle in place continuously was an irritation and
often led to infection of the site. It was also noted that because of the low levels
of insulin available in the blood, users were more prone to diabetic
ketoacidosis if the flow was interrupted. Given their problems and the fact that
they did not provide much better control than multiple injections, pumps fell
out of favor and by the end of the 1980s pump manufacturers where battling
to maintain sales. That notwithstanding, two companies, MiniMed (now part
of Medtronic) and Disetronic Medical Systems of Switzerland, were contin-
ued to provide innovative new pumps during the 1990s.

4.2 Modern Insulin Pumps
Pump technology has matured in the past 25 years, with pumps becoming
smaller and more reliable. Most pumps still use syringe mechanisms driven