Micro infusion drug delivery device

Details Micro infusion drug delivery device Micro infusion drug delivery device

2001-05-01

2003-12-09

Casler, Brian L. (Department: 3763)

Surgery

Means for introducing or removing material from body for...

Treating material introduced into or removed from body...

C604S117000, C604S152000, C604S187000, C604S272000

Reexamination Certificate

active

06659982

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to methods and apparatus for infusing medications into a patient subcutaneously. In particular, the invention relates to an infusion pump that is adapted for use with prepackaged containers for delivering medications to patients from the container to the subcutaneous region of the patient via a catheter or needle, and to infusion needle array devices.
2. Brief Description of the Related Art
Infusion sets and pumps are used to deliver various types of solutions subcutaneously to patients. There are many medical conditions that require the administration of liquid medicaments transcutaneously (through the skin) and subcutaneously for prolonged periods. Diabetes, for example, may be controlled by daily, or more frequent, injections of insulin. The ability to administer numerous small dosages of insulin has been proven to be the best way to insure tight glucose control for a patient. The National Institute of Health (NIH) conducted a long-term study of people with diabetes known as the Diabetes Complications and Control Trial (DCCT) were it was determined that the proper management of diabetes requires 4 or more injections of insulin per day. However, current devices either are not convenient, painless enough, or easy to use by patients. Syringes and insulin pens all require the patients to inject themselves and do not provide a convenient or discreet mechanism to accomplish medication delivery.
Since transcutaneous injections are painful and troublesome, and since each injection represents a possibility for infection, injections are spaced at intervals as far apart as possible, resulting in peak and valley concentrations of the medicament in the bloodstream or at the site in the body requiring the medicament, the peak concentrations occurring shortly after the administration of the medicament and the low, or valley, concentrations occurring shortly before the administration of the next injection. This method of administration exposes the patient to the possibility of overdose at peak levels and underdose at valley levels, but was nevertheless the standard method for many years in the absence of a better alternative.
Recently, systems have been developed in which a catheter is semi-permanently implanted in a patient to provide access to a transcutaneous site in a patient's body, and a liquid medicament is supplied to the catheter from a reservoir. However, many patients find that the infusion site forms small red marks that are the result of irritation from the infusion at a single point. Infusing the medication either by bolus injection or reducing the amount of medication infused at any one specific site relieves this irritation.
Insigler and Kirtz (Diabetics, 28: 196-203, 1979) describe a portable insulin dosage regulating apparatus which uses an electrically driven mini-pump with an insulin reservoir to periodically dispense a predetermined number of insulin units (U). A small electronic control box is used to set the basal rate of 0.4 U/hr in stages of 0.2 U each. A switch is used to trigger a program that infuses a higher dose for a period of one hour, after which the system automatically goes back to the basal rate.
Thomas et al. U.S. Pat. No. 3,963,380, issued Jun. 15, 1976, describes a micropump driven by piezoelectric disk benders. Although the pump draws only a small current, it requires a voltage of about 100 volts to drive the pump.
Tamborlane et al. (
The New England Journal of Medicine,
300: 573-578, No. 11, Mar. 15, 1979) describe a portable subcutaneous insulin delivery system which uses a battery driven syringe pump. The apparatus is bulky and heavy.
A peristaltic motor driven pump has been described by Albisser et al. (Med. Progr. Technol. 5: 187-193 [1978]). The pump weighs 525 g. and consumes 60 milliwatts at maximum pumping rates. This system has a continuous duty cycle. It is bulky and heavy and consumes a relatively large amount of power.
Additionally, a number of devices have been developed for administering insulin, drugs, or other substances to persons and animals. As self-administration of certain substances, such as insulin, is common, it is important that devices designed for self-administration be simple to operate, reliable, and accurate. The current devices available for the patient include syringes, pumps, or injection pens. Each of these devices do not provide for both a convenient, easy to use, and discreet means of injecting medication. The patients must inject themselves either in public, or use expensive bulky devices.
The different types of infusion pumps in the prior art include elastomeric pumps which squeeze the solution from flexible containers, such as balloons, into tubing for delivery to the patient. Spring loaded pumps have also been provided to pressurize the solution containers or reservoirs. Infusion pumps have also been provided with cartridges containing flexible compartments that are squeezed by pressure rollers for discharging the solutions, such as the pump shown in U.S. Pat. No. 4,741,736. These types of infusion pumps, however, require special containers and are not adaptable for using standard pre-filled single dose containers for solutions.
Where infusion pumps cannot use the standard pre-filled single dose containers, it is necessary to separately fill the containers with the medication from larger vials. The transfer of medication to the cartridges, balloons, reservoirs and other specialized containers is a difficult and problematic process for people with chronic illnesses such as diabetes who must take insulin to adequately process their glucose. The need has therefore been recognized for an infusion pump system which obviates the limitations and disadvantages of existing pumps of this type, and which is adapted for use with standard pre-filled single dose containers
Additionally, the currently available devices for infusing medication subcutaneously require the patient to insert a needle or flexible catheter through the skin into the subcutaneous region. Patients find this either painful, inconvenient, or very invasive. The result is that the majority of patients do not utilize pumps and infusion sets which have a major advantage over traditional injection therapy consisting of periodic injections with syringes.
Morphologically, the composite epithelial layer of the skin, also called the epidermis, is the part of the skin endowed with the barrier against penetration, and it consists of four layers. These layers are an outermost layer called the stratum corneum and three underlying layers, called the stratum granulosum, the stratum malpighii, and the stratum germinativum. The stratum corneum is a heterogenous layer of flattened, relatively dry, keratinised cells with a dense underlying layer commonly called the horny layer. In the past, it was generally held that this horny layer acted as the barrier to the penetration of external substances into the body. See J. Invest. Dermat., Vol 50, pages 19 to 26, 1968. Now, it is generally held that the whole stratum corneum and not a discrete cellular layer functions as a barrier to the penetration of substances into the body. The whole stratum corneum is considered to be a barrier because of a chemical keratin-phospholipid complex that exists in the stratum corneum and acts along with the horny layer as a barrier to the penetration of substances into the body. For the purposes of the present invention, the whole stratum corneum is considered as the natural barrier to penetration. J. Invest. Dermat., Vol 50, pages 371 to 379, 1968; and, ibid, Vol 56, pages 72 to 78, 1971.
The stratum corneum, which is about 15 microns thick when dry and about 48 microns thick when filly hydrated, acts as a barrier for an extremely large variety of compounds. The barrier is maintained for compounds with large molecular volumes, for compounds substituted with functional groups, for small soluble molecules, for non-electrolytes, and the like. See J. Invest. Dermat., Vol 52, pages 63 to 70, 196

Affiliated with

Also associated with

Rating

Micro infusion drug delivery device does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Micro infusion drug delivery device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Micro infusion drug delivery device will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3113860