Device Proposal

Progesterone Pump

This device design is similar to a morphine pump. Morphine pumps deliver pain medication straight to spinal cord. It is a hockey puck sized device placed under the abdomen wall. A catheter delivers drugs to the spinal fluid space and is controlled externally for release/amount of release. The pump has to be refilled every 3 months and it's done by inserting a needle through the abdominal wall.

Progesterone Release

Our proposed device will have a progesterone pump, which will pump the hormone progesterone and will be smaller than the morphine pump because we don't need the progesterone every day or even that much of it. The device will have a sensor which will be inserted into the uterine artery which is outside the uterus and will sense levels of estradiol in the blood. The sensor uses semi-conducting polymer and horseradish peroxidase to detect the estradiol levels.

Where Device Will be Located in The Body

Diagram of where the ovarian artery and uterine artery are

When estradiol levels reach the average normal peak(around 400 pg/ml) , the pump releases progesterone into the ovarian artery, right before entry into the ovary. Progesterone lowers androgen levels in the body, and helps regulate hormones. Hormone imbalance is the main contributor for lack of ovulation in PCOS. Progesterone continues to increase until estradiol levels are sensed a second time ( by the sensor) , indicating the second peak of estradiol, and begin to decrease progesterone release.

End of Progesterone Release

Surgical Procedure

The pump is essentially going to be inserted under the skin of the abdominal wall. In the case of PCOS it will be inserted close to the uterus. General anesthesia is used during this procedure. The catheter will be threaded down to the ovarian artery which will pump out the progesterone while the sensor will be placed at the uterine artery to detect the estradiol levels and when the progesterone is to be delivered and stopped. After the procedure the cut is closed with stitches or staples. Overall this entire procedure will last around 3-4 hours.

The risks are pretty synonymous with the risks of any surgery including, pain, numbness, infections, or the failure of anesthesia. The implant is something that will be permanent. The Progesterone pump will be small so the cut/scar will be minimal and will fade overtime.

After the surgery the patient is to be in the hospital for a couple days. The date at which the patient feels better and is permitted to leave is dependent on the nature of their own independent cognitive skills and age. They will only need to return if there are complications and every 6 months to check if they need a refill. The estradiol sensor can also be adjusted with an external controller. So the doctor can adjust the dosage of progesterone as needed on a case-by case basis

Biosensor Technology

There is an electromechanical biosensor which happens to detect estradiol using semiconducting polymer and horseradish peroxidase modified platinum electrode. estradiol is a co-substrate for the horseradish peroxidase enzyme. Horseradish peroxidase doesn’t interact with Estradiol when there is water present. It seems that the biosensor is sensitive to this and can detect as small as a 105 nm amount of estradiol. This is convenient because in pcos estradiol levels peak to around 400 pg/ml so the fact that this biosensor can sense levels smaller would mean it could be very accurate with little margin of error.

According to the journal, RSC Advances, this biosensor has been successful in hormone detection. An advantage of horseradish peroxidase (HRP) is that it is available easily as well as being affordable. HRP is in a class called oxidoreductases which is a group that has hydrogen peroxide (electron acceptor). HRP is widely used in research because of its availability and large scale production so it is a well known compound. The hardest part of the structure of the biosensor is the effectiveness of the biofilm immobilization which goes on the surface of an electrode. The structure of the surface is the backbone to the device. Polymers that conduct serve as a 3-D matrix for the dumping of biomolecules.

Components of the Pump

The pump is made of a pump reservoir , suture loop, catheter access loop and the catheter port. The catheter is a single piece, silicone catheter that has a pre-inserted hydrophilic stiffening stylet, that assists the placement of the catheter. The catheter depth starts at 5 cm from the distal end of the catheter, and extends to a distance of 30 cm. The catheter obtains a tungsten-filled tip that enhances radiopacity, and includes side-holes at the tip for dispersion of the infustate into the ovarian artery. The catheter has a radiopaque lock to assist it in connecting it to the programmable pump.The catheter’s components include catheter ( 1.3 mm OD x 110 cm x 0.6 mm ID), one catheter lock, one hub flushing (0.6 mm x 13 mm (0.5 in.), one needle ( 1.8mm x 89 mm (3.5 in.), one stylet- hydrophilic flush-through, one syringe(12mL), two wings, suture that include two anchors angled, one wing suture that includes one wing suture with one anchor straight.

The pump is a teardrop-shaped pump with a triple redundancy flow controller system. It is a battery powered pump that has a rigid titanium housing. The triple redundancy flow control system was designed for precision and accuracy of the flow rate. The flow rate accuracy is not dependent on normal operational environmental conditions that include altitude, temperature and reservoir volume. The device can be easily identified by the use of the programmer to inquire about the system. The pump’s components include one programmable pump, one need (non-coring, 0.7 mm x 38 mm (1.5 in.)), and one needle catheter access (0.9 mm x 45 mm (1.75 in.)). The pump itself last about 10 years. The septum, which includes the refill and CAP lasts about 1000 punctures maximum. The external properties material is titanium Polyphenylsulfone access ports. The thickness is about 20 mm, and the diameter is about 69 mm. The average volume displacement is roughly 100ml, and the weight (unfilled) is 150 grams. The drug reservoir is made out of titanium, and it’s usable capacity is 20 mL. The precision dosing system is made of titanium, stainless steel silicone rubber. The refill septum is made of silicon rubber. The access needed is a huber point 22G non-coring needle. The catheter access septum mater is made of silicon rubber and the access needle is a lancet point with a side hole. The bacteria filter is made of Polyvinylidene fluoride, and it’s pore size is 0.22 microns.

External Controller

To be able to program the pump an external controller is needed to adjust the levels of progesterone given and to program the biosensor on the sensitivity of the level of estradiol that should be received. The external controller will be able to communicate with the pump with wireless radio frequency telemetry. It should have two LCD screens. One with the estradiol level sensed and the other with the level of progesterone being pumped. The doctor should be able to have a code that will be adjustable to change the amounts released and amount sensed by monitoring the patient over a couple months so that the levels are adjusted specifically to every case of PCOS.

Clinical Relevance

The function of this device is so that people with PCOS that are wishing to conceive will be able to without having to take a pill every day. Our goal was to mostly focus on fertility and balancing hormone levels in PCOS without causing weight gain. By Increasing progesterone to decrease estrogen dominance it would rebalance estrogen-progesterone levels and can increase fertility and likelihood of maintaining and completing a pregnancy.

Progestin which is a, synthetic hormone that mimics progesterone, is already used in IUDs but it is not useful because it is constantly released into the body and too much progesterone causes water weight. This device will only release progesterone when needed to and can be adjusted on release outside the body through an external controller because PCOS is different in every patient.

The limitations to this device is that it would only be able to last about 4-7 years like the morphine pump, and we are unsure about the complications of the placement of the pump during pregnancy. Although the hormones will help the baby come to full term, we would need to do more research on the placement to make sure that the pump would not migrate or impede on the functions of the other organs. The surgery complications can include headaches, infection, and leak in the ovarian artery

Drug Overdose and Under dose can occur at the beginning of use of the progesterone pump since each individual with PCOS may need a different range of progesterone to be able to induce ovulation. A doctor will be in contact with the patient for the first couple of months to evaluate how much progesterone is needed for the patient. The catheter used can leak, tear, kink or become disconnected.

The pump reservoir would be able to hold about 20 mL of progesterone. For PCOS patients they will need 150 mg of progesterone about every 3-5 days. So it should be able to last about 1.5 years before needing to be refilled. The pump is about 1 inch thick and 3 inches wide.

The pros of this device in the case of usage is that it can minimize the side effects of an oral drug, because it can control the amount needed. No need for unncessary amounts of the medication.

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