Development and in vitro evaluation of a flow-adjustable elastic drug infusion pump

Author(s):  
S-W Choi ◽  
S-M Kang ◽  
H-Y Kim ◽  
K-W Nam

Passive-type drug infusion pumps have several advantages over active-type pumps including a simple drug chamber structure and relatively high operational stability. However, conventional passive-type infusion pumps also have several limitations compared to active ejection pumps, such as a fixed flowrate and monotonic flow pattern. To enhance the clinical feasibility of using passive-type drug infusion pumps, flow readjustment and flow regulation abilities are needed. This paper proposes a new portable elastic drug infusion pump that integrates the advantages of active and passive infusion pumps to improve clinical feasibility. The proposed infusion pump incorporates a passively driven drug chamber and an actively adjusted flow controller, which can adjust and regulate various target flowrates and adjust the flow pattern in accordance with the patient’s time-varying physiological status. The proposed infusion pump uses the contraction force of an expanded elastic membrane to extract the drug from the drug chamber for delivery into the patient’s body through an outlet catheter. It also utilizes a flow sensor, a flow resistor, and a motor-driven flow restrictor that can monitor the real-time flowrate through the outlet catheter and automatically regulate the actual flowrate around the target value. Experiments on the proposed system resulted in actual injection rates of 0.49 ± 0.03 (mean ± standard deviation), 0.98 ± 0.03, 1.49 ± 0.04, and 1.99 ± 0.03 ml/h when the target injection rate was set to 0.5, 1.0, 1.5, and 2.0 ml/h, respectively. During the entire period of operation from the fully filled state to the totally empty state, an inner-chamber pressure of >100 mmHg was maintained, which shows that the proposed infusion pump can stably maintain its target flowrate as the amount of drug remaining to be injected decreases. It appears that the proposed drug infusion pump can be applied to a wide variety of patient treatments that require short-term, accurate, and stable drug delivery.

Author(s):  
Gun Ho Kim ◽  
Sung Uk Yun ◽  
Jung Hoon Ro ◽  
Kyoung Won Nam

Medication infusion pumps are the most popular device in almost all areas of a hospital; therefore, it is important to frequently inspect the accuracy of the infusion pump operation to prevent underdose/overdose accidents. However, the conventional infusion pump inspection devices are not suitable for quick and convenient on-site inspection by nurses. In this study, a new IR estimation technique for peristaltic infusion pumps that facilitates on-site pre-screening test with shorter inspection time was proposed. A thin membrane potentiometer was attached to a catheter and the actual IR was estimated based on a time interval between two successive line pushes of an identical cam follower using power function estimation. To evaluate the performance of the proposed IR estimation technique, in vitro experiments were performed using 11 infusion pumps (three for Infusion Pump SET 1 ( IPSET-1) and eight for Infusion Pump SET 2 ( IPSET-2)) with the same model. In experiments, error rate between the actual and the measured values (using conventional inspection device) were 0.04–1.17% range for IPSET-1 and 2.09–4.32% for IPSET-2, and those between the actual and the estimated values (using proposed method) were 0.02–0.62% range for IPSET-1 and 1.31–4.23% for IPSET-2. The proposed technique had almost equivalent performance with a commercial inspection device, but the time for inspection was reduced to almost one third. We expect that the proposed technique can provide a tool for simple and convenient on-site pre-screening of infusion pumps by nurses to improve patient safety.


Author(s):  
Stéphanie Genay ◽  
Bertrand Décaudin ◽  
Sébastien Lédé ◽  
Frédéric Feutry ◽  
Christine Barthélémy ◽  
...  

AbstractThis study aimed to compare


2002 ◽  
Vol 96 (4) ◽  
pp. 849-854 ◽  
Author(s):  
Haim Lavon ◽  
Avi Shupak ◽  
Dror Tal ◽  
Avishai Ziser ◽  
Amir Abramovich ◽  
...  

Background Many hyperbaric facilities use infusion pumps inside the chamber. It is therefore important to ensure that this equipment will perform accurately during hyperbaric conditions. The authors tested the function and accuracy of the Imed 965 and Infutec 520 volumetric infusion pumps, the Easy-pump MZ-257 peristaltic infusion pump, and the Graseby 3100 syringe pump. Methods The authors calculated the deviations of infused volumes at low and high rates (12-18 and 60-100 ml/h) on three different hyperbaric protocols (up to 2.5, 2.8, and 6 atmospheres absolute [ATA]), resembling a standard hyperbaric oxygen treatment and US Navy treatment tables used for decompression illness and for arterial gas embolism. Two examples of each pump model were examined in every experiment. Results The Easy-pump MZ-257 failed to function completely beyond a chamber pressure of 1.4 ATA, making it unsuitable for use inside the hyperbaric chamber. The Graseby 3100 failed to respond to all keyboard functions at 2.5-2.8 ATA, making it unsuitable for use in most hyperbaric treatments. The Imed 965 performed within an acceptable volume deviation (< or =10%) during most hyperbaric conditions. During the compression phase of the profiles used, and for the low infusion rates only, exceptional volume deviations of 20-40% were monitored. The Infutec 520 demonstrated an acceptable deviation (within 10%) throughout all the hyperbaric profiles used, unaffected by changes in ambient pressure or infusion rate. Conclusions Commercially available infusion pumps operating during hyperbaric conditions demonstrate substantial variations in performance and accuracy. It is therefore important that the hyperbaric facility staff make a careful examination of such instruments to anticipate possible deviations in the accuracy of the equipment during use.


Neurosurgery ◽  
2010 ◽  
Vol 66 (2) ◽  
pp. E402-E403 ◽  
Author(s):  
Brandon G. Rocque ◽  
A. Leland Albright

Abstract OBJECTIVE Intrathecal infusion using an implantable pump is a common method of delivering medication for spasticity or chronic pain. The classic site for placement of the pump is in the abdominal wall. In some patients, there are confounding factors that make placement of an abdominal pump impractical. The purpose of this study was to report the implantation of Synchromed II pumps (Medtronic, Inc, Minneapolis, Minnesota) in the infraclavicular fossa. METHODS Four patients, aged 13 to 33 years, underwent infraclavicular placement of a Synchromed II infusion pump. In one patient, severe scoliosis and hip joint contractures precluded placement of the pump in the traditional position. Another patient had several ostomies on the abdominal wall, leaving no place for the pump. In a third, a combination of scoliosis and ostomy rendered the abdomen inappropriate for pump placement. RESULTS In 3 patients, a 20-mL pump was placed in the infraclavicular fossa. In the fourth, a 40-mL pump was placed in the left infraclavicular fossa. All patients tolerated the operation well. There were no postoperative reports of local pain or discomfort. One patient died from unrelated respiratory compromise several months after pump placement. At last follow-up (average of 11 months), the pumps were functioning well, and there were no wound-related complications. Selected pre- and postoperative photographs are presented. CONCLUSION The infraclavicular fossa is a viable alternative to the abdomen as the site for placement of a drug infusion pump.


2010 ◽  
Vol 2;13 (1;2) ◽  
pp. 151-156
Author(s):  
Denise WIlkes

Background: In most patients, cancer pain is effectively treated with conservative medical management consisting of oral and/or transdermal analgesics. Cancer patients tend to fail conservative medical management near the end of their life expectancy, thus requiring alternative routes of analgesia such as intravenous, epidural, or intrathecal. The intrathecal route provides the most effective analgesia due to the close proximity of the opioid receptors in the spinal cord. Though there are many techniques that exist for intrathecal drug delivery, complications can limit effectiveness such as infection, bleeding, cerebrospinal fluid (CSF) leaks, post-dural puncture headaches (PDPH), pump and/or catheter malfunctions, or limitations of technical expertise. Therefore, an important goal in palliative cancer pain therapy is to use equipment that is going to have the fewest number of complications and will be the most familiar to the health care providers. We describe the combination of the Medtronic Indura 1P catheter, which has the least catheter-related complications and can be used with any external drug infusion pump. These are regular infusion pumps that the health care workers are familiar with so they can provide excellent and efficient service to the patient. Methods: In an operating room, the intrathecal catheter was placed using sterile technique under fluoroscopic guidance. The epidural space was identified with loss of resistance technique. Then the introducer needle (supplied in the Indura 1P catheter kit) was advanced until free-flowing CSF was obtained. The spinal catheter was advanced into the intrathecal space through the introducer needle to lumbar 2-3 level. The catheter was tunneled subcutaneously 10 cm lateral to the catheter exit site. A syringe filling device was inserted into the catheter opening and was secured with silk suture. A luer lock syringe was attached to the syringe filling device and CSF was aspirated. The syringe filling device was capped and later attached to an external drug infusion pump. Results: We report the successful use of the Medtronic Indura 1P, one piece intrathecal catheter, connected to the external drug pump for a 3 week period in a patient with metastatic cervical cancer for palliative pain control. Limitations: Case report only. Conclusion: This technique is simple to perform by pain specialists. The catheter modification allows the use of the Medtronic intrathecal catheter with standard external drug infusion pumps. This facilitates the patient’s care in the hospice setting. Key words: Intrathecal drug delivery, palliative medicine, intrathecal analgesia, intrathecal catheter complications, cancer pain, end of life pain control


2019 ◽  
Author(s):  
Roger J. W. Hill ◽  
Pasquale F. Innominato ◽  
Francis Lévi ◽  
Annabelle Ballesta

AbstractAimsPrecision medicine requires accurate technologies for drug administration and proper systems pharmacology approaches for patient data analysis. Here, plasma pharmacokinetics (PK) data of the OPTILIV trial in which cancer patients received oxaliplatin, 5-fluorouracil and irinotecan via chronomodulated schedules delivered by an infusion pump into the hepatic artery were mathematically investigated.MethodsA pump-to-patient model was designed in order to accurately represent the drug solution dynamics from the pump to the patient blood. It was connected to semi-mechanistic PK models to analyse inter-patient variability in PK parameters.ResultsLarge time delays of up to 1h41 between the actual pump start and the time of drug detection in patient blood was predicted by the model and confirmed by PK data. Sudden delivery spike in the patient artery due to glucose rinse after drug administration accounted for up to 10.7% of the total drug dose. New model-guided delivery profiles were designed to precisely lead to the drug exposure intended by clinicians. Next, the complete mathematical framework achieved a very good fit to individual time-concentration PK profiles and concluded that inter-subject differences in PK parameters was the lowest for irinotecan, intermediate for oxaliplatin and the largest for 5-fluorouracil. Clustering patients according to their PK parameter values revealed two patient subgroups for each drug in which inter-patient variability was largely decreased compared to that in the total population.ConclusionsThis study provides a complete mathematical framework to optimize drug infusion pumps and inform on inter-patient PK variability, a step towards precise and personalized cancer chronotherapy.Author summaryAccuracy and safety of infusion pumps remain a critical issue in the clinics and the development of accurate mathematical models to optimize drug administration though such devices has a key part to play in the advancement of precision medicine. Here, PK data from cancer patient receiving irinotecan, oxaliplatin and 5-fluorouracil into the hepatic artery via an infusion pump was mathematically investigated. A pump-to-patient model was designed and revealed significant inconsistencies between intended drug profiles and actual plasma concentrations. This mathematical model was then used to suggest improved profiles in order to minimise error and optimise delivery. Physiologically-based PK models of the three drugs were then linked to the pump-to-patient model. The whole framework achieved a very good fit to data and allowed quantifying inter-patient variability in PK parameters and linking them to potential clinical biomarkers via patient clustering. The developed methodology improves our understanding of patient-specific drug pharmacokinetics towards personalized drug administration.


Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.


1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.


1974 ◽  
Vol 77 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Gustav Wägar

ABSTRACT Whether the short-term regulation of thyroidal protein synthesis by TSH occurs at the transcriptional or the translational level was tested by measuring the effect of actinomycin D (act D) on the TSH-induced stimulation of L-14C-leucine incorporation into the thyroidal proteins of rats. TSH was injected 6 h before the rats were killed. The thyroid glands were then removed and incubated in vitro in the presence of L-14C-leucine for 2 h. The pronounced stimulation of leucine incorporation in the TSH-treated animals was depressed as compared with controls but still significant even when the animals had been pre-treated with 100 μg act D 24 and 7 h before sacrifice. On the other hand, act D strongly decreased incorporation of 3H-uridine into RNA. Short-term regulation of thyroidal protein synthesis by TSH appears to be partly but not wholly dependent on neosynthesis of RNA. Hence regulation may partly occur at the translation level of protein synthesis.


1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S27-S40 ◽  
Author(s):  
T. Kobayashi ◽  
T. Kigawa ◽  
M. Mizuno ◽  
T. Watanabe

ABSTRACT There are several in vitro methods to analyse the function of the adenohypophysis or the mechanisms of its regulation. The present paper deals with single cell culture, organ culture and short term incubation techniques by which the morphology and gonadotrophin-secreting function of the adenohypophysis were studied. In trypsin-dispersed cell culture, the adenohypophysial cells showed extensive propagation to form numerous cell colonies and finally develop into a confluent monolayer cell sheet covering completely the surface of culture vessels. Almost all of the cultured cells, however, became chromophobic, at least at the end of the first week of cultivation, when gonadotrophin was detectable neither in the culture medium nor in the cells themselves. After the addition of the hypothalamic extract, gonadotrophin became detectable again, and basophilic or PAS-positive granules also reappeared within the cells, suggesting that the gonadotrophs were stimulated by the extract to produce gonadotrophin. In organ culture and short term incubation, the incorporation of [3H] leucine into the adenohypophysial cells in relation to the addition of hypothalamic extract was examined. It was obvious that the ability to incorporate [3H] leucine into the gonadotrophs in vitro was highly dependent upon the presence of the hypothalamic extract.


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