The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Pesach Shvartzman - One of the best experts on this subject based on the ideXlab platform.
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Continuous subcutaneous delivery of medications for home care palliative patients—using an infusion set or a pump?
Supportive Care in Cancer, 2010Co-Authors: Sasson Menahem, Pesach ShvartzmanAbstract:Purpose The purpose of this study was to evaluate safety, feasibility, and efficacy of continuous drug delivery by the subcutaneous route through a solution bag connected to an infusion set compared with an infusion pump in a home palliative care setting. Methods Patients in need of continuous subcutaneous medication delivery for pain control, nausea, and/or vomiting were recruited. The study was designed as a double-blind, crossover study. The patient was connected to two parallel subcutaneous lines running simultaneously, connected together to a line entering the subcutaneous tissue. One line is connected to an infusion set and the other to a pump. The infusion set included a 500-cc solution bag connected to a 1.5-m plastic tube containing a Drip Chamber controlled by a roller clamp that is gravity driven without hyaluronidase. Active medications were randomly assigned to start in either administration method and switched after 24 h. An independent research assistant evaluated symptom control and side effects at baseline and every 24 h for 2 days using a structured questionnaire. Another independent research assistant connected the lines after adding medications and evaluated technical and clinical failures. Results Twenty-seven patients were recruited, and of them, 18 completed the study. Incidents in fluid administration were more common through the infusion set (18 times) compared to the pump (only twice). On the other hand, no clinical significant change was noted in the average symptom levels and side effects when medications were given through the infusion set versus the pump. No local edema or irritation was observed in either way of administration. Conclusions In a home palliative care setting with a medical staff on call for 24 h, using medications for symptom control can be considered to be infused to a fluid solution bag through an infusion set instead of using a syringe driver or a pump when there is a responsible caregiver to follow up on the fluid. Subcutaneous constant drug delivery through a pump is more accurate.
Richard Merchant - One of the best experts on this subject based on the ideXlab platform.
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An infusion rate monitor for use in intravenous therapy
Anesthesia and Analgesia, 2013Co-Authors: R.n. Merchant, R. Yee, J. Wiedman, Craig Robson, Richard MerchantAbstract:Introduction: Management of intravenous fluid administration is a core anesthesia task and new parameters are constantly appearing. Liberal, restricted, and now goal-directed fluid therapy are management paradigms. Conventional fluid monitor/controller pumps are widespread but expensive, prone to alarming and failure, often difficult to program, and frequently not available. As a consequence they are little-used in routine OR management save forthe control of vasoactive medications. The infusion rate monitor is device to assist clinicians in simple and routine fluid management tasks. The primary focus of this project was to design a user interface (Ul) and make improvements with the acquisition of user feedback. The results observed thus far will give the direction and narrow the scope for future design changes. Methods: The infusion monitor attaches to an unmodified Drip Chamber and measures the rate of infusion through an optical sensor. Once the device is calibrated in the settings menu, the device then displays in real-time the necessary IV therapy parameters. The prototype was fabricated and tested in a laboratory environment to analyze the functionality of the Drip detector and Ul. The device then received feedback from medical personnel and fellow engineers through a revision process. Participants were given a brief introduction, but relevant operational instructions were undisclosed, allowing for an authentic test of usability. Participants were tasked to set the parameters of the device and then run the program. While on video, they voiced their thought process and immediate concerns about the device. Results: Measurements show that optical Drip detection is 100% accurate before factoring in a UI. Due to the choice of microcontroller for this research, implementing a TFT display fora UI, decreases efficiency of drop detection to ~95%. The first revision of the device was evaluated by four different users: a university professor, and three university students. Users reported five key issues with the design: Intuitive menu navigation, menu and user-parameter selection, system responsiveness, and overall device bulkiness. The user based study for the first revision showed that 100% of users required assistance to operate the device. The second revision was then evaluated by four new users: an anesthesiologist, an industry engineer, and two university students. Users consistently reported that accuracy of the parameter selection was an issue, as was physical size of the device. Results showed that with the second revision, improvements to software were implemented. This allowed users to successfully and independently interact with the device with no training. Discussion: Overall, these results suggest that with further usability testing on clinicians in the field, the design features and UI can be further focused to adequately suit their needs.
Sasson Menahem - One of the best experts on this subject based on the ideXlab platform.
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Continuous subcutaneous delivery of medications for home care palliative patients—using an infusion set or a pump?
Supportive Care in Cancer, 2010Co-Authors: Sasson Menahem, Pesach ShvartzmanAbstract:Purpose The purpose of this study was to evaluate safety, feasibility, and efficacy of continuous drug delivery by the subcutaneous route through a solution bag connected to an infusion set compared with an infusion pump in a home palliative care setting. Methods Patients in need of continuous subcutaneous medication delivery for pain control, nausea, and/or vomiting were recruited. The study was designed as a double-blind, crossover study. The patient was connected to two parallel subcutaneous lines running simultaneously, connected together to a line entering the subcutaneous tissue. One line is connected to an infusion set and the other to a pump. The infusion set included a 500-cc solution bag connected to a 1.5-m plastic tube containing a Drip Chamber controlled by a roller clamp that is gravity driven without hyaluronidase. Active medications were randomly assigned to start in either administration method and switched after 24 h. An independent research assistant evaluated symptom control and side effects at baseline and every 24 h for 2 days using a structured questionnaire. Another independent research assistant connected the lines after adding medications and evaluated technical and clinical failures. Results Twenty-seven patients were recruited, and of them, 18 completed the study. Incidents in fluid administration were more common through the infusion set (18 times) compared to the pump (only twice). On the other hand, no clinical significant change was noted in the average symptom levels and side effects when medications were given through the infusion set versus the pump. No local edema or irritation was observed in either way of administration. Conclusions In a home palliative care setting with a medical staff on call for 24 h, using medications for symptom control can be considered to be infused to a fluid solution bag through an infusion set instead of using a syringe driver or a pump when there is a responsible caregiver to follow up on the fluid. Subcutaneous constant drug delivery through a pump is more accurate.
Caldwell Wm - One of the best experts on this subject based on the ideXlab platform.
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An updated and more accurate Drip infusion solution monitoring system - biomed 2013.
Biomedical sciences instrumentation, 2013Co-Authors: Hidekuni Ogawa, Maki H, Yoshiharu Yonezawa, Amano H, Allen W. Hahn, Tsukamoto S, Caldwell WmAbstract:: We have developed a Drip infusion solution monitoring system for hospital and care facility use that is much more accurate than our previous reported system. The system consists of two electrodes and an acceleration sensor. The electrodes, which are wrapped around the infusion supply polyvinyl chloride (PVC) tube from the solution bag and the Drip Chamber, measure the growth and fall of each drop of infusion solution. The Drip rate is detected from the fall of each drop. In addition, the acceleration sensor is attached to the outside of the Drip Chamber and detects the tilt angle of that Chamber. The injected infusion solution amount is calculated by the infusion solution quantity per one drop and the Drip rate. However, the quantity changes depend on the tilt angle of the Drip Chamber. The quantity of each drop is then corrected by the tilt angle of the Drip Chamber.
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A Drip infusion warning system.
Biomedical sciences instrumentation, 2012Co-Authors: Ogawa H, Maki H, Yoshiharu Yonezawa, Amano H, Allen W. Hahn, Caldwell WmAbstract:: We have developed a Drip infusion warning system for hospital and care facility use. In general, two kinds of infusion sets are used, which have drop factors of either 20 or 60. (A drop factor is the number of drops to deliver 1 ml of infusion solution.) When an infusion set having a 20 drop factor is used, the number of drops per Drip is adjusted to 20. If an infusion set has a drop factor of 60, then the infusion volume rate becomes three times as much. This may result in legal consequences if the patient is injured. In this study, a Drip infusion warning system detects whether the infusion is a 20 or a 60 drop factor. The system consists of two electrodes, one wrapped around the infusion supply polyvinyl-chloride tube, and another one around the Drip Chamber. The electrical impedance between two electrodes is changed by the growth and fall of each drop of fluid. The drop growth length especially changes, depending on the type of infusion set used. Therefore, the two types of infusion sets can be identified by monitoring the drop length. Our warning system detects whether the infusion set used corresponds to a 20 or 60 drop factor, so the system can reduce human errors.
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Relationship between frequency and impedance change in an infusion rate measurement system employing a capacitance sensor - biomed 2011.
Biomedical sciences instrumentation, 2011Co-Authors: Amano H, Hidekuni Ogawa, Maki H, Yoshiharu Yonezawa, Allen W. Hahn, Tsukamoto S, Caldwell WmAbstract:: We have been searching for a suitable frequency range for an electrical impedance measurement infusion solution Drip monitoring system, which we have previously reported. This electrical impedance, which is formed between two electrodes wrapped around the infusion supply polyvinyl-chloride tube and around the Drip Chamber, is changed by the growth and fall of each drop of fluid. Thus, the Drip rate can be detected by measuring this impedance. However, many different kinds of infusion solutions such as glucose, amino acid, soya oil, and lactated Ringers solution are used in hospitals and care facilities. Therefore, it was necessary to find a suitable frequency for driving the capacitance-change sensor with a wide range of infusion solutions. In this study, the sensor electrical impedance change of 16 infusion solutions was measured from 1 kHz up to 1 MHz. The Drip impedance produced by 5% glucose solution, 10% glucose solution and soya oil indicated the maximum sensor output change at 10 kHz, 20 kHz, and 70 kHz, respectively. The other 13 infusion solutions increased up to 10 kHz, and were constant from 10 kHz to 1 MHz. However, the growth, fall, and Drip rate of the drops of all the infusion solutions were monitored by measuring the impedance change from 10 kHz to 30 kHz. Our experimental results indicated that most suitable excitation range for the infusion monitoring system is from 10 kHz to 30 kHz. Thus, we can now fine-tune the system for optimal sensing.
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A new Drip infusion monitoring system - biomed 2010.
Biomedical sciences instrumentation, 2010Co-Authors: Hidekuni Ogawa, Maki H, Yoshiharu Yonezawa, Allen W. Hahn, Caldwell WmAbstract:: A new Drip infusion solution monitoring system has been developed for hospital and care facility use. The system detects and counts the fall of each Drip Chamber drop of fluid. Two non-contacting copper foil electrodes are used; one wrapped around the infusion supply polyvinyl-chloride tube under the solution bag and another around the Drip Chamber, forming two capacitors. Drip infusion fluids have electrical conductivity, so the capacitors are a series-connected electrical impedance. A thirty kHz sine wave is applied to the infusion tube electrode and the capacity-coupled signal on the Drip Chamber electrode is the transducer output. When an infusion fluid drop is forming, its diameter, and therefore Drip Chamber capacitance, are increasing, causing change in the output signal. When the drop reaches sufficient diameter to fall, the Drip Chamber capacitance decreases, which briefly returns the output signal to baseline. Therefore, the growth, fall, and Drip rate of each drop of fluid can be detected from the output signal waveform. The system also has advantages of being insensitive to ambient light type and intensity, and detects when the infusion bag is empty.
G. Scheiber - One of the best experts on this subject based on the ideXlab platform.
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Die Plethysmo-Mechanomyographie (PMG)
Der Anaesthesist, 1994Co-Authors: G. Pohlen, F. c. Ribeiro, G. ScheiberAbstract:Ideal evaluation of neuromuscular blockade can be done by mechanical or electromyographical registration of muscle contractions evoked by ulnar nerve stimulation. Unfortunately, devices needed for such registration are expensive or complicated to set up, and thus are not often used for routine monitoring in anaesthesia. In this study, we describe a simple and low-priced method permitting intra- and postoperative monitoring of neuromuscular blocking agents. The accuracy of plethysmomechanomyography (PMG) was evaluated by comparing simultaneous electromyographic (EMG) and plethysmographic measurements. Methods. For plethysmographic registration of muscle response to nerve stimulation a simple infusion system is twisted there to five times around one hand and connected to an anaesthetic monitor via a pressure transducer. The Drip Chamber is fixed about 20 cm above the hand (Fig. 1). Then, the infusion system is then filled up with physiologic saline solution and the clamp is nearly closed. Electric stimulation can be carried out using any nerve stimulator. Using this method, PMG mainly records the contractions of abductor digiti minimi muscle, but also partly those of the interossei. Evoked muscle contractions cause stretching of the infusion system, which leads to pressure changes proportional to the strength of contraction. The muscle response to "train-of-four" (TOF) stimulation of the ulnar nerve was recorded simultaneously by EMG and PMG in 11 patients (ASA class I or II) undergoing neurosurgical procedures and therefore requiring muscle relaxation. After induction of anaesthesia by injection of etomidate and fentanyl, supramaximal stimulation and control values (T_0) were defined. Anaesthesia was maintained by supplementation with nitrous oxide/oxygen (1:2) and muscle relaxation was carried out with vecuronium. We used the integrated nerve stimulator of a Datex Relaxograph NMT-100 EMG monitor and proceeded to stimulate the ulnar nerve at the forearm with supramaximal strength. The PMG was registered by a Siemens Siredoc 220 printer connected to a Siemens Sirecust 1281 anaesthetic monitor. First twitch ratio (T_1/T_0) and TOF ratio (T_4/T_1) were calculated from these recordings. The EMG recordings were made by a Datex Relaxograph NMT-100 monitor, which automatically computes T_1/T_0 and T_4/T_1. The comparison of EMG and PMG values was carried out by simple linear regression. Statistical evaluation was performed using analysis of variance. Results. A plethysmographically registered graph of the TOF-evoked muscle response is illustrated in Fig. 2. Simultaneous EMG and PMG recordings of onset and recovery from a nondepolarizing blockade are shown in Fig. 3. A strong positive correlation ( P
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Plethysmomechanomyography (PMG). A simple method of monitoring neuromuscular transmission
1994Co-Authors: G. Pohlen, F. C. Ribeiro, G. ScheiberAbstract:Ideal evaluation of neuromuscular blockade can be done by mechanical or electromyographical registration of muscle contractions evoked by ulnar nerve stimulation. Unfortunately, devices needed for such registration are expensive or complicated to set up, and thus are not often used for routine monitoring in anaesthesia. In this study, we describe a simple and low-priced method permitting intra- and postoperative monitoring of neuromuscular blocking agents. The accuracy of plethysmomechanomyography (PMG) was evaluated by comparing simultaneous electromyographic (EMG) and plethysmographic measurements. Methods. For plethysmographic registration of muscle response to nerve stimulation a simple infusion system is twisted there to five times around one hand and connected to an anaesthetic monitor via a pressure transducer. The Drip Chamber is fixed about 20 cm above the hand (Fig. 1). Then, the infusion system is then filled up with physiologic saline solution and the clamp is nearly closed. Electric stimulation can be carried out using any nerve stimulator. Using this method, PMG mainly records the contractions of abductor digiti minimi muscle, but also partly those of the interossei. Evoked muscle contractions cause stretching of the infusion system, which leads to pressure changes proportional to the strength of contraction. The muscle response to "train-of-four" (TOF) stimulation of the ulnar nerve was recorded simultaneously by EMG and PMG in 11 patients (ASA class I or II) undergoing neurosurgical procedures and therefore requiring muscle relaxation. After induction of anaesthesia by injection of etomidate and fentanyl, supramaximal stimulation and control values (T0) were defined. Anaesthesia was maintained by supplementation with nitrous oxide/oxygen (1:2) and muscle relaxation was carried out with vecuronium. We used the integrated nerve stimulator of a Datex Relaxograph NMT-100 EMG monitor and proceeded to stimulate the ulnar nerve at the forearm with supramaximal strength. The PMG was registered by a Siemens Siredoc 220 printer connected to a Siemens Sirecust 1281 anaesthetic monitor. First twitch ratio (T1/T0) and TOF ratio (T4/T1) were calculated from these recordings. The EMG recordings were made by a Datex Relaxograph NMT-100 monitor, which automatically computes T1/T0 and T4/T1. The comparison of EMG and PMG values was carried out by simple linear regression. Statistical evaluation was performed using analysis of variance. Results. A plethysmographically registered graph of the TOF-evoked muscle response is illustrated in Fig. 2. Simultaneous EMG and PMG recordings of onset and recovery from a nondepolarizing blockade are shown in Fig. 3. A strong positive correlation (P
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Die Plethysmo-Mechanomyographie (PMG)@@@Plethysmomechanomyography (PMG). A simple method of monitoring neuromuscular transmission
Anaesthesist, 1994Co-Authors: G. Pohlen, F. C. Ribeiro, G. ScheiberAbstract:: Ideal evaluation of neuromuscular blockade can be done by mechanical or electromyographical registration of muscle contractions evoked by ulnar nerve stimulation. Unfortunately, devices needed for such registration are expensive or complicated to set up, and thus are not often used for routine monitoring in anaesthesia. In this study, we describe a simple and low-priced method permitting intra- and postoperative monitoring of neuromuscular blocking agents. The accuracy of plethysmomechanomyography (PMG) was evaluated by comparing simultaneous electromyographic (EMG) and plethysmographic measurements. METHODS. For plethysmographic registration of muscle response to nerve stimulation a simple infusion system is twisted there to five times around one hand and connected to an anaesthetic monitor via a pressure transducer. The Drip Chamber is fixed about 20 cm above the hand (Fig. 1). Then, the infusion system is then filled up-with physiologic saline solution and the clamp is nearly closed. Electric stimulation can be carried out using any nerve stimulator. Using this method, PMG mainly records the contractions of abductor digiti minimi muscle, but also partly those of the interossei. Evoked muscle contractions cause stretching of the infusion system, which leads to pressure changes proportional to the strength of contraction. The muscle response to "train-of-four" (TOF) stimulation of the ulnar nerve was recorded simultaneously by EMG and PMG in 11 patients (ASA class I or II) undergoing neurosurgical procedures and therefore requiring muscle relaxation. After induction of anaesthesia by injection of etomidate and fentanyl, supramaximal stimulation and control values (T0) were defined. Anaesthesia was maintained by supplementation with nitrous oxide/oxygen (1:2) and muscle relaxation was carried out with vecuronium. We used the integrated nerve stimulator of a Datex Relaxograph NMT-100 EMG monitor and proceeded to stimulate the ulnar nerve at the forearm with supramaximal strength. The PMG was registered by a Siemens Siredoc 220 printer connected to a Siemens Sirecust 1281 anaesthetic monitor. First twitch ratio (T1/T0) and TOF ratio (T4/T1) were calculated from these recordings. The EMG recordings were made by a Datex Relaxograph NMT-100 monitor, which automatically computes T1/T0 and T4/T1. The comparison of EMG and PMG values was carried out by simple linear regression. Statistical evaluation was performed using analysis of variance. RESULTS. A plethysmographically registered graph of the TOF-evoked muscle response is illustrated in Fig. 2. Simultaneous EMG and PMG recordings of onset and recovery from a nondepolarizing blockade are shown in Fig. 3. A strong positive correlation (P < 0.001) of EMG and PMG was found with correlation coefficients of 0.98 for T1/T0 and of 0.97 for T4/T1. The mean difference between values of both methods was 5%, maximally 18% (T1/T0) and 20% (T4/T1). CONCLUSIONS. Mechanomyography and EMG are well established methods of neuromuscular monitoring. Our data demonstrate that PMG provides a reliable measurement of neuromuscular transmission that correlates well with EMG. Since only materials of daily use in anaesthesia are needed, no substantial costs will arise when the plethysmographic method of measurement is used for routine anesthetic monitoring.
