Developing a Novel Prosthetic Hand with Wireless Wearable Sensor Technology Based on User Perspectives: A Pilot Study.

Myoelectric hands are beneficial tools in the daily activities of people with upper-limb deficiencies. Because traditional myoelectric hands rely on detecting muscle activity in residual limbs, they are not suitable for individuals with short stumps or paralyzed limbs. Therefore, we developed a novel electric prosthetic hand that functions without myoelectricity, utilizing wearable wireless sensor technology for control. As a preliminary evaluation, our prototype hand with wireless button sensors was compared with a conventional myoelectric hand (Ottobock). Ten healthy therapists were enrolled in this study. The hands were fixed to their forearms, myoelectric hand muscle activity sensors were attached to the wrist extensor and flexor muscles, and wireless button sensors for the prostheses were attached to each user's trunk. Clinical evaluations were performed using the Simple Test for Evaluating Hand Function and the Action Research Arm Test. The fatigue degree was evaluated using the modified Borg scale before and after the tests. While no statistically significant differences were observed between the two hands across the tests, the change in the Borg scale was notably smaller for our prosthetic hand (p = 0.045). Compared with the Ottobock hand, the proposed hand prosthesis has potential for widespread applications in people with upper-limb deficiencies.

Individual indicators of appropriate hypnotic level during propofol anesthesia: highest alpha power and effect-site concentrations of propofol at loss of response.

BACKGROUND: Electroencephalogram (EEG) waveforms vary widely among individuals, this decreases the usefulness of BIS™ monitors for assessing the effects of propofol. Practically, anesthesia is only seen as too deep when evidence of burst-suppression is seen. We designed an experiment to help towards better assessment of individual anesthetic needs. First, to mark the Ce (effect-site concentration) of propofol at loss of response to calling name and gently shaking shoulders (LOR), we defined Ce-LOR. To mark the transient power increase in the alpha range (9-14 Hz), common to all patients, when propofol concentration gradually increases, we defined Ce-alpha as the highest recorded alpha power for Ce. We also defined Ce-OBS as the Ce of propofol at initial observation of burst-suppression. Then we tried to predict Ce-LOR and Ce-alpha from Ce-OBS, vice versa, and considered the significance of these parameters. METHODS: We enrolled 26 female patients (age 33-65) who were undergoing scheduled mastectomy. During anesthesia, we recorded all raw EEG packets as well as EEG-derived parameters on a computer from BIS-XP™ monitor. Propofol was infused using a TCI pump. Target concentration was adjusted so that Ce of propofol was gradually increased. RESULTS: We obtained the following regression equation; Ce-alpha or Ce-OBS = Ce-LOR × 0.87 + 1.06 + dummy × 0.83 (for Ce-alpha dummy = 0, and for Ce-OBS = 1; adjusted r = 0.90, p < 2.2e-16) by ANCOVA. At Ce-alpha, BIS was 50.2 ± 7.7. CONCLUSION: Ce-alpha and Ce-OBS could be estimated from Ce-LOR. Based on Ce-LOR it is possible to manage the hypnotic level of individual patients.

[Anesthetic Management of Three Patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy].

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronically progressing or relapsing disease caused by immune-mediated peripheral neuropathy. We report the anesthetic management of three CIDP patients who underwent elective orthopedic surgeries. Owing to the risk of neuraxial anesthetics triggering demyelination, general anesthesia was selected to avoid epidural or spinal anesthesia or other neuraxial blockade. It was also judged prudent to avoid prolonged perioperative immobilization, which might compress vulnerable peripheral nerves. For Patient 1, general anesthesia was induced with propofol, remifentanil, and sevoflurane, and was maintained with sevoflurane and remifentanil. For Patients 2 and 3, general anesthesia was induced and maintained with propofol and remifentanil. For tracheal intubation, under careful monitoring with peripheral nerve stimulators, minimal doses of rocuronium (0.6-0.7 mg x kg(-1)) were administered. When sugammadex was administered to reverse the effect of rocuronium, all patients rapidly regained muscular strength. Postoperative courses were satisfactory without sequelae.

Proposal of bioinstrumentation using flex sensor for amputated upper limb.

We previously proposed a new bioinstrumentation using the shape deformation of the amputated upper limbs without using the myoelectricity generated on the skin of the upper limbs. However many electronic parts were required owing to a bridge circuit and multi-amplifier circuits so as to amplify a tiny voltage of strain gages. Moreover, the surplus heat might occur by the overcurrent owing to low resistance value of strain gages. Therefore, in this study, we apply a flex sensor to this system instead of strain gages to solve the above problems.

Proposal of bioinstrumentation using shape deformation of amputated upper limb.

Some upper limb amputees have been annually supplied with myoelectric prostheses by social rehabilitation promotion services. However, the persons supplied with the prostheses have been limited because a supply system has not been established yet. Accordingly, we propose a new bioinstrumentation using the shape deformation of the amputated upper limbs without using the myoelectricity generated on the skin of the upper limbs. The repeatability is superior to the myoelectricity because the shape deformation is directly measured by strain gages and also the cost is much superior to the myoelectricity.

The impact of nitrous oxide on electroencephalographic bicoherence during isoflurane anesthesia.

BACKGROUND: We previously reported that electroencephalographic (EEG) bicoherence, the degree of phase coupling among the frequency components of a signal, showed 2 peaks during isoflurane anesthesia. Hayashi et al. (Br J Anaesth 2007;99:389-95) also revealed that the peak frequency of bicoherence around 10 Hz increased when ketamine was added. Because nitrous oxide (N(2)O) and ketamine share several common features, they are often treated as the same category of anesthetic. Here, we investigated the effect of N(2)O on EEG bicoherence and other EEG derivatives during isoflurane anesthesia. METHODS: Twenty patients (aged 34-72 years, ASA physical status I and II) of either gender who underwent elective laparoscopic surgery were included. Raw EEG data, along with EEG-derived parameters, were recorded using an A-1050 Bispectral Index (BIS) monitor and our self-authored Bispectral Analyzer for BIS software. We compared 2 peaks of EEG bicoherence (pBIC-low, around 4 Hz; and pBIC-high, around 10 Hz), as well as BIS and spectral edge frequency 95% (SEF95). Anesthesia was induced with 3 mg · kg(-1) thiopental and 3 µg · kg(-1) fentanyl. After tracheal intubation, anesthesia was maintained with isoflurane (expired concentration at 1.0%), oxygen, and nitrogen. Fentanyl was added and maintained at an estimated effect-site concentration of >1.5 ng · mL(-1). We obtained baseline data 1 hour after induction of anesthesia, then 70% N(2)O was added for 30 minutes. RESULTS: Before N(2)O, pBIC-low and pBIC-high were 49.3% ± 8.3% and 42.4% ± 11.0%. Ten minutes after starting N(2)O, pBIC-high decreased to 14.9% ± 5.9% (P < 0.001), and it was statistically significantly lower throughout the N(2)O period. Meanwhile, pBIC-low transiently decreased to 37.2% ± 12.8% (P = 0.01) during the early phase of N(2)O administration. Before N(2)O, BIS and SEF95 were 43.2 ± 4.9 and 13.1 ± 2.0 Hz, respectively. Both BIS and SEF95 slightly but statistically significantly decreased during N(2)O administration. Fifteen minutes after starting N(2)O, BIS and SEF95 were 35.7 ± 6.2 (P < 0.001) and 8.6 ± 1.8 Hz (P < 0.001) and they decreased more when large δ waves emerged. Fifteen minutes after stopping N(2)O, BIS, SEF95, as well as pBIC-low and pBIC-high returned to pre-N(2)O values. CONCLUSION: Dissimilar to the effect of ketamine, N(2)O significantly decreases pBIC-high during isoflurane anesthesia.

[Case of a schizophrenic patient refusing emergent operation for ovarian torsion].

We report a case of a schizophrenic patient who rejected an emergent operation for ovarian torsion. A 48-year-old woman with ovarian torsion strictly turned down emergent surgery against the recommendation of her gynecologist, who could not communicate with her. In response to his request, a psychiatrist examined and diagnosed her as schizophrenia. Therefore, she was transferred to our hospital for management in closed wards. She was so paranoiac and self-defensive that we, the psychiatrist, the gynecologist, and the anesthesiologist, could not obtain informed consent for the operation from her. Because this was an emergent and life-threatening case, we attempted anesthesia and surgery with the consent of her mother and uncle. First, we took her not directly to the operating room but to ICU to relieve her anxiety and fear. Then, we intubated her under sedation and analgesia. Finally, we took her to the operating room and started the operation. Anesthesia was maintained with 1.5-2.0% sevoflurane and fentanyl (total 9 microg x kg(-1)). The operation was uneventful and she was retransferred to ICU with the tracheal tube in place. Next day she was extubated and left ICU. She was informed by her psychiatrist of the fact that the operation had been performed. Fortunately, her mental status and postoperative course was generally stable.

[Cesarean section in a morbidly obese parturient with borderline personality disorder under combined spinal and epidural anesthesia].

A 21-year-old morbidly obese parturient with a body mass index of 45.5 kg x m(-2) underwent an emergent cesarean section for obstructed labor under combined spinal and epidural anesthesia. At age 15, she was diagnosed as borderline personality disorder. In spite of the drug therapy, her mental status was unstable. During anesthesia and surgery, her psychiatrist attended beside her to ease her anxiety and mental stress. An experienced anesthesiologist encouraged her and maintained her in the sitting position during epidural catheterization and spinal puncture. The distance between the skin and the epidural space was about 6.5 cm at the L3-4 interspace via midline approach. An epidural catheter was inserted 5 cm cephalad. Subsequently, the L4-5 subarachnoid space was accessed at a depth of about 7.0 cm. A 3 ml bolus of 0.5% hyperbaric bupivacaine was given. The anesthetic level was T4 at the start of the operation. Throughout the surgery, sufficient analgesia was obtained and any complication such as severe hypotension or respiratory depression did not develop and her postoperative course was uneventful.

Vocal cord paralysis after surgery to the descending thoracic aorta via left posterolateral thoracotomy.

Vocal cord paralysis is one of the frequently encountered complications after aortic surgery. However, reports of vocal cord paralysis after aortic surgery have been limited. In a retrospective cohort study of vocal cord paralysis after aortic surgery at a general hospital, we sought factors related to its development after aortic surgery to the descending thoracic aorta via left posterolateral thoracotomy. We reviewed data for a total of 69 patients who, between 1989 and 1995, underwent aortic surgery to the descending thoracic aorta. We assessed factors associated with the development of vocal cord paralysis and postoperative complications. Postoperative vocal cord paralysis appeared in 19 patients. Multiple logistic regression analysis revealed two risk factors for vocal cord paralysis: chronic dilatation of the aorta at the left subclavian artery (odds ratio = 8.67) and anastomosis proximal to the left subclavian artery (odds ratio = 17.7). The duration of mechanical ventilation was significantly prolonged for patients with vocal cord paralysis. Certain surgical factors associated with left subclavian artery increase the risk of vocal cord paralysis after surgery on the descending thoracic aorta. Vocal cord paralysis after aortic surgery did not increase aspiration pneumonia but was associated with pulmonary complications.

Vocal cord paralysis after aortic arch surgery: predictors and clinical outcome.

OBJECTIVE: This study is retrospective cohort study of data on vocal cord paralysis after aortic arch surgery collected during 14 years at a general hospital. We investigated factors in the development of vocal cord paralysis after aortic arch surgery and the effect of vocal cord paralysis on clinical course and outcome. METHODS: We reviewed data for 182 patients who underwent aortic arch surgery for aortic arch aneurysm and aortic dissection between 1989 and 2003, of whom 58 patients had proximal aortic repair, 62 had distal arch repair, and 62 had total arch repair. We assessed factors associated with the development of vocal cord paralysis and examined in detail the clinical outcome of patients with vocal cord paralysis. RESULTS: Postoperative vocal cord paralysis occurred in 40 patients. Multiple logistic regression analysis revealed the following risk factors with odds ratios (OR) for vocal cord paralysis: extension of procedures into distal arch (OR, 17.0), chronic dilatation of the aorta at the left subclavian artery (OR, 9.14), and total arch repair (OR, 4.24). Adoption of open-style stent-grafts reduced the incidence of vocal cord paralysis (OR, 0.031). The postoperative occurrence of vocal cord paralysis itself emerges as an independent predictor of pulmonary complications (OR, 4.12) and leads to a longer duration of hospital stay. CONCLUSIONS: The risk of vocal cord paralysis after aortic arch surgery depends on surgical factors, such as aneurysmal involvement of the distal arch, or the application of newer, less invasive surgical procedures. Vocal cord paralysis after aortic arch surgery itself, under aggressive postoperative respiratory management, did not increase aspiration pneumonia but was associated with postoperative complications leading to higher hospital mortality and prolonged hospitalization.

[Anesthetic management of two patients with Brugada-type ECG and of different clinical severity].

Brugada syndrome is an arrhythmia syndrome characterized by typical electrocardiogram (Brugada-type ECG) and development of ventricular fibrillation (Vf) without any distinct structural heart diseases. The essential goal in the management of Brugada syndrome is to avoid the development of Vf. However, there has been no established consensus on pre-operative risk assessment of patients with Brugada-type ECG. We recently experienced two cases of anesthetic managements for patients with Brugada-type ECG. Based on these experiences and recent cardiological progress on the risk stratification of Brugada syndrome, we thoroughly discuss on the peri-operative managements for patients with Brugada-type ECG.

Electroencephalographic bicoherence is sensitive to noxious stimuli during isoflurane or sevoflurane anesthesia.

BACKGROUND: The authors previously reported changes in electroencephalographic bicoherence during isoflurane anesthesia combined with epidural anesthesia. Here, they examined the influence of noxious stimuli on electroencephalographic bicoherence as well as on the Bispectral Index (BIS) and the 95% spectral edge frequency (SEF95). METHODS: The authors enrolled 48 elective abdominal surgery patients (aged 22-77 years; American Society of Anesthesiologists physical status I or II). Raw electroencephalographic signals as well as BIS and SEF95 were recorded on a computer using a BIS monitor (A-1050) and Bispectrum Analyzer (BSA) for BIS (the authors' original software). Using BSA for BIS, the authors evaluated the two peak heights of electroencephalographic bicoherence. Anesthesia was induced with 3 mg/kg thiopental and was maintained with, in air-oxygen, 1.0% isoflurane or 1.5% sevoflurane. After confirming the steady state, the authors recorded baseline values. In experiment 1, they administered 3 microg/kg fentanyl 5 min after incision and investigated the changes in electroencephalographic derivatives at 5 and 10 min after incision. In experiment 2, they administered a similar dose of fentanyl 5 min before incision and investigated the changes in electroencephalographic derivatives immediately before and 5 min after incision. RESULTS: In experiment 1, after incision, both peak heights of electroencephalographic bicoherence significantly decreased but returned to control values after fentanyl administration. By contrast, after incision, BIS and SEF95 showed individual variability. In experiment 2, although fentanyl itself did not affect all electroencephalographic derivatives before incision, the variables remained unchanged after incision. CONCLUSION: Noxious stimuli decreased the peak heights of electroencephalographic bicoherence, an effect that was counteracted by fentanyl analgesia.

[Occupational exposure of operating room staff to anesthetic gases during inhaled induction--a comparison with intravenous anesthesia induction].

BACKGROUND: The risk of occupational exposure to waste anesthetic gases still remains during inhaled induction. In this study we investigated how much we were occupationally exposed to anesthetic gases during induction period. METHODS: Twenty-six adult patients were induced with sevoflurane 5% using a face mask for three minutes and maintained with sevoflurane 1% after end-tracheal intubations (IH-Group). Twenty-two adult patients were induced with intravenous anesthetics and maintained with sevoflurane 1% after end-tracheal intubations(IV-Group). The concentration of sevoflurane was measured by Multi-gas Monitor 1302 (Bruel & Kjaer: Denmark) every 70 seconds. Sample gas was suctioned from breathing zone of anesthesiologists. All of our operating rooms are equipped with waste gas scavenging system. RESULTS: The peak concentration of sevoflurane is significantly higher in IH-Group (15.91 +/- 22.64 ppm) compared with IV-group (0.36 +/- 0.25 ppm). The period when sevoflurane concentration exceeded 0.5 ppm is significantly longer IH-Group (18.55 +/- 10.51 min.) compared to IV-Group (1.92 +/- 4.56 min.). CONCLUSION: The induction with intravenous anesthetics is a better method in order to reduce occupational exposure of anesthesiologists to anesthetic gases.

[Intensive care management of acute pulmonary thromboembolism].

Three patients with acute pulmonary thromboembolism, who had fallen into cardiopulmonary arrest or severe respiratory failure, were treated and saved in our intensive care unit. Two patients were resuscitated with percutaneous cardiopulmonary support device. Two patients underwent surgical embolectomy and we carefully applied positive pressure ventilation to prevent postoperative reperfusion pulmonary edema. Early diagnosis and treatment are essential for saving critically ill patients with acute pulmonary embolism. However, cardiopulmonary resuscitation is often difficult and unsuccessful. Therefore prophylaxis is strongly recommended especially in patients with known risk factors of venous thrombosis. Since reperfusion pulmonary edema is a serious complication after surgical pulmonary embolectomy, careful postoperative respiratory care is needed.

Changes of electroencephalographic bicoherence during isoflurane anesthesia combined with epidural anesthesia.

BACKGROUND: The authors previously reported that, during isoflurane anesthesia, electroencephalographic bicoherence values changed in a fairly restricted region of frequency versus frequency space. The aim of the current study was to clarify the relation between electroencephalographic bicoherence and the isoflurane concentration. METHODS: Thirty elective abdominal surgery patients (male and female, aged 34-77 yr, American Society of Anesthesiologists physical status I-II) were enrolled. After electroencephalogram recording with patients in an awake state, anesthesia was induced with 3 mg/kg thiopental and maintained with oxygen and isoflurane. Continuous epidural anesthesia with 80-100 mg/kg 1% lidocaine was also administered. Using software they developed, the authors continuously recorded the FP1-A1 lead of the electroencephalographic signal and expired isoflurane concentration to an IBM-PC compatible computer. After confirming the steady state of each isoflurane (end-tidal concentration at 0.3, 0.5, 0.7, 0.9, 1.1, 1.3, and 1.5%), electroencephalographic bicoherence values were calculated. RESULTS: In a light anesthetic state, electroencephalographic bicoherence values were low (generally < or = 15.0%). At increased concentrations of isoflurane, two peaks of electroencephalographic bicoherence emerged along the diagonal line (f1=f2). The peak emerged at around 4.0 Hz and grew higher as isoflurane concentration increased until it reached a plateau (43.8 +/- 3.5%, mean +/- SD) at isoflurane 0.9%. The other peak, at about 10.0 Hz, also became significantly higher and reached a plateau (32.6 +/- 9.2%) at isoflurane 0.9%; at isoflurane 1.3%, however, this peak slightly decreased. CONCLUSION: Changes in the height of two electroencephalographic bicoherence peaks correlated well with isoflurane concentration.