High-Matching and Low-Cost Realization of the FHN Neuron Model on Reconfigurable FPGA Board.

The main objectives of neuromorphic engineering are the research, modeling, and implementation of neural functioning in the human brain. We provide a hardware solution that can replicate such a nature-inspired system by merging multiple scientific domains and is based on neural cell processes. This work provides a modified version of the original Fitz-Hugh Nagumo (FHN) neuron using a simple 2V term called Hybrid Piece-Wised Base-2 Model (HPWBM), which accurately reproduces numerous patterns of the original neuron model. With reduced terms, we suggest modifying the original nonlinear term to achieve high matching accuracy and little computing error. Time domain and phase portraits are used to validate the proposed model, which shows that it can reproduce all of the FHN model's properties with high accuracy and little mistake. We provide an effective digital hardware approach for large-scale neuron implementations based on resource-sharing and pipelining strategies. The Hardware Description Language (HDL) is used to construct the hardware on an FPGA as a proof of concept. The recommended model hardly uses 0.48 percent of the resources on a Virtex 4 FPGA board, according to the results of the hardware implementation. The circuit can run at a maximum frequency of 448.236 MHz, according to the static timing study.

Subdural drainage techniques for single burr-hole evacuation of chronic subdural hematoma: two drains frontal-occipital position versus one drain frontal position.

OBJECTIVE: Burr-hole craniostomy with a closed drainage system is the most commonly used technique for chronic subdural hematoma(CSDH), but the reoperation rate for hematoma recurrence is still high. This retrospective study aimed to compare the complications and recurrence of two subdural drains placement with tips frontal-occipital position (TFOP) versus one subdural drain placement with tip frontal position(OFP) following single burr-hole evacuation for the treatment of chronic subdural hematoma(CSDH). METHODS: The authors analyzed data of all CSDH patients who underwent single burr-hole surgery with placement of subdural closed-drainage system(TFOP or OFP techniques) between January 2013 and December 2017. Data analysis included general patient data, complications, recurrence and clinical outcome. RESULTS: A total of 331 patients were included(85 TFOP and 246 OFP). The TFOP group and OFP group were statistically comparable with respect to baseline characteristics except for preoperative Markwalder score (p = 0.019). Midline shift and subdural fluid thickness on first postoperative day were greater in OFP group than the TFOP group (p = 0.028; and p = 0.007, respectively). In addition, patients with OFP had a lower percent of hematoma change after surgery and much more residual subdural air than those with TFOP (p = 0.001; and p < 0.001, respectively). Postoperative complications and clinical outcome between the two groups showed no significant differences. During the 3-month follow-up, the rate of hematoma recurrence was significantly lower among patients treated with TFOP than those treated with OFP (p = 0.039). CONCLUSIONS: The postoperative complications rate did not differ between TFOP group and OFP group for patients with CSDH. Considering the lower rate of recurrence, TFOP following single burr-hole evacuation might be a safe and promising option for CSDH treatment.

Equimolar doses of hypertonic agents (saline or mannitol) in the treatment of intracranial hypertension after severe traumatic brain injury.

BACKGROUND: Mannitol and hypertonic saline (HTS) are effective in reducing intracranial pressure (ICP) after severe traumatic brain injury (TBI). However, their efficacy on the ICP has not been evaluated rigorously. OBJECTIVE: To evaluate the efficacy of repeated bolus dosing of HTS and mannitol in similar osmotic burdens to treat intracranial hypertension (ICH) in patients with severe TBI. METHODS: The authors used an alternating treatment protocol to evaluate the efficacy of HTS with that of mannitol given for ICH episodes in patients treated for severe TBI at their hospital during 2017 to 2019. Doses of similar osmotic burdens (20% mannitol, 2 ml/kg, or 10% HTS, 0.63 ml/kg, administered as a bolus via a central venous catheter, infused over 15 minutes) were given alternately to the individual patient with severe TBI during ICH episodes. The choice of osmotic agents for the treatment of the initial ICH episode was determined on a randomized basis; osmotic agents were alternated for every subsequent ICH episode in each individual patient. intracranial pressure (ICP), mean arterial pressure (MAP), and cerebral perfusion pressure (CPP) were continuously monitored between the beginning of each osmotherapy and the return of ICP to 20 mm Hg. The duration of the effect of ICP reduction (between the beginning of osmotherapy and the return of ICP to 20 mm Hg), the maximum reduction of ICP and its time was recorded after each dose. Serum sodium and plasma osmolality were measured before, 0.5 hours and 3 hours after each dose. Adverse effects such as central pontine myelinolysis (CPM), severe fluctuations of serum sodium and plasma osmolality were assessed to evaluate the safety of repeated dosing of HTS and mannitol. RESULTS: Eighty three patients with severe TBI were assessed, including 437 ICH episodes, receiving 236 doses of HTS and 221 doses of mannitol totally. There was no significant difference between equimolar HTS and mannitol boluses on the magnitude of ICP reduction, the duration of effect, and the time to lowest ICP achieved (P > .05). The proportion of efficacious boluses was higher for HTS than for mannitol (P = .016), as was the increase in serum sodium (P = .038). The serum osmolality increased immediately after osmotherapy with a significant difference (P = .017). No cases of CPM were detected. CONCLUSION: Repeat bolus dosing of 10% HTS and 20% mannitol appears to be significantly and similarly effective for treating ICH in patients with severe TBI. The proportion of efficacious doses of HTS on ICP reduction may be higher than mannitol.

[Comparison clinical efficacy of 3% hypertonic saline solution with 20% mannitol in treatment of intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage].

OBJECTIVE: To compare the efficacy of 3% hypertonic saline solution with 20% mannitol in treatment of intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage. METHODS: An alternating treatment protocol was used to compare the efficacy of 160 mL 3% hypertonic saline solution (HSS) with 150 mL 20% mannitol for episodes of increased intracranial pressure (ICP) in patients with aneurysmal subarachnoid hemorrhage. The dependent variables were the extent and duration of reduction of increased ICP after each event. RESULTS: Both 3% HSS and 20% mannitol rapidly decreased the ICP in patients with aneurysmal subarachnoid hemorrhage (P <0.01). No difference between two medications in the extent of duration of ICP and reduction of action (P >0.05). CONCLUSION: 3% HSS should be considered as the first-line osmotic drug in treatment of intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage.

[Comparison of 20% mannitol and 15% hypertonic saline in doses of similar osmotic burden for treatment of severe traumatic brain injury with intracranial hypertension].

OBJECTIVE: To compare the effects of 15% hypertonic saline and 20% mannitol in doses of similar osmotic burden for treatment of intracranial hypertension in patients with severe traumatic brain injury. METHODS: We used an alternating treatment protocol to compare the effects of hypertonic saline with that of mannitol given for episodes of increased intracranial pressure (ICP) in patients with severe brain injury. Standard guidelines for the management of severe traumatic brain injury were followed. For episodes of increased ICP, 20% mannitol (2 ml/kg, infused for over 20 min) and 15% saline (0.42 ml/kg, administered as a bolus via a central venous catheter) of similar osmotic burden were given alternately, with the choice of agent for the initial hypertensive event determined on a randomized basis. Reduction of ICP and duration of the action were recorded after each event. RESULTS: The data were collected from 33 patients with 237 hypertensive events. The mean decrease in ICP was 8.7 mm Hg at 28.7∓9.3 min after mannitol treatment as compared with 9.3 mm Hg at 23.6∓7.1 min after treatment with hypertonic saline (P>0.05). The mean duration of the effect was 270 min for mannitol and 318 min for hypertonic saline (P>0.05). CONCLUSIONS: Treatment with 15% hypertonic saline and 20% mannitol in doses of similar osmotic burden produces similar effects in management of increased ICP in patients with severe traumatic brain injury in terms of the time of action onset, maximum ICP reduction, and duration of action.

Effect of resuscitation after selective cerebral ultraprofound hypothermia on expressions of nerve growth factor and glial cell line-derived neurotrophic factor in the brain of monkey.

OBJECTIVE: To investigate the expression of nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) in monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. METHODS: The monkeys were immediately removed brain after death in operation of group A (identical temperature perfusion group) and group B (ultraprofound hypothermia perfusion group). Immunohistochemical technique was used to determine frontal cellular expression of NGF and GDNF. Statistics were analyzed by ANOVA analyses with significance level at P < 0.05. RESULTS: The expressions of NGF and GDNF in the group B were significantly higher than those in the group A (P < 0.05). CONCLUSION: NGF and GDNF increased significantly in the monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. It may be a protective mechanism for neuron survival and neural function recovery.