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Table 2 A comparison of the features of the existing closed-loop DBS devices

From: Advances in closed-loop deep brain stimulation devices

Reference [86] [103] [102] [104] [155] [114] [34, 156] [157, 158]
Recorder and Controller
 Biomarker LFPs/ECoG LFPs and APs LFPs and APs LFPs LFPs LFPs FSCV EEG/ECoG
 Disease type Epilepsy PD PD No special disorder, for behavioral analysis on rodents PD A generic design (no in-vivo validation) PD Epilepsy
 Sensing channels 1 8 4 4 1 4 2 64
 Controllable parameters and programming method Amplitude, by support vector machine algorithm Amplitude, P-W, and frequency Pulse amplitude using spikes discrimination algorithm On-demand, DBS ON and DBS OFF commands by PSD calculations On demand, ON-OFF operation, Evodopa-induced modulations of the LFP beta was used to control the stimulation parameters Amplitude by LFP energy calculation using a programmable
PI-controller
Triangle wave scanning between −0.4 and 1.5 V at a scan rate of either 400 or 1000 V/s, to monitor changes in dopamine Based on a high-efficacy signal processing algorithm, abnormal phase synchrony triggers
the biphasic
stimulations
 C-SS Yes Yes Yes Yes Yes NS Yes NS
Input referred noise NS 5.29 μVrms 3.12 μVrms NS NS 6.3 μVrms NA 5.1 μVrms
 Noise efficiency factor NS NS 2.68 NS NS 3.76 NA 4.4
 CMRR/PSRR >80 dB NS >56 dB NS >100 dB NS NA 75 dB
 Gain - 44 dB ~ 52–66 dB 520 linear 80 dB 54 dB NA 54–60 dB
 Analog filters dc-8 to 500 Hz 0.5 Hz – 10 kHz 1.1 Hz – 10 k Hz 1.5–100 Hz 2–40 Hz 0.64 Hz-6 kHz NA 1 Hz-5 kHz
 Power consumption 100 μW per channel 9 μW per channel 26.9 μW per channel NS NS 245 μW NS 10 μW/channel, 1.4 mW P-D
Stimulator
 Stimulation type CV CC CC CC CV CC CV and CC CC
 Stimulation parameters (amplitude, pulse-width, frequency/period) A: 0–3.5 V,
P-W: 90 μs,
F: 120 Hz
(Activa PC DBS was used)
A: 99 μA default (max 135 μA), P-W: 5–320 μs in 5 μs steps, F: 31 Hz to 1 kHz (130 Hz default) A: 0–95 μA (anodic) and 0–32 μA (cathodic),
P-W: 0–240 μs (anodic) and 0–720 μs (cathodic)
A: 100 μA, P-W: 10 μS–500 mS (200 μS default), F: 0.1 Hz–5 KHz (130 Hz default) A: 2.2 V, F: 130 Hz, P-W: 60 μs (max 200 μs) General channels: A: 0–116 μA, P-W: 1 ms, P: 65 ms.
High-current channels: A: 0–4.2 mA, P-W: 1 ms, P: 65 ms.
A: 50 mV-10 V in VRM and 10 μA-10 mA in CRM, P-W: 50 μs-2 ms, F: 30–120 Hz A: 0.1–1.2 mA, F: 1–200 Hz,
P-W: 40–1000 μs.
 Stimulation pattern Biphasic, passive charge-balanced Biphasic, passive charge-balanced Can be either active or passive charge-balanced, user selects Monophasic, charge-imbalanced Biphasic, asymmetric charge-balanced Biphasic, symmetric charge-balanced Can be either monophasic or biphasic, asymmetrically balanced Biphasic, symmetric charge-balanced
 Stimulation channels 8 for bilateral stimulation 64 4 2 1 6 general-purpose and 2 high-current 4 64
 ADC Linear 8-bit log pipeline logarithmic 10-bit SAR ADCs 16-bit 12-bit ADC logarithmic 10-bit ADC 7.6-bit SAR ADC
 Amplitude resolution NS NS 6-bit resolution 16-bit NS 6-bit resolution NS 8-bit
 Sampling rate/frequency 422 Hz 200 kS/s 35.7 kS/s/ch 500 Hz NS 100 kS/s 100 kS/s Up to 100 kS/s
 Power consumption NS 7.4 μW per channel NS NS NS 138 μW NS 1.5 mW P-D
Other general specifications
 Working duration NS 68 h (923 h) in configuration (stimulation-only operation) mode NS 6–8 h (recording), 50 h (stimulation) NS NS When fully charged: at least 3 h continuous operation NS
 Total power consumption NS 89 μW in normal and 271 μW in configuration modes 375 μW 20 mA average current consumption NS 468 μW NS NS
 Size 39 cm3 19 mm × 27 mm, 0.18 μm CMOS 2.7 mm2 10.9 mm2 SoC 28 mm × 17 mm × 7 mm 12 cm × 7 cm × 2.5 cm 2 mm × 2 mm, 180 nm CMOS NS 4 mm × 3 mm, 0.13 μm CMOS
 Weight including battery NS NS NS 8.5 g 150 g NS NS NS
 Power supply 1.7–2.2 V 1.8 V 1.5 V 3 V Two 1.5 V type AA batteries 5 V rechargeable 740-mAh lithium-polymer battery 1.2 V recording and 3.3 V stimulation boards
 Other features Fully Implantable, telemetry ability - Converting extracellular spikes to electrical stimulations, data telemetry wireless system, reliable transmission of data across 3–5 m distances It is an external portable a DBS device With wireless telemetry and wireless power management Wirelessly controlled Ultra-wideband wireless neural vector analyzer
  1. NS Not stated, NA Not applicable, C-SS Concurrent Sensing and Stimulation, A Amplitude, P-W Pulse-Width, F Frequency, P Period, FSCV Fast-scan cyclic voltammetry, VRM voltage-regulated mode, CRM current-regulated mode, P-D Power Dissipation, CC constant current, CV constant voltage, PD Parkinson disease