Somatics Thymatron System IV User manual

User Manual
Thymatron® System IV
Somatics LLC
720 Commerce Drive, Suite 101
Venice, Florida 34292
Technical Support
USA and Canada
(800) 642 –6761 or [phone]
Fax: [phone]
E-mail: [email protected]
UM-TS4, Rev. 21

Thymatron®System IV Instructions for Use
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CAUTION
User's Manual for Thymatron® System IV
Prescription use only –Federal law restricts this device to sale by or on the order of a
physician.
Electroconvulsive Therapy (ECT) is a complex medical procedure. Its proper and safe conduct requires a staff of
licensed healthcare professionals who are trained and have experienced in-person supervision with the associated
procedures, have received clinical privileges for ECT from the appropriate hospital committee, and have
carefully read and are thoroughly familiar with the medical literature concerning the risks, benefits,
complications, and methods of ECT. Specifically, practitioners intending to use the Thymatron System IV
should be familiar with ECT-related concerns including medical conditions that affect risks, adverse effects,
pre-ECT evaluation, medications used during ECT, ECT procedures and techniques, physiological phenomena,
consent, ECT unit staffing, evaluation of outcome, and post-course ECT management. Practitioners should keep
current with information about these concerns published in major textbooks, in major journals of psychiatry, and
by professional psychiatric organizations. They should also be familiar with the FDA final order of December
26, 2018 (83 FR 66103-66124). Clinicians who administer ECT should participate in continuing education about
ECT.
It is essential that doctors planning to use the Thymatron® System IV device read and follow the warnings and
recommendations of the Task Force Report of the American Psychiatric Association as set forth in “The Practice
of Electroconvulsive Therapy” (APA, 2001), which states, in part, that "A small minority of patients treated with
ECT later report devastating cognitive consequences. Patients may indicate that they have dense amnesia
extending far back into the past for events of personal significance or that broad aspects of cognitive function are
so impaired that the patients are no longer able to engage in former occupations...in some patient self-reports of
profound ECT-induced deficits may reflect objective loss of function...In rare cases, ECT may result in a dense
and persistent retrograde amnesia extending to years..."
It is essential to read all of the information in the Safety Information section of this manual, pages 7 - 9.
Copyright© 1999; 2000; 2001; 2002; 2003; 2004; 2005; 2006; 2009; 2013; 2015; 2016; 2018; 2019 Somatics
LLC. All rights reserved. No portion of this manual may be reproduced by any means without the permission of
Somatics LLC.
Technical Support
USA and Canada
(800) 642 –6761 or [phone]
Fax: [phone]
E-mail: [e-mail]

Thymatron®System IV Instructions for Use
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TABLE OF CONTENTS
INTENDED USE .....................................................................................................................................................6
INTENDED PATIENT POPULATION ..................................................................................................................6
SAFETY INFORMATION......................................................................................................................................7
WARNINGS....................................................................................................................................................7
PRECAUTIONS..............................................................................................................................................7
ADVERSE EVENTS ...............................................................................................................................................9
SERIOUS ADVERSE EVENTS...................................................................................................................10
OTHER RISKS .............................................................................................................................................10
RISKS OF COGNITIVE MEMORY EFFECTS ..........................................................................................11
TECHNIQUE OF ECT...........................................................................................................................................11
TO THE TREATING PHYSICIAN.......................................................................................................................12
RISK REDUCTION FEATURES..........................................................................................................................12
RISK OF PROLONGED SEIZURES AND CARDIAC ARRHITMIAS.....................................................12
RISK OF THYMATRON® COMPONENT FAILURE...............................................................................13
EFFICACY AND SAFETY OF THE THYMATRON® ECT DEVICE...............................................................13
EFFICACY OF THE THYMATRON® ECT DEVICE ...............................................................................13
SAFETY OF THE THYMATRON® ECT DEVICE....................................................................................15
RISK OF BRAIN INJURY ................................................................................................................. 15
MEMORY AND COGNITIVE RISKS............................................................................................... 17
REFERENCES.................................................................................................................................... 19
DISCLAIMER / WARRANTIES ..........................................................................................................................24
SPECIFICATIONS ................................................................................................................................................25
EXPLANATION OF SIGNS AND SYMBOLS....................................................................................................27

Thymatron®System IV Instructions for Use
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FRONT PANEL............................................................................................................................................27
REAR PANEL...............................................................................................................................................27
INSTALLATION...................................................................................................................................................28
OPERATING INSTRUCTIONS............................................................................................................................28
POWER ON/OFF..........................................................................................................................................28
SELF TEST...................................................................................................................................................28
PERCENT ENERGY DIAL..........................................................................................................................29
LIGHT-EMITTING FUNCTION DISPLAYS .............................................................................................29
SAFETY MONITOR CIRCUIT ALARM TEST .........................................................................................30
FRONT PANEL JACKS...............................................................................................................................31
FLEXDIAL™ OPERATION........................................................................................................................31
PAPER LOADING INSTRUCTIONS..........................................................................................................34
STIMULUS CABLE CONNECTION..........................................................................................................34
MONITORING CABLE CONNECTION ....................................................................................................34
LEAD-WIRE CONNECTIONS....................................................................................................................34
SEIZURE MONITORING CONSIDERATIONS ........................................................................................35
MONITORING ELECTRODES APPLICATION........................................................................................35
CHANNELS 3 & 4 SELECTION.................................................................................................................36
STIMULUS ELECTRODES APPLICATION .............................................................................................36
IMPEDANCE TEST (FOR STATIC IMPEDANCE)...................................................................................37
MOUTH PROTECTION...............................................................................................................................38
BASELINE EEG COLLECTION.................................................................................................................38
STIMULUS DOSE SELECTION.................................................................................................................39
STIMULUS PROGRAMS: FACTORY PROGRAMMED..........................................................................40
STIMULUS PROGRAM SELECTION........................................................................................................40

Thymatron®System IV Instructions for Use
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FREQUENCY SELECTION ........................................................................................................................41
PULSEWIDTH SELECTION.......................................................................................................................41
STIMULUS DOSE FOR BILATERAL, BITEMPORAL, BIFRONTAL, LART ECT...............................41
STIMULUS DOSE FOR UNILATERAL ECT............................................................................................41
STIMULUS TITRATION PROCEDURE....................................................................................................42
“BENCHMARK” METHOD FOR SETTING AND ADJUSTING STIMULUS ........................................42
TYPICAL COURSE OF TREATMENT...............................................................................................................43
TARDIVE SEIZURE....................................................................................................................................43
WORSENING OF PSYCHIATRIC SYMPTOMS.......................................................................................43
MANIC SYMPTOMS...................................................................................................................................44
TREATMENT STIMULUS ADMINISTRATION ......................................................................................44
SEIZURE MONITORING............................................................................................................................44
EEG SEIZURE MONITORING ......................................................................................................... 45
AUDIBLE EEG™ SEIZURE MONITOR.......................................................................................... 45
EEG PAPER RECORDING................................................................................................................ 45
ICTAL LINE™ SEIZURE INDICATOR........................................................................................... 45
ENDPOINTS AND INDICES............................................................................................................. 46
GAIN AND POSITION SETTINGS ............................................................................................................47
TURN OFF PRINTING IN A CHANNEL...................................................................................................48
CHANGING EEG GAIN RAPIDLY............................................................................................................48
SEIZURE QUALITY MEASURES..............................................................................................................48
BASELINE RETENTION ............................................................................................................................49
TO ENABLE/DISABLE SEIZURE QUALITY MEASURES.....................................................................49
EEG FREQUENCY MEASURES................................................................................................................49
PRINTER PAPER SPEED SELECTION.....................................................................................................50

Thymatron®System IV Instructions for Use
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TURN OFF PRINTING ENTIRELY.................................................................................................. 50
POWER SPECTRAL ANALYSIS (FFT) SELECTION ..............................................................................50
USER SPECIFIED FLEXDIAL™ SELECTIONS.......................................................................................50
RESET FLEXDIAL™ SETTINGS TO FACTORY VALUES .......................................................... 51
TRANSFERRING DATA BETWEEN A PC AND THYMATRON® SYSTEM IV..................................52
INPUT HOSPITAL NAME FOR THE PRINTED REPORT............................................................. 52
DOWNLOAD PRE-RECORDED TREATMENT DATA FROM PC FOR REPRINTING BY
THYMATRON® SYSTEM IV........................................................................................................... 52
UPLOAD TREATMENT DATA AUTOMATICALLY TO A PC.................................................... 53
DISPLAY EEG/EMG/ECG ON THE PC SCREEN........................................................................... 54
OUTPUT TREATMENT DATA MANUALLY ................................................................................ 55
REPRINT THE LAST TREATMENT................................................................................................ 57
SET DATE & TIME IN PRINTED REPORT.................................................................................... 57
ELECTROMAGNETIC COMPATIBILITY (EMC).............................................................................................58
GENERAL NOTES.......................................................................................................................................58
LIST OF CABLES AND ACCESSORIES...................................................................................................58
ELECTROMAGNETIC EMISSIONS..........................................................................................................59
ELECTROMAGNETIC IMMUNITY..........................................................................................................60
INDEX....................................................................................................................................................................66
ADDENDUM I (FIRMWARE CHANGES) .........................................................................................................68
ADDENDUM II (ELECTRODE PLACEMENT) .................................................................................................70
ADDENDUM III (INSTRUCTIONS TO PATIENT) ...........................................................................................76
ADDENDUM IV (FLEXDIAL FLOW CHART)..................................................................................................78
ADDENDUM V (MOCA TEST)...........................................................................................................................79
ADDENDUM VI (INSTRUCTIONS FOR LEGACY METAL OLD TYPE STIMLUS ELECTRODES)..........80

Thymatron®System IV Instructions for Use
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INTENDED USE
Type of Device:
Device usage:
Application area:
Users:
The Thymatron® System IV is an ECT device
Therapeutic device
For use in treating catatonia, severe major depressive episodes (MDE)
associated with major depressive disorders (MDD) or bipolar disorder (BPD) in
patients age 13 years and older who are treatment-resistant or who require a
rapid response due to the severity of their psychiatric or medical condition.
Alternative available treatments that may or may not be as effective as ECT
include various behavioral and pharmacological interventions.
Psychiatrists
INTENDED PATIENT POPULATION
This device is intended to be used as part of the ECT treatment procedure with patients of age 13 years and
older, under treatment by a medical doctor, a psychologist or a neurologist, with a condition as described in the
Intended Use. Patients must be capable of giving informed consent or have a legally recognized substitute. For
each ECT session, patients should be assessed to be in sufficiently good medical condition to tolerate the
procedure.
ECT does not reliably treat PTSD, other anxiety disorders, personality disorders, or medical disorders that cause
symptoms of major depression, and the Thymatron System IV is not intended for use in treating such disorders.
Anxiety disorders, PTSD, personality disorders, and medical disorders can underlie major depression or coexist
with it, causing suicidality or other depressive symptoms.

Thymatron®System IV Instructions for Use
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SAFETY INFORMATION
Please read the following important safety requirements before using the Thymatron® System IV ECT
Instrument.
WARNINGSVarious medical conditions are associated with substantially increased risk from ECT, including
risk of death. These include unstable or severe cardiovascular conditions (recent myocardial
infarction, unstable angina, poorly-compensated congestive heart failure, severe valvular cardiac
disease), vascular aneurysms susceptible to rupture with increased blood pressure, increased
intracranial pressure, recent cerebral infarction, severe chronic obstructive pulmonary disease, asthma,
pneumonia and anesthesia risk level ASA 4 or 5. Pulmonary risks of ECT associated with general anesthesia
and neuromuscular blocking agents include hypoxemia, hypoventilation, aspiration, and upper-airway
obstruction.
ECT device use may be associated with disorientation, confusion, and memory problems.
When used as intended this device provides short term relief of symptoms. The long-term safety
and effectiveness of ECT treatment has not been demonstrated, and long-term follow-up may be
needed.
Some patients who were suicidal before receiving ECT eventually committed suicide after
receiving ECT, including after receiving ECT with a Thymatron® device.
Administering ECT to a patient with an implanted DBS device can damage the DBS device or
cause it to malfunction and cause injury to the patient.
PRECAUTIONS
For patients with brain tumor, brain aneurysm, myocardial infarction, coronary insufficiency,
heart failure, or aortic aneurysm medical specialists in Neurology or Cardiology should be
consulted to determine additional precautions needed, if any.
Do not remove the top or bottom covers of the Thymatron® System IV. There are no user
serviceable parts inside. Any servicing must be performed by qualified service personnel.
WARNING
WARNING
WARNING
WARNING
WARNING
CAUTION
CAUTION

Thymatron®System IV Instructions for Use
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Do not use any cables or lead wires that appear to be damaged.
The Thymatron® System IV device is defibrillator protected. Nevertheless, for safety reasons, all
cable connections between the Thymatron® System IV ECT Instrument and the patient must be
disconnected prior to initiation of the defibrillation stimulus.
Avoid the risk of accidental shock to medical personnel. Do not contact the patient, or any
conductive surface touching the patient, unless wearing electrically insulated gloves. If holding
the patient’s jaw or touching the patient's head during the electrical stimulus, make sure to use
electrically insulating gloves.
Do not subject the Thymatron® System IV device to extreme moisture, and do not use it after it
has been partially or totally immersed in liquid or when a significant amount of liquid has been
spilled on it. Power the unit off and have it checked by a qualified technician before powering it
on or using it again.
Only use the Thymatron® System IV device with the Somatics’ Treatment and Monitoring
Cables.
The Treatment and Monitoring Cables are not interchangeable and cannot be inserted into the
wrong front panel connector. Attempting to force the Treatment Cable into the connector intended
for the Monitoring Cable (and vice versa) will damage both the connector and the cable.
The ECG function of the Thymatron® System IV device is used only to obtain a heart rate to help
assess the efficacy of the seizure; it is not intended to be used to make diagnoses. Do not use the
Thymatron® System IV ECG function to monitor the patient's heart for any other purpose.
The EMG function of the Thymatron® System IV device is used only to obtain an estimate of the
motor seizure duration to help assess the efficacy of the seizure; it is not intended to be used to
make diagnoses. Do not use the Thymatron® System IV EMG function to monitor the patient's
muscle or nerve activity for any other purpose.
The built-in electroencephalogram (EEG) functions are used only to assist in identifying the
efficacy of the induced seizure and its endpoint. Do not use these EEG functions for any other
purpose. Absence of EEG activity does not prove that seizure activity is absent, because seizure
may occur outside EEG detectability. Seizure can occur while EEG shows nothing.
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION

Thymatron®System IV Instructions for Use
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Do not dispose of your Thymatron® System IV device in the general waste. As per Directive
2002/96/EC for the disposal of electrical and electronic equipment, please contact the
manufacturer for instructions.
Prior to initiating ECT on a patient with a cochlear implant, healthcare professionals should
discuss the issue with an otolaryngologist or audiologist and review the cochlear implant
Instructions for Use.
Thymapad® electrodes are single-use only and must be discarded after the treatment. The
Thymatron® System IV Treatment Cable, Monitoring Cable and lead wires can be cleaned by
wiping them off with a Germicidal Disposable Cloth. Steel stimulus electrodes may be cleaned
with soapy water or alcohol. The Thymatron® device has no special requirements for restricted
environment during transport or storage, beyond Standard Sub-clause 10.1 criteria.
EEG, EMG and ECG are shown only to assess treatment quality and must not be used for
monitoring or diagnosis.
ADVERSE EVENTS
As with any therapy, ECT has risks. Certain patients will experience adverse events in conjunction with
electroconvulsive therapy. Patients should be made aware of these risks and confirm that they fully understand
them prior to consenting to therapy.
Per FDA requirements, the treating doctor should include in the written Informed Consent form of each ECT
patient a statement of the potential adverse effects from ECT as described in this manual.
The most common reported adverse effects of ECT are: Headache. Muscle soreness. Mild to moderate
pain/discomfort, including jaw pain. Nausea. Disorientation immediately after seizure induction. Memory
dysfunction (see further discussion below).
CAUTION
CAUTION
CAUTION
CAUTION

Thymatron®System IV Instructions for Use
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SERIOUS ADVERSE EVENTS
Recent estimates in the medical literature of the mortality rate associated with ECT are 1 per 10,000 patients or 1
per 80,000 treatments.
Other serious adverse events have occurred, including adverse reaction to anesthetic agents / neuromuscular
blocking agents; adverse skin reactions (e.g., skin burns); cardiac complications, including arrhythmia,
ischemia/infarction (i.e., heart attack), acute hypertension, hypotension, and stroke; cognition and memory
impairment; brain injury; dental/oral trauma; general motor dysfunction; physical trauma (i.e., if inadequate
supportive drug treatment is provided to mitigate unconscious violent movements during convulsions) including
fractures, contusions, injury from falls, dental or oral injury; hypomanic or manic symptoms (e.g., treatment-
emergent mania, postictal delirium or excitement); neurological symptoms (e.g., paresthesia, dyskinesias);
tardive seizures; prolonged seizures; non-convulsive status epilepticus; pulmonary complications (e.g.,
aspiration/inhalation of foreign material, pneumonia, hypoxia, respiratory obstruction such as laryngospasm,
pulmonary embolism, prolonged apnea); visual disturbance; auditory complications; onset/exacerbation of
psychiatric symptoms; partial relief of depression enabling completed suicide; homicidality; substance abuse;
coma; falls; and device malfunction (creating potential risks such as excessive dose administration), and death.
Certain patients are more likely to experience severe adverse events, including those with pre-existing cardiac
illness, compromised pulmonary status, a history of brain injury, or medical complications after earlier courses
of anesthesia or ECT. Concurrent administration of antipsychotic (neuroleptic) medication may increase the risks
of adverse cardiac, pulmonary, and neurological events, and falls. Concurrent administration of stimulants may
increase the risks of cardiac and neurological complications, such as prolonged seizure. All of this information
should be assessed in developing the treatment plan for a particular patient.
OTHER RISKS
Completed suicide in ECT patients has a reported rate of 0.5 per 100 patient years, but higher in patients recently
discharged after hospitalization with suicidality. Studies have shown that partial improvement along the course
of ECT, before remission is obtained, can enable suicidal behavior or suicide in patients previously too ill to plan
or commit suicide. Likewise, suicide is a concern after ECT treatment; for instance, one study found that ECT
patients had a slightly higher suicide rate within seven days after their last ECT treatment than non-ECT
inpatients (Munk-Olsen et al., 2007). A meta-analysis found that 30% of patients with treatment-resistant
depression attempt suicide, with a rate for completed suicide of 0.47 per 100 patient years which included
similar incidence following DBS, VNS and ECT (Bergfeld et al., 2018).
ECT may result in worsening of an underlying medical condition either by: (1) ineffective treatment or (2) the
treatment itself, particularly when it exacerbates the symptoms.

Thymatron®System IV Instructions for Use
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RISKS OF COGNITIVE MEMORY EFFECTS
Cognitive side effects are experienced in varying types and severity by ECT patients. ECT treatment may be
associated with disorientation, confusion and memory problems, including short-term (anterograde) and long-
term (retrograde or autobiographical) memory loss following treatment. These side effects tend to go away
within a few days to a few months after the last treatment with ECT. However, incomplete recovery is possible.
In rare cases, patients may experience permanent memory loss or other deficiency in cognition or function.
FDA regulations require that each patient receiving ECT have his cognitive status monitored prior to beginning
ECT and throughout the course of treatment via a formal neuropsychological assessment which includes
evaluation of specific cognitive functions (e.g., orientation, attention, memory, executive function).
Neuropsychology consultation should help select tests for individual patients. One tool that may be helpful in
monitoring along the course is the MoCA (Moirand et al, 2018). Maximum MoCA score is 30, normal is 26 or
higher. Add one point if patient is not educated past high school. See Addendum V and:
https://www.parkinsons.va.gov/resources/MOCA-Test-English.pdf. Additional tests may be desirable, such as
for autobiographical memory.
Studies have shown that the methods used in ECT administration have a significant impact on the nature and
magnitude of cognitive deficits. In general, the American Psychiatric Association recognizes that the following
treatment parameters are each independently associated with more pronounced cognitive side effects:
• Bilateral electrode placement;
• Sine wave stimulation;
• High electrical dosage relative to seizure threshold;
• Closely spaced treatments;
• Larger numbers of treatments;
• Concomitant psychotropic medications;
• High dosage of barbiturate anesthetic agents.
TECHNIQUE OF ECT
Users of ECT devices should carefully follow the specific ECT treatment techniques and procedures outlined in
Chapters 6-11 of the American Psychiatric Association’s “The Practice of Electroconvulsive Therapy:
Recommendations for Treatment, Training and Privileging –A Task Force Report” (2001).
ECT requires general anesthesia with neuromuscular blocking agents and supported ventilation. These should be
administered by a qualified anesthetic specialist.
Requisite pre-ECT medical and psychiatric assessments in every patient include pertinent medical and
psychiatric history, complete physical examination, ECT anesthesia assessment, dental assessment, and any

Thymatron®System IV Instructions for Use
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other clinically appropriate studies as determined by the treating psychiatrist.
Prior to ECT, the patient should ingest nothing by mouth for at least eight hours. At the start of the ECT
procedure, monitoring and stimulus electrodes are attached. Then general anesthesia is given with a
neuromuscular blocking agent and hyperventilation with oxygen. When the muscles are fully relaxed, a mouth
protector is inserted and the electrical stimulus then applied.
During the treatment, EMG, ECG and EEG are monitored for occurrence of generalized seizure and until the
seizure terminates. ECG usually shows heart rate acceleration at seizure onset and deceleration at seizure end.
Typical minimum motor seizure is 20 sec. If the seizure lasts less than 20 sec., consider repeating the stimulus at
an appropriately higher dose. EEG shows brain electrical activity. Endpoints can differ among these because
they reflect different locations in the brain. If seizure continues beyond about 100 seconds, consider termination
by infusing intravenous propofol, midazolam, methohexital or similar short-acting agent. Ventilation is
continued until spontaneous respiration returns. After ECT, the patient is observed for an hour or longer, with
vital sign, lung auscultation, and cognitive function checks.
TO THE TREATING PHYSICIAN
The U.S. Food and Drug Administration (FDA) requires that patients receive in writing and understand
the statements listed in Addendum III before receiving ECT. You may duplicate and disseminate these
"Instructions to Patients" without limitation. Delivery of this required information about ECT should be
witnessed and documented in medical records.
RISK REDUCTION FEATURES
RISK OF PROLONGED SEIZURES AND CARDIAC ARRHYTHMIAS
The two most frequent complications during an ECT treatment session are excessively long seizures and
irregular heart rhythms (Nuttall et al, 2004), both of which can be detected by routine monitoring during the
treatment. The Thymatron®’s integral brain-wave monitor (electroencephalogram, EEG) enhances the safety of
ECT by allowing the treating doctor to detect signs of a prolonged seizure so it can be terminated with
intravenous medication. However, a brain seizure can occur or continue without accompanying EEG activity.
Likewise, a heart monitor (electrocardiogram, ECG) allows the treating doctor to detect irregular heartbeat
patterns as they occur so that they can be managed with intravenous medication. The Somatics Thymatron®
monitors start recording automatically as soon as the ECT stimulus is delivered and continue until they are
turned off by the doctor.
In addition to the paper EEG record, the Somatics Thymatron® device has an auditory EEG monitor that allows
the user to tell without looking at the paper EEG whether or not EEG signs of seizure have stopped. In a study of
82 consecutive ECTs using this auditory EEG, physicians determined the occurrence and the duration of the
induced EEG seizure with a high degree of accuracy (Swartz and Abrams, 1986).

Thymatron®System IV Instructions for Use
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RISK OF THYMATRON® COMPONENT FAILURE
In the extremely rare event of catastrophic failure of an ECT device component, there is a remote possibility of
delivering an electrical stimulus dose in excess of that set by the operator, potentially causing excessive memory
disturbance. To prevent such an occurrence, the Somatics Thymatron® device includes an independent separate
redundant safety circuit that automatically measures the electrical charge of the output each time the stimulus
button is pressed and prevents delivery of any stimulus charge exceeding by more than 5% that set by the
operator. To test the integrity of the electrical connection to the patient, the Somatics Thymatron® device
includes a static impedance test initiated by a button press. The test current is too small to be felt. This test helps
assure good electrode contact and prevent excessive heat release onto the skin.
EFFICACYAND SAFETY OFTHE THYMATRON® ECT DEVICE
The below review of the clinical research literature on electroconvulsive therapy (ECT) focuses on the risks and
benefits of the most widely-used Thymatron® ECT device models: the DG, DGx, and System IV
1
This review
emphasizes controlled studies with random assignment, blind ratings and statistical validation; older
impressionistic reports without validated observations are not included.
Several old reports not involving a Thymatron® ECT device stated concern about potential adverse effects of
ECT on brain function, but the technique of ECT and electronic design of the devices used for this treatment
have since advanced to mitigate those concerns. An old study claiming brain injury in cats receiving electrically-
induced convulsions (Alpers and Hughes, 1942) failed to use muscle-relaxant drugs before stimulation or proper
comparison animals. Breggin (1979) emphasized cerebral petechial hemorrhages (small blood spots on the
brain), but when animals were restrained from banging their heads no petechiae occurred (Siekert et al, 1950).
A prospective study in patients receiving modern ECT that employed blindly-analyzed serial magnetic resonance
images obtained before, 2-3 days after ECT, and 6 months later revealed no evidence of brain injury from ECT
(Coffey et al, 1991).
EFFICACY OF THE THYMATRON® ECT DEVICE
Abbott et al (2013) reported twelve DSM-IV manic-depressive depressed patients treated with a Thymatron®
System IV, rated on the Hamilton scale before and after a course of ECT. They exhibited a statistically
significant mean depression scale improvement of 27.6 points. Nine patients achieved remission; three did not.
Azuma et al (2007) studied 14 treatment-resistant depressives who received bilateral ECT with a Thymatron®
System IV. Highly significant improvement in Hamilton Depression Scale scores was achieved, with 43%
scoring under 8 post-ECT. Postictal suppression measured by the Thymatron® System IV significantly predicted
therapeutic outcome.
Heikman et al (2002a) used a Thymatron® DGx ECT device to treat 24 major depressives randomly assigned to
high-dose right unilateral ECT, moderate-dose right unilateral ECT, or low-dose bifrontal ECT. Blindly-obtained
1
The DG, DGx and Thymatron System IV deliver the same electricity. The Thymatron IV differs from previous models
in monitoring and in ways that the doctor can select the electrical stimulus. Somatics no longer sells the DG or DGx

Thymatron®System IV Instructions for Use
14
Hamilton Depression scale scores at baseline and after the ECT course showed an overall 66% improvement,
with the highest improvement (73%) recorded for the high-dose right unilateral group. Thirteen patients
experienced remission from depression and nine did not.
Heikman et al. (2002b) separately reported that depression showed remission to ECT with a Thymatron® DGx
ECT device in 2 of 24 patients whose depression was of low severity or was accompanied by a somatic or
psychiatric comorbidity. Among patients with higher severity and no comorbidity remission was achieved in ten
and not in six.
Huang CJ et al (2017) studied 95 inpatients with depression receiving at least 6 ECT sessions with a
Thymatron® device. Quality of life, symptom severity, and functioning were assessed before and after ECT on
the Hamilton Depression scale and the Modified Work and Social Adjustment Scale CT. All measures improved
significantly after treatment without significant adverse effects. After ECT, HAMD scores averaged 6.6 (normal)
and ranged from 1 to 34 (severe depression).
Kellner et al (2005) used a Thymatron® DGx to treat 131 unipolar major depressives who expressed high
suicidal intent as shown on item 3 of the Hamilton depression scale. 81% of these patients’ suicide ratings
ultimately dropped to zero, including the 13 patients who had attempted suicide. . Of the 355 patients receiving
ECT, 304 achieved remission and 51 did not. Two males, aged 76 and 80, suicided during the study.
Lin et al (2013) studied 55 treatment-resistant depressives who received ECT with a Thymatron® System IV.
Hamilton depression scale scores and Clinical Global Impression-Severity scores showed significant reductions
after treatment.
Lin CH et al. (2018) compared responses to depression in patients treated with ECT using a Thymatron® System
IV and patients treated with fluoxetine. ECT produced response in 96 of 104 patients (92%) and not 8 patients,
versus a response in 66 of 112 patients (59%) and not in 46 with fluoxetine. ECT patients responded faster and
more frequently experienced headache.
Niemantsverdriet L et al (2009) studied 65 patients with major depression who received bilateral ECT
administered with a Thymatron® System IV using brief pulse or ultra-brief pulse stimulation. Significant and
equal improvement in depression scale scores was achieved with both electrode placements. ECT response
occurred in 48 patients and not in 17; remission occurred in 29 and not in 36.
Petrides et al (2001) used a Thymatron® DGx device to treat 253 patients with unipolar major depression with
bilateral ECT at 50% above threshold. By blindly-obtained Hamilton Depression Scale ratings, overall remission
rate was 87% (no remission 13%). In psychotic depression remission rate was 95% (no remission 5%); by
definition psychotic depression is severe.
Prudic et al. (2004) performed a study using undisclosed ECT devices including sine wave devices, in which
clinical remission from depression was obtained in 30.3% to 46.7% at hospitals in the New York City
community. Relapse after initial remission was more frequent in patients with a comorbid personality disorder.

Thymatron®System IV Instructions for Use
15
The authors hypothesized but did not establish a cause of the low efficacy.
Ranjkesh et al (2005) randomly assigned 39 DSM-IV patients with major depression to receive courses of 8
bifrontal, bitemporal, or right unilateral ECT with a Thymatron® DGx ECT device. Blindly-obtained Hamilton
Depression scale ratings at baseline and after the 8th ECT revealed 73% improvement overall.
In Sackeim et al. (1993), a study that did not did not use a Thymatron device, 59% of patients who responded to
ECT relapsed within twelve months.
Tran et al (2017) presented the case of a 25-year-old woman hospitalized for a major depressive episode and
suicidality in the context of bipolar 1 disorder, whose symptoms fully remitted with 1 ECT with a Thymatron®
device.
Williams et al (2008) used a Thymatron® DGx ECT device to administer 1.5 times threshold bitemporal ECT to
515 patients with DSM-IV unipolar major depression, obtaining a 68% reduction in Hamilton Depression scale
scores after treatment. Remission occurred in 329 patients (64%) and not in 186.
In Winokur, et al. (1990), a study conducted before Thymatron devices were available and when sine wave ECT
devices were common, patients experienced more rehospitalizations after ECT than matched patients who did
not receive ECT. The authors did not establish a cause.
SAFETY OF THE THYMATRON® ECT DEVICE
RISK OF BRAIN INJURY
Bai T et al. (2019) studied 61 depressed patients receving ECT with a Thymatron® System IV device compared
with 23 healthy controls. ECT was found to increase local activity of the dorsomedial prefrontal cortex and
enhanced connectivity with the posterior cingulate cortex that was positively correlated with clinical
improvement. These findings support the functional plasticity of the dorsomedial prefrontal cortex and its
reorganization by ECT that may underlie its antidepressant effect. The study reported no signs of injury.
Bouckaert et al. (2016) obtained structural magnetic resonance images in 88 severely depressed elderly patients
who received courses of ECT with a Thymatron® System IV device. Following ECT there was a significant
improvement in depression scale scores, a significant but short-lived increase in hippocampal volume, and no
change in serum levels of brain-derived neurotrophic factor. The authors concluded that ECT-induced
hippocampal growth is a transient phenomenon possibly related to ECT-induced normalization of physical
activity levels. They reported no signs of injury.
Cano et al. (2017) studied 12 patients with treatment-resistant depression who received bilateral ECT with a
Thymatron® System IV device and compared them with 10 healthy controls on high-resolution structural MRI
and hippocampal metabolite concentrations before and after a course of treatment. ECT-induced regional gray
matter volume increases in the left medial temporal lobe revealed a significant positive association with clinical

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improvement, which was not true for neuroinflammatory changes as measured by hippocampal metabolites. The
authors concluded that structural, but not metabolic, changes in the left medial temporal lobe are useful
neuroimaging biomarkers of ECT-induced clinical improvement in treatment-resistant depression.
Cano et al. (2018) used MRI to assess whole-brain gray matter volume in 24 subjects with treatment-resistant
depression before and after courses of bilateral or right-unilateral ECT given with a Thymatron® System IV
device. Bilateral ECT induced bilateral gray matter volume increases in the limbic system, compared with gray
matter volume increases limited to the right hemisphere after right-unilateral ECT. These are signs of neuronal
increase.
Doddi SR et al. (2018) reported a 72 year old man with severe depression following a subarachnoid hemorrhage
demonstrated on CT who received 9 bifrontal ECTs 33 days post-hemorrhage with a Thymatron® System IV
device, with dramatic improvement in sequential Montgomery-Asberg Depression Scale scores, and Mini-
Mental State Scores that ranged from 28-30, all within the normal range. A repeat CT scan after the first ECT
showed no intracranial hemorrhage or any other acute intracranial process. Five months later he remained in full
remission. There were no reported signs of injury.
Ende et al. (2000) used proton magnetic resonance spectroscopic imaging to study hippocampal effects of the
Thymatron® DG ECT device as reflected in N-acetylaspartate signals. In 17 patients receiving either unilateral
or bilateral ECT (all of whom improved with treatment), no differences were found from 30 control subjects in
hippocampal N-acetylaspartate signals, finding no evidence for ECT-induced hippocampal atrophy or cell death.
Gryglewski G et al. (2018) carried out Magnetic Resonance Imaging scans in 14 patients with unipolar
treatment-resistant depression before and after courses of right unilateral ECT administered with a Thymatron®
System IV device. Increases in volume of the right hippocampus, right amygdala, and right putamen by were
observed, localized in the basal and lateral nuclei, and the corticoamygdaloid transition area of the amygdala, the
hippocampal-amygdaloid transition area and the granule cell layer of the dentate gyrus. Cortical thickness
increased in the temporal, parietal and insular cortices of the right hemisphere. These lateralized ECT-induced
structural changes occurred in hippocampal subfields and amygdala nuclei that have been specifically implicated
in the pathophysiology of depression and that retain a high potential for neuroplasticity in adulthood. These are
signs of neuronal increase and not injury.
Hirano et al. (2017) used task-related functional near-infrared spectroscopy to compare 108 healthy controls with
30 patients with major depressive disorder or bipolar depression before and after an ECT series administered
with a Thymatron® System IV device. Pre-ECT, patients exhibited significantly smaller oxyhemoglobin values
in the bilateral frontal cortex during a verbal fluency task than healthy controls, values that increased
significantly after ECT. A decrease in depression severity was significantly correlated with an increase in
oxyhemoglobin values in the right ventrolateral prefrontal cortex. ECT normalized the impaired functional
responses during the cognitive task, demonstrating that the acute therapeutic effects of ECT may restore
abnormal functional responses to cognitive tasks in the frontal brain regions of depressives.
Kranaster L et al. (2014) analyzed serum levels of the established brain injury markers protein S-100 and

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neuron-specific enolase in 19 patients with depression at baseline and throughout courses of ECT administered
with a Thymatron® System IV ECT device. Protein S-100 and enolase levels remained stable throughout the
treatment course, demonstrating no neuronal cell injury markers in patients receiving ECT.
Sartorius et al. (2016) conducted a prospective study of whole brain gray matter volume in a sample of 18
patients with treatment-resistant manic-depressive illness who received ECT with a Thymatron® System IV
device. Highly significant gray matter increases were observed in the hippocampus, amygdala, and temporal
regions, adding further support to the hypothesis that ECT enables cerebral plasticity, and refuting older claims
that ECT induces brain damage.
Sartorius et al. (2018) obtained whole brain magnetic resonance imaging scans in 92 major depressives before
and after ECT administered with a Thymatron® System IV device. Significant gray matter volume increases
were observed in the hippocampus and amygdala that did not correlate with psychopathology, age, gender or
number of ECT sessions.
MEMORY AND COGNITIVE RISKS
Possible cognitive side effects of ECT include disorientation, orbital-frontal syndrome, forgetting (retrograde
amnesia), learning impairment (anterograde amnesia), and delirium. Possible causes of delirium include tardive
seizure and occult seizure. Cognitive side effects can be affected by treatment method including stimulus dose,
electrode placement, stimulus pulse width, anesthesia details, long seizure duration, neurological and medical
conditions, and medications. Case reports suggest that some medications (e.g., lithium) predispose to cognitive
deficits, and others (e.g., memantine, rivastigmine) may decrease them (Alizadeh et al., 2015; van Schaik et al.
2015).
Ng et al (2000) used a Thymatron® DGx to treat 32 major depressives with courses of right-unilateral ECT
(mean=9.4). The mean percentage recall of Personal Memory test items recorded at baseline was 68% after 6
ECTs, 72% at treatment endpoint, and 87% one month later. Wechsler Adult Intelligence Scale scores did not
change with ECT.
Nuninga et al. (2018) evaluated 48 depressed patients and 19 controls with various cognitive tests, including for
working memory, verbal fluency, visuospatial abilities, verbal/visual memory and learning, processing speed,
inhibition, attention and task-switching, and premorbid IQ. Patients underwent these assessments at baseline
(n = 43), after ten bitemporal ECT sessions with a Thymatron® System IV device (n = 39), and six months after
the tenth ECT session (n = 25). Healthy controls underwent the same cognitive assessment at baseline and after
five-weeks. Within the patient group, transient adverse cognitive side effects were observed for verbal memory
and learning and verbal fluency. None of the cognitive functioning domains tested showed persisting
impairments after six months. Autobiographical memory was not assessed.
Obbels J et al. (2018) assessed 110 subjects (mean age 73) with unipolar major depression who were referred for
ECT. Subjects underwent baseline cognitive testing and then received an average of 14 treatments with a
Thymatron® System IV device (right unilateral, 60%; bilateral, 7%; initially unilateral switched to bilateral,
33%). The same cognitive testing was repeated 6 months after the last ECT, though 26% of subjects declined

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retesting at this follow-up. There were no statistically significant changes from baseline to 6 months post-ECT in
any of the neuropsychological assessments (visual memory, verbal memory, delayed recall, and executive
function). In examinations of patient-level data, cognition significantly improved in 14% of patients and
significantly declined in 12%.
In a series of 81 elderly depressed patients treated with a Thymatron® System IV device, Mini-Mental State
Examination scores were not below pretreatment levels one week post-ECT, although some had preexisting
brain atrophy (Oudega et al., 2014). In another series of 65 similarly treated elderly patients, deficits in executive
function and processing speed appeared only transiently (Dybedal et al., 2016).
Schat et al (2007) used a Thymatron® DGx ECT device to treat 83 DSM-IV medication-free patients with
unipolar depression who had been evaluated at baseline on tests of behavioral (everyday) and semantic memory.
One year after a course of bilateral or unilateral ECT, neither everyday nor semantic memory scores were
reduced from baseline; bilateral ECT was associated with significantly improved semantic memory scores.
Other studies have reported that cognitive performance after ECT with a Thymatron® device exceeded
pretreatment performance. In a group of 31 patients with major depressive disorder assessed prior to and 6 weeks
after non-standardized ECT, large improvements were found six weeks after ECT in processing speed,
attention/vigilance, and visual learning, with other cognitive domains not changed from baseline (Mohn & Rund,
2016).
Smith GE et al (2010) conducted a randomized controlled trial in unipolar major depressives, comparing
multiple memory test effects after 12 and 24 weeks of ECT with the Thymatron® System IV device and
pharmacotherapy with a nortriptyline-lithium combination. Twelve-week objective anterograde memory scores
and 24-week subjective memory scores were significantly improved for both treatment groups compared with
baseline. There were no clinically significant memory outcome differences between ECT and drug therapy for
depression.
van Oostrom et al (2018) studied 19 medication-free treatment-resistant major depressives. They underwent a
whole-brain magnetic resonance imaging scan and a neuropsychological examination one week before and
within 1 week after the course of ECT with a Thymatron® System IV device. With ECT, hippocampal volumes
increased significantly. This increase correlated with a decrease in cognitive functioning. Bouckaert et al (2016)
reported that such increases are transient.
Verwijk et al (2014) assessed global cognitive function, memory, and executive functions in 42 depressed
patients before and one week and 6 months after courses of ECT administered with a Thymatron® System IV
device. There was no decline for any of the neurocognitive tests after ECT. Medium to large post-ECT
improvements in neurocognitive functioning one week post-ECT were statistically significant for the Mini-
Mental State Examination, Visual Association Test, 10 Words Verbal Learning Test, and Expanded Mental
Control Test.
Ziegelmayer C et al (2017) examined neurocognitive performance in a sample of 20 treatment-resistant ECT-
naive depressed subjects. Cognitive functioning was assessed at baseline, 1 week, and 6 months after 12 to 15
unilateral ECTs with a Thymatron® System IV device. No adverse effects were observed in any of the cognitive

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domains examined.
Falconer et al (2010) treated 24 patients with severe depression with a course of bilateral ECT administered with
a Thymatron® DGx device. Patients were assessed before ECT, during ECT, within the week after ECT and 1
month after ECT with a battery of visual memory tests including spatial and pattern recognition memory,
pattern-location associative learning, and delayed matching. Patients showed significant impairments in visual
and visuospatial memory both during and within the week after ECT. Other deficits resolved within 1 month
following ECT, but not those in spatial recognition memory. Later testing was not reported.
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