The management of hematological malignancies justifies the completion of a complete assessment before the start of treatment. This assessment includes imaging tests (computed tomography, position emission tomography, cavitary scintigraphy), biology and very often an exploration of the bone marrow by anterior or posterior iliac biopsy. Pains related to the disease (node compression, invasion of solid organs) are taken care of at the diagnosis and often relieved by the start of the specific treatment.

However, pain related to medical procedure is often overlooked and can lead to psychological trauma in some patients who may refuse to repeat these essential actions to assess the response to treatment.

Anxiety contributes to pain and various relaxation techniques have already proven their effectiveness. The goal of the protocol is to reduce the pain and anxiety associated with medical procedure by using virtual reality with a helmet proposed at the time of the gesture.

Today, one third of the population suffers from anxiety and 20% of French people suffer from chronic pain. Many health situations or pathologies lead to difficult or painful care. The impact of drug solutions to relieve patients is often limited and more and more scientific studies are demonstrating the benefits of virtual reality to reduce pain, anxiety and addictions.

In 2011, following an experience of close to patient, a person created "l'Effet Papillon", a social enterprise that aims to create a concrete social impact in the lives of people with cancer, in situations of fragility or isolation and those who accompany them. Since 2011 the social enterprise has supported nearly 3,000 patients and today, the Butterfly Effect is a real partner of health actors by adopting a holistic approach to wellness in the face of disease and fragility.

Taking full advantage of the benefits of virtual reality that, used in medical settings, can reduce pain and anxiety, Bliss is a 3D Interactive application designed to meet the needs of escape and relaxation of people in isolation and / or or stress.

Bliss has been developed for and with patients in partnership with physicians, researchers and experts in virtual reality for therapeutic purposes.

Bliss offer a new tool for relaxation and well-being that relaxes and distracts users from moments of stress or anxiety.

The management of hematological malignancies justifies the completion of a complete assessment before the start of treatment. This assessment includes imaging tests (computed tomography, position emission tomography, cavitary scintigraphy), biology and very often an exploration of the bone marrow by anterior or posterior iliac biopsy. Pains related to the disease (node compression, invasion of solid organs) are taken care of at the diagnosis and often relieved by the start of the specific treatment.

However, pain related to medical procedure is often overlooked and can lead to psychological trauma in some patients who may refuse to repeat these essential actions to assess the response to treatment. Anxiety contributes to pain and various relaxation techniques have already proven their effectiveness.

During the osteo-medullary biopsy the patient will lie on his stomach with his hands positioned under the head. This position is the one recommended by the French Society of Hematology for an osteo-medullary biopsy.

The osteo-medullary biopsy remains independent of the object of the study and will be carried out according to the national recommendations.

For patients randomized to the "Standard" arm, the treatment will be the same as that proposed outside the study (a gas mixture composed of 50% Nitrous Oxide, 50% Oxygen + 1 bottle of xylocaine® 20 mL at the concentration of 10 mg / mL).

For randomized patients in the "Virtual Reality" arm, the VR session should begin 5 minutes before the start of the procedure (+ 1 bottle of Xylocaine® 20 mL at a concentration of 10 mg / mL). The VR session will last between 15 and 30 minutes depending on the speed programmed. The patient can continue the session if the gesture ends before the end of the virtual reality program.

The goal of the protocol is to reduce the pain and anxiety associated with medical procedure by using virtual reality with a helmet proposed at the time of the gesture.

Inclusion Criteria:

1. Patient with malignant haematological pathology
2. Patient who must have an osteo-medullary biopsy for diagnostic purposes
3. Age ≥ 18 years
4. Performance Status < 3
5. Patient with no pelvic bone pain before inclusion
6. Patient with normal coagulation balance (TP, Activated Partial Thromboplastin Time, fibrin) and platelet count> 50 G / L
7. Patient affiliated to the social security scheme
8. Patient giving written consent before any specific procedure related to the study

Exclusion Criteria:

1. Patient regularly taking antalgic treatments from stage 2 or 3
2. Patient with congenital coagulation disorder or acquired or taking anticoagulant therapy such as: fluindione, acenocoumarol, warfarin, dabigatran, apixaban or rivaroxaban
3. Contraindication to a gas mixture composed of 50% Nitrous Oxide, 50% Oxygen administration: true allergy, severe respiratory failure requiring continuous oxygen therapy, emphysema, pneumothorax, history of air embolism or diving accident, epilepsy or uncontrolled neurological disorder, unsubstituted vitamin deficiency B12 and folic acid, abdominal gas distension
4. Any contraindication to the use of the headset: pacemaker or other implanted medical device
5. Pregnancy or breastfeeding
6. Persons deprived of liberty, under guardianship or under guardianship
7. Dementia, mental impairment or psychiatric condition that may compromise patient informed consent and / or protocol compliance and follow-up of the trial
8. Patient unable to undergo protocol monitoring for psychological, social, family or geographical reasons